Use Of Diffusion Tensor Imaging Research Articles

Utility of diffusion tensor imaging and generalized q-sampling imaging for predicting short-term clinical effect of deep brain stimulation in Parkinson’s disease

PurposeTo assess whether diffusion tensor imaging (DTI) and generalized q-sampling imaging (GQI) metrics could preoperatively predict the clinical outcome of deep brain stimulation (DBS) in patients with Parkinson’s disease (PD).MethodsIn this single-center retrospective study, from September 2021 to March 2023, preoperative DTI and GQI examinations of 44 patients who underwent DBS surgery, were analyzed. To evaluate motor functions, the Unified Parkinson’s Disease Rating Scale (UPDRS) during on- and off-medication and Parkinson’s Disease Questionnaire-39 (PDQ-39) scales were used before and three months after DBS surgery. The study population was divided into two groups according to the improvement rate of scales: ≥ 50% and < 50%. Five target regions, reported to be affected in PD, were investigated. The parameters having statistically significant difference were subjected to a receiver operating characteristic (ROC) analysis.ResultsQuantitative anisotropy (qa) values from globus pallidus externus, globus pallidus internus (qa_Gpi), and substantia nigra exhibited significant distributional difference between groups in terms of the improvement rate of UPDRS-3 scale during on-medication (p = 0.003, p = 0.0003, and p = 0.0008, respectively). In ROC analysis, the best parameter in predicting DBS response included qa_Gpi with a cut-off value of 0.01370 achieved an area under the ROC curve, accuracy, sensitivity, and specificity of 0.810, 73%, 62.5%, and 85%, respectively. Optimal cut-off values of ≥ 0.01864 and ≤ 0.01162 yielded a sensitivity and specificity of 100%, respectively.ConclusionThe imaging parameters acquired from GQI, particularly qa_Gpi, may have the ability to non-invasively predict the clinical outcome of DBS surgery.

Cerebellar Mutism Syndrome and Dentato-Thalamo-Cortical Tract Disruption in Diffusion Tractography Following Surgery for Medulloblastoma.

Background Cerebellar mutism syndrome (CMS), a complication following medulloblastoma surgery, has been linked to dentato-thalamo-cortical tract (DTCT) injury; the association of the degree of DTCT injury with severity of CMS-related symptoms has not been investigated. Purpose To investigate the association between severity of CMS-related symptoms and degree and patterns of DTCT injury with use of diffusion tensor imaging (DTI), and if laterality of injury influences neurologic symptoms. Materials and Methods This retrospective case-control study used prospectively collected clinical and DTI data on patients with medulloblastoma enrolled in a clinical trial (between July 2016 and February 2020) and healthy controls (between April and November 2017), matched with the age range of the participants with medulloblastoma. CMS was divided into types 1 (CMS1) and 2 (CMS2). Multivariable logistic regression was used to investigate the relationship between CMS likelihood and DTCT injury. Results Overall, 82 participants with medulloblastoma (mean age, 11.0 years ± 5.2 [SD]; 53 male) and 35 healthy controls (mean age, 18.0 years ± 3.06; 18 female) were included. In participants with medulloblastoma, DTCT was absent bilaterally (AB), absent on the right side (AR), absent on the left side (AL), or present bilaterally (PB), while it was PB in all healthy controls. Odds of having CMS were associated with higher degree of DTCT damage (AB, odds ratio = 272.7 [95% CI: 269.68, 275.75; P < .001]; AR, odds ratio = 14.40 [95% CI: 2.84, 101.48; P < .001]; and AL, odds ratio = 8.55 [95% CI: 1.15, 74.14; P < .001). Left (coefficient = -0.07, χ2 = 12.4, P < .001) and right (coefficient = -0.15, χ2 = 33.82, P < .001) DTCT volumes were negatively associated with the odds of CMS. More participants with medulloblastoma with AB showed CMS1; unilateral DTCT absence prevailed in CMS2. Lower DTCT volumes correlated with more severe ataxia. Unilateral DTCT injury caused ipsilateral dysmetria; AB caused symmetric dysmetria. PB indicated better neurologic outcome. Conclusion The severity of CMS-associated mutism, ataxia, and dysmetria was associated with DTCT damage severity. DTCT damage patterns differed between CMS1 and CMS2. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Dorigatti Soldatelli and Ertl-Wagner in this issue.

Validation of diffusion tensor imaging for diagnosis of traumatic brain injury

Background and PurposeWith an increased need for standardized methodology in accurate diagnosis of Traumatic Brain Injury (TBI), Diffusion Tensor Imaging (DTI) has provided promising diagnostic results as an adjunct modality yet remains underutilized. The purpose of this study was to validate the use of DTI with Statistical Parametric Mapping (SPM) for Traumatic Brain Injury (TBI) supporting its use as a diagnostic tool. Materials and MethodsThis study was retrospective and compared controls to patients clinically diagnosed with TBI. Forty-two controls (mean age = 34.1; range, 19 - 58; 28 Males and 13 Females) were screened (n = 41) for cognitive impairment and neurological abnormality. Two cohorts, each of eighteen patients (first cohort: mean age, 41.8; range, 23 - 70; 9 Males and 9 Females; second cohort: mean age, 45.7; range, 23 - 68; 9 Males and 9 Females) clinically diagnosed with TBI (n = 36) were pooled. DTI image acquisition was obtained using a 3 Tesla MRI scanner. DTI images were analyzed through voxel-based t-tests using SPM comparing each individual to the normative control group to generate z-maps for each individual control and each individual patient with a TBI. Test statistics were ranged for p-values (0.001-0.05) and cluster extent values (0, 30, 60, 65, 70, 75). Area Underneath A Receiver Operating Characteristic Curve (AUCROC) was used to validate diagnostic capability. AUCROC analysis was conducted on all sets of p-value and extent threshold values. Significance of results was determined by examining the AUCROC values. Results and ConclusionsA maximal AUCROC of 1.000 was obtained across the p-value range and cluster extent thresholding values specified across the two cohorts. The high AUCROC supports validation of the methodology presented and the use of diffusion tensor imaging and SPM as an adjunct diagnostic tool for TBI.

Multiple surgical resections for progressive IDH wildtype glioblastoma—is it beneficial?

PurposeThe role of repeat resection for recurrent glioblastoma (rGB) remains equivocal. This study aims to assess the overall survival and complications rates of single or repeat resection for rGB.MethodsA single-centre retrospective review of all patients with IDH-wildtype glioblastoma managed surgically, between January 2014 and January 2022, was carried out. Patient survival and factors influencing prognosis were analysed, using Kaplan–Meier and Cox regression methods.ResultsFour hundred thirty-two patients were included, of whom 329 underwent single resection, 83 had two resections and 20 patients underwent three resections. Median OS (mOS) in the cohort who underwent a single operation was 13.7 months (95% CI: 12.7–14.7 months). The mOS was observed to be extended in patients who underwent second or third-time resection, at 22.9 months and 44.7 months respectively (p < 0.001). On second operation achieving > 95% resection or residual tumour volume of < 2.25 cc was significantly associated with prolonged survival. There was no significant difference in overall complication rates between primary versus second (p = 0.973) or third-time resections (p = 0.312). The use of diffusion tensor imaging (DTI) guided resection was associated with reduced post-operative neurological deficit (RR 0.37, p = 0.002), as was use of intraoperative ultrasound (iUSS) (RR 0.45, p = 0.04).ConclusionsThis study demonstrates potential prolongation of survival for rGB patients undergoing repeat resection, without significant increase in complication rates with repeat resections. Achieving a more complete repeat resection improved survival. Moreover, the use of intraoperative imaging adjuncts can maximise tumour resection, whilst minimising the risk of neurological deficit.

Microstructural Changes in the Brainstem Auditory Pathway in Children With Hearing Loss.

To assess the utility of diffusion tensor imaging of the auditory pathway in children with sensorineural hearing loss (SNHL). Retrospective cohort study. A single academic tertiary children's hospital. Sixteen pediatric patients with bilateral SNHL of at least moderate severity in the poorer ear (eight male; mean age, 5.3 ± 4.9 yrs). Controls consisted of age- and sex-matched children with normal hearing who were imaged for nonotologic, non-neurologic medical concerns and found to have normal magnetic resonance imaging (MRI). Three Tesla MRI scanners were used for diffusion tensor imaging. Quantitative diffusion tensor metrics were extracted from the superior olivary nucleus (SON), inferior colliculus (IC), and ipsilateral fiber tracts between the SON and IC delineated by tractography. We identified differences in fractional anisotropy of the SON between the SNHL cohort and controls (0.377 ± 0.056 vs. 0.422 ± 0.052; p = 0.009), but not in the IC. There were no differences in the mean diffusivity (MD) values in the IC and SON. Among younger children (≤5 yrs), MD was decreased in the SNHL cohort compared with controls in the IC (0.918 ± 0.051 vs. 1.120 ± 0.142; p < 0.001). However, among older children (>5 yrs), there were no differences in MD (1.124 ± 0.198 vs. 0.997 ± 0.103; p = 0.119). There were no differences in MD or fractional anisotropy in the white matter fibers of the IC-SON tract. Our results suggest abnormal neural tracts along the central auditory pathway among children with SNHL. Longitudinal studies should assess the prognostic value of these MRI-based findings for assessing long-term outcomes and determining intervention efficacy.

Utility of Diffusion Tensor Imaging in Assessing Corticospinal Tracts for the Management of Brain Tumors: A Cross-Sectional Observational Study.

Introduction Intra-axial brain tumors are a significant health problem and present several diagnostic and treatment challenges.Conventional magnetic resonance imaging (MRI) has posedseveral limitations, such as the inabilityto delineate the detailed anatomy of fibers in structures like the brainstem and the inability to accurately judge the extent of tumor infiltration.Diffusion tensor imaging (DTI), based on the concepts of isotropic and anisotropic diffusion, is capable of visualizing and segmenting white fiber bundles in high detail and providing crucial information about tumor boundaries, extent, neighboring tracts, and more. This information can be very useful in initial non-invasive diagnosis, preoperative tumor grading, biopsy planning, surgical planning, and prognosis. Methods and materials This is a cross-sectional observational study in a tertiary care setup, conducted over a one-year period. The study was performed in Seth Gordhandas Sunderdas Medical College (Seth G.S. Medical College) and King Edward VII Memorial Hospital (K.E.M. Hospital), a tertiary care hospital located in Mumbai, India. Fiber tractography was performed and was used to visualize the corticospinal tracts passing through the length of the brainstem. Changes in the degree of infiltration, destruction, and displacement of the corticospinal tracts were observed carefully. Adult patients who were diagnosed with brain tumors, willing to participate in the study, and capable of providing written informed consent prior to study registration were included. The DTI findings along with information from other investigations were used to decide the best course of management for each case. Results The study included 30 participants with a mean age of 46.0 ± 17.1 years, 63.3% and 37.7% being male and female, respectively. According to the lesion's location, the pons was found to be the most often affected area in 23.33% of cases, followed by the temporo-parietal region (13.3%) and the frontal region (13.3%). These lesions had heterogenous enhancement in 63.3% of the instances and homogeneous enhancement in 36.7% of the cases, according to a contrast study. According to their consistency, the lesions were further divided into two categories: solid lesions, which were present in 66.7% of instances, and cystic lesions, which were present in 90% of cases. Results from the diffusion tensor technique revealed that infiltration accounted for 40.0% of cases, displacement for 76.7%, and loss of white fiber tracts for 20.0%. DTI findings were significantly associated withthe type of planned management and with the presence of post-management neurological deficit. Conclusion DTI played a complementary role in the assessment of tumors and can be used to improve surgical planning and therapeutic decision making. Preservation of corticospinal tracts is vital to prevent motor impairment. Availability of qualitative data with the depiction of corticospinal tracts in a three-dimensional projection and their relation with the brain tumors by DTI greatly helps in preoperative decision making and surgical approach.

The Use of Diffusion Tensor Imaging in the Identification of Acute Rejection and Chronic Allograft Nephropathy After Renal Transplantation.

Identifying the cause of renal allograft dysfunction is important for the clinical management of kidney transplant recipients. To evaluate the diagnostic efficiency of diffusion tensor imaging (DTI) for identifying allografts with acute rejection (AR) and chronic allograft nephropathy (CAN). Prospective. Seventy-seven renal transplant patients (aged 42.5 ± 9.5 years), including 29 patients with well-functioning stable allografts (Control group), 25 patients diagnosed with acute rejection (AR group), and 23 patients diagnosed with chronic allograft nephropathy (CAN group). 1.5 T/T2-weighted imaging and DTI. The serum creatinine, proteinuria, pathologic results, and fractional anisotropy (FA) values were obtained and compared among the three groups. One-way analysis of variance; correlation analysis; independent-sample t-test; intraclass correlation coefficients and receiver operating characteristic curves. Statistical significance was set to a P-value <0.05. The AR and CAN groups presented with significantly elevated serum creatinine as compared with the Control group (191.8 ± 181.0 and 163.1 ± 115.8 μmol/L vs. 82.3 ± 20.9 μmol/L). FA decreased in AR group (cortical/medullary: 0.13 ± 0.02/0.31 ± 0.07) and CAN group (cortical/medullary: 0.11 ± 0.02/0.27 ± 0.06), compared with the Control group (cortical/medullary: 0.15 ± 0.02/0.35 ± 0.05). Cortical FA in the AR group was higher than in the CAN group. The area under the curve (AUC) for identifying AR from normal allografts was 0.756 and 0.744 by cortical FA and medullary FA, respectively. The AUC of cortical FA and medullary FA for differentiating CAN from normal allografts was 0.907 and 0.830, respectively. The AUC of cortical FA and medullary FA for distinguishing AR and CAN from normal allografts was 0.828 and 0.785, respectively. Cortical FA was able to distinguish between AR and CAN with an AUC of 0.728. DTI was able to detect patients with dysfunctional allografts. Cortical FA can further distinguish between AR and CAN. 2 TECHNICAL EFFICACY: Stage 2.

Diffusion tensor and kurtosis imaging reveal microstructural changes in the trigeminal nerves of patients with trigeminal neuralgia.

To evaluate the use of diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI) for detection of microstructural changes in the trigeminal nerves of trigeminal neuralgia (TN) patients. Forty TN patients and 40 healthy controls were examined using 3T magnetic resonance imaging (MRI) to evaluate DTI and DKI parameters in trigeminal nerves. One-way ANOVA was used to test the differences in age, sex, and DTI and DKI parameters between the TN-affected sides, TN-unaffected sides, and controls. For parameters with inter-group differences, pairwise comparisons were performed. Then, the difference ratios (DRs) of the parameters with statistical differences were calculated and used for the receiver operating characteristic (ROC) analysis to assess their diagnostic performance. In addition, for the DTI and DKI parameter values with differences, we used pure DTI and DKI values to perform the ROC analysis. Compared to the unaffected sides and controls, the FA, MK, and Kr of the affected sides of TN patients were significantly reduced, while ADC was significantly increased (p < 0.05). The diagnostic efficiency of the FA DRs (AUC: 0.974; cutoff value: 0.038; sensitivity: 100%; specificity: 95.0%) was the highest among all DTI and DKI parameters. The DRs of FA and MK more efficiently diagnosed TN than pure FA and MK values. DTI and DKI allowed detection of microstructural changes in TN-affected trigeminal nerves. FA DR was the best independent predictor of microstructural changes in TN. Both DTI and DKI can be used for noninvasive quantitative evaluation of the changes in the microstructure of the cisternal segment of the cranial nerves in clinical practice. • Diffusion tensor imaging (DTI) can be used to evaluate the in vivo integrity of white matter and nerve fiber pathway. • Diffusion kurtosis imaging (DKI) has been shown to be considerable sensitive to microstructural changes. • DTI combined with DKI can comprehensively evaluate the status of the TN-affected trigeminal nerve.

Altered Brain Glymphatic Flow at Diffusion-Tensor MRI in Rapid Eye Movement Sleep Behavior Disorder.

Background Brain glymphatic dysfunction may contribute to the development of α-synucleinopathies. Yet, noninvasive imaging and quantification remain lacking. Purpose To examine glymphatic function of the brain in isolated rapid eye movement sleep behavior disorder (RBD) and its relevance to phenoconversion with use of diffusion-tensor imaging (DTI) analysis along the perivascular space (ALPS). Materials and Methods This prospective study included consecutive participants diagnosed with RBD, age- and sex-matched control participants, and participants with Parkinson disease (PD) who were enrolled and examined between May 2017 and April 2020. All study participants underwent 3.0-T brain MRI including DTI, susceptibility-weighted and susceptibility map-weighted imaging, and/or dopamine transporter imaging using iodine 123-2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl)-nortropane SPECT at the time of participation. Phenoconversion status to α-synucleinopathies was unknown at the time of MRI. Participants were regularly followed up and monitored for any signs of α-synucleinopathies. The ALPS index reflecting glymphatic activity was calculated by a ratio of the diffusivities along the x-axis in the projection and association neural fibers to the diffusivities perpendicular to them and compared according to the groups with use of the Kruskal-Wallis and Mann-Whitney U tests. The phenoconversion risk in participants with RBD was evaluated according to the ALPS index with use of a Cox proportional hazards model. Results Twenty participants diagnosed with RBD (12 men; median age, 73 years [IQR, 66-76 years]), 20 control participants, and 20 participants with PD were included. The median ALPS index was lower in the group with RBD versus controls (1.53 vs 1.72; P = .001) but showed no evidence of a difference compared with the group with PD (1.49; P = .68). The conversion risk decreased with an increasing ALPS index (hazard ratio, 0.57 per 0.1 increase in the ALPS index [95% CI: 0.35, 0.93]; P = .03). Conclusion DTI-ALPS in RBD demonstrated a more severe reduction of glymphatic activity in individuals with phenoconversion to α-synucleinopathies. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Filippi and Balestrino in this issue.

Periventricular White Matter Fractional Anisotropy as a Biomarker of Cerebral Small Vessel Disease (P11-6.007)

<h3>Objective:</h3> To evaluate the utility of Diffusion Tensor Imaging (DTI)-based microstructural metrics in periventricular white matter (PVWM) versus total white matter as a biomarker of cerebral small vessel disease (CSVD). <h3>Background:</h3> PVWM, supplied exclusively by small arteries, has the lowest cerebral blood flow (CBF) in the brain and a high frequency of white matter hyperintensities (WMH) in aging. Accordingly, PVWM tissue may be particularly sensitive to CSVD. We compared DTI parameters in normal-appearing periventricular white matter (NA-PVWM) to normal-appearing white matter (NAWM) as a whole and assessed their correlations with WMH and vascular risk factors in an older cohort. <h3>Design/Methods:</h3> Multimodal MRI data from N=100 cognitively normal older subjects in the Penn Alzheimer’s Disease Research Center were analyzed. An established CBF-based PVWM mask was used to extract mean values for DTI metrics (fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD)). We derived WMH lesion masks from FLAIR MRI to calculate total WMH volume and to exclude WMH voxels from WM and PVWM regions. <h3>Results:</h3> Cohort mean age was 73(6) years with 61% females. All DTI metrics were significantly higher in NA-PVWM compared to NAWM (all P&lt;0.001). Only FA in both NAWM (P=0.010) and NA-PVWM (P=0.007) was significantly associated with hypertension. None of the DTI metrics were associated with diabetes, hypercholesterolemia, or smoking. After adjustment for age and sex, diffusivity values in both NA-PVWM and NAWM correlated similarly with total WMH volume (all P&lt;0.001, except P=0.003 for AD in NA-PVWM), whereas FA was significantly correlated with WMH volume only in NA-PVWM (P&lt;0.001). <h3>Conclusions:</h3> PVWM differs from total WM in microstructural characteristics derived from DTI. FA in NA-PVWM was associated with hypertension and with overall WMH burden, suggesting that FA in PVWM may be a potential biomarker of CSVD. <b>Disclosure:</b> Dr. Shakibajahromi has nothing to disclose. Dr. Dolui has nothing to disclose. The institution of Dr. Brown has received research support from National Institute of Health. Mr. Tackett has nothing to disclose. Mr. Khandelwal has nothing to disclose. Shokufeh Sadaghiani, 1129 has nothing to disclose. Dr. Taghvaei has nothing to disclose. Paul Yushkevich has nothing to disclose. Dr. Wolk has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Neuronix. Dr. Wolk has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Functional Neuromodulation. Dr. Wolk has received personal compensation in the range of $5,000-$9,999 for serving as a CME Speaker with MJH Life Sciences. Dr. Detre has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Hura Imaging. The institution of Dr. Detre has received research support from NIH. Dr. Detre has received personal compensation in the range of $500-$4,999 for serving as a grant proposal reviewer with NIH, VA, European Science Foundation,Deutsche Forschungsgemeinschaft.

Benefits of high-dielectric pad for neuroimaging study in 7-Tesla MRI

This study aimed to evaluate whether the use of a high-dielectric pad is effective in increasing transmit and receive sensitivity in areas of low signal intensity in the human brain at high magnetic fields and assess its usefulness in neuroimaging studies. The novelty of this study lies in the first reported use of diffusion tensor imaging (DTI) results to evaluate the effect of the pad on neuroimaging. Six volunteers underwent MR scanning using a 7 T MR system. T1-weighted images (T1w) and diffusion-weighted images (DWI) were acquired to demonstrate the benefits of a high-dielectric pad made of barium titanate (BaTiO3). For all imaging experiments, two datasets were acquired per person, one with and one without a high-dielectric pad. Enhancement of signal sensitivity in neuroimaging has been analyzed by DTI study. Higher signal intensities and spatial contrast were demonstrated in the in T1w images acquired using high-dielectric pad than in those acquired without high-dielectric pad. Especially in DTI studies, increased quantitative anisotropy (QA) signals were observed in the corticospinal tract (CST), frontopontine tract (FPT), splenium of corpus callosum (SCC), fornix (FX), inferior fronto-occipital fasciculus (IFOF), cerebellum (CB), middle cerebellar peduncle (MCP), and body of corpus callosum (BCC) (FDR < 0.05). The signal differences accounted for an overall 20% increase. A high-dielectric pad is effective in enhancing signal intensity in human brain images acquired using 7 T MRI. Our results show that the use of such pad can increase the spatial resolution, tissue contrast, and signal intensity in neuroimaging studies. These findings suggest that high-dielectric pads may provide a relatively simple and low-cost method for spatiotemporal brain imaging studies.

Use of diffusion tensor imaging in distinguishing neoplastic and infective intra-axial brain lesions: An intergroup and etiology wise inter sub-group analysis - Experience from a tertiary health care center in Northern India

Use of diffusion tensor imaging in distinguishing neoplastic and infective intra-axial brain lesions: An intergroup and etiology wise inter sub-group analysis - Experience from a tertiary health care center in Northern India

Quantitative Analysis in Cervical Spinal Cord Injury Patients Using Diffusion Tensor Imaging and Tractography.

ObjectiveTo investigate the clinical usefulness of diffusion tensor imaging (DTI) and tractography in the prediction of outcomes after traumatic cervical spinal cord injury (SCI) and to assess whether the predictability is different between DTI and tractography administered before and after surgery.MethodsSixty-one subjects with traumatic cervical SCI were randomly assigned to preop or postop groups and received DTI accordingly. Among the patients who had DTI before surgery, we assigned 10 patients who had received repeated DTI examinations at 8 weeks after injury to the follow-up group. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were obtained from DTI, and imaginary fiber and crossing fiber numbers were calculated from the tractography. Neurological status and functional status were assessed at 4 and 8 weeks after SCI.ResultsThe neurologic and functional statuses of both groups improved after 4 weeks. Out of the initial 61 patients who were enrolled in the study, the failure rate of DTI image analysis was significantly higher in the postop group (n=17, 41.5%) than in the preop group (n=6, 20%). The FA values and fiber numbers in the preop group tended to be higher than those in the postop group, whereas ADC values were lower in the preop group. When comparing the tractographic findings in the follow-up group, imaginary fiber numbers at the C6 and C7 levels and crossing fiber numbers from the C3 to C6 levels were significantly decreased after surgery. Several DTI and tractographic parameters (especially the ADC value at the C4 level and imaginary fiber numbers at the C6 level) showed significant correlations with neurologic and functional statuses in both the preop and postop groups. These findings were most prominent when DTI and physical examination were simultaneously performed.ConclusionPreoperative DTI and tractography demonstrated better FA and ADC values with lower interpretation failure rates than those obtained after surgery, whereas postoperative data significantly reflected the patient’s clinical state at the time of evaluation. Therefore, DTI and tractography could be useful in predicting clinical outcomes after traumatic cervical SCI and should be interpreted separately before and after spine surgery.

Utility of diffusion tensor imaging in differentiating benign from malignant hepatic focal lesions.

To assess the diagnostic accuracy of diffusion tensor imaging (DTI) in the characterization of hepatic focal lesions (HFLs) and compare it to diffusion-weighted imaging (DWI). Prospective analysis was done for 49 patients (23 male and 26 female) with 74 HFLs who underwent dynamic MRI, DWI, and DTI. Apparent diffusion coefficient (ADC) values from DWI, fractional anisotropy (FA) values, and mean diffusivity (MD) values from DTI were measured by two independent radiologists. HFLs were classified into benign and malignant HFLs; the latter were subdivided into HCC and non-HCC lesions. Binary logistic regression was performed to analyze the associations between the DTI parameters and the distinction of malignant lesions. The ADC, MD, and FA at cutoff values of ≤ 1.17 × 10-3 mm2/s, ≤ 1.71 × 10-3 mm2/s, and > 0.29, respectively, are excellent discriminators for differentiating malignant and benign HFLs. The mean ADC and MD values of hemangiomas were significantly higher than HCC and non-HCC malignant lesions. In contrast, the mean FA values of hemangiomas were significantly lower than those of non-HCC malignant lesions and HCCs. The ADC and MD were very good discriminators at cutoff values of > 1.03 × 10-3 mm2/s and > 1.12 × 10-3 mm2/s, respectively. The FA at a cutoff value > 0.38 is an excellent discriminator for HCC versus non-HCC malignant lesions. Only FA value > 0.38 was a statistically significant independent predictor of HCC versus non-HCC lesions among the three parameters. There was an excellent inter-observer agreement with ICC > 0.9. MD and FA of DTI are non-invasive, very good, and excellent discriminators superior to ADC measured by DWI for the differentiation of HFLs. • The ADC, MD, and FA at cutoff values of ≤ 1.17 × 10-3 mm2/s, ≤ 1.71 × 10-3 mm2/s, and > 0.29, respectively, are excellent discriminators for differentiating malignant and benign HFLs. • The mean ADC and MD values of hemangiomas were significantly higher than those of HCC and non-HCC malignant lesions. In contrast, the mean FA values of hemangiomas were significantly lower than those of non-HCC malignant lesions and HCCs, respectively. • Multivariate regression analysis revealed that only FA value > 0.38 was a statistically significant independent predictor of HCC vs. non-HCC lesions. A lesion with FA > 0.38 has 34 times higher odds of being HCC rather than non-HCC lesions.

Diffusion tensor imaging and diffusion-weighted imaging on axillary lymph node status in breast cancer patients.

PURPOSE This article will examine the usefulness of diffusion tensor imaging (DTI) and diffusion-weighted imaging (DWI) on the assessment of axillary lymph nodes (ALN) of breast cancer patients. METHODS Axillary lymph nodes in 66 breast cancer patients were examined by DTI and DWI, and the largest lymph node with increased cortical thickness in axilla was selected. Morphological features, apparent diffusion coefficient (ADC), volume anisotropy, and fractional anisotropy values were measured by using a special software. Imaging findings and histopathological results were recorded. RESULTS Metastatic ALN were detected in 43 (65.1%) patients. Cortical thickness of the metastatic ALN was significantly higher than the non-metastatic ALNs (P < .001), and the long-axis-to-shortaxis ratio was significantly lower in metastatic ALNs (P < .001). There was a statistically significant difference between the ALN status and fatty hilum presence (P < .001). Apparent diffusion coefficient values of metastatic ALNs were statistically lower than those of non-metastatic ALNs (P < .001) using a cutoff value of 1.26 × 10-3 mm2 /s for b=500 ADC and 1.21 × 10-3 mm2 /s for b=800 ADC which had 97.7% sensitivity and 91.3% specificity. Fractional anisotropy and volume anisotropy values were significantly different between both groups. A cutoff value of 0.47 for b-500 fractional anisotropy had 83.7% sensitivity, 69.6% specificity 69.6% positive predictive value, and 83.7% negative predictive value. A cutoff value of 0.33 for b=500 volume anisotropy had 76.7% sensitivity, 78.3% specificity, 86.8% positive predictive value, and 64.3% negative predictive value. CONCLUSION Apparent diffusion coefficient value of metastatic ALNs was found to be significantly lower than those of non-metastatic ALN, and DTI metrics of metastatic ALN were found to be significantly higher than those of non-metastatic ALN. Overall, ADC had a better diagnostic performance than morphological features, fractional anisotropy, and volume anisotropy. Diffusion tensor imagingderived diffusion metrics may be used to complement breast magnetic resonance imaging in the future after further standardization of the imaging parameters.

Use of diffusion tensor imaging as a prognostic biomarker after decompression surgery for carpal tunnel syndrome.

Magnetic resonance diffusion tensor imaging (MR-DTI) has been increasingly applied for carpal tunnel syndrome (CTS) diagnosis, but relatively little is known about the effect of CTS treatment on median nerve (MN) integrity and functional outcome prediction. To assess how structural changes in MR-DTI of the MN correlates with symptom severity, functional status, and electrophysiological parameters in patients suffering from CTS before and after decompression surgery. Nine wrists were prospectively enrolled to perform MR-DTI pre- and postoperatively. The apparent diffusion coefficients (ADC) and fractional anisotropy (FA) of the MN were examined in three different regions-distal radioulnar joint, pisiform bone, and hamate bone-and correlated with clinical and electrophysiological parameters. Postoperatively, mean Boston Carpal Tunnel Questionnaire scores decreased 1.55 points (range = 0.08-3; P = 0.0172) and 1.01 points (-0.13 to 1.88; P = 0.0381) in the symptomatic and functional domains, respectively. Postoperative clinical improvement was reflected in proximal FA elevation (P = 0.0078), but not in diffusivity in comparison to baseline examination. Preoperative electrophysiological parameters were correlated with a reduction in the pre- (sensory latencies [rho = -0.6826; P = 0.0312]) and postoperative (motor latencies [rho = -0.7488; P = 0.0325]) distal FA values. Higher sensory amplitudes indicated higher postoperative proximal FA values (rho = 0.7618; P = 0.0280) ​​and lower postoperative proximal ADC values (rho = -0.9047; P = 0.0020). Our study demonstrated that pre- and postoperative proximal FA values are useful biomarkers for the structural evaluation of the MN in patients with CTS. Symptomatic improvement can be better predicted by analyzing FA changes.

The Utilization of Diffusion Tensor Imaging as an Image-Guided Tool in Brain Tumor Resection Surgery: A Systematic Review.

Simple SummaryDiffusion tensor imaging (DTI) is an image-guided tool, especially in brain tumor resection surgery. Neuroimaging tools are essential for operative planning, particularly for maximizing tumor resection and, at the same time, preserving brain function. In this systematic review, we discuss the utilization of DTI in brain tumor resection, by looking into its ability to assess the perioperative approach, as well as evaluating its benefits for successful surgery. The present study proposes to use DTI as a vital neuroimaging tool for preoperative planning in brain tumor resection surgery.The diffusion tensor imaging technique has been recognized as a neuroimaging tool for in vivo visualization of white matter tracts. However, DTI is not a routine procedure for preoperative planning for brain tumor resection. Our study aimed to systematically evaluate the effectiveness of DTI and the outcomes of surgery. The electronic databases, PubMed/MEDLINE and Scopus, were searched for relevant studies. Studies were systematically reviewed based on the application of DTI in pre-surgical planning, modification of operative planning, re-evaluation of preoperative DTI data intraoperatively, and the outcome of surgery decisions. Seventeen studies were selected based on the inclusion and exclusion criteria. Most studies agreed that preoperative planning using DTI improves postoperative neuro-deficits, giving a greater resection yield and shortening the surgery time. The results also indicate that the re-evaluation of preoperative DTI intraoperatively assists in a better visualization of white matter tract shifts. Seven studies also suggested that DTI modified the surgical decision of the initial surgical approach and the rate of the GTR in tumor resection surgery. The utilization of DTI may give essential information on white matter tract pathways, for a better surgical approach, and eventually reduce the risk of neurologic deficits after surgery.

Application of Magnetic Resonance DTI Technique in Evaluating the Effect of Postoperative Exercise Rehabilitation

Magnetic resonance diffusion tensor imaging (DTI) is a new kind of magnetic resonance imaging technology. Its imaging principle is to distinguish different pathological tissues according to the movement of water molecules, which is higher than regular magnetic resonance diffusion-weighted imaging. Magnetic resonance diffusion tensor imaging has exact utility price in medical analysis and sickness evaluation. However, there are few researches on the utility of diffusion tensor imaging in the rehabilitation comparison of patients. This paper explores the utility of magnetic resonance DTI science in evaluating the impact of postoperative patients' exercising rehabilitation. Taking stroke patients as an example, through giving patients rehabilitation training method, using magnetic resonance DTI technology, the motor function rehabilitation of patients was evaluated, and FA changes of the affected side and healthy side and Fugl–Meyer score of two groups of patients before and after rehabilitation were observed. The software outcomes exhibit that, in the contrast of rehabilitation therapy impact of motor feature in sufferers with cerebral infarction, the use of magnetic resonance DTI technological know-how gives a foundation for clinicians to deeply apprehend the CST involvement of patients, which helps to scientifically evaluate the effect and quality of limb motor rehabilitation training of patients and provides a basis for disease treatment.

Diffusion tensor imaging in glioblastoma patients treated with volumetric modulated arc radiotherapy: a longitudinal study

Background Chemo- and radiotherapy (RT) is standard treatment for patients with high-grade glioma, but may cause side-effects on the patient’s cognitive function. Aim Use of diffusion tensor imaging (DTI) to investigate the longitudinal changes in normal-appearing brain tissue in glioblastoma patients undergoing modern arc-based RT with volumetric modulated arc therapy (VMAT) or helical tomotherapy. Materials and methods The study included 27 patients newly diagnosed with glioblastoma and planned for VMAT or tomotherapy. All subjects underwent magnetic resonance imaging at the start of RT and at week 3, 6, 15, and 26. Fourteen subjects were additionally imaged at week 52. The DTI data were co-registered to the dose distribution maps. Longitudinal changes in fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) were assessed in the corpus callosum, the centrum semiovale, the hippocampus, and the amygdala. Results Significant longitudinal changes in FA, MD, and RD were mainly found in the corpus callosum. In the other examined brain structures, only sparse and transient changes were seen. No consistent correlations were found between biodose, age, or gender and changes in DTI parameters. Conclusion Longitudinal changes in MD, FA, and RD were observed but only in a limited number of brain structures and the changes were smaller than expected from literature. The results suggest that modern, arc-based RT may have less negative effect on normal-appearing parts of the brain tissue up to 12 months after radiotherapy.

Clinical Utility of Diffusion Tensor Imaging as a Biomarker to Identify Microstructural Changes in Pediatric Spinal Cord Injury.

Lack of clarity about the neurological consequence of spinal cord injury (SCI) in children causes speculation about diagnoses, recovery potential, and treatment effectiveness. Diffusion tensor imaging (DTI) has shown promising results as a biomarker to evaluate spinal cord integrity at a microstructural level. To look at the difference between pediatric participants with and without SCI to determine which DTI metrics best categorize spinal cord tissue damage and to correlate DTI metrics with two clinical measures: Capabilities of the Upper Extremity Test (CUE-T) and Spinal Cord Independence Measure version III (SCIM-III). This single-site, prospective study included pediatric participants with SCI (n = 26) and typically developed (TD) control subjects (n = 36). All participants underwent two magnetic resonance imaging (MRI) scans on a 3T MR scanner. Participants with SCI also completed the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI), CUE-T, and SCIM-III outcomes measures. This study found significant strength of association between fractional anisotropy (FA) and upper extremity muscle strength (UEMS) in participants with SCI. Most DTI parameters showed a significant difference between participants with SCI and TD participants and a moderate correlation with the CUE-T total score. Regional effects on group differences were found to be significant. This study demonstrates the strength of association between DTI parameters and clinical measures in the pedantic SCI population. It illustrates DTI as a potential biomarker of SCI location and severity in the pediatric SCI population.