scholarly journals Diffusion tensor imaging of occult injury of optic radiation following optic neuritis in multiple sclerosis

2016 ◽  
Vol 12 (4) ◽  
pp. 2505-2510 ◽  
Author(s):  
Jiafeng Chen ◽  
Lijun Zhu ◽  
He Li ◽  
Ziwen Lu ◽  
Xin Chen ◽  
...  
2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Scott C. Kolbe ◽  
Anneke van der Walt ◽  
Helmut Butzkueven ◽  
Alexander Klistorner ◽  
Gary F. Egan ◽  
...  

Previous studies have reported diffusion tensor imaging (DTI) changes within the optic radiations of patients after optic neuritis (ON). We aimed to study optic radiation DTI changes over 12 months following acute ON and to study correlations between DTI parameters and damage to the optic nerve and primary visual cortex (V1). We measured DTI parameters [fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD)] from the optic radiations of 38 acute ON patients at presentation and 6 and 12 months after acute ON. In addition, we measured retinal nerve fibre layer thickness, visual evoked potential amplitude, optic radiation lesion load, and V1 thickness. At baseline, FA was reduced and RD and MD were increased compared to control. Over 12 months, FA reduced in patients at an average rate of −2.6% per annum (control = −0.51%;p=0.006). Change in FA, RD, and MD correlated with V1 thinning over 12 months (FA:R=0.450,p=0.006; RD:R=-0.428,p=0.009; MD:R=-0.365,p=0.029). In patients with no optic radiation lesions, AD significantly correlated with RNFL thinning at 12 months (R=0.489,p=0.039). In conclusion, DTI can detect optic radiation changes over 12 months following acute ON that correlate with optic nerve and V1 damage.


2013 ◽  
Vol 19 (12) ◽  
pp. 1610-1617 ◽  
Author(s):  
Maria A Rocca ◽  
Sarlota Mesaros ◽  
Paolo Preziosa ◽  
Elisabetta Pagani ◽  
Tatjana Stosic-Opincal ◽  
...  

Background: Optic radiation (OR) damage occurs in multiple sclerosis (MS). Objectives: The purpose of this study was to explore the contribution of local and distant mechanisms associated with OR damage in MS. Methods: Diffusion tensor (DT) magnetic resonance imaging (MRI) tractography probability maps of the ORs were derived from 102 MS patients and 11 controls. Between-group differences of OR normal-appearing white matter (NAWM) damage and topographical distribution of OR damage were assessed using quantitative and voxel-wise analyses, considering the influence of previous optic neuritis (ON+) and T2 OR lesions (T2 OR+). Results: OR NAWM diffusivity abnormalities were more severe in ON+ patients vs patients without previous optic neuritis (ON–) and T2 OR+ vs T2 OR– patients. Damage to the anterior portions of the ORs was more severe in ON+ vs ON– patients. Compared to controls and T2 OR– patients, T2 OR+ patients experienced a more distributed pattern of DT MRI abnormalities along the ORs, with an increased axial diffusivity limited to the anterior portions of the ORs. In T2 OR+ group, ON+ vs ON– patients showed DT MRI abnormalities in the middle portion of the ORs, in correspondence with focal lesions. OR damage correlated with OR T2 lesion volume, visual dysfunction and optic nerve atrophy. Conclusions: Both trans-synaptic degeneration secondary to optic nerve damage and Wallerian degeneration due to local T2 lesions contribute to OR damage in MS.


2012 ◽  
Vol 53 (2) ◽  
pp. 825 ◽  
Author(s):  
Scott C. Kolbe ◽  
Mark Marriott ◽  
Anneke van der Walt ◽  
Joanne Fielding ◽  
Alexander Klistorner ◽  
...  

2011 ◽  
Vol 33 (3) ◽  
pp. 557-564 ◽  
Author(s):  
Lauren V. Zollinger ◽  
Tae Ho Kim ◽  
Kenneth Hill ◽  
Eun K. Jeong ◽  
John W. Rose

2018 ◽  
Vol 281 ◽  
pp. 78-84 ◽  
Author(s):  
Niccolò Piaggio ◽  
Simona Schiavi ◽  
Matteo Martino ◽  
Giulia Bommarito ◽  
Matilde Inglese ◽  
...  

2016 ◽  
Vol 125 (Supplement_1) ◽  
pp. 139-146 ◽  
Author(s):  
Cormac G. Gavin ◽  
H. Ian Sabin

OBJECTIVEThe integration of modern neuroimaging into treatment planning has increased the therapeutic potential and safety of stereotactic radiosurgery. The authors report their method of integrating stereotactic diffusion tensor imaging (DTI) tractography into conventional treatment planning for Gamma Knife radiosurgery (GKRS). The aim of this study was to demonstrate the feasibility of this technique and to address some of the technical limitations of previously reported techniques.METHODSTwenty patients who underwent GKRS composed the study cohort. They consisted of 1 initial test case (a patient with a vestibular schwannoma), 5 patients with arteriovenous malformations, 9 patients with cerebral metastases, 1 patient with parasagittal meningioma, and 4 patients with vestibular schwannoma. DT images were obtained at the time of standard GKRS protocol MRI (T1 and T2 weighted) for treatment, with the patient's head secured by a Leksell stereotactic frame. All studies were performed using a 1.5-T magnet with a single-channel head coil. DTI was performed with diffusion gradients in 32 directions and coregistered with the volumetric T1-weighted study. DTI postprocessing by means of commercially available software allowed tensor computation and the creation of directionally encoded color–, apparent diffusion coefficient–, and fractional anisotropy–mapped sequences. In addition, the software allowed visualized critical tracts to be exported as a structural volume and integrated into GammaPlan as an “organ at risk” during shot planning. Combined images were transferred to GammaPlan and integrated into treatment planning.RESULTSStereotactic DT images were successfully acquired in all patients, with generation of correct directionally encoded color images. Tract generation with the software was straightforward and reproducible, particularly for axial tracts such as the optic radiation and the arcuate fasciculus. Corticospinal tract visualization was hampered by some artifacts from the base of the stereotactic frame, but this was overcome by a combination of frame/MRI volume adjustment and DTI seeding parameters. Coregistration of the DTI series with the T1-weighted treatment volume at the time of imaging was essential for the generation of correct tensor data. All patients with the exception of the vestibular schwannoma cases had treatment pathology in the vicinity of eloquent tracts and/or the cortex. No new neurological deficits due to radiation were recorded at the short-term follow-up.CONCLUSIONSRecent reports in the medical literature have suggested that white matter tracts (particularly the optic radiation and arcuate fasciculus) are more vulnerable to radiation during stereotactic radiosurgery than previously thought. Integration of stereotactic tractography into GKRS represents a promising tool for preventing GKRS complications by reduction in radiation doses to functional organs at risk, including critical cortical areas and subcortical white matter tracts.


2004 ◽  
Vol 10 (2) ◽  
pp. 188-196 ◽  
Author(s):  
Emmanuelle Cassol ◽  
Jean-Philippe Ranjeva ◽  
Danielle Ibarrola ◽  
Claude Mékies ◽  
Claude Manelfe ◽  
...  

Our objectives were to determine the reproducibility of diffusion tensor imaging (DTI) in volunteers and to evaluate the ability of the method to monitor longitudinal changes occurring in the normal-appearing white matter (NAWM) of patients with multiple sclerosis (MS). DTI was performed three-mo nthly for one year in seven MS patients: three relapsing-remitting (RRMS), three secondary progressive (SPMS) and one relapsing SP. They were selected with a limited cerebral lesion load. Seven age- and sex-matched controls also underwent monthly examinations for three months. Diffusivity and anisotropy were quantified over the segmented whole supratentorial white matter, with the indices of trace (Tr) and fractional anisotropy (FA). Results obtained in volunteers show the reproducibility of the method. Patients had higher trace and lower anisotropy than matched controls (P B-0.0001). O ver the follow-up, both Tr and FA indicated a recovery after the acute phase in RRMS and a progressive shift towards abnormal values in SPMS. A lthough this result is not statistically significant, it suggests that DTI is sensitive to microscopic changes occurring in tissue of normal appearance in conventional images and could be useful for monitoring the course of the disease, even though it was unable to clearly distinguish between the various physiopathological processes involved.


2012 ◽  
Vol 81 (10) ◽  
pp. 2697-2701 ◽  
Author(s):  
Fernanda Miraldi Clemente Pessôa ◽  
Fernanda Cristina Rueda Lopes ◽  
João Victor Altamiro Costa ◽  
Soniza Vieira Alves Leon ◽  
Romeu Côrtes Domingues ◽  
...  

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