Diffusion Tensor Fractional Anisotropy Research Articles

Outcome Prediction by Combining Corticospinal Tract Lesion Load with Diffusion-tensor Fractional Anisotropy in Patients after Hemorrhagic Stroke.

The objective of this study was to evaluate the predictive precision of combining the corticospinal tract lesion load (CST-LL) with the diffusion-tensor fractional anisotropy of the corticospinal tract (CST-FA) in the lesioned hemispheres regarding motor outcomes. Patients with putaminal and/or thalamic hemorrhage who had undergone computed tomography (CT) soon after onset in our hospital were retrospectively enrolled. The CST-LL was calculated after registration of the CT images to a standard brain. Diffusion-tensor imaging was performed during the second week after onset. Standardized automated tractography was employed to calculate the CST-FA. Outcomes were assessed at discharge from our affiliated rehabilitation facility using total scores of the motor component of the Stroke Impairment Assessment Set (SIAS-motor total; null to full, 0 to 25). Multivariate regression analysis was performed with CST-LL and CST-FA as explanatory variables and SIAS-motor total as a target value. Twenty-five patients participated in this study. SIAS-motor total ranged from 0 to 25 (median, 17). CST-LL ranged from 0.298 to 7.595 (median, 2.522) mL, and the lesion-side CST-FA ranged from 0.211 to 0.530 (median, 0.409). Analysis revealed that both explanatory variables were detected as statistically significant contributory factors. The estimated t values indicated that the contributions of these two variables were almost equal. The obtained regression model accounted for 63.9% of the variability of the target value. Incorporation of the CST-LL with the lesion-side CST-FA enhances the precision of the stroke outcome prediction model.

Brain regions associated with Brunnstrom and functional independence measure scores in patients after a stroke: a tract-based spatial statistics study.

[Purpose] We aimed to assess diffusion tensor fractional anisotropy to outline the brain regions associated with the long-term motor and cognitive functional outcomes of patients with stroke. [Participants and Methods] Eighty patients from our previous study were enrolled. Fractional anisotropy maps were acquired on days 14-21 after stroke onset, and tract-based spatial statistics were applied. Outcomes were scored using the Brunnstrom recovery stage and Functional Independence Measure motor and cognition components. Fractional anisotropy images were assessed in relation to outcome scores using the general linear model. [Results] For both the right (n=37) and left (n=43) hemisphere lesion groups, the corticospinal tract and the anterior thalamic radiation were most strongly associated with the Brunnstrom recovery stage. In contrast, the cognition component involved large regions encompassing the anterior thalamic radiation, superior longitudinal fasciculus, inferior longitudinal fasciculus, uncinate fasciculus, cingulum bundle, forceps major, and forceps minor. The results for the motor component were intermediate between those for the Brunnstrom recovery stage and those for the cognition component. [Conclusion] Motor-related outcomes were associated with fractional anisotropy decreases in the corticospinal tract, whereas cognitive outcomes were related to broad regions of association and commissural fibers. This knowledge will help scheduling appropriate rehabilitative treatments.

Use of diffusion-weighted imaging and diffusion tensor imaging in assessment of myometrial invasion in patients of endometrial carcinoma and its correlation with histopathological grading (Prospective study)

BackgroundEndometrial cancer (EMC) is considered one of the most common gynecological cancers worldwide. In particular, the depth of myometrial invasion and histological grade of endometrial cancers (EMCs) are strong prognostic factors. Diffusion tensor measurements as mean diffusivity (MD) and fractional anisotropy (FA) values could be useful for assessing the depth of tumor invasion and its histological grade. The study aimed to evaluate the role of diffusion-weighted imaging (DWI) and diffusion tensor imaging in the detection of myometrial invasion in cases of endometrial carcinoma and prediction of its grade in vivo.ResultsThis study included 50 female patients with pathologically proved endometrial carcinoma, and their ages ranged from 38 to 67 years; the mean age was 56.15 years (± 8.229 standard deviation “SD”). There was a significant statistical difference regarding the mean values of diffusion tensor fractional anisotropy (DT-FA), diffusion tensor mean diffusivity (DT-MD) and diffusion-weighted apparent diffusion coefficient(DW-ADC) values in differentiating between intact and infiltrated myometrium with (P value ≤ 0.001). The accuracy of DT-MD, DT-FA and DWI-ADC was 98%, 90% and 86%, respectively, in the detection of myometrial invasion. There was a statistically significant difference in the mean values of DT-FA, DT-MD and DW-ADC for differentiating endometrioid adenocarcinoma grades with the overall P values (˂0.001). The accuracy of DT-FA, DT- MD and DWI-ADC for differentiating grade 3 from grade 1 or 2 endometrioid adenocarcinoma was 94.9%, 84.6% and 74.4%, respectively. For differentiating grade 1 from grade 2 or 3 endometrioid adenocarcinoma, the accuracy of DT-FA, DT-MD and DWI-ADC was 90%, 89.7% and 84.6%, respectively. Mean DT-FA, DT-MD and DW-ADC values were inversely proportional to the degree of pathological grading with r = − 0.867, − 0.762 and − 0.706, respectively.ConclusionDiffusion tensor imaging and DWI are helpful in the assessment of myometrial invasion and have a high negative correlation with histopathological grading in patients with endometrial cancer.

Secondary Publication：Reduced Diffusion Tensor Fractional Anisotropy in the Left Arcuate Fasciculus of Patients with Aphasia Caused by Acute Cerebral Infarct

Secondary Publication：Reduced Diffusion Tensor Fractional Anisotropy in the Left Arcuate Fasciculus of Patients with Aphasia Caused by Acute Cerebral Infarct

Extracting diffusion tensor fractional anisotropy and mean diffusivity from 3-direction DWI scans using deep learning.

To develop and evaluate machine-learning methods that reconstruct fractional anisotropy (FA) values and mean diffusivities (MD) from 3-direction diffusion MRI (dMRI) acquisitions. Two machine-learning models were implemented to map undersampled dMRI signals with high-quality FA and MD maps that were reconstructed from fully sampled DTI scans. The first model was a previously described multilayer perceptron (MLP), which maps signals and FA/MD values from a single voxel. The second was a convolutional neural network U-Net model, which maps dMRI slices to full FA/MD maps. Each method was trained on dMRI brain scans (N = 46), and reconstruction accuracies were compared with conventional linear-least-squares (LLS) reconstructions. In an independent testing cohort (N = 20), 3-direction U-Net reconstructions had significantly lower absolute FA error than both 3-direction MLP (U-Net3-dir : 0.06 ± 0.01 vs. MLP3-dir : 0.08 ± 0.01, P < 1 × 10-5 ) and 6-direction LLS (LLS6-dir : 0.09 ± 0.03, P = 1 × 10-5 ). The MD errors were not significantly different among 3-direction MLP (0.06 ± 0.01 × 10-3 mm2 /s), 3-direction U-Net (0.06 ± 0.01 × 10-3 mm2 /s), and 6-direction LLS (0.07 ± 0.02 × 10-3 mm2 /s, P > .1). The proposed U-Net model reconstructed FA from 3-direction dMRI scans with improved accuracy compared with both a previously described MLP approach and LLS fitting from 6-direction scans. The MD reconstruction accuracies did not differ significantly between reconstructions.

Outcome in Stroke Patients Is Associated with Age and Fractional Anisotropy in the Cerebral Peduncles: A Multivariate Regression Study.

ABSTRACTObjectives:Diffusion tensor fractional anisotropy (FA) in the corticospinal tracts has been used to assess the long-term outcome in stroke patients. Patient age and the type of stroke may also affect outcomes. In this study, we investigated the associations of age, type of stroke, and FA in the ipsilesional and contralesional cerebral peduncles with stroke outcomes. Methods:This study involved 80 patients with stroke (40 hemorrhagic, 40 ischemic) that we had investigated previously. Diffusion tensor FA images were obtained between 14 and 21 days post-stroke. FA values in the ipsilesional and contralesional cerebral peduncles were extracted and their ratio (rFA) was calculated. Outcome was assessed using the Brunnstrom stage, the motor component of the Functional Independence Measure (FIM-motor) at discharge, and the length of stay until discharge from rehabilitation. Using forward stepwise multivariate regression, we assessed the associations of rFA, contralesional FA, age, and type of stroke with outcome measures. Results:rFA and contralesional FA were included in the final model for the Brunnstrom stage in the upper limbs. There was a strong association between hemorrhagic stroke and poorer lower extremity function. rFA, contralesional FA, and age were included in the final model for FIM-motor and length of stay. The effect of rFA on all outcome measures was stronger than that of contralesional FA. The effect of age on FIM-motor was as strong as that of rFA. Conclusions:Neural damage in the corticospinal tracts (indicated by rFA) had the strongest effect on outcome measures, whereas the level of disability (measured by FIM-motor) was associated with a broader range of factors, including age.

Damage to the dominant arcuate fasciculus degrades auditory comprehension in non-fluent aphasia

Objective To investigate the correlation between damage to the dominant arcuate fasciculus (AF) and the occurrence of auditory comprehension dysfunction in post-stroke aphasia. Methods Eighteen stroke survivors with non-fluent aphasia were recruited into the observation group, and nine healthy counterparts were chosen for the control group. All received diffusion tensor imaging (DTI) scans and fractional anisotropy (FA) values were measured. A Chinese aphasia battery was used to evaluate the aphasics′ language functioning, with the listening true or false, listening recognition and oral instruction auditory comprehension sub-scales used as the observation indices. Results There were significant differences between the two groups in the FA value of the dominant AF. Spearman correlation showed that the FA value of the dominant AF was positively related to the listening recognition results. Conclusions Damage to the dominant AF may be one of the reasons for auditory comprehension dysfunction in post-stroke aphasia. It is significantly related to listening recognition. Key words: Diffusion tensor imaging; Stroke; Aphasia; Arcuate fasciculus; Auditory comprehension

Comparison of Fractional Anisotropy from Tract-Based Spatial Statistics with and without Lesion Masking in Patients with Intracerebral Hemorrhage: A Technical Note

Background: Diffusion-tensor fractional anisotropy (FA) is an index of neural-fiber damage in patients following stroke. To better characterize FA, tract-based spatial statistics (TBSS) is frequently used, which involves spatial transformation into the standard brain space. Despite its utility, this technique is susceptible to space-occupying hematoma in patients with intracerebral hemorrhage. To correct this, “lesion making” has been proposed. Here, FA values from TBSS without lesion masking and TBSS with lesion masking were compared, and the clinical utility was evaluated. Methods: Forty patients from our previously published work were entered into the study. Diffusion-tensor imagings were acquired 14-21 days after onset and FA maps were generated. Lesion masks were produced in reference with nondiffusion (b = 0) brain images. Two types (with or without lesion masking) of TBSS were then performed. For both types, using individual data we extracted mean FA values within for the corticospinal tract (CST) and the superior longitudinal fasciculus (SLF). FA ratio (rFA) between the lesioned hemisphere and the unaffected hemisphere was then calculated. The two sets of the data were then compared by assessing residuals of mean root sum square error (RMSE). Results: Although rFA obtained from TBSS with lesion masking tended to be slightly smaller, the estimated RMSE was .025 for both the CST and the SLF. Conclusions: The estimated FA differences between the two sets of TBSS were very small. Considering the time for manual labor for producing lesion masks, regular TBSS without lesion masking may be sufficient in terms of clinical utility.

The relationships between diffusion-tensor fractional anisotropy within cerebral peduncles and outcomes among patients with hemiparesis due to cerebral infarction

This study aimed to evaluate the relationships between diffusion-tensor fractional anisotropy (FA) within cerebral peduncles and outcomes among patients with hemiparesis due to cerebral infarction. Diffusion-tensor FA brain images were acquired 14–21 days after cerebral infarction. The ratio of FA values within the cerebral peduncles of the affected and unaffected hemispheres (rFA) was calculated for each patient ( n = 40) and assessed for correlation with Brunnstrom stage (BRS: 1–6), motor component of the functional independence measure (FIM-motor: 13–91), and the total length of stay (LOS) until discharge from rehabilitation ( P < 0.05). The rFA values were 0.582–1.037 (median: 0.881) and BRS scores were 1–6 (median: 5) for shoulder/elbow/forearm, 2–6 (median: 4.5) for hand, and 3–6 (median: 5) for lower extremities. FIM-motor scores were 51–91 (median, 79.5) and LOS ranged from 45 to 195 days (median: 130 days). Correlation coefficients were statistically significant between rFA and shoulder/elbow/forearm BRS (0.646), hand BRS (0.621), lower extremity BRS (0.637), FIM-motor (0.337), and LOS (−0.446). Diffusion-tensor FA values correlated with outcome measurements. This observation suggests that FA values within cerebral peduncles may subserve as an index for outcome prediction of patients after cerebral infarction.

Utility of Fractional Anisotropy in Cerebral Peduncle for Stroke Outcome Prediction: Comparison of Hemorrhagic and Ischemic Strokes

Diffusion-tensor fractional anisotropy (FA) has been used for predicting stroke outcome. However, most previous studies focused on patients with either hemorrhagic or ischemic stroke. The aim of this study was to assess the correlation between FA and outcome for patients with hemorrhagic stroke and those with ischemic stroke, and then compare their correlation patterns. This study sampled 40 hemorrhagic and 40 ischemic stroke patients from our previously published reports. Diffusion-tensor images were obtained on days 14-21, and FA images were generated, after which the ratio of FA within the cerebral peduncles of the affected and unaffected hemispheres (rFA) was calculated. Outcome was assessed using Brunnstrom stage (BRS), motor component of the functional independence measure (FIM-motor), and total length of hospital stay (LOS) at discharge from our affiliated rehabilitation hospital. The data were then compared between the hemorrhage and the infarct groups. Correlation analyses between rFA and outcome assessments were performed separately for both groups and then were compared between the groups. The hemorrhage group exhibited significantly more severe BRS, longer LOS, and lower rFA than the infarct group. The correlations between rFA and outcome measures were all statistically significant for both the hemorrhage and the infarct groups. The correlation patterns for BRS and LOS were very similar between the hemorrhage and the infarct groups. However, such similarity was not evident for FIM-motor. FA in the cerebral peduncles may be used to predict extremity functions and LOS for both types of stroke.

Diffusion Tensor Fractional Anisotropy in the Superior Longitudinal Fasciculus Correlates with Functional Independence Measure Cognition Scores in Patients with Cerebral Infarction

This study aimed to determine the relationship between fiber tract degeneration measured by diffusion-tensor imaging (DTI) and outcome of patients after cerebral infarction. Fractional anisotropy (FA) maps were generated by DTI in patients 14-21 days after the first infarction and were analyzed by tract-based spatial statistics (TBSS). Mean FA values within the corticospinal tract (CST) and the superior longitudinal fasciculus (SLF) were extracted from individual TBSS data. Relationships between FA ratios (rFAs, lesioned to non-lesioned hemisphere) and outcomes assessed by Brunnstrom stage (BRS) and Functional Independence Measure (FIM) motor and cognition scores were examined using Spearman's rank correlation test. Forty patients (21 left and 19 right hemisphere lesions) were entered into an analytical database. BRS ranged from 1 to 6 (median, 5) for shoulder, elbow, or forearm; from 2 to 6 (median, 4.5) for hand or finger; and from 3 to 6 (median, 5) for lower extremity. FIM motor ranged from 51 to 91 (median, 79.5), and FIM cognition ranged from 16 to 35 (median, 29). rFA values in the CST ranged from .692 to 1.053 (median, .933), and those in the SLF ranged from .778 to 1.076 (median, .965). Mann-Whitney U test (P <.05) revealed no significant differences between the left and the right hemisphere lesion groups. Individual rFA values in the CST correlated with BRS scores (r = .585-0.654), whereas those in the SLF correlated with FIM cognition scores (r = .409, P <.05). DTI-FA values in the SLF and CST may be useful for outcome prediction of cognitive function and extremity function, respectively.

Reduced Diffusion Tensor Fractional Anisotropy in the Left Arcuate Fasciculus of Patients with Aphasia Caused by Acute Cerebral Infarct.

Magnetic resonance diffusion tensor imaging (DTI) is a new technique that evaluates neural fiber integrity within the brain. We conducted DTI in patients exhibiting aphasia during the acute stage post-infarct and investigated the neural tracts responsible by comparison with DTI data from age-matched controls. Fractional anisotropy (FA) maps were generated from diffusion tensor brain images obtained from aphasic patients 14-21 days following their first infarct. Tract-based spatial statistics (TBSS) analysis was then applied. In addition, regions of interest (ROIs) were set within the right and left arcuate fasciculus, and mean FA values were extracted from individual TBSS data. The ratios between FA values in the left and right hemispheres were compared with those of the control group. The study examined 10 aphasic patients and 21 age-matched controls. Brain maps from TBSS analysis revealed significantly reduced FA in the left arcuate fasciculus of the patient group compared with that in the control group. Further ROI analyses confirmed significantly lower left/right arcuate fasciculus FA ratios in aphasic patients versus controls (median [range]: 0.955 [0.739-1.023] vs. 1.006 [0.982-1.088]; P = 0.0001 by Wilcoxon rank sum test). These results suggest that FA in the left arcuate fasciculus decreased in association with aphasia after cerebral infarct. Because patients in the acute stage have not yet experienced the neural recovery that occurs in the chronic stage, the findings indicate that the left arcuate fasciculus is a crucial neural structure in aphasia.

Hippocampal Metabolites Correlate with Neuroimaging Outcomes in the Piglet

By combining magnetic resonance imaging (MRI) and metabolomic profiling techniques, the objective of this study was to elucidate relationships between brain structure and hippocampal metabolites in the piglet. Two-day-old, vaginally-delivered male piglets (n=24) were artificially reared using standardized procedures and feeding a custom milk replacer formulated to meet piglet nutrient requirements. At 30 d of age, piglets underwent MRI procedures, and brain tissue was collected 24 h post-imaging for metabolomic and lipodomic profiling of hippocampal tissue. Analysis of MRI data in 19 brain regions yielded volumetric estimates as well as microstructural details measured by diffusion tensor fractional anisotropy (FA), and radial (RD), axial (AD), and mean (MD) diffusivities, which provide directional characterization of water movement within axons. Comparison of fatty acids in n-3, n-6, and n-9 categories with MRI measures yielded correlations (P < 0.05) in 150 of 2726, 162 of 3596, and 129 of 2494 possible outcomes, respectively. Neuroimaging outcomes that were highly correlative across fatty acid categories included MD, RD, and AD in the internal capsule and right hippocampus, suggesting ongoing myelination in the piglet brain. Nervonic acid, a fatty acid known to be prevalent at peak myelination, was correlated with 26 of 58 total outcomes, further supporting the link between metabolism and neurodevelopment. In conclusion, significant correlations between metabolic and structural outcomes in the neonatal piglet brain emphasize targets whereby dietary manipulation may alter neurodevelopmental patterns. Supported by Mead Johnson Nutrition.

Outcome Assessment of Hemiparesis due to Intracerebral Hemorrhage Using Diffusion Tensor Fractional Anisotropy

This study aimed to evaluate the prognostic efficacy of magnetic resonance diffusion tensor fractional anisotropy (FA) for patients with hemiparesis due to intracerebral hemorrhage. Diffusion tensor FA brain images were acquired 14-21days after putaminal and/or thalamic hemorrhage. The ratio of FA values within the cerebral peduncles of the affected and unaffected hemispheres (rFA) was calculated for each patient (n=40) and assessed for correlation with Brunnstrom stage (BRS, 1-6), motor component of the functional independence measure (FIM-motor, 13-91), and the total length of stay (LOS) until discharge from rehabilitation (P<.05). Ordinal logistic regression analyses were conducted to determine the relationships between rFA and specific outcomes as measured by BRS range (poor, BRS 1 or 2; moderate, BRS 3 or 4; and good, BRS 5 or 6; P<.05). The rFA values were .571-1.043 (median, .856) and BRS scores were 1-6 (median, 4) for shoulder/elbow/forearm, 1-6 (median, 4) for hand, and 2-6 (median, 4) for lower extremities. FIM-motor scores were 58-86 (median, 78) and LOS ranged from 42 to 225days (median, 175.5days). Correlation coefficients were statistically significant between rFA and shoulder/elbow/forearm BRS (.696), hand BRS (.779), lower extremity BRS (.631), FIM-motor (.442), and LOS (-.598). Logistic model fit was moderate for shoulder/elbow/forearm BRS (R(2)=.221) and lower extremity BRS (R(2)=.277), but was much higher for hand BRS (R(2)=.441). Diffusion tensor FA values are predictive of clinical outcome from hemiparesisduetoputaminal and/or thalamic hemorrhage, particularly hand function recovery.

Thalamic-hippocampal-prefrontal disruption in relapsing-remitting multiple sclerosis.

BackgroundCortical, thalamic and hippocampal gray matter atrophy in relapsing–remitting MS (RRMS) is associated cognitive deficits. However, the role of interconnecting white matter pathways including the fornix, cingulum, and uncinate fasciculus (UF) is less well studied.ObjectiveTo assess MS damage to a hippocampal–thalamic–prefrontal network and the relative contributions of its components to specific cognitive domains.MethodsWe calculated diffusion tensor fractional anisotropy (FA) in the fornix, cingulum and UF as well as thalamic and hippocampal volumes in 27 RRMS patients and 20 healthy controls. A neuropsychological battery was administered and 4 core tests known to be sensitive to MS changes were used to assess cognitive impairment. To determine the relationships between structure and cognition, all tests were grouped into 4 domains: attention/executive function, processing speed, verbal memory, and spatial memory. Univariate correlations with structural measures and depressive symptoms identified potential contributors to cognitive performance and subsequent linear regression determined their relative effects on performance in each domain. For significant predictors, we also explored the effects of laterality and axial versus radial diffusivity.ResultsRRMS patients had worse performance on the Symbol Digit Modalities Test, but no significant impairment in the 4 cognitive domains. RRMS had reduced mean FA of all 3 pathways and reduced thalamic and hippocampal volumes compared to controls. In RRMS we found that thalamic volume and BDI predicted attention/executive function, UF FA predicted processing speed, thalamic volume predicted verbal memory, and UF FA and BDI predicted spatial memory.ConclusionsHippocampal–thalamic–prefrontal disruption affects cognitive performance in early RRMS with mild to minimal cognitive impairment, confirming both white and gray matter involvement in MS and demonstrating utility in assessing functional networks to monitor cognition.

Relationship between Diffusion Tensor Fractional Anisotropy and Long-term Motor Outcome in Patients with Hemiparesis after Middle Cerebral Artery Infarction

Magnetic resonance diffusion tensor fractional anisotropy (DTI-FA) is often used to characterize neural damage after stroke. Here we assessed the relationship between DTI-FA and long-term motor outcome in patients after middle cerebral artery (MCA) infarction. Fractional anisotropy (FA) maps were generated from diffusion tensor brain images obtained from 16 patients 14-18 days postinfarction, and tract-based spatial statistics (TBSS) analysis was applied. Regions of interest were set within the right and left corticospinal tracts, and mean FA values were extracted from individual TBSS data. Hemiparesis motor outcome was evaluated according to Brunnstrom stage (BRS: 1-6, severe-normal) for separate shoulder/elbow/forearm, hand, and lower extremity functions, as well as the motor component score of the Functional Independence Measure (FIM-motor: 13-91, null-full) 5-7 months after onset. Ratios between FA values in the affected and unaffected hemispheres (rFA) were assessed by BRS and FIM-motor scores. rFA values were .636-.984 (median, .883) and BRS scores were 1-6 (median, 3) for shoulder/elbow/forearm, 2-6 (median, 3) for hand, and 3-6 (median, 5) for the lower extremities. FIM-motor scores were 51-90 (median, 75). Analysis revealed significant relationships between rFA and BRS data (correlation coefficient: .687 for shoulder/elbow/forearm, .579 for hand, and .623 for lower extremities) but no significance relationship between rFA and FIM-motor scores. The results suggest that DTI-FA is applicable for predicting the long-term outcome of extremity functions after MCA infarction.

Improved DTI registration allows voxel-based analysis that outperforms Tract-Based Spatial Statistics

Tract-Based Spatial Statistics (TBSS) is a popular software pipeline to coregister sets of diffusion tensor Fractional Anisotropy (FA) images for performing voxel-wise comparisons. It is primarily defined by its skeleton projection step intended to reduce effects of local misregistration. A white matter “skeleton” is computed by morphological thinning of the inter-subject mean FA, and then all voxels are projected to the nearest location on this skeleton. Here we investigate several enhancements to the TBSS pipeline based on recent advances in registration for other modalities, principally based on groupwise registration with the ANTS-SyN algorithm. We validate these enhancements using simulation experiments with synthetically-modified images. When used with these enhancements, we discover that TBSS's skeleton projection step actually reduces algorithm accuracy, as the improved registration leaves fewer errors to warrant correction, and the effects of this projection's compromises become stronger than those of its benefits. In our experiments, our proposed pipeline without skeleton projection is more sensitive for detecting true changes and has greater specificity in resisting false positives from misregistration. We also present comparative results of the proposed and traditional methods, both with and without the skeleton projection step, on three real-life datasets: two comparing differing populations of Alzheimer's disease patients to matched controls, and one comparing progressive supranuclear palsy patients to matched controls. The proposed pipeline produces more plausible results according to each disease's pathophysiology.

S4-3. Relationship between diffusion-tensor fractional anisotropy and long-term outcome in patients with hemiparesis after intracerebral hemorrhage: A clinical applicability for outcome prediction

We assessed the relationship between fractional anisotropy (FA) values of magnetic resonance-diffusion tensor imaging (DTI) and long-term outcome in patients with hemiparesis after intracerebral hemorrhage ( N = 16). DTI data were obtained on days 14–18. FA values within the cerebral peduncle were analyzed using a computer-automated method. Motor outcome of hemiparesis was evaluated using Brunnstrom stage (six-point scale: severe to normal) for separate shoulder/elbow/forearm, wrist/hand, and lower extremity functions when patients were discharged from a long-term rehabilitation facility 2–7 months after onset. In addition, the motor component of the functional independence measure (FIM-motor) was scored. The ratio of FA values in the affected hemisphere to those in the unaffected hemisphere (rFA) was assessed in relation to the clinical data (Spearman’s rank correlation test, P R = 0.841 for shoulder/elbow/forearm; 0.855 for wrist/hand). Although statistically significant, the relationship between rFA and lower extremity function ( R = 0.713) was less evident. The relationship between rFA and lower extremity and FIM-motor scores was moderate ( R = 0.579). These findings suggest that DTI is a potentially useful tool for outcome prediction, especially for upper extremity function.

Relationship between Diffusion Tensor Fractional Anisotropy and Motor Outcome in Patients with Hemiparesis after Corona Radiata Infarct

This study examined the relationship between fractional anisotropy (FA) values of magnetic resonance-diffusion tensor imaging (DTI) and motor outcome (1 month after onset) in 15 patients with hemiparesis after ischemic stroke of corona radiata lesions. DTI data were obtained on days 14-18. FA values within the cerebral peduncle were analyzed using a computer-automated method. Motor outcome of hemiparesis was evaluated according to Brunnstrom stage (BRS; 6-point scale: severe to normal) for separate shoulder/elbow/forearm, wrist/hand, and lower extremity functions. The ratio of FA values in the affected hemisphere to those in the unaffected hemisphere (rFA) was assessed in relation to the BRS data (Spearman rank correlation test, P<.05). rFA values ranged from .715 to 1.002 (median=.924). BRS ranged from 1 to 6 (median=4) for shoulder/elbow/forearm, from 1 to 6 (median=5) for wrist/hand, and from 2 to 6 (median=4) for the lower extremities. Analysis revealed statistically significant relationships between rFA and upper extremity functions (correlation coefficient=.679 for shoulder/elbow/forearm and .706 for wrist/hand). Although slightly less evident, the relationship between rFA and lower extremity function was also statistically significant (correlation coefficient=.641). FA values within the cerebral peduncle are moderately associated with the outcome of both upper and lower extremity functions, suggesting that DTI may be applicable for outcome prediction in stroke patients with corona radiata infarct.

Relationship between diffusion-tensor fractional anisotropy and long-term outcome in patients with hemiparesis after intracerebral hemorrhage

We assessed the relationship between fractional anisotropy (FA) values of magnetic resonance-diffusion tensor imaging (DTI) and long-term outcome (3-7 months after onset) in patients with hemiparesis after intracerebral hemorrhage (N = 12). DTI data were obtained on days 14-18. FA values within the cerebral peduncle were analyzed using a computer-automated method. Motor outcome of hemiparesis was evaluated using Brunnstrom stage (six-point scale: severe to normal) for separate shoulder/elbow/forearm, wrist/hand, and lower extremity functions when patients were discharged from a long-term rehabilitation facility 3-7 months after onset. In addition, the motor component of the functional independence measure (FIM-motor) was scored. The ratio of FA values in the affected hemisphere to those in the unaffected hemisphere (rFA) was assessed in relation to the clinical data (Spearman's rank correlation test, P < 0.05). Analysis revealed a statistically significant relationship between rFA and upper extremity function (R = 0.863 for shoulder/elbow/forearm; 0.834 for wrist/hand). Although statistically significant, the relationship between rFA and lower extremity function was less evident (R = 0.609). In contrast, analysis of rFA and FIM-motor scores did not reveal statistical significance. FA values within the cerebral peduncle are tightly associated with long-term outcomes of upper extremity function.