scholarly journals DIFFUSION TENSOR TRACTOGRAPHY

Neurosurgery ◽  
2008 ◽  
Vol 63 (3) ◽  
pp. 452-459 ◽  
Author(s):  
Wai Hoe Ng ◽  
Dennis Lai-Hong Cheong ◽  
Kathleen Joy Khu ◽  
Govidasamy Venkatesh ◽  
Yee Kong Ng ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Magnetic Resonance ◽  
Fractional Anisotropy ◽  
Corticospinal Tract ◽  
Tumor Volume ◽  
Diffusion Tensor ◽  
Diffusion Tensor Tractography ◽  
Significant Difference ◽  
Fiber Number ◽  
And Diffusion

ABSTRACT OBJECTIVE Benign extracerebral lesions such as meningiomas may cause hemiparesis by compression and deviation without infiltrating the white matter. We used magnetic resonance diffusion tensor imaging and diffusion tensor tractography to investigate the effects of benign extracerebral lesions on the corticospinal tract (CST). METHODS Thirteen patients with extracerebral lesions (11 benign meningiomas and 2 benign cysts) underwent magnetic resonance diffusion tensor imaging and diffusion tensor tractography of the CST using fiber assignment by continuous tractography. The CST was reconstructed and assessed by comparing the ipsilateral and unaffected contralateral fibers. The tumor volume, relative fractional anisotropy, fiber deviation, relative fiber number, and relative fiber per voxel were compared between patients without and with temporary presurgical hemiparesis. RESULTS Seven patients without hemiparesis and five patients with temporary hemiparesis were analyzed; one patient had permanent weakness and was excluded from analysis. There was no significant difference in the tumor volume, relative fractional anisotropy, presence of cerebral edema, or CST deviation between groups. In patients with temporary hemiparesis, the median relative fiber number (mean, 0.35 ± 0.32) and relative fiber per voxel (mean, 0.49 ± 0.14) were significantly reduced compared with patients without hemiparesis (0.92 ± 0.55, P = 0.04; and 0.96 ± 0.28, P < 0.01, respectively). CONCLUSION In patients with benign extracerebral lesions, reduction in fiber number and fiber per voxel, but not fiber deviation, correlated with temporary hemiparesis. Clinical recovery was possible even if the CST fibers detected by diffusion tensor tractography were reduced by benign extracerebral lesions.

Clinical significance of diffusion tensor tractography as a predictor of functional recovery after laminoplasty in patients with cervical compressive myelopathy

2012 ◽  
Vol 17 (2) ◽  
pp. 147-152 ◽  
Author(s):  
Masaya Nakamura ◽  
Kanehiro Fujiyoshi ◽  
Osahiko Tsuji ◽  
Tsunehiko Konomi ◽  
Naobumi Hosogane ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Diffusion Tensor Imaging ◽  
Recovery Rate ◽  
Diffusion Tensor ◽  
Diffusion Tensor Tractography ◽  
Recovery Rates ◽  
Significant Difference ◽  
Cervical Compressive Myelopathy ◽  
Compressive Myelopathy ◽  
And Diffusion

Object This study was conducted to determine whether postoperative changes in the fractional anisotropy (FA) value and diffusion tensor imaging of the cervical spinal cord can predict functional outcome for patients with cervical compressive myelopathy (CCM). Methods Twenty patients with CCM were treated by laminoplasty from 2008 to 2009. Both T2-weighted MRI and diffusion tensor imaging were performed before and after surgery. The FA values were analyzed and fiber tracking was performed. The fiber tract (FT) ratio was calculated according to the following formula: (number of fibers at the compressed level)/(number of fibers at the C-2 level) × 100%. The Japanese Orthopaedic Association scoring system for cervical myelopathy was used to determine pre- and postoperative neurological status of the patients, and the Hirabayashi method was used to calculate the recovery rate. Results There was no significant difference in recovery rates between patients with and those without intramedullary high signal intensity on preoperative T2-weighted images. Substantial differences in FA value among spinal cord, bone, and CSF made it difficult to obtain a precise FA value for the compressed spinal cord. There was a significant correlation between the preoperative FT ratio and the recovery rate (p = 0.0006). A poor outcome (recovery rate < 40%) could be anticipated for CCM patients with preoperative FT ratios below 60%. Conclusions The preoperative FT ratio correlated significantly with the recovery rates in CCM patients. Preoperative diffusion tensor tractography can be a new prognostic predictor for neurological recovery in CCM patients after laminoplasty.

scholarly journals Longitudinal Magnetic Resonance Spectroscopy and Diffusion Tensor Imaging in Sheep (Ovis aries) With Quinolinic Acid Lesions of the Striatum: Time-Dependent Recovery of N-Acetylaspartate and Fractional Anisotropy

2020 ◽  
Vol 79 (10) ◽  
pp. 1084-1092
Author(s):  
Adam B O’Connell ◽  
Timothy R Kuchel ◽  
Sunthara R Perumal ◽  
Victoria Sherwood ◽  
Daniel Neumann ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Fractional Anisotropy ◽  
Quinolinic Acid ◽  
Diffusion Tensor ◽  
Ovis Aries ◽  
Resonance Spectroscopy ◽  
Neuronal Marker ◽  
And Diffusion

Abstract We created an excitotoxic striatal lesion model of Huntington disease (HD) in sheep, using the N-methyl-d-aspartate receptor agonist, quinolinic acid (QA). Sixteen sheep received a bolus infusion of QA (75 µL, 180 mM) or saline, first into the left and then (4 weeks later) into the right striatum. Magnetic resonance spectroscopy (MRS) and diffusion tensor imaging (DTI) of the striata were performed. Metabolite concentrations and fractional anisotropy (FA) were measured at baseline, acutely (1 week after each surgery) and chronically (5 weeks or greater after the surgeries). There was a significant decrease in the neuronal marker N-acetylaspartate (NAA) and in FA in acutely lesioned striata of the QA-lesioned sheep, followed by a recovery of NAA and FA in the chronically lesioned striata. NAA level changes indicate acute death and/or impairment of neurons immediately after surgery, with recovery of reversibly impaired neurons over time. The change in FA values of the QA-lesioned striata is consistent with acute structural disruption, followed by re-organization and glial cell infiltration with time. Our study demonstrates that MRS and DTI changes in QA-sheep are consistent with HD-like pathology shown in other model species and that the MR investigations can be performed in sheep using a clinically relevant human 3T MRI scanner.

Changes in the corticospinal tract after wearing prosthesis in bilateral transtibial amputation

2017 ◽  
Vol 41 (5) ◽  
pp. 507-511
Author(s):  
Sang Yoon Lee ◽  
Si Hyun Kang ◽  
Don-Kyu Kim ◽  
Kyung Mook Seo ◽  
Hee Joon Ro ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Diffusion Tensor Imaging ◽  
Magnetic Resonance ◽  
Primary Motor Cortex ◽  
Corticospinal Tract ◽  
Diffusion Tensor ◽  
Brain Magnetic Resonance Imaging ◽  
Resonance Imaging ◽  
Transtibial Amputation

Background:After amputation, the brain is known to be reorganized especially in the primary motor cortex. We report a case to show changes in the corticospinal tract in a patient with serial bilateral transtibial amputations using diffusion tensor imaging.Case Description and Methods:A 78-year-old man had a transtibial amputation on his left side in 2008 and he underwent a right transtibial amputation in 2011. An initial brain magnetic resonance imaging with a diffusion tensor imaging was performed before starting rehabilitation on his right transtibial prosthesis, and a follow-up magnetic resonance imaging with diffusion tensor imaging was performed 2 years after this.Findings and Outcomes:In the initial diffusion tensor imaging, the number of fiber lines in his right corticospinal tract was larger than that in his left corticospinal tract. At follow-up diffusion tensor imaging, there was no definite difference in the number of fiber lines between both corticospinal tracts.Conclusion:We found that side-to-side corticospinal tract differences were equalized after using bilateral prostheses.Clinical relevanceThis case report suggests that diffusion tensor imaging tractography could be a useful method to understand corticomotor reorganization after using prosthesis in transtibial amputation.

Magnetic resonance changes with spectroscopy and diffusion tensor imaging after acute cyanide poisoning in a child

2010 ◽  
Vol 73 (1) ◽  
pp. e5-e8
Author(s):  
Darshana Dattatray Rasalkar ◽  
Winnie Chiu-wing Chu ◽  
Kam-lau Cheung ◽  
David Ka-wai Yeung ◽  
Lin Shi ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Magnetic Resonance ◽  
Diffusion Tensor ◽  
Cyanide Poisoning ◽  
And Diffusion
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