Fractional Anisotropy–Threshold Dependence in Tract-Based Diffusion Tensor Analysis: Evaluation of the Uncinate Fasciculus in Alzheimer Disease

Taoka, Toshiaki; Morikawa, Masayuki; Akashi, Toshiaki; Miyasaka, Toshiteru; Nakagawa, Hiroyuki; Kiuchi, Kuniaki; Kishimoto, Toshifumi; Kichikawa, Kimihiko

doi:10.3174/ajnr.a1698

Cited by 56 publications

(39 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This makes the measurements slightly more objective and somewhat more speciˆc than ROI analysis, but one must keep in mind that the results diŠer depending on the arbitrarily chosen stop criteria. 48 This issue will be addressed again later.…”

Section: Ischemic Strokementioning

confidence: 98%

“…A recent study by Taoka's group has shown that the selection of the FA threshold in‰uences the measurement of diŠusion tensor parameters when tract-based analysis is performed. 48 It becomes apparent from this study that the operator-deˆned threshold of FA acts as aˆlter, below which all voxels are omitted from theˆnal analysis. Whether such arbitrary selection of threshold is clinically relevant remains unknown and warrants future research.…”

Section: Future Researchmentioning

confidence: 99%

See 1 more Smart Citation

MR Tractography: A Review of Its Clinical Applications

Yamada

Sakai

Akazawa

et al. 2009

MRMS

272

174

View full text Add to dashboard Cite

Section: Ischemic Strokementioning

confidence: 98%

Section: Future Researchmentioning

confidence: 99%

MR Tractography: A Review of Its Clinical Applications

Yamada

Sakai

Akazawa

et al. 2009

MRMS

272

174

View full text Add to dashboard Cite

“…Using the full tensor data, fractional anisotropy (FA) can be calculated for the index of the white matter anisotropic properties. These 2 metrics, ADC and FA, are now widely used to diagnose or evaluate disorders of the central nervous system, including stroke, 3 multiple sclerosis, 4 neoplasms, [5][6][7] neuropsychiatric disease, [8][9][10] and degenerative disease [11][12][13][14] in clinical situations. Despite their usefulness, however, FA and ADC have limitations.…”

Section: Introductionmentioning

confidence: 99%

Visualizing Non-Gaussian Diffusion: Clinical Application of q-Space Imaging and Diffusional Kurtosis Imaging of the Brain and Spine

Hori

Fukunaga

Masutani

et al. 2012

MRMS

104

View full text Add to dashboard Cite

Recently, non-Gaussian diŠusion-weighted imaging (DWI) techniques, including qspace imaging (QSI) and diŠusional kurtosis imaging (DKI), have emerged as advanced methods to evaluate tissue microstructure in vivo using water diŠusion. QSI and DKI have shown promising results in clinical applications, such as in the evaluation of brain tumors (e.g., grading gliomas), degenerative diseases (e.g., speciˆc diagnosis of Parkinson disease), demyelinating diseases (e.g., assessment of normal-appearing tissue of multiple sclerosis), and cerebrovascular diseases (e.g., assessment of the microstructural environment of fresh infarctions). Representative metrics in clinical use are the full width at half maximum, also known as the mean displacement of the probability density function curve, which is derived from QSI, and diŠusional kurtosis, which is derived from DKI. These new metrics may provide information on tissue structure in addition to that provided by conventional Gaussian DWI investigations that use the apparent diŠusion coe‹cient and fractional anisotropy, recognized indices for evaluating disease and normal development in the brain and spine. In some clinical situations, sensitivity for detecting pathological conditions is higher using QSI and DKI than conventional DWI and diŠusion tensor imaging (DTI) because DWI and DTI calculations are based on the assumption that water molecules follow a Gaussian distribution, whereas hindrance of the distribution of water molecules by complex and restricted structures in actual neural tissues produces distributions that are far from Gaussian. We review the technical aspects and clinical applications of QSI and DKI, focusing on clinical use and in vivo studies and highlighting diŠerences from conventional diŠusional metrics.

show abstract

“…FA constraints are routinely used for rough segmentation of WM and non-WM [27,41,42] making use of low anisotropy of GM and fluid. In particular, FA thresholds are used to constrain streamlines to WM regions in deterministic fibre tractography [43][44][45]. However, more accurate tissue segmentation as well as elimination of PVE in diffusion MRI images require an application of dedicated methods.…”

Section: Discussionmentioning

confidence: 99%