We have located links that may give you full text access.
Quantification of Myelinated Nerve Fraction and Degeneration in Spinal Cord Neuropil by SHIFT MRI.
Journal of Magnetic Resonance Imaging : JMRI 2020 October 25
BACKGROUND: Neurodegeneration is a complex cellular process linked to prompt changes in myelin integrity and gradual neuron loss. Current imaging techniques offer estimations of myelin volumes in lesions/remyelinated areas but are limited to detect subtle injury.
PURPOSE: To investigate whether measurements detected by a signal hierarchically isolated as a function of time-to-echo (SHIFT) MRI technique can determine changes in myelin integrity and fiber axolemma.
STUDY TYPE: Prospective animal model.
ANIMAL MODEL: Surgically demyelinated spinal cord (SC) injury model in rodents (n = 6).
FIELD STRENGTH/SEQUENCE: Gradient-echo spin-echo at 3T.
ASSESSMENT: Multicompartment T2 relaxations were computed by SHIFT MRI in 75-microns-resolution images of the SC injury penumbra region 2 weeks post-trauma. G-ratio and axolemma delamination were assessed by transmission electron microscopy (TEM) in intact and injured samples. SC myelinated nerve fraction was computed by SHIFT MRI prospectively and assessed histologically.
STATISTICAL TESTS: Relations between SHIFT-isolated T2 -components and TEM measurements were studied using linear regression and t-tests. Pearson's correlation and significance were computed to determine the SHIFT's sensitivity to detect myelinated fibers ratio in gray matter. Regularized least-squares-based ranking analysis was employed to determine SHIFT MRI's ability to discern intact and injured myelinated nerves.
RESULTS: Biexponential signals isolated by SHIFT MRI for intact vs. lesion penumbra exhibited changes in T2 , shifting from intermediate components (25 ± 2 msec) to long (43 ± 11 msec) in white matter, and similarly in gray matter regions-of-interest (31 ± 2 to 46 ± 16 msec). These changes correlated highly with TEM g-ratio and axon delamination measurements (P < 0.05). Changes in short T2 components were observed but not statistically significant (8.5 ± 0.5 to 7 ± 3 msec, P = 0.445, and 4.0 ± 0.9 to 7 ± 3 msec, P = 0.075, respectively). SHIFT MRI's ability to detect myelinated fibers within gray matter was confirmed (P < 0.001).
DATA CONCLUSION: Changes detected by SHIFT MRI are associated with abnormal intermembrane spaces formed upon mild injury, directly correlated with early neuro integrity loss. Level of Evidence 1 Technical Efficacy Stage 2.
PURPOSE: To investigate whether measurements detected by a signal hierarchically isolated as a function of time-to-echo (SHIFT) MRI technique can determine changes in myelin integrity and fiber axolemma.
STUDY TYPE: Prospective animal model.
ANIMAL MODEL: Surgically demyelinated spinal cord (SC) injury model in rodents (n = 6).
FIELD STRENGTH/SEQUENCE: Gradient-echo spin-echo at 3T.
ASSESSMENT: Multicompartment T2 relaxations were computed by SHIFT MRI in 75-microns-resolution images of the SC injury penumbra region 2 weeks post-trauma. G-ratio and axolemma delamination were assessed by transmission electron microscopy (TEM) in intact and injured samples. SC myelinated nerve fraction was computed by SHIFT MRI prospectively and assessed histologically.
STATISTICAL TESTS: Relations between SHIFT-isolated T2 -components and TEM measurements were studied using linear regression and t-tests. Pearson's correlation and significance were computed to determine the SHIFT's sensitivity to detect myelinated fibers ratio in gray matter. Regularized least-squares-based ranking analysis was employed to determine SHIFT MRI's ability to discern intact and injured myelinated nerves.
RESULTS: Biexponential signals isolated by SHIFT MRI for intact vs. lesion penumbra exhibited changes in T2 , shifting from intermediate components (25 ± 2 msec) to long (43 ± 11 msec) in white matter, and similarly in gray matter regions-of-interest (31 ± 2 to 46 ± 16 msec). These changes correlated highly with TEM g-ratio and axon delamination measurements (P < 0.05). Changes in short T2 components were observed but not statistically significant (8.5 ± 0.5 to 7 ± 3 msec, P = 0.445, and 4.0 ± 0.9 to 7 ± 3 msec, P = 0.075, respectively). SHIFT MRI's ability to detect myelinated fibers within gray matter was confirmed (P < 0.001).
DATA CONCLUSION: Changes detected by SHIFT MRI are associated with abnormal intermembrane spaces formed upon mild injury, directly correlated with early neuro integrity loss. Level of Evidence 1 Technical Efficacy Stage 2.
Full text links
Related Resources
Trending Papers
Heart failure with preserved ejection fraction: diagnosis, risk assessment, and treatment.Clinical Research in Cardiology : Official Journal of the German Cardiac Society 2024 April 12
Proximal versus distal diuretics in congestive heart failure.Nephrology, Dialysis, Transplantation 2024 Februrary 30
Efficacy and safety of pharmacotherapy in chronic insomnia: A review of clinical guidelines and case reports.Mental Health Clinician 2023 October
World Health Organization and International Consensus Classification of eosinophilic disorders: 2024 update on diagnosis, risk stratification, and management.American Journal of Hematology 2024 March 30
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.
By using this service, you agree to our terms of use and privacy policy.
Your Privacy Choices
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app