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Diffusion MRI

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5540: 726:, to indicate that the diffusion process is not free in tissues, but hindered and modulated by many mechanisms (restriction in closed spaces, tortuosity around obstacles, etc.) and that other sources of IntraVoxel Incoherent Motion (IVIM) such as blood flow in small vessels or cerebrospinal fluid in ventricles also contribute to the signal attenuation. At the end, images are "weighted" by the diffusion process: In those diffusion-weighted images (DWI) the signal is more attenuated the faster the diffusion and the larger the b factor is. However, those diffusion-weighted images are still also sensitive to T1 and T2 relaxivity contrast, which can sometimes be confusing. It is possible to calculate "pure" diffusion maps (or more exactly ADC maps where the ADC is the sole source of contrast) by collecting images with at least 2 different values, 5616: 2615:
diffusion leads to movement of water molecules along trajectories that proceed along multiple directions over time, leading to a complex projection onto the Cartesian axes. This pattern is reproducible if the same conditions and forces are applied to the same tissue in the same way. If there is an internal anisotropic organization of the tissue that constrains diffusion, then this fact will be reflected in the pattern of diffusion. The relationship between the properties of driving force that generate diffusion of the water molecules and the resulting pattern of their movement in the tissue can be described by a tensor. The collection of molecular displacements of this physical property can be described with nine components—each one associated with a pair of axes
2910:) describe the rotation of the ellipsoid relative to the orthogonal axes of the Cartesian coordinate system. These six variables can be represented by a matrix similar to the tensor matrix defined at the start of this section (since diffusion is symmetric, then we only need six instead of nine components—the components below the diagonal elements of the matrix are the same as the components above the diagonal). This is what is meant when it is stated that the components of a matrix of a second order tensor can be represented by an ellipsoid—if the diffusion values of the six terms of the quadric ellipsoid are placed into the matrix, this generates an ellipsoid angled off the orthogonal grid. Its shape will be more elongated if the relative anisotropy is high. 2382:. Diffusion itself is tensorial, but in many cases the objective is not really about trying to study brain diffusion per se, but rather just trying to take advantage of diffusion anisotropy in white matter for the purpose of finding the orientation of the axons and the magnitude or degree of anisotropy. Tensors have a real, physical existence in a material or tissue so that they do not move when the coordinate system used to describe them is rotated. There are numerous different possible representations of a tensor (of rank 2), but among these, this discussion focuses on the ellipsoid because of its physical relevance to diffusion and because of its historical significance in the development of diffusion anisotropy imaging in MRI. 952:
this condition, the ADC seems to depend on the choice of b values (the ADC seems to decrease when using larger b values), as the plot of ln(S/So) is not linear with the b factor, as expected from the above equations. This deviation from a free diffusion behavior is what makes diffusion MRI so successful, as the ADC is very sensitive to changes in tissue microstructure. On the other hand, modeling diffusion in tissues is becoming very complex. Among most popular models are the biexponential model, which assumes the presence of 2 water pools in slow or intermediate exchange and the cumulant-expansion (also called Kurtosis) model, which does not necessarily require the presence of 2 pools.
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gradient pulses, according to the Stejskal and Tanner method. This combination is not trivial, as cross-terms arise between all gradient pulses. The equation set by Stejskal and Tanner then becomes inaccurate and the signal attenuation must be calculated, either analytically or numerically, integrating all gradient pulses present in the MRI sequence and their interactions. The result quickly becomes very complex given the many pulses present in the MRI sequence, and as a simplification, Le Bihan suggested gathering all the gradient terms in a "b factor" (which depends only on the acquisition parameters) so that the signal attenuation simply becomes:
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six or more different diffusion weighted acquisitions, each obtained with a different orientation of the diffusion sensitizing gradients. In some methods, hundreds of measurements—each making up a complete image—are made to generate a single resulting calculated image data set. The higher information content of a DTI voxel makes it extremely sensitive to subtle pathology in the brain. In addition the directional information can be exploited at a higher level of structure to select and follow neural tracts through the brain—a process called
5555: 5644:. This vector can be color-coded, yielding a cartography of the tracts' position and direction (red for left-right, blue for superior-inferior, and green for anterior-posterior). The brightness is weighted by the fractional anisotropy which is a scalar measure of the degree of anisotropy in a given voxel. Mean diffusivity (MD) or trace is a scalar measure of the total diffusion within a voxel. These measures are commonly used clinically to localize white matter lesions that do not show up on other forms of clinical MRI. 303:
is applied in the same magnitude but with opposite direction to refocus or rephase the spins. The refocusing will not be perfect for protons that have moved during the time interval between the pulses, and the signal measured by the MRI machine is reduced. This "field gradient pulse" method was initially devised for NMR by Stejskal and Tanner who derived the reduction in signal due to the application of the pulse gradient related to the amount of diffusion that is occurring through the following equation:
189:(DBSI) further separates DTI signals into discrete anisotropic diffusion tensors and a spectrum of isotropic diffusion tensors to better differentiate sub-voxel cellular structures. For example, anisotropic diffusion tensors correlate to axonal fibers, while low isotropic diffusion tensors correlate to cells and high isotropic diffusion tensors correlate to larger structures (such as the lumen or brain ventricles). DBSI has been shown to differentiate some types of 2360:-value) and direction of the so-called magnetic diffusion gradient, as well as on the local microstructure in which the water molecules diffuse. The more attenuated the image is at a given position, the greater diffusion there is in the direction of the diffusion gradient. In order to measure the tissue's complete diffusion profile, one needs to repeat the MR scans, applying different directions (and possibly strengths) of the diffusion gradient for each scan. 9064: 3088: 5608: 5454: 5778:
maxima, pointing in opposite directions. If two tracts cross in the voxel, there will be two pairs of maxima, and so on. We can still use tensor mathematics to use the maxima to select groups of gradients to package into several different tensor ellipsoids in the same voxel, or use more complex higher-rank tensor analyses, or we can do a true "model free" analysis that picks the maxima, and then continue to do the tractography.
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This is often true, but it can be estimated that in more than 30% of the voxels in a standard resolution brain image, there are at least two different neural tracts traveling in different directions that pass through each other. In the classic diffusion ellipsoid tensor model, the information from the crossing tract appears as noise or unexplained decreased anisotropy in a given voxel.
124:) reflects the best estimate of the rate of water diffusion at that location. Because the mobility of water is driven by thermal agitation and highly dependent on its cellular environment, the hypothesis behind DWI is that findings may indicate (early) pathologic change. For instance, DWI is more sensitive to early changes after a stroke than more traditional MRI measurements such as 2309: 4338: 1781: 5340: 3950: 299:-weighted images, contrast is produced by measuring the loss of coherence or synchrony between the water protons. When water is in an environment where it can freely tumble, relaxation tends to take longer. In certain clinical situations, this can generate contrast between an area of pathology and the surrounding healthy tissue. 2577: 2921:" the matrix. This has two important meanings in imaging. The idea is that there are two equivalent ellipsoids—of identical shape but with different size and orientation. The first one is the measured diffusion ellipsoid sitting at an angle determined by the axons, and the second one is perfectly aligned with the three 1496: 5777:
to add more evenly spaced apices to the original icosahedron (20 faces)—an idea that also had its precedents in paleomagnetism research several decades earlier. We want to know which direction lines turn up the maximum anisotropic diffusion measures. If there is a single tract, there will be only two
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Diffusion tensor imaging (DTI) is a magnetic resonance imaging technique that enables the measurement of the restricted diffusion of water in tissue in order to produce neural tract images instead of using this data solely for the purpose of assigning contrast or colors to pixels in a cross-sectional
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leads to diffusion restriction, and the difference between images with various DWI weighting will therefore be minor, leading to an ADC image with low signal in the infarcted area. A decreased ADC may be detected minutes after a cerebral infarction. The high signal of infarcted tissue on conventional
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can also be investigated using MR spectroscopic approaches). MRI can be made sensitive to the motion of molecules. Regular MRI acquisition utilizes the behavior of protons in water to generate contrast between clinically relevant features of a particular subject. The versatile nature of MRI is due to
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it is usually necessary to know only the magnitude and orientation of the primary axis or vector. This primary axis—the one with the greatest length—is the largest eigenvalue and its orientation is encoded in its matched eigenvector. Only one axis is needed as it is assumed the largest eigenvalue is
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are "off diagonal". It then becomes possible to do a vector processing step in which we rewrite our matrix and replace it with a new matrix multiplied by three different vectors of unit length (length=1.0). The matrix is diagonalized because the off-diagonal components are all now zero. The rotation
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A tensor is often a physical or biophysical property that determines the relationship between two vectors. When a force is applied to an object, movement can result. If the movement is in a single direction, the transformation can be described using a vector—a tensor of rank 1. However, in a tissue,
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that is otherwise inherent to conventional DWI. ADC imaging does so by acquiring multiple conventional DWI images with different amounts of DWI weighting, and the change in signal is proportional to the rate of diffusion. Contrary to DWI images, the standard grayscale of ADC images is to represent a
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To sensitize MRI images to diffusion, the magnetic field strength (B1) is varied linearly by a pulsed field gradient. Since precession is proportional to the magnet strength, the protons begin to precess at different rates, resulting in dispersion of the phase and signal loss. Another gradient pulse
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tumors, and also to monitor tumor response to treatment over time. DWI can also be collected to visualize the whole body using a technique called 'diffusion-weighted whole-body imaging with background body signal suppression' (DWIBS). Some more specialized diffusion MRI techniques such as diffusion
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if the medium is anisotropic (it would be the surface of a sphere for an isotropic medium). The ellipsoid formalism functions also as a mathematical method of organizing tensor data. Measurement of an ellipsoid tensor further permits a retrospective analysis, to gather information about the process
3045:" or characteristic vectors. They contain the orientation information of the original ellipsoid. The three axes of the ellipsoid are now directly along the main orthogonal axes of the coordinate system so we can easily infer their lengths. These lengths are the eigenvalues or characteristic values. 2654:
Diffusion from a point source in the anisotropic medium of white matter behaves in a similar fashion. The first pulse of the Stejskal Tanner diffusion gradient effectively labels some water molecules and the second pulse effectively shows their displacement due to diffusion. Each gradient direction
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In DTI, each voxel has one or more pairs of parameters: a rate of diffusion and a preferred direction of diffusion—described in terms of three-dimensional space—for which that parameter is valid. The properties of each voxel of a single DTI image are usually calculated by vector or tensor math from
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In order to localize this signal attenuation to get images of diffusion one has to combine the pulsed magnetic field gradient pulses used for MRI (aimed at localization of the signal, but those gradient pulses are too weak to produce a diffusion related attenuation) with additional "motion-probing"
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Early in the development of DTI based tractography, a number of researchers pointed out a flaw in the diffusion tensor model. The tensor analysis assumes that there is a single ellipsoid in each imaging voxel—as if all of the axons traveling through a voxel traveled in exactly the same direction.
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Although this ADC concept has been extremely successful, especially for clinical applications, it has been challenged recently, as new, more comprehensive models of diffusion in biological tissues have been introduced. Those models have been made necessary, as diffusion in tissues is not free. In
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of some crystals. Water will then diffuse more rapidly in the direction aligned with the internal structure (axial diffusion), and more slowly as it moves perpendicular to the preferred direction (radial diffusion). This also means that the measured rate of diffusion will differ depending on the
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which is the square root of the sum of squares (SRSS) of the diffusivity differences, divided by the SRSS of the diffusivities. When the second and third axes are small relative to the principal axis, the number in the numerator is almost equal the number in the denominator. We also multiply by
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applied a heated point to a polished crystal surface that had been coated with wax. In some materials that had "isotropic" structure, a ring of melt would spread across the surface in a circle. In anisotropic crystals the spread took the form of an ellipse. In three dimensions this spread is an
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Note, there is ongoing debate about the best way to preprocess DW-MRI. Several in-vivo studies have shown that the choice of software and functions applied (directed at correcting artefacts arising from e.g. motion and eddy-currents) have a meaningful impact on the DTI parameter estimates from
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The Q-Ball method of tractography is an implementation in which David Tuch provides a mathematical alternative to the tensor model. Instead of forcing the diffusion anisotropy data into a group of tensors, the mathematics used deploys both probability distributions and some classic geometric
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and major brain nuclei, or in the body—where the diffusion rate appears to be the same when measured along any axis. However, DWI also remains sensitive to T1 and T2 relaxation. To entangle diffusion and relaxation effects on image contrast, one may obtain quantitative images of the diffusion
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The idea of a tensor in physical science evolved from attempts to describe the quantity of physical properties. The first properties they were applied to were those that can be described by a single number, such as temperature. Properties that can be described this way are called
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provides a mathematical basis for passing a large number of evenly spaced gradient trajectories through the voxel—each coinciding with one of the apices of the icosahedron. We can then look into the voxel from a large number of different directions (typically 40 or more). We use
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is the diffusion tensor. Aside from describing the amount of diffusion, it is often important to describe the relative degree of anisotropy in a voxel. At one extreme would be the sphere of isotropic diffusion and at the other extreme would be a cigar or pencil shaped very thin
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Once we have measured the voxel from six or more directions and corrected for attenuations due to T2 and T1 effects, we can use information from our calculated ellipsoid tensor to describe what is happening in the voxel. If you consider an ellipsoid sitting at an angle in a
5143: 4014:). However, this proves to be very susceptible to measurement noise, so increasingly complex measures were developed to capture the measure while minimizing the noise. An important element of these calculations is the sum of squares of the diffusivity differences = ( 2596:; these can be considered tensors of rank 0, or 0th-order tensors. Tensors can also be used to describe quantities that have directionality, such as mechanical force. These quantities require specification of both magnitude and direction, and are often represented with a 2582:
The same matrix of numbers can have a simultaneous second use to describe the shape and orientation of an ellipse and the same matrix of numbers can be used simultaneously in a third way for matrix mathematics to sort out eigenvectors and eigenvalues as explained below.
5694:). Tractography is a useful tool for measuring deficits in white matter, such as in aging. Its estimation of fiber orientation and strength is increasingly accurate, and it has widespread potential implications in the fields of cognitive neuroscience and neurobiology. 1944: 6174:
Vavasour, Irene M; Sun, Peng; Graf, Carina; Yik, Jackie T; Kolind, Shannon H; Li, David KB; Tam, Roger; Sayao, Ana-Luiza; Schabas, Alice; Devonshire, Virginia; Carruthers, Robert; Traboulsee, Anthony; Moore, GR Wayne; Song, Sheng-Kwei; Laule, Cornelia (March 2022).
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variations in the MRI magnet) are applied that can determine at least 3 directional vectors (use of 6 different gradients is the minimum and additional gradients improve the accuracy for "off-diagonal" information), it is possible to calculate, for each
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The fractional anisotropy can also be separated into linear, planar, and spherical measures depending on the "shape" of the diffusion ellipsoid. For example, a "cigar" shaped prolate ellipsoid indicates a strongly linear anisotropy, a "flying saucer" or
2391: 3325:. In the setting of the DTI tensor ellipsoid, we can consider each of these as a measure of the diffusivity along each of the three primary axes of the ellipsoid. This is a little different from the ADC since that was a projection on the axis, while 136:(DSI), was used in deriving the Connectome data sets; DSI is a variant of diffusion-weighted imaging that is sensitive to intra-voxel heterogeneities in diffusion directions caused by crossing fiber tracts and thus allows more accurate mapping of 5438: 4825: 3426:
This quantity is an assessment of the degree of restriction due to membranes and other effects and proves to be a sensitive measure of degenerative pathology in some neurological conditions. It can also be called the perpendicular diffusivity
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The ellipsoid itself has a principal long axis and then two more small axes that describe its width and depth. All three of these are perpendicular to each other and cross at the center point of the ellipsoid. We call the axes in this setting
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for magnetization would change with the addition of diffusion. Torrey modified Bloch's original description of transverse magnetization to include diffusion terms and the application of a spatially varying gradient. Since the magnetization
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Ye, Zezhong; Price, Richard L.; Liu, Xiran; Lin, Joshua; Yang, Qingsong; Sun, Peng; Wu, Anthony T.; Wang, Liang; Han, Rowland H.; Song, Chunyu; Yang, Ruimeng; Gary, Sam E.; Mao, Diane D.; Wallendorf, Michael; Campian, Jian L. (2020-10-15).
4656: 4056:). We use the square root of the sum of squares to obtain a sort of weighted average—dominated by the largest component. One objective is to keep the number near 0 if the voxel is spherical but near 1 if it is elongate. This leads to the 2066: 1296: 5539: 164:
coefficient, or more exactly the apparent diffusion coefficient (ADC). The ADC concept was introduced to take into account the fact that the diffusion process is complex in biological tissues and reflects several different mechanisms.
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applied measures the movement along the direction of that gradient. Six or more gradients are summed to get all the measurements needed to fill in the matrix, assuming it is symmetric above and below the diagonal (red subscripts).
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Recently, more advanced models of the diffusion process have been proposed that aim to overcome the weaknesses of the diffusion tensor model. Amongst others, these include q-space imaging and generalized diffusion tensor imaging.
4975: 4333:{\displaystyle \mathrm {FA} ={\frac {\sqrt {3((\lambda _{1}-\operatorname {E} )^{2}+(\lambda _{2}-\operatorname {E} )^{2}+(\lambda _{3}-\operatorname {E} )^{2})}}{\sqrt {2(\lambda _{1}^{2}+\lambda _{2}^{2}+\lambda _{3}^{2})}}}} 216:. The diffusion tensor model is a rather simple model of the diffusion process, assuming homogeneity and linearity of the diffusion within each image voxel. From the diffusion tensor, diffusion anisotropy measures such as the 1273: 3535: 1174: 4430: 2925:
axes. The term "diagonalize" refers to the three components of the matrix along a diagonal from upper left to lower right (the components with red subscripts in the matrix at the start of this section). The variables
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Makris N, Worth AJ, Sorensen AG, Papadimitriou GM, Wu O, Reese TG, et al. (December 1997). "Morphometry of in vivo human white matter association pathways with diffusion-weighted magnetic resonance imaging".
3111:, water molecules are moving due to diffusion and they move at equal rates in all directions. By knowing the detailed effects of diffusion gradients we can generate a formula that allows us to convert the signal 272:-weighted image, water molecules in a sample are excited with the imposition of a strong magnetic field. This causes many of the protons in water molecules to precess simultaneously, producing signals in MRI. In 4496: 5697:
The use of DTI for the assessment of white matter in development, pathology and degeneration has been the focus of over 2,500 research publications since 2005. It promises to be very helpful in distinguishing
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Niendorf T, Dijkhuizen RM, Norris DG, van Lookeren Campagne M, Nicolay K (December 1996). "Biexponential diffusion attenuation in various states of brain tissue: implications for diffusion-weighted imaging".
3421: 1776:{\displaystyle {\frac {d{\vec {M}}}{dt}}=\gamma {\vec {M}}\times {\vec {B}}-{\frac {M_{x}{\vec {i}}+M_{y}{\vec {j}}}{T_{2}}}-{\frac {(M_{z}-M_{0}){\vec {k}}}{T_{1}}}+\nabla \cdot {\vec {D}}\nabla {\vec {M}}} 211:
More extended DTI scans derive neural tract directional information from the data using 3D or multidimensional vector algorithms based on six or more gradient directions, sufficient to compute the diffusion
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Le Bihan D, Breton E, Lallemand D, Grenier P, Cabanis E, Laval-Jeantet M (November 1986). "MR imaging of intravoxel incoherent motions: application to diffusion and perfusion in neurologic disorders".
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of a matrix is done by finding a second matrix that it can be multiplied with followed by multiplication by the inverse of the second matrix—wherein the result is a new matrix in which three diagonal (
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Wade, Ryckie G.; Tam, Winnie; Perumal, Antonia; Pepple, Sophanit; Griffiths, Timothy T.; Flather, Robert; Haroon, Hamied A.; Shelley, David; Plein, Sven; Bourke, Grainne; Teh, Irvin (2023-10-13).
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Traditionally, in diffusion-weighted imaging (DWI), three gradient-directions are applied, sufficient to estimate the trace of the diffusion tensor or 'average diffusivity', a putative measure of
3750: 3273: 5554: 2872: 5335:{\displaystyle \mathrm {RA} ={\frac {\sqrt {(\lambda _{1}-\operatorname {E} )^{2}+(\lambda _{2}-\operatorname {E} )^{2}+(\lambda _{3}-\operatorname {E} )^{2}}}{{\sqrt {3}}\operatorname {E} }}} 433: 5572:. Tumors are in many instances highly cellular, giving restricted diffusion of water, and therefore appear with a relatively high signal intensity in DWI. DWI is commonly used to detect and 3945:{\displaystyle {\begin{aligned}\mathrm {tr} (\Lambda )/3&=\mathrm {tr} (V^{-1}V\Lambda )/3\\&=\mathrm {tr} (V\Lambda V^{-1})/3\\&=\mathrm {tr} (D)/3\\&=ADC_{i}\end{aligned}}} 2174: 1074: 3350:. Historically, this is closest to what Richards originally measured with the vector length in 1991. The diffusivities in the two minor axes are often averaged to produce a measure of 6323:
Ye, Zezhong; Srinivasa, Komal; Meyer, Ashely; Sun, Peng; Lin, Joshua; Viox, Jeffrey D.; Song, Chunyu; Wu, Anthony T.; Song, Sheng-Kwei; Dahiya, Sonika; Rubin, Joshua B. (2021-02-26).
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In present-day clinical neurology, various brain pathologies may be best detected by looking at particular measures of anisotropy and diffusivity. The underlying physical process of
2741: 2572:{\displaystyle {\bar {D}}={\begin{vmatrix}D_{\color {red}xx}&D_{xy}&D_{xz}\\D_{xy}&D_{\color {red}yy}&D_{yz}\\D_{xz}&D_{yz}&D_{\color {red}zz}\end{vmatrix}}} 6649:
Liu C, Bammer R, Moseley ME (2003). "Generalized Diffusion Tensor Imaging (GDTI): A Method for Characterizing and Imaging Diffusion Anisotropy Caused by Non-Gaussian Diffusion".
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David Tuch was among the first to describe a solution to this problem. The idea is best understood by conceptually placing a kind of geodesic dome around each image voxel. This
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de Sénarmont HH (1848). "Mémoire sur la conductibilité des substances cristalisées pour la chaleur" [Memoir on the conductivity of crystallized substances for heat].
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Wedeen VJ, Wang RP, Schmahmann JD, Benner T, Tseng WY, Dai G, et al. (July 2008). "Diffusion spectrum magnetic resonance imaging (DSI) tractography of crossing fibers".
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represents diffusion in a plane, and a sphere is indicative of isotropic diffusion, equal in all directions. If the eigenvalues of the diffusion vector are sorted such that
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Le Bihan, Denis; Breton, E. (1985). "Imagerie de diffusion in-vivo par résonance magnétique nucléaire" [In-vivo diffusion imaging by nuclear magnetic resonance].
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method that produces in vivo magnetic resonance images of biological tissues sensitized with the local characteristics of molecular diffusion, generally water (but other
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of the brain as well as for studies of other body tissues (see below). DWI is most applicable when the tissue of interest is dominated by isotropic water movement e.g.
4564: 3558: 1491:{\displaystyle {\frac {d{\vec {M}}}{dt}}=\gamma {\vec {M}}\times {\vec {B}}-{\frac {M_{x}{\vec {i}}+M_{y}{\vec {j}}}{T_{2}}}-{\frac {(M_{z}-M_{0}){\vec {k}}}{T_{1}}}} 567: 547: 503: 3014: 2984: 2954: 2207: 1955: 93:. Water molecule diffusion patterns can therefore reveal microscopic details about tissue architecture, either normal or in a diseased state. A special kind of DWI, 6276:"Diffusion Histology Imaging Combining Diffusion Basis Spectrum Imaging (DBSI) and Machine Learning Improves Detection and Classification of Glioblastoma Pathology" 6224:
Ye, Zezhong; George, Ajit; Wu, Anthony T.; Niu, Xuan; Lin, Joshua; Adusumilli, Gautam; Naismith, Robert T.; Cross, Anne H.; Sun, Peng; Song, Sheng-Kwei (May 2020).
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in relation to the white matter tracts (infiltration, deflection), has been one of the most important initial applications. In surgical planning for some types of
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Manenti G, Carlani M, Mancino S, Colangelo V, Di Roma M, Squillaci E, Simonetti G (June 2007). "Diffusion tensor magnetic resonance imaging of prostate cancer".
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grid then you can consider the projection of that ellipse onto the three axes. The three projections can give you the ADC along each of the three axes ADC
1189: 220:(FA), can be computed. Moreover, the principal direction of the diffusion tensor can be used to infer the white-matter connectivity of the brain (i.e. 3467: 2356:
A more precise statement of the image acquisition process is that the image-intensities at each position are attenuated, depending on the strength (
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Griffiths, Timothy T.; Flather, Robert; Teh, Irvin; Haroon, Hamied A.; Shelley, David; Plein, Sven; Bourke, Grainne; Wade, Ryckie G. (2021-07-22).
4346: 3138:. The ADC in anisotropic tissue varies depending on the direction in which it is measured. Diffusion is fast along the length of (parallel to) an 6876:"Signal evolution and infarction risk for apparent diffusion coefficient lesions in acute ischemic stroke are both time- and perfusion-dependent" 197:
with higher specificity and sensitivity than conventional DTI. DBSI has also been useful in determining microstructure properties of the brain.
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Le Bihan D, Mangin JF, Poupon C, Clark CA, Pappata S, Molko N, Chabriat H (April 2001). "Diffusion tensor imaging: concepts and applications".
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Samara, Amjad; Li, Zhaolong; Rutlin, Jerrel; Raji, Cyrus A.; Sun, Peng; Song, Sheng-Kwei; Hershey, Tamara; Eisenstein, Sarah A. (August 2021).
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The most common application of conventional DWI (without DTI) is in acute brain ischemia. DWI directly visualizes the ischemic necrosis in
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image. It also provides useful structural information about muscle—including heart muscle—as well as other tissues such as the prostate.
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Stejskal EO, Tanner JE (1 January 1965). "Spin Diffusion Measurements: Spin Echoes in the Presence of a Time-Dependent Field Gradient".
5742:: metrics derived from DTI (FA and RD) can differentiate asymptomatic adults from those with compression of the ulnar nerve at the elbow 4837: 8892: 3359: 8164: 6839:
Le Bihan D (August 2013). "Apparent diffusion coefficient and beyond: what diffusion MR imaging can tell us about tissue structure".
6177:"Characterization of multiple sclerosis neuroinflammation and neurodegeneration with relaxation and diffusion basis spectrum imaging" 4668: 4508: 143:
Diffusion-weighted images are very useful to diagnose vascular strokes in the brain. It is also used more and more in the staging of
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Westin CF, Maier SE, Mamata H, Nabavi A, Jolesz FA, Kikinis R (June 2002). "Processing and visualization for diffusion tensor MRI".
9000: 5138:{\displaystyle C_{a}=C_{l}+C_{p}=1-C_{s}={\frac {\lambda _{1}+\lambda _{2}-2\lambda _{3}}{\lambda _{1}+\lambda _{2}+\lambda _{3}}}} 3134:, because the measurement misses all the local effects and treats the attenuation as if all the movement rates were solely due to 8530: 7451:
Takahara, Taro; Kwee, Thomas C. (2010). "Diffusion-Weighted Whole-Body Imaging with Background Body Signal Suppression (DWIBS)".
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subscript to signify that this is what the isotropic diffusion coefficient would be with the effects of anisotropy averaged out.
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Taylor DG, Bushell MC (April 1985). "The spatial mapping of translational diffusion coefficients by the NMR imaging technique".
7762:"Meta-analysis of the normal diffusion tensor imaging values of the median nerve and how they change in carpal tunnel syndrome" 7981:
Basser PJ, Pajevic S (2007). "Spectral decomposition of a 4th-order covariance tensor: applications to diffusion tensor MRI".
7546:"Diffusion Tensor Imaging for Diagnosing Root Avulsions in Traumatic Adult Brachial Plexus Injuries: A Proof-of-Concept Study" 7486:"Diffusion kurtosis MRI as a predictive biomarker of response to neoadjuvant chemotherapy in high grade serous ovarian cancer" 1939:{\displaystyle {\vec {D}}=D\cdot {\vec {I}}=D\cdot {\begin{bmatrix}1&0&0\\0&1&0\\0&0&1\end{bmatrix}},} 599: 151:
as the 'gold standard' for this type of disease. Diffusion tensor imaging is being developed for studying the diseases of the
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can differentiate normal nerves (as shown in the tractogram of the spinal cord and brachial plexus and 3D 4k reconstruction
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and non-invasively. Molecular diffusion in tissues is not random, but reflects interactions with many obstacles, such as
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as well as software that generates images from the resulting data that uses the diffusion of water molecules to generate
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King MD, Houseman J, Roussel SA, van Bruggen N, Williams SR, Gadian DG (December 1994). "q-Space imaging of the brain".
2773: 2094:. Anisotropic diffusion will have a similar solution for the diffusion tensor, except that what will be measured is the 8928: 8807: 8547: 8456: 6432:
Zhang Y, Wang S, Wu L, Huo Y (Jan 2011). "Multi-channel diffusion tensor image registration via adaptive chaotic PSO".
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At this point, it is helpful to consider the mathematics of ellipsoids. An ellipsoid can be described by the formula:
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tissue. Consequently, this is the topic of a multinational study directed by the diffusion-study group of the ISMRM.
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of the water molecules preferentially along their main direction. Such preferentially oriented diffusion is called
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kurtosis imaging (DKI) have also been shown to predict the response of cancer patients to chemotherapy treatment.
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this capability of producing contrast related to the structure of tissues at the microscopic level. In a typical
7130: 1014: 8812: 8659: 8559: 8542: 7416:
Koh DM, Collins DJ (June 2007). "Diffusion-weighted MRI in the body: applications and challenges in oncology".
5853: 5475: 5471: 8755: 5640:) that describes the 3-dimensional shape of diffusion. The fiber direction is indicated by the tensor's main 3029:
angles required to get to this equivalent position now appear in the three vectors and can be read out as the
8938: 8792: 8391: 8266: 8258: 8157: 5678:
within white matter. Fiber tracking algorithms can be used to track a fiber along its whole length (e.g. the
6924: 5510:
in the form of a cytotoxic edema, appearing as a high DWI signal within minutes of arterial occlusion. With
2678: 9049: 8983: 8915: 8905: 8883: 8654: 8622: 8253: 5560:
DWI showing cortical ribbon-like high signal consistent with diffusion restriction in a patient with known
1818:
For the simplest case where the diffusion is isotropic the diffusion tensor is a multiple of the identity:
148: 6678:
Relevance of the information about the diffusion distribution in invo given by kurtosis in q-space imaging
6382:"Nucleus accumbens microstructure mediates the relationship between obesity and eating behavior in adults" 3099:
causes a group of water molecules to move out from a central point, and gradually reach the surface of an
2659: 2374:
Diffusion MRI relies on the mathematics and physical interpretations of the geometric quantities known as
8713: 8681: 8664: 4000:. The simplest measure is obtained by dividing the longest axis of the ellipsoid by the shortest = ( 3147: 2922: 2667:
showed in the 1850s, diffusion exhibits many of the same patterns as those seen in the transfer of heat.
1001: 5623:
The imaging of this property is an extension of diffusion MRI. If a series of diffusion gradients (i.e.
8787: 8522: 8262: 3430: 144: 6226:"Deep learning with diffusion basis spectrum imaging for classification of multiple sclerosis lesions" 9028: 8696: 8686: 8003: 5433:{\displaystyle \mathrm {VR} ={\frac {\lambda _{1}\lambda _{2}\lambda _{3}}{\operatorname {E} ^{3}}}} 4820:{\displaystyle C_{p}={\frac {2(\lambda _{2}-\lambda _{3})}{\lambda _{1}+\lambda _{2}+\lambda _{3}}}} 9067: 9018: 8797: 8676: 8649: 8410: 8195: 8150: 7138:. Proceedings of the Society for Magnetic Resonance in Medicine. Vol. 11. Berlin. p. 412. 5729: 4070: 2324:, is an MRI image that more specifically shows diffusion than conventional DWI, by eliminating the 39: 7149:
Vaillancourt DE, Spraker MB, Prodoehl J, Abraham I, Corcos DM, Zhou XJ, et al. (April 2009).
6502:
Posse S, Cuenod CA, Le Bihan D (September 1993). "Human brain: proton diffusion MR spectroscopy".
3617: 3590: 3563: 2917:, we can apply a useful technique from standard matrix mathematics and linear algebra—that is to " 2298:
The standard grayscale of DWI images is to represent increased diffusion restriction as brighter.
8966: 8802: 8743: 8728: 8617: 8439: 8415: 5739: 5546: 5464: 4651:{\displaystyle C_{l}={\frac {\lambda _{1}-\lambda _{2}}{\lambda _{1}+\lambda _{2}+\lambda _{3}}}} 3168:. This leads to the idea of describing the average diffusivity in the voxel which will simply be 5860:, and so on, but the generality, which covers arrays of all sizes, may obscure rather than help. 1789: 8837: 8706: 8637: 8444: 7998: 7907:"High angular resolution diffusion imaging reveals intravoxel white matter fiber heterogeneity" 7151:"High-resolution diffusion tensor imaging in the substantia nigra of de novo Parkinson disease" 5749: 5745: 5699: 2369: 2308: 2061:{\displaystyle {M}={M}_{\text{bloch}}e^{-{\frac {1}{3}}\gamma ^{2}G^{2}t^{3}D}\sim e^{-bD_{0}}} 5912:
Merboldt KD, Hanicke W, Frahm J (1985). "Self-diffusion NMR imaging using stimulated echoes".
3543: 178:
in the brain or muscle fibers in the heart—has an internal fibrous structure analogous to the
9098: 8701: 8632: 8498: 8381: 8300: 8207: 4058: 3116: 3048: 1535: 1080: 552: 532: 488: 217: 3130:
interfere with the free diffusion, we are measuring an "apparent diffusion coefficient", or
2989: 2959: 2929: 2182: 9044: 8733: 8671: 8493: 7990: 7773: 7497: 6757: 6546: 6336: 5956: 5921: 5787: 5637: 2914: 2600:. A three-dimensional vector can be described with three components: its projection on the 2593: 2266: 2239: 2212: 963: 756: 729: 441: 275: 248: 5748:: Metrics derived from DTI (lower FA and MD) differentiate healthy adults from those with 8: 8990: 8868: 8691: 8427: 7954:
Hext GR (1963). "The estimation of second-order tensors with related tests and designs".
5679: 5668: 5531: 5515: 5507: 3108: 2332: 2325: 1084: 703: 90: 7994: 7777: 7544:
Wade RG, Tanner SF, Teh I, Ridgway JP, Shelley D, Chaka B, et al. (16 April 2020).
7501: 6761: 6550: 6340: 6000:"Mapping complex tissue architecture with diffusion spectrum magnetic resonance imaging" 5960: 5925: 5806:, matrix mathematics and vector mathematics to process the analysis of the tensor data. 8978: 8827: 8822: 8723: 8606: 8461: 8212: 8112: 8075:"Comparison of distortion correction preprocessing pipelines for DTI in the upper limb" 8055: 8016: 7936: 7859: 7802: 7761: 7737: 7704: 7680: 7655: 7621: 7572: 7545: 7518: 7485: 7484:
Deen SS, Priest AN, McLean MA, Gill AB, Brodie C, Crawford R, et al. (July 2019).
7393: 7366: 7274: 7249: 7175: 7166: 7150: 7111: 6985: 6963: 6900: 6875: 6730: 6625: 6618:
Principles and Application of Self-Diffusion Measurements by Nuclear Magnetic Resonance
6598: 6484: 6406: 6381: 6357: 6324: 6300: 6275: 6250: 6225: 6201: 6176: 6151: 6126: 6072: 6029: 5980: 3978: 3958: 2077: 1516: 1180: 983: 683: 572: 512: 506: 468: 241: 204:. Clinically, trace-weighted images have proven to be very useful to diagnose vascular 194: 78: 7226: 2611:
axes. Vectors of this sort can be considered tensors of rank 1, or 1st-order tensors.
8817: 8782: 8777: 8718: 8466: 8315: 8116: 8104: 8096: 8059: 7928: 7887: 7851: 7807: 7789: 7742: 7724: 7685: 7654:
Wade RG, Whittam A, Teh I, Andersson G, Yeh FC, Wiberg M, Bourke G (9 October 2020).
7613: 7577: 7523: 7464: 7433: 7398: 7367:"Magnetic resonance diffusion-perfusion mismatch in acute ischemic stroke: An update" 7320: 7279: 7230: 7180: 7103: 7049: 7026: 6977: 6905: 6856: 6722: 6681: 6629: 6590: 6519: 6476: 6411: 6362: 6325:"Diffusion histology imaging differentiates distinct pediatric brain tumor histology" 6305: 6255: 6206: 6156: 6107: 6064: 6060: 6021: 5984: 5972: 5968: 5933: 4970:{\displaystyle C_{s}={\frac {3\lambda _{3}}{\lambda _{1}+\lambda _{2}+\lambda _{3}}}} 70: 7641:"DTI (Quantitative), a new and advanced MRI procedure for evaluation of Concussions" 7625: 7339: 6989: 6734: 6602: 6515: 6488: 6103: 2651:. These can be written as a matrix similar to the one at the start of this section. 208:
in the brain, by early detection (within a couple of minutes) of the hypoxic edema.
9093: 9088: 8644: 8503: 8275: 8227: 8086: 8047: 8020: 8008: 7963: 7940: 7918: 7863: 7841: 7797: 7781: 7732: 7716: 7675: 7667: 7605: 7567: 7557: 7513: 7505: 7456: 7425: 7388: 7378: 7310: 7269: 7261: 7222: 7170: 7162: 7115: 7095: 7016: 6967: 6959: 6895: 6887: 6848: 6765: 6712: 6658: 6621: 6582: 6554: 6511: 6468: 6441: 6401: 6393: 6352: 6344: 6295: 6287: 6245: 6237: 6196: 6188: 6146: 6138: 6099: 6076: 6056: 6033: 6011: 5964: 5929: 3997: 2664: 2597: 2379: 6291: 8853: 8305: 8271: 8244: 8239: 8173: 8012: 7905:
Tuch DS, Reese TG, Wiegell MR, Makris N, Belliveau JW, Wedeen VJ (October 2002).
7460: 6891: 6787: 5725: 4436: 3135: 2312:
ADC image of the same case of cerebral infarction as seen on DWI in section above
1509: 1268:{\displaystyle {\frac {\partial \rho (x,t)}{\partial t}}=D\nabla ^{2}\rho (x,t).} 160: 45: 7967: 7878: 6662: 8995: 7785: 7720: 7671: 7509: 7315: 7298: 7297:
Grand S, Tahon F, Attye A, Lefournier V, Le Bas JF, Krainik A (December 2013).
7265: 6348: 5803: 5707: 5624: 5573: 5561: 1288: 7760:
Rojoa, Djamila; Raheman, Firas; Rassam, Joseph; Wade, Ryckie G. (2021-10-22).
7132:
Vector analysis of diffusion images in experimental allergic encephalomyelitis
6192: 6125:
Wang Y, Wang Q, Haldar JP, Yeh FC, Xie M, Sun P, et al. (December 2011).
5545:
DWI showing restricted diffusion in the medial dorsal thalami consistent with
3530:{\displaystyle \mathrm {tr} (\Lambda )=\lambda _{1}+\lambda _{2}+\lambda _{3}} 1169:{\displaystyle {\frac {\partial \rho (x,t)}{\partial t}}=-\nabla \cdot J(x,t)} 9082: 8627: 8596: 8584: 8337: 8232: 8100: 7793: 7728: 7562: 7053: 7046:
Physical Properties of Crystals: Their Representation by Tensors and Matrices
6571: 5774: 5511: 4425:{\textstyle \operatorname {E} =(\lambda _{1}+\lambda _{2}+\lambda _{3})/3\,.} 3123: 1284: 129: 125: 86: 7891: 6852: 6769: 6685: 6445: 9010: 8863: 8858: 8765: 8589: 8574: 8508: 8108: 7932: 7855: 7811: 7746: 7689: 7581: 7527: 7437: 7402: 7324: 7283: 7234: 7184: 7107: 7030: 6981: 6909: 6860: 6726: 6620:. Advances in Magnetic and Optical Resonance. Vol. 12. pp. 1–89. 6586: 6472: 6415: 6366: 6309: 6259: 6210: 6160: 6142: 6127:"Quantification of increased cellularity during inflammatory demyelination" 6068: 6025: 5833: 5823: 5810: 5714: 5683: 5675: 5664: 5581: 3457:
Another commonly used measure that summarizes the total diffusivity is the
3288: 3042: 2350: 1533:
is a vector, there are 3 diffusion equations, one for each dimension. The
224:; trying to see which part of the brain is connected to which other part). 221: 175: 152: 105: 102: 66: 7617: 7609: 6594: 6523: 6480: 6111: 5976: 5809:
In some cases, the full set of tensor properties is of interest, but for
8933: 8488: 8320: 8310: 8290: 8280: 8222: 8217: 8186: 7383: 7344: 6929: 5765: 5687: 5667:, surgery is aided by knowing the proximity and relative position of the 5641: 3294: 3127: 3112: 3076: 2764: 190: 156: 7429: 5998:
Wedeen VJ, Hagmann P, Tseng WY, Reese TG, Weisskoff RM (December 2005).
3722:{\displaystyle \mathrm {MD} =(\lambda _{1}+\lambda _{2}+\lambda _{3})/3} 8569: 8332: 8327: 8295: 8051: 6241: 5828: 5783: 5585: 5478: in this section. Unsourced material may be challenged and removed. 4980:
Each measure lies between 0 and 1 and they sum to unity. An additional
3087: 1088: 179: 8091: 8074: 7923: 7906: 7846: 7829: 7099: 7003:
Basser PJ, Pajevic S, Pierpaoli C, Duda J, Aldroubi A (October 2000).
6972: 6815: 6717: 6700: 6558: 6397: 6016: 5999: 5607: 2385:
The following matrix displays the components of the diffusion tensor:
8896: 8832: 8285: 5619:
DTI of a healthy human brachial plexus. Taken from Wade et al., 2020.
5597: 3100: 3096: 2760: 74: 8035: 7886:. Proceedings of the 7th Annual Meeting of the ISMRM. Philadelphia. 5852:
Several full mathematical treatments of general tensors exist, e.g.
5453: 4491:{\displaystyle \lambda _{1}\geq \lambda _{2}\geq \lambda _{3}\geq 0} 8919: 8036:"Uber eine geometrische Anwendung der Abelschen Integralgleichnung" 7069:
Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences
7022:
10.1002/1522-2594(200010)44:4<625::AID-MRM17>3.0.CO;2-O
5703: 5569: 3063:) components have numbers in them but the off-diagonal components ( 1005: 8142: 7148: 4880:{\displaystyle \lambda _{1}\simeq \lambda _{2}\simeq \lambda _{3}} 1501:
which has terms for precession, T2 relaxation, and T1 relaxation.
8948: 8351: 7200:
Geometrical diffusion measures for MRI from tensor basis analysis
7198:
Westin CF, Peled S, Gudbjartsson H, Kikinis R, Jolesz FA (1997).
5814:
aligned with the main axon direction to accomplish tractography.
5710: 2744: 82: 7594: 6699:
Jensen JH, Helpern JA, Ramani A, Lu H, Kaczynski K (June 2005).
3416:{\displaystyle \lambda _{\perp }=(\lambda _{2}+\lambda _{3})/2.} 2770:
As it turns out, three more components can be added as follows:
8943: 6680:. Proceedings, 12th ISMRM Annual Meeting. Kyoto. p. 1238. 5652: 5633: 5593: 4711:{\displaystyle \lambda _{1}\simeq \lambda _{2}\gg \lambda _{3}} 4551:{\displaystyle \lambda _{1}\gg \lambda _{2}\simeq \lambda _{3}} 3300: 2375: 213: 205: 7197: 6949: 6458: 6089: 5706:. Applications in brain research include the investigation of 3329:
is an actual measurement of the ellipsoid we have calculated.
8970: 8181: 5691: 5660: 5629: 201: 171: 121: 7880:
High angular resolution diffusion imaging of the human brain
7876: 4984:
can used to describe the deviation from the spherical case:
3041:
components of each of them. Those three vectors are called "
1004:
gives a relationship between the flux and the concentration
28: 5589: 4099:
so that FA has a maximum value of 1. The whole formula for
3139: 3016:
are along the diagonal (red subscripts), but the variables
137: 8137: 7128: 7002: 6874:
An H, Ford AL, Vo K, Powers WJ, Lee JM, Lin W (May 2011).
6748:
Torrey HC (1956). "Bloch Equations with Diffusion Terms".
6046: 5786:
and vector mathematics developed nearly 100 years ago—the
5611:
Tractographic reconstruction of neural connections via DTI
5148:
There are other metrics of anisotropy used, including the
3115:
of an MRI voxel into a numerical measure of diffusion—the
2898:
still describe ellipsoids, but the additional components (
1087:
relates the time derivative of the concentration with the
7702: 7296: 7085: 5518:, the latter can be quantified by DWI and perfusion MRI. 3304:. The long one pointing along the axon direction will be 3082: 465:
is the signal intensity without the diffusion weighting,
237: 3122:. When various barriers and restricting factors such as 670:{\displaystyle {\frac {S(TE)}{S_{0}}}=\exp(-b\cdot ADC)} 7877:
Tuch DS, Weisskoff RM, Belliveau JW, Wedeen VJ (1999).
7653: 7212: 5997: 5682:, through which the motor information transit from the 5588:
of the tracts can be measured. The architecture of the
941:{\displaystyle \mathrm {ADC} (x,y,z)=\ln/(b_{1}-b_{2})} 16:
Method of utilizing water in magnetic resonance imaging
7904: 7759: 7247: 6616:
KÀrger, Jörg; Pfeifer, Harry; Heink, Wilfried (1988).
5514:
detecting both the infarcted core and the salvageable
4349: 2415: 1949:
then the Bloch-Torrey equation will have the solution
1875: 140:
trajectories than other diffusion imaging approaches.
7705:"Diffusion tensor imaging in cubital tunnel syndrome" 7248:
Alexander AL, Lee JE, Lazar M, Field AS (July 2007).
7129:
Richards TL, Heide AC, Tsuruda JS, Alvord EC (1992).
6698: 5674:
Diffusion tensor imaging data can be used to perform
5358: 5161: 4993: 4896: 4840: 4727: 4671: 4567: 4511: 4445: 4112: 4073: 3981: 3961: 3748: 3657: 3620: 3593: 3566: 3546: 3470: 3433: 3362: 3177: 2992: 2962: 2932: 2776: 2681: 2394: 2269: 2242: 2215: 2185: 2107: 2080: 1958: 1827: 1792: 1548: 1519: 1299: 1192: 1100: 1017: 986: 966: 789: 759: 732: 706: 686: 602: 575: 555: 535: 515: 491: 471: 444: 312: 278: 251: 8072: 7543: 7483: 6675: 5911: 700:, is replaced by an apparent diffusion coefficient, 170:(DTI) is important when a tissue—such as the neural 6501: 6322: 3339:is also called the longitudinal diffusivity or the 3268:{\displaystyle (ADC_{x}+ADC_{y}+ADC_{z})/3=ADC_{i}} 6615: 6379: 6173: 5432: 5334: 5137: 4969: 4879: 4819: 4710: 4650: 4550: 4498:, then the measures can be calculated as follows: 4490: 4424: 4332: 4091: 3987: 3967: 3944: 3721: 3633: 3606: 3579: 3552: 3529: 3446: 3415: 3267: 3008: 2978: 2948: 2867:{\displaystyle ax^{2}+by^{2}+cz^{2}+dyz+ezx+fxy=1} 2866: 2735: 2571: 2363: 2282: 2255: 2228: 2201: 2168: 2086: 2060: 1938: 1807: 1775: 1525: 1490: 1267: 1168: 1068: 992: 972: 940: 772: 745: 718: 692: 669: 581: 561: 541: 521: 497: 477: 457: 427: 291: 264: 7823: 7821: 6124: 3298:. The lengths are symbolized by the Greek letter 1283:With no diffusion present, the change in nuclear 569:is the time between the two pulses, and finally, 428:{\displaystyle {\frac {S(TE)}{S_{0}}}=\exp \left} 9080: 6648: 2071:The exponential term will be referred to as the 132:rates. A variant of diffusion weighted imaging, 6781: 6779: 5655:such as trauma and in defining the severity of 5580:The principal application is in the imaging of 7818: 7337: 7290: 7005:"In vivo fiber tractography using DT-MRI data" 6873: 6536: 6431: 6230:Annals of Clinical and Translational Neurology 5882: 5530:DWI showing necrosis (shown as brighter) in a 2913:When the ellipsoid/tensor is represented by a 2169:{\displaystyle A=e^{-\sum _{i,j}b_{ij}D_{ij}}} 8158: 7980: 6427: 6425: 6272: 6223: 5946: 5878: 5876: 2336:DWI is a result of its partial T2 weighting. 183:direction from which an observer is looking. 147:, where it is a serious candidate to replace 55:Diffusion-weighted magnetic resonance imaging 7450: 7206: 7202:. ISMRM '97. Vancouver Canada. p. 1742. 7122: 7066: 6832: 6776: 5651:Tract-specific localization of white matter 3461:—which is the sum of the three eigenvalues, 2670: 120:(DWI), the intensity of each image element ( 6669: 3644:If we divide this sum by three we have the 2339: 73:in MR images. It allows the mapping of the 8165: 8151: 7415: 6867: 6422: 6083: 5873: 3332:The diffusivity along the principal axis, 3104:of diffusion in each voxel of the tissue. 3091:Visualization of DTI data with ellipsoids. 2329:smaller magnitude of diffusion as darker. 1069:{\displaystyle J(x,t)=-D\nabla \rho (x,t)} 27: 8090: 8002: 7922: 7845: 7801: 7736: 7679: 7571: 7561: 7539: 7537: 7517: 7392: 7382: 7314: 7273: 7174: 7020: 6971: 6899: 6816:"MRI Physics: Diffusion-Weighted Imaging" 6809: 6807: 6716: 6405: 6356: 6299: 6249: 6200: 6150: 6015: 5885:Comptes Rendus de l'AcadĂ©mie des Sciences 5802:For DTI, it is generally possible to use 5736:) from traumatically injured nerve roots. 5494:Learn how and when to remove this message 4418: 3311:and the two small axes will have lengths 1278: 9001:Orthogonal polarization spectral imaging 7358: 6925:"Diffusion weighted MRI in acute stroke" 6838: 6676:Chabert S, Mecca CC, Le Bihan D (2004). 5636:(i.e. a symmetric positive definite 3×3 5614: 5606: 3142:, and slower perpendicularly across it. 3086: 2307: 1083:. Then, given conservation of mass, the 7455:. Medical Radiology. pp. 227–252. 7250:"Diffusion tensor imaging of the brain" 2098:(ADC). In general, the attenuation is: 529:is the strength of the gradient pulse, 77:process of molecules, mainly water, in 9081: 7534: 7418:AJR. American Journal of Roentgenology 7364: 7338:Weerakkody Y, Gaillard F, et al. 6804: 6785: 6747: 5568:Another application area of DWI is in 3560:is a diagonal matrix with eigenvalues 3083:Measures of anisotropy and diffusivity 2759:determine if the quadric describes an 2736:{\displaystyle ax^{2}+by^{2}+cz^{2}=1} 2209:terms incorporate the gradient fields 8146: 7303:Diagnostic and Interventional Imaging 7088:Journal of Magnetic Resonance Imaging 5584:where the location, orientation, and 1179:Putting the two together, we get the 8033: 7953: 7827: 7638: 7299:"Perfusion imaging in brain disease" 5839: 5721:Applications for peripheral nerves: 5476:adding citations to reliable sources 5447: 3075:) are 0. The second matrix provides 1287:over time is given by the classical 101:), has been used extensively to map 8172: 7043: 2586: 13: 8808:Sestamibi parathyroid scintigraphy 7660:Clinical and Translational Imaging 7167:10.1212/01.wnl.0000340982.01727.6e 6964:10.1097/01.rli.0000264059.46444.bf 6813: 6626:10.1016/b978-0-12-025512-2.50004-x 5405: 5363: 5360: 5314: 5280: 5236: 5192: 5166: 5163: 4350: 4237: 4193: 4149: 4117: 4114: 3975:is the matrix of eigenvectors and 3891: 3888: 3850: 3840: 3837: 3812: 3789: 3786: 3764: 3757: 3754: 3662: 3659: 3547: 3482: 3475: 3472: 3292:and the measures of their lengths 1758: 1740: 1235: 1219: 1196: 1142: 1127: 1104: 1045: 955: 797: 794: 791: 556: 396: 14: 9115: 8126: 6922: 3447:{\displaystyle \lambda _{\perp }} 3343:or even the parallel diffusivity 2551: 2487: 2423: 680:Also, the diffusion coefficient, 485:is the signal with the gradient, 9063: 9062: 6061:10.1016/j.neuroimage.2008.03.036 5553: 5538: 5523: 5452: 2747:surface. The relative values of 780:, of the b factor according to: 187:Diffusion Basis Spectrum Imaging 8565:Cholangiopancreatography (MRCP) 8066: 8027: 7974: 7947: 7898: 7870: 7753: 7696: 7647: 7632: 7588: 7477: 7444: 7409: 7331: 7241: 7191: 7142: 7079: 7060: 7037: 6996: 6943: 6916: 6741: 6692: 6642: 6609: 6565: 6539:The Journal of Chemical Physics 6530: 6516:10.1148/radiology.188.3.8351339 6495: 6452: 6373: 6316: 6266: 6104:10.1148/radiology.161.2.3763909 5949:Physics in Medicine and Biology 5846: 5592:in parallel bundles, and their 5463:needs additional citations for 5443: 3107:In an isotropic medium such as 2364:Mathematical foundation—tensors 111: 8813:Radioactive iodine uptake test 8079:Magnetic Resonance in Medicine 7911:Magnetic Resonance in Medicine 7834:Magnetic Resonance in Medicine 7009:Magnetic Resonance in Medicine 6705:Magnetic Resonance in Medicine 6575:Magnetic Resonance in Medicine 6461:Magnetic Resonance in Medicine 6217: 6167: 6118: 6040: 6004:Magnetic Resonance in Medicine 5991: 5940: 5905: 5657:diffuse traumatic brain injury 5418: 5411: 5326: 5320: 5296: 5292: 5286: 5264: 5252: 5248: 5242: 5220: 5208: 5204: 5198: 5176: 4773: 4747: 4407: 4368: 4362: 4356: 4324: 4270: 4262: 4253: 4249: 4243: 4221: 4209: 4205: 4199: 4177: 4165: 4161: 4155: 4133: 4130: 3901: 3895: 3866: 3844: 3815: 3793: 3767: 3761: 3708: 3669: 3485: 3479: 3402: 3376: 3235: 3178: 2401: 2318:apparent diffusion coefficient 2096:apparent diffusion coefficient 1855: 1834: 1799: 1767: 1752: 1718: 1709: 1683: 1658: 1633: 1605: 1590: 1561: 1508:mathematically showed how the 1469: 1460: 1434: 1409: 1384: 1356: 1341: 1312: 1259: 1247: 1214: 1202: 1163: 1151: 1122: 1110: 1063: 1051: 1033: 1021: 935: 909: 901: 898: 880: 862: 844: 831: 819: 801: 664: 643: 618: 609: 589:is the diffusion-coefficient. 549:is the duration of the pulse, 328: 319: 1: 8793:Radionuclide ventriculography 8267:Lower gastrointestinal series 8259:Upper gastrointestinal series 7453:Diffusion-Weighted MR Imaging 7227:10.1016/s1361-8415(02)00053-1 6292:10.1158/1078-0432.ccr-20-0736 5914:Journal of Magnetic Resonance 5867: 4092:{\displaystyle 1/{\sqrt {2}}} 1815:is now the diffusion tensor. 8984:Optical coherence tomography 8906:Myocardial perfusion imaging 8494:Dental panoramic radiography 8013:10.1016/j.sigpro.2006.02.050 7461:10.1007/978-3-540-78576-7_14 7365:Chen F, Ni YC (March 2012). 7044:Nye, John Frederick (1957). 6892:10.1161/STROKEAHA.110.610501 5934:10.1016/0022-2364(85)90111-8 3634:{\displaystyle \lambda _{3}} 3607:{\displaystyle \lambda _{2}} 3580:{\displaystyle \lambda _{1}} 2743:. This equation describes a 2303: 2293: 231: 149:positron emission tomography 7: 6663:10.1560/HB5H-6XBR-1AW1-LNX9 6651:Israel Journal of Chemistry 5817: 5755: 5647:Applications in the brain: 10: 9120: 9104:Magnetic resonance imaging 8788:Ventilation/perfusion scan 8263:Small-bowel follow-through 7786:10.1038/s41598-021-00353-z 7721:10.1038/s41598-021-94211-7 7672:10.1007/s40336-020-00393-x 7510:10.1038/s41598-019-47195-4 7371:World Journal of Radiology 7316:10.1016/j.diii.2013.06.009 7266:10.1016/j.nurt.2007.05.011 6349:10.1038/s41598-021-84252-3 6181:Multiple Sclerosis Journal 5969:10.1088/0031-9155/30/4/009 5797: 2367: 1808:{\displaystyle {\vec {D}}} 145:non-small-cell lung cancer 134:diffusion spectrum imaging 118:diffusion weighted imaging 9058: 9037: 9029:Dynamic angiothermography 9009: 8965: 8914: 8891: 8881: 8846: 8773: 8763: 8754: 8697:Abdominal ultrasonography 8605: 8521: 8481: 8400: 8359: 8350: 8203: 8194: 8180: 8133:PNRC: About Diffusion MRI 7968:10.1093/biomet/50.3-4.353 7828:Tuch DS (December 2004). 6193:10.1177/13524585211023345 2671:Mathematics of ellipsoids 2660:Henri Hureau de SĂ©narmont 65:) is the use of specific 38: 26: 21: 9019:Non-contact thermography 8798:Radionuclide angiography 8650:Doppler echocardiography 7563:10.3389/fsurg.2020.00019 6280:Clinical Cancer Research 5596:sheaths, facilitate the 3553:{\displaystyle \Lambda } 2340:Diffusion tensor imaging 960:Given the concentration 236:Diffusion imaging is an 168:Diffusion tensor imaging 95:diffusion tensor imaging 8803:Radioisotope renography 6952:Investigative Radiology 6853:10.1148/radiol.13130420 6770:10.1103/PhysRev.104.563 6446:10.4304/jcp.6.4.825-829 5740:Cubital Tunnel Syndrome 5547:Wernicke encephalopathy 2874:. Many combinations of 562:{\displaystyle \Delta } 542:{\displaystyle \delta } 498:{\displaystyle \gamma } 8838:Gastric emptying study 7215:Medical Image Analysis 6788:"Restricted Diffusion" 6587:10.1002/mrm.1910360607 6473:10.1002/mrm.1910320605 5750:carpal tunnel syndrome 5746:Carpal Tunnel Syndrome 5659:. The localization of 5620: 5612: 5434: 5336: 5139: 4971: 4881: 4821: 4712: 4652: 4552: 4492: 4426: 4334: 4093: 3989: 3969: 3946: 3723: 3635: 3608: 3581: 3554: 3531: 3448: 3417: 3269: 3092: 3010: 3009:{\displaystyle cz^{2}} 2980: 2979:{\displaystyle by^{2}} 2950: 2949:{\displaystyle ax^{2}} 2868: 2737: 2573: 2370:Principal axis theorem 2313: 2284: 2257: 2230: 2203: 2202:{\displaystyle b_{ij}} 2170: 2088: 2062: 1940: 1809: 1777: 1527: 1492: 1279:Magnetization dynamics 1269: 1170: 1070: 994: 974: 942: 774: 747: 720: 694: 671: 583: 563: 543: 523: 499: 479: 459: 429: 293: 266: 8499:X-ray motion analysis 8382:X-ray microtomography 8301:Hysterosalpingography 8208:Pneumoencephalography 7610:10.1002/ana.410420617 5618: 5610: 5602:anisotropic diffusion 5435: 5337: 5140: 4972: 4882: 4822: 4713: 4653: 4553: 4493: 4427: 4335: 4094: 4059:fractional anisotropy 3990: 3970: 3947: 3724: 3636: 3609: 3582: 3555: 3532: 3449: 3418: 3270: 3117:diffusion coefficient 3090: 3011: 2981: 2951: 2869: 2738: 2574: 2311: 2285: 2283:{\displaystyle G_{z}} 2258: 2256:{\displaystyle G_{y}} 2231: 2229:{\displaystyle G_{x}} 2204: 2171: 2089: 2063: 1941: 1810: 1778: 1536:Bloch-Torrey equation 1528: 1493: 1270: 1171: 1081:diffusion coefficient 1071: 995: 975: 973:{\displaystyle \rho } 943: 775: 773:{\displaystyle b_{2}} 748: 746:{\displaystyle b_{1}} 721: 695: 672: 584: 564: 544: 524: 500: 480: 460: 458:{\displaystyle S_{0}} 430: 294: 292:{\displaystyle T_{2}} 267: 265:{\displaystyle T_{1}} 218:fractional anisotropy 9024:Contact thermography 8734:Emergency ultrasound 8672:Transcranial Doppler 8423:Abdominal and pelvis 7550:Frontiers in Surgery 7384:10.4329/wjr.v4.i3.63 6434:Journal of Computers 6143:10.1093/brain/awr307 6137:(Pt 12): 3590–3601. 5788:Funk Radon Transform 5702:from other types of 5472:improve this article 5356: 5159: 4991: 4894: 4838: 4725: 4669: 4565: 4509: 4443: 4347: 4110: 4071: 3979: 3959: 3746: 3655: 3618: 3591: 3564: 3544: 3468: 3431: 3360: 3175: 2990: 2960: 2930: 2774: 2679: 2392: 2267: 2240: 2213: 2183: 2105: 2078: 1956: 1825: 1790: 1546: 1517: 1297: 1190: 1098: 1015: 984: 964: 787: 757: 730: 704: 684: 600: 573: 553: 533: 513: 489: 469: 442: 310: 276: 249: 8991:Confocal microscopy 8869:Indium-111 WBC scan 8692:Echoencephalography 8428:Virtual colonoscopy 7995:2007SigPr..87..220B 7778:2021NatSR..1120935R 7598:Annals of Neurology 7502:2019NatSR...910742D 7430:10.2214/AJR.06.1403 7048:. Clarendon Press. 6762:1956PhRv..104..563T 6551:1965JChPh..42..288S 6341:2021NatSR..11.4749Y 5961:1985PMB....30..345T 5926:1985JMagR..64..479M 5700:Alzheimer's disease 5690:and the peripheral 5680:corticospinal tract 5669:corticospinal tract 5532:cerebral infarction 5508:cerebral infarction 5150:relative anisotropy 4323: 4305: 4287: 3109:cerebrospinal fluid 2333:Cerebral infarction 2320:(ADC) image, or an 1085:continuity equation 719:{\displaystyle ADC} 8979:Optical tomography 8828:Dacryoscintigraphy 8823:Immunoscintigraphy 8462:Whole body imaging 8213:Dental radiography 8138:White Matter Atlas 8052:10.1007/BF01456824 7766:Scientific Reports 7709:Scientific Reports 7490:Scientific Reports 7340:"Ischaemic stroke" 6786:Elster AD (2021). 6329:Scientific Reports 6242:10.1002/acn3.51037 5621: 5613: 5430: 5332: 5135: 4982:anisotropy measure 4967: 4877: 4817: 4708: 4648: 4548: 4488: 4422: 4330: 4309: 4291: 4273: 4089: 3985: 3965: 3942: 3940: 3719: 3631: 3604: 3577: 3550: 3527: 3444: 3413: 3352:radial diffusivity 3265: 3093: 3006: 2976: 2946: 2864: 2733: 2569: 2563: 2558: 2494: 2430: 2314: 2280: 2253: 2226: 2199: 2166: 2137: 2084: 2058: 1936: 1927: 1805: 1773: 1523: 1488: 1265: 1181:diffusion equation 1166: 1066: 990: 970: 938: 770: 743: 716: 690: 667: 579: 559: 539: 519: 507:gyromagnetic ratio 495: 475: 455: 425: 289: 262: 195:multiple sclerosis 79:biological tissues 9076: 9075: 9038:Target conditions 8961: 8960: 8957: 8956: 8877: 8876: 8818:Bone scintigraphy 8783:Scintimammography 8778:Cholescintigraphy 8623:contrast-enhanced 8517: 8516: 8477: 8476: 8467:Full-body CT scan 8367:General operation 8346: 8345: 8316:Angiocardiography 8092:10.1002/mrm.29881 7983:Signal Processing 7924:10.1002/mrm.10268 7847:10.1002/mrm.20279 7470:978-3-540-78575-0 7309:(12): 1241–1257. 7254:Neurotherapeutics 7161:(16): 1378–1384. 7100:10.1002/jmri.1076 6792:mriquestions.com/ 6718:10.1002/mrm.20508 6635:978-0-12-025512-2 6559:10.1063/1.1695690 6398:10.1002/oby.23201 6286:(20): 5388–5399. 6017:10.1002/mrm.20642 5891:(15): 1109–1112. 5840:Explanatory notes 5504: 5503: 5496: 5428: 5330: 5312: 5305: 5133: 4965: 4815: 4646: 4328: 4327: 4265: 4103:looks like this: 4087: 3988:{\displaystyle D} 3968:{\displaystyle V} 3641:on its diagonal. 3341:axial diffusivity 2404: 2122: 2087:{\displaystyle A} 1995: 1976: 1858: 1837: 1802: 1770: 1755: 1735: 1721: 1675: 1661: 1636: 1608: 1593: 1576: 1564: 1526:{\displaystyle M} 1486: 1472: 1426: 1412: 1387: 1359: 1344: 1327: 1315: 1226: 1134: 993:{\displaystyle J} 693:{\displaystyle D} 632: 582:{\displaystyle D} 522:{\displaystyle G} 478:{\displaystyle S} 410: 342: 52: 51: 9111: 9066: 9065: 8889: 8888: 8771: 8770: 8761: 8760: 8645:Echocardiography 8504:Hounsfield scale 8357: 8356: 8276:Cholecystography 8201: 8200: 8192: 8191: 8167: 8160: 8153: 8144: 8143: 8121: 8120: 8094: 8070: 8064: 8063: 8031: 8025: 8024: 8006: 7978: 7972: 7971: 7962:(3–4): 353–373. 7951: 7945: 7944: 7926: 7902: 7896: 7895: 7885: 7874: 7868: 7867: 7849: 7840:(6): 1358–1372. 7830:"Q-ball imaging" 7825: 7816: 7815: 7805: 7757: 7751: 7750: 7740: 7700: 7694: 7693: 7683: 7651: 7645: 7644: 7636: 7630: 7629: 7592: 7586: 7585: 7575: 7565: 7541: 7532: 7531: 7521: 7481: 7475: 7474: 7448: 7442: 7441: 7424:(6): 1622–1635. 7413: 7407: 7406: 7396: 7386: 7362: 7356: 7355: 7353: 7352: 7335: 7329: 7328: 7318: 7294: 7288: 7287: 7277: 7245: 7239: 7238: 7210: 7204: 7203: 7195: 7189: 7188: 7178: 7146: 7140: 7139: 7137: 7126: 7120: 7119: 7083: 7077: 7076: 7064: 7058: 7057: 7041: 7035: 7034: 7024: 7000: 6994: 6993: 6975: 6947: 6941: 6940: 6938: 6937: 6920: 6914: 6913: 6903: 6886:(5): 1276–1281. 6871: 6865: 6864: 6836: 6830: 6829: 6827: 6826: 6811: 6802: 6801: 6799: 6798: 6783: 6774: 6773: 6745: 6739: 6738: 6720: 6711:(6): 1432–1440. 6696: 6690: 6689: 6673: 6667: 6666: 6646: 6640: 6639: 6613: 6607: 6606: 6569: 6563: 6562: 6534: 6528: 6527: 6499: 6493: 6492: 6456: 6450: 6449: 6429: 6420: 6419: 6409: 6392:(8): 1328–1337. 6377: 6371: 6370: 6360: 6320: 6314: 6313: 6303: 6270: 6264: 6263: 6253: 6221: 6215: 6214: 6204: 6171: 6165: 6164: 6154: 6122: 6116: 6115: 6087: 6081: 6080: 6055:(4): 1267–1277. 6044: 6038: 6037: 6019: 6010:(6): 1377–1386. 5995: 5989: 5988: 5944: 5938: 5937: 5909: 5903: 5902: 5897: 5880: 5861: 5850: 5713:, as well as in 5557: 5542: 5527: 5499: 5492: 5488: 5485: 5479: 5456: 5448: 5439: 5437: 5436: 5431: 5429: 5427: 5426: 5425: 5403: 5402: 5401: 5392: 5391: 5382: 5381: 5371: 5366: 5341: 5339: 5338: 5333: 5331: 5329: 5313: 5308: 5304: 5303: 5276: 5275: 5260: 5259: 5232: 5231: 5216: 5215: 5188: 5187: 5175: 5174: 5169: 5144: 5142: 5141: 5136: 5134: 5132: 5131: 5130: 5118: 5117: 5105: 5104: 5094: 5093: 5092: 5077: 5076: 5064: 5063: 5053: 5048: 5047: 5029: 5028: 5016: 5015: 5003: 5002: 4976: 4974: 4973: 4968: 4966: 4964: 4963: 4962: 4950: 4949: 4937: 4936: 4926: 4925: 4924: 4911: 4906: 4905: 4886: 4884: 4883: 4878: 4876: 4875: 4863: 4862: 4850: 4849: 4826: 4824: 4823: 4818: 4816: 4814: 4813: 4812: 4800: 4799: 4787: 4786: 4776: 4772: 4771: 4759: 4758: 4742: 4737: 4736: 4717: 4715: 4714: 4709: 4707: 4706: 4694: 4693: 4681: 4680: 4657: 4655: 4654: 4649: 4647: 4645: 4644: 4643: 4631: 4630: 4618: 4617: 4607: 4606: 4605: 4593: 4592: 4582: 4577: 4576: 4557: 4555: 4554: 4549: 4547: 4546: 4534: 4533: 4521: 4520: 4497: 4495: 4494: 4489: 4481: 4480: 4468: 4467: 4455: 4454: 4431: 4429: 4428: 4423: 4414: 4406: 4405: 4393: 4392: 4380: 4379: 4339: 4337: 4336: 4331: 4329: 4322: 4317: 4304: 4299: 4286: 4281: 4266: 4261: 4260: 4233: 4232: 4217: 4216: 4189: 4188: 4173: 4172: 4145: 4144: 4126: 4125: 4120: 4098: 4096: 4095: 4090: 4088: 4083: 4081: 3998:prolate spheroid 3994: 3992: 3991: 3986: 3974: 3972: 3971: 3966: 3951: 3949: 3948: 3943: 3941: 3937: 3936: 3915: 3908: 3894: 3880: 3873: 3865: 3864: 3843: 3829: 3822: 3808: 3807: 3792: 3774: 3760: 3728: 3726: 3725: 3720: 3715: 3707: 3706: 3694: 3693: 3681: 3680: 3665: 3646:mean diffusivity 3640: 3638: 3637: 3632: 3630: 3629: 3613: 3611: 3610: 3605: 3603: 3602: 3586: 3584: 3583: 3578: 3576: 3575: 3559: 3557: 3556: 3551: 3536: 3534: 3533: 3528: 3526: 3525: 3513: 3512: 3500: 3499: 3478: 3453: 3451: 3450: 3445: 3443: 3442: 3422: 3420: 3419: 3414: 3409: 3401: 3400: 3388: 3387: 3372: 3371: 3274: 3272: 3271: 3266: 3264: 3263: 3242: 3234: 3233: 3215: 3214: 3196: 3195: 3015: 3013: 3012: 3007: 3005: 3004: 2985: 2983: 2982: 2977: 2975: 2974: 2955: 2953: 2952: 2947: 2945: 2944: 2873: 2871: 2870: 2865: 2821: 2820: 2805: 2804: 2789: 2788: 2742: 2740: 2739: 2734: 2726: 2725: 2710: 2709: 2694: 2693: 2587:Physical tensors 2578: 2576: 2575: 2570: 2568: 2567: 2560: 2559: 2543: 2542: 2528: 2527: 2511: 2510: 2496: 2495: 2479: 2478: 2462: 2461: 2447: 2446: 2432: 2431: 2406: 2405: 2397: 2380:symmetric matrix 2289: 2287: 2286: 2281: 2279: 2278: 2262: 2260: 2259: 2254: 2252: 2251: 2235: 2233: 2232: 2227: 2225: 2224: 2208: 2206: 2205: 2200: 2198: 2197: 2175: 2173: 2172: 2167: 2165: 2164: 2163: 2162: 2150: 2149: 2136: 2093: 2091: 2090: 2085: 2067: 2065: 2064: 2059: 2057: 2056: 2055: 2054: 2031: 2030: 2026: 2025: 2016: 2015: 2006: 2005: 1996: 1988: 1978: 1977: 1974: 1972: 1963: 1945: 1943: 1942: 1937: 1932: 1931: 1860: 1859: 1851: 1839: 1838: 1830: 1814: 1812: 1811: 1806: 1804: 1803: 1795: 1782: 1780: 1779: 1774: 1772: 1771: 1763: 1757: 1756: 1748: 1736: 1734: 1733: 1724: 1723: 1722: 1714: 1708: 1707: 1695: 1694: 1681: 1676: 1674: 1673: 1664: 1663: 1662: 1654: 1651: 1650: 1638: 1637: 1629: 1626: 1625: 1615: 1610: 1609: 1601: 1595: 1594: 1586: 1577: 1575: 1567: 1566: 1565: 1557: 1550: 1532: 1530: 1529: 1524: 1497: 1495: 1494: 1489: 1487: 1485: 1484: 1475: 1474: 1473: 1465: 1459: 1458: 1446: 1445: 1432: 1427: 1425: 1424: 1415: 1414: 1413: 1405: 1402: 1401: 1389: 1388: 1380: 1377: 1376: 1366: 1361: 1360: 1352: 1346: 1345: 1337: 1328: 1326: 1318: 1317: 1316: 1308: 1301: 1274: 1272: 1271: 1266: 1243: 1242: 1227: 1225: 1217: 1194: 1175: 1173: 1172: 1167: 1135: 1133: 1125: 1102: 1075: 1073: 1072: 1067: 1002:Fick's first law 999: 997: 996: 991: 979: 977: 976: 971: 947: 945: 944: 939: 934: 933: 921: 920: 908: 879: 878: 869: 843: 842: 800: 779: 777: 776: 771: 769: 768: 752: 750: 749: 744: 742: 741: 725: 723: 722: 717: 699: 697: 696: 691: 676: 674: 673: 668: 633: 631: 630: 621: 604: 588: 586: 585: 580: 568: 566: 565: 560: 548: 546: 545: 540: 528: 526: 525: 520: 504: 502: 501: 496: 484: 482: 481: 476: 464: 462: 461: 456: 454: 453: 434: 432: 431: 426: 424: 420: 416: 412: 411: 403: 390: 389: 380: 379: 370: 369: 343: 341: 340: 331: 314: 298: 296: 295: 290: 288: 287: 271: 269: 268: 263: 261: 260: 48: 31: 19: 18: 9119: 9118: 9114: 9113: 9112: 9110: 9109: 9108: 9079: 9078: 9077: 9072: 9054: 9033: 9005: 8953: 8939:PET mammography 8910: 8873: 8859:Gallium-67 scan 8854:Octreotide scan 8842: 8750: 8601: 8513: 8473: 8396: 8377:High-resolution 8342: 8306:Skeletal survey 8272:Cholangiography 8185: 8176: 8174:Medical imaging 8171: 8129: 8124: 8071: 8067: 8034:Funk P (1919). 8032: 8028: 8004:10.1.1.104.9041 7979: 7975: 7952: 7948: 7903: 7899: 7883: 7875: 7871: 7826: 7819: 7758: 7754: 7701: 7697: 7652: 7648: 7639:Soll E (2015). 7637: 7633: 7593: 7589: 7542: 7535: 7482: 7478: 7471: 7449: 7445: 7414: 7410: 7363: 7359: 7350: 7348: 7336: 7332: 7295: 7291: 7246: 7242: 7211: 7207: 7196: 7192: 7147: 7143: 7135: 7127: 7123: 7084: 7080: 7065: 7061: 7042: 7038: 7001: 6997: 6948: 6944: 6935: 6933: 6921: 6917: 6872: 6868: 6837: 6833: 6824: 6822: 6812: 6805: 6796: 6794: 6784: 6777: 6750:Physical Review 6746: 6742: 6697: 6693: 6674: 6670: 6657:(1–2): 145–54. 6647: 6643: 6636: 6614: 6610: 6570: 6566: 6535: 6531: 6500: 6496: 6457: 6453: 6430: 6423: 6378: 6374: 6321: 6317: 6271: 6267: 6222: 6218: 6172: 6168: 6123: 6119: 6088: 6084: 6045: 6041: 5996: 5992: 5945: 5941: 5910: 5906: 5895: 5881: 5874: 5870: 5865: 5864: 5851: 5847: 5842: 5820: 5800: 5758: 5726:Brachial plexus 5708:neural networks 5564: 5558: 5549: 5543: 5534: 5528: 5500: 5489: 5483: 5480: 5469: 5457: 5446: 5421: 5417: 5404: 5397: 5393: 5387: 5383: 5377: 5373: 5372: 5370: 5359: 5357: 5354: 5353: 5307: 5306: 5299: 5295: 5271: 5267: 5255: 5251: 5227: 5223: 5211: 5207: 5183: 5179: 5173: 5162: 5160: 5157: 5156: 5126: 5122: 5113: 5109: 5100: 5096: 5095: 5088: 5084: 5072: 5068: 5059: 5055: 5054: 5052: 5043: 5039: 5024: 5020: 5011: 5007: 4998: 4994: 4992: 4989: 4988: 4958: 4954: 4945: 4941: 4932: 4928: 4927: 4920: 4916: 4912: 4910: 4901: 4897: 4895: 4892: 4891: 4871: 4867: 4858: 4854: 4845: 4841: 4839: 4836: 4835: 4808: 4804: 4795: 4791: 4782: 4778: 4777: 4767: 4763: 4754: 4750: 4743: 4741: 4732: 4728: 4726: 4723: 4722: 4702: 4698: 4689: 4685: 4676: 4672: 4670: 4667: 4666: 4639: 4635: 4626: 4622: 4613: 4609: 4608: 4601: 4597: 4588: 4584: 4583: 4581: 4572: 4568: 4566: 4563: 4562: 4542: 4538: 4529: 4525: 4516: 4512: 4510: 4507: 4506: 4476: 4472: 4463: 4459: 4450: 4446: 4444: 4441: 4440: 4437:oblate spheroid 4410: 4401: 4397: 4388: 4384: 4375: 4371: 4348: 4345: 4344: 4318: 4313: 4300: 4295: 4282: 4277: 4256: 4252: 4228: 4224: 4212: 4208: 4184: 4180: 4168: 4164: 4140: 4136: 4124: 4113: 4111: 4108: 4107: 4082: 4077: 4072: 4069: 4068: 4055: 4048: 4042:) + ( 4041: 4034: 4028:) + ( 4027: 4020: 4013: 4006: 3980: 3977: 3976: 3960: 3957: 3956: 3939: 3938: 3932: 3928: 3913: 3912: 3904: 3887: 3878: 3877: 3869: 3857: 3853: 3836: 3827: 3826: 3818: 3800: 3796: 3785: 3778: 3770: 3753: 3749: 3747: 3744: 3743: 3737: 3711: 3702: 3698: 3689: 3685: 3676: 3672: 3658: 3656: 3653: 3652: 3625: 3621: 3619: 3616: 3615: 3598: 3594: 3592: 3589: 3588: 3571: 3567: 3565: 3562: 3561: 3545: 3542: 3541: 3521: 3517: 3508: 3504: 3495: 3491: 3471: 3469: 3466: 3465: 3438: 3434: 3432: 3429: 3428: 3405: 3396: 3392: 3383: 3379: 3367: 3363: 3361: 3358: 3357: 3349: 3338: 3324: 3317: 3310: 3259: 3255: 3238: 3229: 3225: 3210: 3206: 3191: 3187: 3176: 3173: 3172: 3167: 3161: 3155: 3136:Brownian motion 3085: 3049:Diagonalization 3000: 2996: 2991: 2988: 2987: 2970: 2966: 2961: 2958: 2957: 2940: 2936: 2931: 2928: 2927: 2816: 2812: 2800: 2796: 2784: 2780: 2775: 2772: 2771: 2721: 2717: 2705: 2701: 2689: 2685: 2680: 2677: 2676: 2673: 2589: 2562: 2561: 2550: 2546: 2544: 2535: 2531: 2529: 2520: 2516: 2513: 2512: 2503: 2499: 2497: 2486: 2482: 2480: 2471: 2467: 2464: 2463: 2454: 2450: 2448: 2439: 2435: 2433: 2422: 2418: 2411: 2410: 2396: 2395: 2393: 2390: 2389: 2372: 2366: 2342: 2306: 2296: 2274: 2270: 2268: 2265: 2264: 2247: 2243: 2241: 2238: 2237: 2220: 2216: 2214: 2211: 2210: 2190: 2186: 2184: 2181: 2180: 2155: 2151: 2142: 2138: 2126: 2118: 2114: 2106: 2103: 2102: 2079: 2076: 2075: 2050: 2046: 2039: 2035: 2021: 2017: 2011: 2007: 2001: 1997: 1987: 1983: 1979: 1973: 1968: 1967: 1959: 1957: 1954: 1953: 1926: 1925: 1920: 1915: 1909: 1908: 1903: 1898: 1892: 1891: 1886: 1881: 1871: 1870: 1850: 1849: 1829: 1828: 1826: 1823: 1822: 1794: 1793: 1791: 1788: 1787: 1762: 1761: 1747: 1746: 1729: 1725: 1713: 1712: 1703: 1699: 1690: 1686: 1682: 1680: 1669: 1665: 1653: 1652: 1646: 1642: 1628: 1627: 1621: 1617: 1616: 1614: 1600: 1599: 1585: 1584: 1568: 1556: 1555: 1551: 1549: 1547: 1544: 1543: 1518: 1515: 1514: 1510:Bloch equations 1480: 1476: 1464: 1463: 1454: 1450: 1441: 1437: 1433: 1431: 1420: 1416: 1404: 1403: 1397: 1393: 1379: 1378: 1372: 1368: 1367: 1365: 1351: 1350: 1336: 1335: 1319: 1307: 1306: 1302: 1300: 1298: 1295: 1294: 1281: 1238: 1234: 1218: 1195: 1193: 1191: 1188: 1187: 1126: 1103: 1101: 1099: 1096: 1095: 1079:where D is the 1016: 1013: 1012: 985: 982: 981: 965: 962: 961: 958: 956:Diffusion model 929: 925: 916: 912: 904: 874: 870: 865: 838: 834: 790: 788: 785: 784: 764: 760: 758: 755: 754: 737: 733: 731: 728: 727: 705: 702: 701: 685: 682: 681: 626: 622: 605: 603: 601: 598: 597: 574: 571: 570: 554: 551: 550: 534: 531: 530: 514: 511: 510: 490: 487: 486: 470: 467: 466: 449: 445: 443: 440: 439: 402: 395: 391: 385: 381: 375: 371: 365: 361: 357: 353: 336: 332: 315: 313: 311: 308: 307: 283: 279: 277: 274: 273: 256: 252: 250: 247: 246: 234: 161:cerebral cortex 114: 44: 34: 17: 12: 11: 5: 9117: 9107: 9106: 9101: 9096: 9091: 9074: 9073: 9071: 9070: 9059: 9056: 9055: 9053: 9052: 9047: 9041: 9039: 9035: 9034: 9032: 9031: 9026: 9021: 9015: 9013: 9007: 9006: 9004: 9003: 8998: 8996:Endomicroscopy 8993: 8988: 8987: 8986: 8975: 8973: 8963: 8962: 8959: 8958: 8955: 8954: 8952: 8951: 8946: 8941: 8936: 8931: 8925: 8923: 8912: 8911: 8909: 8908: 8902: 8900: 8886: 8879: 8878: 8875: 8874: 8872: 8871: 8866: 8861: 8856: 8850: 8848: 8844: 8843: 8841: 8840: 8835: 8830: 8825: 8820: 8815: 8810: 8805: 8800: 8795: 8790: 8785: 8780: 8774: 8768: 8758: 8752: 8751: 8749: 8748: 8747: 8746: 8741: 8731: 8726: 8721: 8716: 8711: 8710: 8709: 8704: 8694: 8689: 8684: 8679: 8674: 8669: 8668: 8667: 8662: 8657: 8652: 8642: 8641: 8640: 8635: 8630: 8625: 8620: 8611: 8609: 8603: 8602: 8600: 8599: 8594: 8593: 8592: 8587: 8582: 8572: 8567: 8562: 8557: 8556: 8555: 8545: 8540: 8539: 8538: 8527: 8525: 8519: 8518: 8515: 8514: 8512: 8511: 8506: 8501: 8496: 8491: 8485: 8483: 8479: 8478: 8475: 8474: 8472: 8471: 8470: 8469: 8459: 8454: 8449: 8448: 8447: 8442: 8432: 8431: 8430: 8420: 8419: 8418: 8413: 8404: 8402: 8398: 8397: 8395: 8394: 8389: 8384: 8379: 8374: 8369: 8363: 8361: 8354: 8348: 8347: 8344: 8343: 8341: 8340: 8335: 8330: 8325: 8324: 8323: 8318: 8308: 8303: 8298: 8293: 8288: 8283: 8278: 8269: 8256: 8247: 8242: 8237: 8236: 8235: 8225: 8220: 8215: 8210: 8204: 8198: 8189: 8178: 8177: 8170: 8169: 8162: 8155: 8147: 8141: 8140: 8135: 8128: 8127:External links 8125: 8123: 8122: 8085:(2): 773–783. 8065: 8026: 7989:(2): 220–236. 7973: 7946: 7917:(4): 577–582. 7897: 7869: 7817: 7752: 7695: 7666:(6): 419–431. 7646: 7631: 7604:(6): 951–962. 7587: 7533: 7476: 7469: 7443: 7408: 7357: 7330: 7289: 7260:(3): 316–329. 7240: 7205: 7190: 7141: 7121: 7094:(4): 534–546. 7078: 7059: 7036: 7015:(4): 625–632. 6995: 6958:(6): 412–419. 6942: 6915: 6866: 6831: 6803: 6775: 6756:(3): 563–565. 6740: 6691: 6668: 6641: 6634: 6608: 6581:(6): 847–857. 6564: 6545:(1): 288–292. 6529: 6510:(3): 719–725. 6494: 6467:(6): 707–713. 6451: 6440:(4): 825–829. 6421: 6372: 6315: 6265: 6236:(5): 695–706. 6216: 6187:(3): 418–428. 6166: 6117: 6098:(2): 401–407. 6082: 6039: 5990: 5955:(4): 345–349. 5939: 5920:(3): 479–486. 5904: 5871: 5869: 5866: 5863: 5862: 5858:component free 5844: 5843: 5841: 5838: 5837: 5836: 5831: 5826: 5819: 5816: 5804:linear algebra 5799: 5796: 5757: 5754: 5753: 5752: 5743: 5737: 5719: 5718: 5695: 5672: 5625:magnetic field 5566: 5565: 5562:MELAS syndrome 5559: 5552: 5550: 5544: 5537: 5535: 5529: 5522: 5502: 5501: 5460: 5458: 5451: 5445: 5442: 5441: 5440: 5424: 5420: 5416: 5413: 5410: 5407: 5400: 5396: 5390: 5386: 5380: 5376: 5369: 5365: 5362: 5343: 5342: 5328: 5325: 5322: 5319: 5316: 5311: 5302: 5298: 5294: 5291: 5288: 5285: 5282: 5279: 5274: 5270: 5266: 5263: 5258: 5254: 5250: 5247: 5244: 5241: 5238: 5235: 5230: 5226: 5222: 5219: 5214: 5210: 5206: 5203: 5200: 5197: 5194: 5191: 5186: 5182: 5178: 5172: 5168: 5165: 5146: 5145: 5129: 5125: 5121: 5116: 5112: 5108: 5103: 5099: 5091: 5087: 5083: 5080: 5075: 5071: 5067: 5062: 5058: 5051: 5046: 5042: 5038: 5035: 5032: 5027: 5023: 5019: 5014: 5010: 5006: 5001: 4997: 4978: 4977: 4961: 4957: 4953: 4948: 4944: 4940: 4935: 4931: 4923: 4919: 4915: 4909: 4904: 4900: 4874: 4870: 4866: 4861: 4857: 4853: 4848: 4844: 4832:spherical case 4828: 4827: 4811: 4807: 4803: 4798: 4794: 4790: 4785: 4781: 4775: 4770: 4766: 4762: 4757: 4753: 4749: 4746: 4740: 4735: 4731: 4705: 4701: 4697: 4692: 4688: 4684: 4679: 4675: 4659: 4658: 4642: 4638: 4634: 4629: 4625: 4621: 4616: 4612: 4604: 4600: 4596: 4591: 4587: 4580: 4575: 4571: 4545: 4541: 4537: 4532: 4528: 4524: 4519: 4515: 4487: 4484: 4479: 4475: 4471: 4466: 4462: 4458: 4453: 4449: 4421: 4417: 4413: 4409: 4404: 4400: 4396: 4391: 4387: 4383: 4378: 4374: 4370: 4367: 4364: 4361: 4358: 4355: 4352: 4341: 4340: 4326: 4321: 4316: 4312: 4308: 4303: 4298: 4294: 4290: 4285: 4280: 4276: 4272: 4269: 4264: 4259: 4255: 4251: 4248: 4245: 4242: 4239: 4236: 4231: 4227: 4223: 4220: 4215: 4211: 4207: 4204: 4201: 4198: 4195: 4192: 4187: 4183: 4179: 4176: 4171: 4167: 4163: 4160: 4157: 4154: 4151: 4148: 4143: 4139: 4135: 4132: 4129: 4123: 4119: 4116: 4086: 4080: 4076: 4053: 4046: 4039: 4032: 4025: 4018: 4011: 4004: 3984: 3964: 3953: 3952: 3935: 3931: 3927: 3924: 3921: 3918: 3916: 3914: 3911: 3907: 3903: 3900: 3897: 3893: 3890: 3886: 3883: 3881: 3879: 3876: 3872: 3868: 3863: 3860: 3856: 3852: 3849: 3846: 3842: 3839: 3835: 3832: 3830: 3828: 3825: 3821: 3817: 3814: 3811: 3806: 3803: 3799: 3795: 3791: 3788: 3784: 3781: 3779: 3777: 3773: 3769: 3766: 3763: 3759: 3756: 3752: 3751: 3735: 3730: 3729: 3718: 3714: 3710: 3705: 3701: 3697: 3692: 3688: 3684: 3679: 3675: 3671: 3668: 3664: 3661: 3628: 3624: 3601: 3597: 3574: 3570: 3549: 3538: 3537: 3524: 3520: 3516: 3511: 3507: 3503: 3498: 3494: 3490: 3487: 3484: 3481: 3477: 3474: 3441: 3437: 3424: 3423: 3412: 3408: 3404: 3399: 3395: 3391: 3386: 3382: 3378: 3375: 3370: 3366: 3347: 3336: 3322: 3315: 3308: 3276: 3275: 3262: 3258: 3254: 3251: 3248: 3245: 3241: 3237: 3232: 3228: 3224: 3221: 3218: 3213: 3209: 3205: 3202: 3199: 3194: 3190: 3186: 3183: 3180: 3163: 3157: 3151: 3124:cell membranes 3084: 3081: 3003: 2999: 2995: 2973: 2969: 2965: 2943: 2939: 2935: 2863: 2860: 2857: 2854: 2851: 2848: 2845: 2842: 2839: 2836: 2833: 2830: 2827: 2824: 2819: 2815: 2811: 2808: 2803: 2799: 2795: 2792: 2787: 2783: 2779: 2732: 2729: 2724: 2720: 2716: 2713: 2708: 2704: 2700: 2697: 2692: 2688: 2684: 2672: 2669: 2663:ellipsoid. As 2588: 2585: 2580: 2579: 2566: 2557: 2554: 2549: 2545: 2541: 2538: 2534: 2530: 2526: 2523: 2519: 2515: 2514: 2509: 2506: 2502: 2498: 2493: 2490: 2485: 2481: 2477: 2474: 2470: 2466: 2465: 2460: 2457: 2453: 2449: 2445: 2442: 2438: 2434: 2429: 2426: 2421: 2417: 2416: 2414: 2409: 2403: 2400: 2365: 2362: 2341: 2338: 2305: 2302: 2295: 2292: 2277: 2273: 2250: 2246: 2223: 2219: 2196: 2193: 2189: 2177: 2176: 2161: 2158: 2154: 2148: 2145: 2141: 2135: 2132: 2129: 2125: 2121: 2117: 2113: 2110: 2083: 2069: 2068: 2053: 2049: 2045: 2042: 2038: 2034: 2029: 2024: 2020: 2014: 2010: 2004: 2000: 1994: 1991: 1986: 1982: 1971: 1966: 1962: 1947: 1946: 1935: 1930: 1924: 1921: 1919: 1916: 1914: 1911: 1910: 1907: 1904: 1902: 1899: 1897: 1894: 1893: 1890: 1887: 1885: 1882: 1880: 1877: 1876: 1874: 1869: 1866: 1863: 1857: 1854: 1848: 1845: 1842: 1836: 1833: 1801: 1798: 1784: 1783: 1769: 1766: 1760: 1754: 1751: 1745: 1742: 1739: 1732: 1728: 1720: 1717: 1711: 1706: 1702: 1698: 1693: 1689: 1685: 1679: 1672: 1668: 1660: 1657: 1649: 1645: 1641: 1635: 1632: 1624: 1620: 1613: 1607: 1604: 1598: 1592: 1589: 1583: 1580: 1574: 1571: 1563: 1560: 1554: 1522: 1499: 1498: 1483: 1479: 1471: 1468: 1462: 1457: 1453: 1449: 1444: 1440: 1436: 1430: 1423: 1419: 1411: 1408: 1400: 1396: 1392: 1386: 1383: 1375: 1371: 1364: 1358: 1355: 1349: 1343: 1340: 1334: 1331: 1325: 1322: 1314: 1311: 1305: 1289:Bloch equation 1280: 1277: 1276: 1275: 1264: 1261: 1258: 1255: 1252: 1249: 1246: 1241: 1237: 1233: 1230: 1224: 1221: 1216: 1213: 1210: 1207: 1204: 1201: 1198: 1177: 1176: 1165: 1162: 1159: 1156: 1153: 1150: 1147: 1144: 1141: 1138: 1132: 1129: 1124: 1121: 1118: 1115: 1112: 1109: 1106: 1077: 1076: 1065: 1062: 1059: 1056: 1053: 1050: 1047: 1044: 1041: 1038: 1035: 1032: 1029: 1026: 1023: 1020: 989: 969: 957: 954: 949: 948: 937: 932: 928: 924: 919: 915: 911: 907: 903: 900: 897: 894: 891: 888: 885: 882: 877: 873: 868: 864: 861: 858: 855: 852: 849: 846: 841: 837: 833: 830: 827: 824: 821: 818: 815: 812: 809: 806: 803: 799: 796: 793: 767: 763: 740: 736: 715: 712: 709: 689: 678: 677: 666: 663: 660: 657: 654: 651: 648: 645: 642: 639: 636: 629: 625: 620: 617: 614: 611: 608: 578: 558: 538: 518: 494: 474: 452: 448: 436: 435: 423: 419: 415: 409: 406: 401: 398: 394: 388: 384: 378: 374: 368: 364: 360: 356: 352: 349: 346: 339: 335: 330: 327: 324: 321: 318: 286: 282: 259: 255: 233: 230: 113: 110: 108:in the brain. 89:, fibers, and 87:macromolecules 50: 49: 42: 36: 35: 32: 24: 23: 15: 9: 6: 4: 3: 2: 9116: 9105: 9102: 9100: 9097: 9095: 9092: 9090: 9087: 9086: 9084: 9069: 9061: 9060: 9057: 9051: 9048: 9046: 9043: 9042: 9040: 9036: 9030: 9027: 9025: 9022: 9020: 9017: 9016: 9014: 9012: 9008: 9002: 8999: 8997: 8994: 8992: 8989: 8985: 8982: 8981: 8980: 8977: 8976: 8974: 8972: 8968: 8964: 8950: 8947: 8945: 8942: 8940: 8937: 8935: 8932: 8930: 8927: 8926: 8924: 8921: 8917: 8913: 8907: 8904: 8903: 8901: 8898: 8894: 8890: 8887: 8885: 8880: 8870: 8867: 8865: 8864:Ga-68-DOTATOC 8862: 8860: 8857: 8855: 8852: 8851: 8849: 8845: 8839: 8836: 8834: 8831: 8829: 8826: 8824: 8821: 8819: 8816: 8814: 8811: 8809: 8806: 8804: 8801: 8799: 8796: 8794: 8791: 8789: 8786: 8784: 8781: 8779: 8776: 8775: 8772: 8769: 8767: 8762: 8759: 8757: 8753: 8745: 8742: 8740: 8737: 8736: 8735: 8732: 8730: 8727: 8725: 8722: 8720: 8717: 8715: 8712: 8708: 8705: 8703: 8700: 8699: 8698: 8695: 8693: 8690: 8688: 8685: 8683: 8680: 8678: 8677:Intravascular 8675: 8673: 8670: 8666: 8663: 8661: 8658: 8656: 8653: 8651: 8648: 8647: 8646: 8643: 8639: 8636: 8634: 8631: 8629: 8626: 8624: 8621: 8619: 8616: 8615: 8613: 8612: 8610: 8608: 8604: 8598: 8597:Synthetic MRI 8595: 8591: 8588: 8586: 8583: 8581: 8578: 8577: 8576: 8573: 8571: 8568: 8566: 8563: 8561: 8558: 8554: 8551: 8550: 8549: 8546: 8544: 8541: 8537: 8534: 8533: 8532: 8529: 8528: 8526: 8524: 8520: 8510: 8507: 8505: 8502: 8500: 8497: 8495: 8492: 8490: 8487: 8486: 8484: 8480: 8468: 8465: 8464: 8463: 8460: 8458: 8455: 8453: 8450: 8446: 8443: 8441: 8438: 8437: 8436: 8433: 8429: 8426: 8425: 8424: 8421: 8417: 8414: 8412: 8409: 8408: 8406: 8405: 8403: 8399: 8393: 8390: 8388: 8387:Electron beam 8385: 8383: 8380: 8378: 8375: 8373: 8370: 8368: 8365: 8364: 8362: 8358: 8355: 8353: 8349: 8339: 8338:Orbital x-ray 8336: 8334: 8331: 8329: 8326: 8322: 8319: 8317: 8314: 8313: 8312: 8309: 8307: 8304: 8302: 8299: 8297: 8294: 8292: 8289: 8287: 8284: 8282: 8279: 8277: 8273: 8270: 8268: 8264: 8260: 8257: 8255: 8251: 8248: 8246: 8243: 8241: 8238: 8234: 8233:Bronchography 8231: 8230: 8229: 8226: 8224: 8221: 8219: 8216: 8214: 8211: 8209: 8206: 8205: 8202: 8199: 8197: 8193: 8190: 8188: 8183: 8179: 8175: 8168: 8163: 8161: 8156: 8154: 8149: 8148: 8145: 8139: 8136: 8134: 8131: 8130: 8118: 8114: 8110: 8106: 8102: 8098: 8093: 8088: 8084: 8080: 8076: 8069: 8061: 8057: 8053: 8049: 8045: 8041: 8037: 8030: 8022: 8018: 8014: 8010: 8005: 8000: 7996: 7992: 7988: 7984: 7977: 7969: 7965: 7961: 7957: 7950: 7942: 7938: 7934: 7930: 7925: 7920: 7916: 7912: 7908: 7901: 7893: 7889: 7882: 7881: 7873: 7865: 7861: 7857: 7853: 7848: 7843: 7839: 7835: 7831: 7824: 7822: 7813: 7809: 7804: 7799: 7795: 7791: 7787: 7783: 7779: 7775: 7771: 7767: 7763: 7756: 7748: 7744: 7739: 7734: 7730: 7726: 7722: 7718: 7714: 7710: 7706: 7699: 7691: 7687: 7682: 7677: 7673: 7669: 7665: 7661: 7657: 7650: 7642: 7635: 7627: 7623: 7619: 7615: 7611: 7607: 7603: 7599: 7591: 7583: 7579: 7574: 7569: 7564: 7559: 7555: 7551: 7547: 7540: 7538: 7529: 7525: 7520: 7515: 7511: 7507: 7503: 7499: 7495: 7491: 7487: 7480: 7472: 7466: 7462: 7458: 7454: 7447: 7439: 7435: 7431: 7427: 7423: 7419: 7412: 7404: 7400: 7395: 7390: 7385: 7380: 7376: 7372: 7368: 7361: 7347: 7346: 7341: 7334: 7326: 7322: 7317: 7312: 7308: 7304: 7300: 7293: 7285: 7281: 7276: 7271: 7267: 7263: 7259: 7255: 7251: 7244: 7236: 7232: 7228: 7224: 7221:(2): 93–108. 7220: 7216: 7209: 7201: 7194: 7186: 7182: 7177: 7172: 7168: 7164: 7160: 7156: 7152: 7145: 7134: 7133: 7125: 7117: 7113: 7109: 7105: 7101: 7097: 7093: 7089: 7082: 7074: 7071:(in French). 7070: 7063: 7055: 7051: 7047: 7040: 7032: 7028: 7023: 7018: 7014: 7010: 7006: 6999: 6991: 6987: 6983: 6979: 6974: 6969: 6965: 6961: 6957: 6953: 6946: 6932: 6931: 6926: 6919: 6911: 6907: 6902: 6897: 6893: 6889: 6885: 6881: 6877: 6870: 6862: 6858: 6854: 6850: 6847:(2): 318–22. 6846: 6842: 6835: 6821: 6817: 6810: 6808: 6793: 6789: 6782: 6780: 6771: 6767: 6763: 6759: 6755: 6751: 6744: 6736: 6732: 6728: 6724: 6719: 6714: 6710: 6706: 6702: 6695: 6687: 6683: 6679: 6672: 6664: 6660: 6656: 6652: 6645: 6637: 6631: 6627: 6623: 6619: 6612: 6604: 6600: 6596: 6592: 6588: 6584: 6580: 6576: 6568: 6560: 6556: 6552: 6548: 6544: 6540: 6533: 6525: 6521: 6517: 6513: 6509: 6505: 6498: 6490: 6486: 6482: 6478: 6474: 6470: 6466: 6462: 6455: 6447: 6443: 6439: 6435: 6428: 6426: 6417: 6413: 6408: 6403: 6399: 6395: 6391: 6387: 6383: 6376: 6368: 6364: 6359: 6354: 6350: 6346: 6342: 6338: 6334: 6330: 6326: 6319: 6311: 6307: 6302: 6297: 6293: 6289: 6285: 6281: 6277: 6269: 6261: 6257: 6252: 6247: 6243: 6239: 6235: 6231: 6227: 6220: 6212: 6208: 6203: 6198: 6194: 6190: 6186: 6182: 6178: 6170: 6162: 6158: 6153: 6148: 6144: 6140: 6136: 6132: 6128: 6121: 6113: 6109: 6105: 6101: 6097: 6093: 6086: 6078: 6074: 6070: 6066: 6062: 6058: 6054: 6050: 6043: 6035: 6031: 6027: 6023: 6018: 6013: 6009: 6005: 6001: 5994: 5986: 5982: 5978: 5974: 5970: 5966: 5962: 5958: 5954: 5950: 5943: 5935: 5931: 5927: 5923: 5919: 5915: 5908: 5900: 5894: 5890: 5887:(in French). 5886: 5879: 5877: 5872: 5859: 5855: 5849: 5845: 5835: 5832: 5830: 5827: 5825: 5822: 5821: 5815: 5812: 5807: 5805: 5795: 5791: 5789: 5785: 5779: 5776: 5775:tessellations 5772: 5767: 5762: 5751: 5747: 5744: 5741: 5738: 5735: 5731: 5727: 5724: 5723: 5722: 5716: 5712: 5709: 5705: 5701: 5696: 5693: 5689: 5685: 5681: 5677: 5673: 5670: 5666: 5662: 5658: 5654: 5650: 5649: 5648: 5645: 5643: 5639: 5635: 5631: 5626: 5617: 5609: 5605: 5603: 5599: 5595: 5591: 5587: 5583: 5578: 5575: 5571: 5563: 5556: 5551: 5548: 5541: 5536: 5533: 5526: 5521: 5520: 5519: 5517: 5513: 5512:perfusion MRI 5509: 5498: 5495: 5487: 5484:December 2013 5477: 5473: 5467: 5466: 5461:This section 5459: 5455: 5450: 5449: 5422: 5414: 5408: 5398: 5394: 5388: 5384: 5378: 5374: 5367: 5352: 5351: 5350: 5348: 5323: 5317: 5309: 5300: 5289: 5283: 5277: 5272: 5268: 5261: 5256: 5245: 5239: 5233: 5228: 5224: 5217: 5212: 5201: 5195: 5189: 5184: 5180: 5170: 5155: 5154: 5153: 5151: 5127: 5123: 5119: 5114: 5110: 5106: 5101: 5097: 5089: 5085: 5081: 5078: 5073: 5069: 5065: 5060: 5056: 5049: 5044: 5040: 5036: 5033: 5030: 5025: 5021: 5017: 5012: 5008: 5004: 4999: 4995: 4987: 4986: 4985: 4983: 4959: 4955: 4951: 4946: 4942: 4938: 4933: 4929: 4921: 4917: 4913: 4907: 4902: 4898: 4890: 4889: 4888: 4872: 4868: 4864: 4859: 4855: 4851: 4846: 4842: 4833: 4809: 4805: 4801: 4796: 4792: 4788: 4783: 4779: 4768: 4764: 4760: 4755: 4751: 4744: 4738: 4733: 4729: 4721: 4720: 4719: 4703: 4699: 4695: 4690: 4686: 4682: 4677: 4673: 4664: 4640: 4636: 4632: 4627: 4623: 4619: 4614: 4610: 4602: 4598: 4594: 4589: 4585: 4578: 4573: 4569: 4561: 4560: 4559: 4543: 4539: 4535: 4530: 4526: 4522: 4517: 4513: 4504: 4499: 4485: 4482: 4477: 4473: 4469: 4464: 4460: 4456: 4451: 4447: 4438: 4432: 4419: 4415: 4411: 4402: 4398: 4394: 4389: 4385: 4381: 4376: 4372: 4365: 4359: 4353: 4319: 4314: 4310: 4306: 4301: 4296: 4292: 4288: 4283: 4278: 4274: 4267: 4257: 4246: 4240: 4234: 4229: 4225: 4218: 4213: 4202: 4196: 4190: 4185: 4181: 4174: 4169: 4158: 4152: 4146: 4141: 4137: 4127: 4121: 4106: 4105: 4104: 4102: 4084: 4078: 4074: 4065: 4061: 4060: 4052: 4049: âˆ’  4045: 4038: 4035: âˆ’  4031: 4024: 4021: âˆ’  4017: 4010: 4003: 3999: 3982: 3962: 3933: 3929: 3925: 3922: 3919: 3917: 3909: 3905: 3898: 3884: 3882: 3874: 3870: 3861: 3858: 3854: 3847: 3833: 3831: 3823: 3819: 3809: 3804: 3801: 3797: 3782: 3780: 3775: 3771: 3742: 3741: 3740: 3738: 3732:which equals 3716: 3712: 3703: 3699: 3695: 3690: 3686: 3682: 3677: 3673: 3666: 3651: 3650: 3649: 3647: 3642: 3626: 3622: 3599: 3595: 3572: 3568: 3522: 3518: 3514: 3509: 3505: 3501: 3496: 3492: 3488: 3464: 3463: 3462: 3460: 3455: 3439: 3435: 3410: 3406: 3397: 3393: 3389: 3384: 3380: 3373: 3368: 3364: 3356: 3355: 3354: 3353: 3346: 3342: 3335: 3330: 3328: 3321: 3314: 3307: 3303: 3302: 3297: 3296: 3291: 3290: 3283: 3281: 3260: 3256: 3252: 3249: 3246: 3243: 3239: 3230: 3226: 3222: 3219: 3216: 3211: 3207: 3203: 3200: 3197: 3192: 3188: 3184: 3181: 3171: 3170: 3169: 3166: 3160: 3154: 3149: 3143: 3141: 3137: 3133: 3129: 3125: 3121: 3118: 3114: 3110: 3105: 3102: 3098: 3089: 3080: 3079:information. 3078: 3074: 3070: 3066: 3062: 3058: 3054: 3050: 3046: 3044: 3040: 3036: 3032: 3027: 3023: 3019: 3001: 2997: 2993: 2971: 2967: 2963: 2941: 2937: 2933: 2924: 2920: 2916: 2911: 2909: 2905: 2901: 2897: 2893: 2889: 2885: 2881: 2877: 2861: 2858: 2855: 2852: 2849: 2846: 2843: 2840: 2837: 2834: 2831: 2828: 2825: 2822: 2817: 2813: 2809: 2806: 2801: 2797: 2793: 2790: 2785: 2781: 2777: 2768: 2766: 2762: 2758: 2754: 2750: 2746: 2730: 2727: 2722: 2718: 2714: 2711: 2706: 2702: 2698: 2695: 2690: 2686: 2682: 2668: 2666: 2661: 2656: 2652: 2650: 2646: 2642: 2638: 2634: 2630: 2626: 2622: 2618: 2612: 2610: 2606: 2603: 2599: 2595: 2584: 2564: 2555: 2552: 2547: 2539: 2536: 2532: 2524: 2521: 2517: 2507: 2504: 2500: 2491: 2488: 2483: 2475: 2472: 2468: 2458: 2455: 2451: 2443: 2440: 2436: 2427: 2424: 2419: 2412: 2407: 2398: 2388: 2387: 2386: 2383: 2381: 2377: 2371: 2361: 2359: 2354: 2352: 2346: 2337: 2334: 2330: 2327: 2323: 2319: 2310: 2301: 2299: 2291: 2275: 2271: 2248: 2244: 2221: 2217: 2194: 2191: 2187: 2159: 2156: 2152: 2146: 2143: 2139: 2133: 2130: 2127: 2123: 2119: 2115: 2111: 2108: 2101: 2100: 2099: 2097: 2081: 2074: 2051: 2047: 2043: 2040: 2036: 2032: 2027: 2022: 2018: 2012: 2008: 2002: 1998: 1992: 1989: 1984: 1980: 1969: 1964: 1960: 1952: 1951: 1950: 1933: 1928: 1922: 1917: 1912: 1905: 1900: 1895: 1888: 1883: 1878: 1872: 1867: 1864: 1861: 1852: 1846: 1843: 1840: 1831: 1821: 1820: 1819: 1816: 1796: 1764: 1749: 1743: 1737: 1730: 1726: 1715: 1704: 1700: 1696: 1691: 1687: 1677: 1670: 1666: 1655: 1647: 1643: 1639: 1630: 1622: 1618: 1611: 1602: 1596: 1587: 1581: 1578: 1572: 1569: 1558: 1552: 1542: 1541: 1540: 1538: 1537: 1520: 1511: 1507: 1502: 1481: 1477: 1466: 1455: 1451: 1447: 1442: 1438: 1428: 1421: 1417: 1406: 1398: 1394: 1390: 1381: 1373: 1369: 1362: 1353: 1347: 1338: 1332: 1329: 1323: 1320: 1309: 1303: 1293: 1292: 1291: 1290: 1286: 1285:magnetization 1262: 1256: 1253: 1250: 1244: 1239: 1231: 1228: 1222: 1211: 1208: 1205: 1199: 1186: 1185: 1184: 1182: 1160: 1157: 1154: 1148: 1145: 1139: 1136: 1130: 1119: 1116: 1113: 1107: 1094: 1093: 1092: 1091:of the flux: 1090: 1086: 1082: 1060: 1057: 1054: 1048: 1042: 1039: 1036: 1030: 1027: 1024: 1018: 1011: 1010: 1009: 1007: 1003: 987: 967: 953: 930: 926: 922: 917: 913: 905: 895: 892: 889: 886: 883: 875: 871: 866: 859: 856: 853: 850: 847: 839: 835: 828: 825: 822: 816: 813: 810: 807: 804: 783: 782: 781: 765: 761: 738: 734: 713: 710: 707: 687: 661: 658: 655: 652: 649: 646: 640: 637: 634: 627: 623: 615: 612: 606: 596: 595: 594: 590: 576: 536: 516: 508: 492: 472: 450: 446: 421: 417: 413: 407: 404: 399: 392: 386: 382: 376: 372: 366: 362: 358: 354: 350: 347: 344: 337: 333: 325: 322: 316: 306: 305: 304: 300: 284: 280: 257: 253: 243: 239: 229: 225: 223: 219: 215: 209: 207: 203: 198: 196: 192: 188: 184: 181: 177: 173: 169: 165: 162: 158: 154: 150: 146: 141: 139: 135: 131: 130:T2 relaxation 127: 123: 119: 109: 107: 104: 100: 96: 92: 88: 84: 80: 76: 72: 68: 67:MRI sequences 64: 60: 56: 47: 43: 41: 37: 33:DTI Color Map 30: 25: 22:Diffusion MRI 20: 9099:Neuroimaging 9045:Acute stroke 9011:Thermography 8766:scintigraphy 8756:Radionuclide 8744:pre-hospital 8590:Tractography 8579: 8509:Radiodensity 8411:calcium scan 8372:Quantitative 8082: 8078: 8068: 8043: 8039: 8029: 7986: 7982: 7976: 7959: 7955: 7949: 7914: 7910: 7900: 7879: 7872: 7837: 7833: 7772:(1): 20935. 7769: 7765: 7755: 7715:(1): 14982. 7712: 7708: 7698: 7663: 7659: 7649: 7634: 7601: 7597: 7590: 7553: 7549: 7496:(1): 10742. 7493: 7489: 7479: 7452: 7446: 7421: 7417: 7411: 7377:(3): 63–74. 7374: 7370: 7360: 7349:. Retrieved 7343: 7333: 7306: 7302: 7292: 7257: 7253: 7243: 7218: 7214: 7208: 7199: 7193: 7158: 7154: 7144: 7131: 7124: 7091: 7087: 7081: 7072: 7068: 7062: 7045: 7039: 7012: 7008: 6998: 6955: 6951: 6945: 6934:. Retrieved 6928: 6918: 6883: 6879: 6869: 6844: 6840: 6834: 6823:. Retrieved 6819: 6795:. Retrieved 6791: 6753: 6749: 6743: 6708: 6704: 6694: 6677: 6671: 6654: 6650: 6644: 6617: 6611: 6578: 6574: 6567: 6542: 6538: 6532: 6507: 6503: 6497: 6464: 6460: 6454: 6437: 6433: 6389: 6385: 6375: 6332: 6328: 6318: 6283: 6279: 6268: 6233: 6229: 6219: 6184: 6180: 6169: 6134: 6130: 6120: 6095: 6091: 6085: 6052: 6048: 6042: 6007: 6003: 5993: 5952: 5948: 5942: 5917: 5913: 5907: 5888: 5884: 5848: 5834:Tractography 5824:Connectogram 5811:tractography 5808: 5801: 5792: 5780: 5770: 5763: 5759: 5720: 5715:connectomics 5684:motor cortex 5676:tractography 5671:and a tumor. 5665:brain tumors 5646: 5622: 5601: 5582:white matter 5579: 5567: 5505: 5490: 5481: 5470:Please help 5465:verification 5462: 5444:Applications 5347:volume ratio 5346: 5344: 5149: 5147: 4981: 4979: 4831: 4829: 4662: 4660: 4502: 4500: 4433: 4342: 4100: 4063: 4057: 4050: 4043: 4036: 4029: 4022: 4015: 4008: 4001: 3954: 3733: 3731: 3645: 3643: 3539: 3458: 3456: 3425: 3351: 3344: 3340: 3333: 3331: 3326: 3319: 3312: 3305: 3299: 3293: 3289:eigenvectors 3287: 3284: 3279: 3277: 3164: 3158: 3152: 3144: 3131: 3128:microtubules 3119: 3106: 3094: 3072: 3068: 3064: 3060: 3056: 3052: 3047: 3043:eigenvectors 3038: 3034: 3030: 3025: 3021: 3017: 2912: 2907: 2903: 2899: 2895: 2891: 2887: 2883: 2879: 2875: 2769: 2756: 2752: 2748: 2674: 2657: 2653: 2648: 2644: 2640: 2636: 2632: 2628: 2624: 2620: 2616: 2613: 2608: 2604: 2601: 2590: 2581: 2384: 2373: 2357: 2355: 2351:tractography 2347: 2343: 2331: 2326:T2 weighting 2321: 2317: 2315: 2300: 2297: 2178: 2095: 2072: 2070: 1948: 1817: 1785: 1534: 1503: 1500: 1282: 1178: 1078: 959: 950: 679: 591: 437: 301: 235: 226: 222:tractography 210: 199: 191:brain tumors 186: 185: 176:white matter 167: 166: 153:white matter 142: 133: 117: 115: 112:Introduction 106:tractography 103:white matter 98: 94: 62: 58: 54: 53: 8934:Cardiac PET 8707:renal tract 8682:Gynecologic 8614:Techniques 8585:restriction 8560:Angiography 8543:Neurography 8489:Fluoroscopy 8435:Angiography 8416:angiography 8360:Techniques: 8321:Aortography 8311:Angiography 8291:Cystography 8281:Mammography 8223:Myelography 8218:Sialography 8187:radiography 8046:: 129–135. 7892:10027851300 7345:Radiopaedia 6930:Radiopaedia 6820:XRayPhysics 6686:10018514722 6335:(1): 4749. 5766:icosahedron 5688:spinal cord 5642:eigenvector 4663:planar case 4503:linear case 3295:eigenvalues 3278:We use the 3113:attenuation 3077:eigenvector 2919:diagonalize 2765:hyperboloid 2073:attenuation 1506:H.C. Torrey 157:grey matter 9083:Categories 8847:Full body: 8633:endoscopic 8607:Ultrasound 8536:functional 8333:Lymphogram 8328:Venography 8296:Arthrogram 7956:Biometrika 7351:2017-10-15 7075:: 459–461. 6973:2108/34611 6936:2017-10-15 6825:2017-10-15 6814:Hammer M. 6797:2018-03-15 6049:NeuroImage 5868:References 5829:Connectome 5784:tomography 5586:anisotropy 2665:Adolf Fick 2368:See also: 2179:where the 1089:divergence 180:anisotropy 9050:Pregnancy 8929:Brain PET 8897:gamma ray 8833:DMSA scan 8687:Obstetric 8580:diffusion 8575:Sequences 8553:perfusion 8445:Pulmonary 8392:Cone beam 8286:Pyelogram 8117:264099038 8101:0740-3194 8060:121103537 8040:Math. Ann 7999:CiteSeerX 7794:2045-2322 7729:2045-2322 7155:Neurology 7054:576214706 6923:Bhuta S. 6841:Radiology 6504:Radiology 6092:Radiology 5985:250787827 5854:classical 5598:diffusion 5415:λ 5409:⁡ 5395:λ 5385:λ 5375:λ 5324:λ 5318:⁡ 5290:λ 5284:⁡ 5278:− 5269:λ 5246:λ 5240:⁡ 5234:− 5225:λ 5202:λ 5196:⁡ 5190:− 5181:λ 5124:λ 5111:λ 5098:λ 5086:λ 5079:− 5070:λ 5057:λ 5037:− 4956:λ 4943:λ 4930:λ 4918:λ 4869:λ 4865:≃ 4856:λ 4852:≃ 4843:λ 4806:λ 4793:λ 4780:λ 4765:λ 4761:− 4752:λ 4700:λ 4696:≫ 4687:λ 4683:≃ 4674:λ 4637:λ 4624:λ 4611:λ 4599:λ 4595:− 4586:λ 4540:λ 4536:≃ 4527:λ 4523:≫ 4514:λ 4483:≥ 4474:λ 4470:≥ 4461:λ 4457:≥ 4448:λ 4399:λ 4386:λ 4373:λ 4360:λ 4354:⁡ 4311:λ 4293:λ 4275:λ 4247:λ 4241:⁡ 4235:− 4226:λ 4203:λ 4197:⁡ 4191:− 4182:λ 4159:λ 4153:⁡ 4147:− 4138:λ 3859:− 3851:Λ 3813:Λ 3802:− 3765:Λ 3700:λ 3687:λ 3674:λ 3623:λ 3596:λ 3569:λ 3548:Λ 3519:λ 3506:λ 3493:λ 3483:Λ 3440:⊥ 3436:λ 3394:λ 3381:λ 3369:⊥ 3365:λ 3148:Cartesian 3101:ellipsoid 3097:diffusion 2923:Cartesian 2761:ellipsoid 2658:In 1848, 2402:¯ 2304:ADC image 2294:Grayscale 2124:∑ 2120:− 2041:− 2033:∼ 1999:γ 1985:− 1868:⋅ 1856:→ 1847:⋅ 1835:→ 1800:→ 1768:→ 1759:∇ 1753:→ 1744:⋅ 1741:∇ 1719:→ 1697:− 1678:− 1659:→ 1634:→ 1612:− 1606:→ 1597:× 1591:→ 1582:γ 1562:→ 1504:In 1956, 1470:→ 1448:− 1429:− 1410:→ 1385:→ 1363:− 1357:→ 1348:× 1342:→ 1333:γ 1313:→ 1245:ρ 1236:∇ 1220:∂ 1200:ρ 1197:∂ 1146:⋅ 1143:∇ 1140:− 1128:∂ 1108:ρ 1105:∂ 1049:ρ 1046:∇ 1040:− 980:and flux 968:ρ 923:− 829:⁡ 653:⋅ 647:− 641:⁡ 557:Δ 537:δ 493:γ 405:δ 400:− 397:Δ 383:δ 363:γ 359:− 351:⁡ 232:Mechanism 91:membranes 75:diffusion 9068:Category 8920:positron 8440:Coronary 8109:37831659 7933:12353272 7856:15562495 7812:34686721 7747:34294771 7690:33282795 7626:18718789 7582:32373625 7528:31341212 7438:17515386 7403:22468186 7325:23876408 7284:17599699 7235:12044998 7185:19129507 7108:11276097 7031:11025519 6990:14173858 6982:17507813 6910:21454821 6861:23882093 6735:11865594 6727:15906300 6603:25910939 6489:19766099 6416:34227242 6367:33637807 6310:32694155 6260:32304291 6211:34132126 6161:22171354 6069:18495497 6026:16247738 5818:See also 5773:-tuple" 5756:Research 5704:dementia 5570:oncology 5516:penumbra 5345:and the 4834:, where 4830:For the 4665:, where 4661:For the 4505:, where 4501:For the 1006:gradient 242:moieties 71:contrast 9094:Tensors 9089:Imaging 8967:Optical 8949:PET-MRI 8729:Carotid 8724:Scrotal 8618:doppler 8548:Cardiac 8457:Thyroid 8401:Targets 8352:CT scan 8021:6080176 7991:Bibcode 7941:2048187 7864:1368461 7803:8536657 7774:Bibcode 7738:8298404 7681:7708343 7618:9403488 7573:7177010 7519:6656714 7498:Bibcode 7394:3314930 7275:2041910 7176:2677508 7116:7269302 6901:3384724 6758:Bibcode 6595:8946350 6547:Bibcode 6524:8351339 6481:7869892 6407:8928440 6386:Obesity 6358:7910493 6337:Bibcode 6301:7572819 6251:7261762 6202:9665421 6152:3235568 6112:3763909 6077:2660208 6034:8586494 5977:4001161 5957:Bibcode 5922:Bibcode 5899:8814916 5798:Summary 5711:in vivo 5686:to the 5653:lesions 2894:, and 2745:quadric 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8531:Brain 8482:Other 8182:X-ray 8113:S2CID 8056:S2CID 8017:S2CID 7937:S2CID 7884:(PDF) 7860:S2CID 7622:S2CID 7136:(PDF) 7112:S2CID 6986:S2CID 6731:S2CID 6599:S2CID 6485:S2CID 6131:Brain 6073:S2CID 6030:S2CID 5981:S2CID 5893:INIST 5630:voxel 5590:axons 5574:stage 3459:Trace 3162:, ADC 3156:, ADC 2763:or a 1975:bloch 202:edema 172:axons 122:voxel 8739:FAST 8452:Head 8105:PMID 8097:ISSN 7929:PMID 7888:NAID 7852:PMID 7808:PMID 7790:ISSN 7743:PMID 7725:ISSN 7686:PMID 7614:PMID 7578:PMID 7524:PMID 7465:ISBN 7434:PMID 7399:PMID 7321:PMID 7280:PMID 7231:PMID 7181:PMID 7104:PMID 7050:OCLC 7027:PMID 6978:PMID 6906:PMID 6857:PMID 6723:PMID 6682:NAID 6630:ISBN 6591:PMID 6520:PMID 6477:PMID 6412:PMID 6363:PMID 6306:PMID 6256:PMID 6207:PMID 6157:PMID 6108:PMID 6065:PMID 6022:PMID 5973:PMID 5734:here 5632:, a 3614:and 3318:and 3140:axon 3126:and 3024:and 1539:is: 753:and 193:and 40:MeSH 8916:PET 8884:ECT 8882:3D/ 8764:2D/ 8665:ICE 8660:TEE 8655:TTE 8523:MRI 8254:DXR 8250:DXA 8245:KUB 8240:AXR 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2605:y 2565:| 2556:z 2553:z 2548:D 2540:z 2537:y 2533:D 2525:z 2522:x 2518:D 2508:z 2505:y 2501:D 2492:y 2489:y 2484:D 2476:y 2473:x 2469:D 2459:z 2456:x 2452:D 2444:y 2441:x 2437:D 2428:x 2425:x 2420:D 2413:| 2408:= 2399:D 2358:b 2276:z 2272:G 2249:y 2245:G 2222:x 2218:G 2195:j 2192:i 2188:b 2160:j 2157:i 2153:D 2147:j 2144:i 2140:b 2134:j 2131:, 2128:i 2116:e 2112:= 2109:A 2082:A 2052:0 2048:D 2044:b 2037:e 2028:D 2023:3 2019:t 2013:2 2009:G 2003:2 1993:3 1990:1 1981:e 1970:M 1965:= 1961:M 1934:, 1929:] 1923:1 1918:0 1913:0 1906:0 1901:1 1896:0 1889:0 1884:0 1879:1 1873:[ 1865:D 1862:= 1853:I 1844:D 1841:= 1832:D 1797:D 1765:M 1750:D 1738:+ 1731:1 1727:T 1716:k 1710:) 1705:0 1701:M 1692:z 1688:M 1684:( 1671:2 1667:T 1656:j 1648:y 1644:M 1640:+ 1631:i 1623:x 1619:M 1603:B 1588:M 1579:= 1573:t 1570:d 1559:M 1553:d 1521:M 1482:1 1478:T 1467:k 1461:) 1456:0 1452:M 1443:z 1439:M 1435:( 1422:2 1418:T 1407:j 1399:y 1395:M 1391:+ 1382:i 1374:x 1370:M 1354:B 1339:M 1330:= 1324:t 1321:d 1310:M 1304:d 1263:. 1260:) 1257:t 1254:, 1251:x 1248:( 1240:2 1232:D 1229:= 1223:t 1215:) 1212:t 1209:, 1206:x 1203:( 1164:) 1161:t 1158:, 1155:x 1152:( 1149:J 1137:= 1131:t 1123:) 1120:t 1117:, 1114:x 1111:( 1064:) 1061:t 1058:, 1055:x 1052:( 1043:D 1037:= 1034:) 1031:t 1028:, 1025:x 1022:( 1019:J 988:J 936:) 931:2 927:b 918:1 914:b 910:( 906:/ 902:] 899:) 896:z 893:, 890:y 887:, 884:x 881:( 876:1 872:S 867:/ 863:) 860:z 857:, 854:y 851:, 848:x 845:( 840:2 836:S 832:[ 823:= 820:) 817:z 814:, 811:y 808:, 805:x 802:( 798:C 795:D 792:A 766:2 762:b 739:1 735:b 714:C 711:D 708:A 688:D 665:) 662:C 659:D 656:A 650:b 644:( 635:= 628:0 624:S 619:) 616:E 613:T 610:( 607:S 577:D 517:G 473:S 451:0 447:S 422:] 418:D 414:) 408:3 393:( 387:2 377:2 373:G 367:2 355:[ 345:= 338:0 334:S 329:) 326:E 323:T 320:( 317:S 285:2 281:T 258:1 254:T 97:( 57:(

Index


MeSH
D038524
MRI sequences
contrast
diffusion
biological tissues
in vivo
macromolecules
membranes
white matter
tractography
voxel
T1
T2 relaxation
axonal
non-small-cell lung cancer
positron emission tomography
white matter
grey matter
cerebral cortex
axons
white matter
anisotropy
brain tumors
multiple sclerosis
edema
strokes
tensor
fractional anisotropy

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