Rapid myelin water imaging for the assessment of cervical spinal cord myelin damage

Adam V Dvorak; Emil Ljungberg; Irene M Vavasour; Hanwen Liu; Poljanka Johnson; Alexander Rauscher; John L K Kramer; Roger Tam; David K B Li; Cornelia Laule; Laura Barlow; Hannah Briemberg; Alex L MacKay; Anthony Traboulsee; Piotr Kozlowski; Neil Cashman; Shannon H Kolind

doi:10.1016/j.nicl.2019.101896

Rapid myelin water imaging for the assessment of cervical spinal cord myelin damage

Neuroimage Clin. 2019:23:101896. doi: 10.1016/j.nicl.2019.101896. Epub 2019 Jun 17.

Authors

Adam V Dvorak¹, Emil Ljungberg², Irene M Vavasour³, Hanwen Liu⁴, Poljanka Johnson⁵, Alexander Rauscher⁶, John L K Kramer⁷, Roger Tam⁸, David K B Li⁹, Cornelia Laule¹⁰, Laura Barlow¹¹, Hannah Briemberg¹², Alex L MacKay¹³, Anthony Traboulsee¹², Piotr Kozlowski¹⁴, Neil Cashman¹², Shannon H Kolind¹⁵

Affiliations

¹ Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada; International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada. Electronic address: adam.dvorak@ubc.ca.
² Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, De Crespigny Park PO89, London SE5 8AF, United Kingdom.
³ Radiology, University of British Columbia, 2775 Laurel Street, Vancouver, BC V5Z 1M9, Canada.
⁴ Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada; International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada.
⁵ Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada.
⁶ Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada; Radiology, University of British Columbia, 2775 Laurel Street, Vancouver, BC V5Z 1M9, Canada; Pediatrics, University of British Columbia, 4480 Oak Street BC Children's Hospital Vancouver, BC V6H 3V4, Canada; UBC MRI Research Centre, University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC, V6T 2B5, Canada.
⁷ International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada; School of Kinesiology, University of British Columbia, 210-6081 University Boulevard, Vancouver, BC V6T 1Z1, Canada.
⁸ Radiology, University of British Columbia, 2775 Laurel Street, Vancouver, BC V5Z 1M9, Canada; School of Biomedical Engineering, University of British Columbia, 2222 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada.
⁹ Radiology, University of British Columbia, 2775 Laurel Street, Vancouver, BC V5Z 1M9, Canada; Medicine (Neurology), University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC, V6T 2B5, Canada; UBC MRI Research Centre, University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC, V6T 2B5, Canada.
¹⁰ Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada; Radiology, University of British Columbia, 2775 Laurel Street, Vancouver, BC V5Z 1M9, Canada; International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada; Pathology & Laboratory Medicine, University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC V6T 2B5, Canada.
¹¹ Radiology, University of British Columbia, 2775 Laurel Street, Vancouver, BC V5Z 1M9, Canada; UBC MRI Research Centre, University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC, V6T 2B5, Canada.
¹² Medicine (Neurology), University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC, V6T 2B5, Canada.
¹³ Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada; Radiology, University of British Columbia, 2775 Laurel Street, Vancouver, BC V5Z 1M9, Canada.
¹⁴ Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada; Radiology, University of British Columbia, 2775 Laurel Street, Vancouver, BC V5Z 1M9, Canada; International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada; UBC MRI Research Centre, University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC, V6T 2B5, Canada.
¹⁵ Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada; Radiology, University of British Columbia, 2775 Laurel Street, Vancouver, BC V5Z 1M9, Canada; International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada; Medicine (Neurology), University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC, V6T 2B5, Canada.

Abstract

Background: Rapid myelin water imaging (MWI) using a combined gradient and spin echo (GRASE) sequence can produce myelin specific metrics for the human brain. Spinal cord MWI could be similarly useful, but technical challenges have hindered routine application. GRASE rapid MWI was recently successfully implemented for imaging of healthy cervical spinal cord and may complement other advanced imaging methods, such as diffusion tensor imaging (DTI) and quantitative T₁ (qT₁).

Objective: To demonstrate the feasibility of cervical cord GRASE rapid MWI in multiple sclerosis (MS), primary lateral sclerosis (PLS) and neuromyelitis optica spectrum disorder (NMO), with comparison to DTI and qT₁ metrics.

Methods: GRASE MWI, DTI and qT₁ data were acquired in 2 PLS, 1 relapsing-remitting MS (RRMS), 1 primary-progressive MS (PPMS) and 2 NMO subjects, as well as 6 age (±3 yrs) and sex matched healthy controls (HC). Internal cord structure guided template registrations, used for region of interest (ROI) analysis. Z score maps were calculated for the difference between disease subject and mean HC metric values.

Results: PLS subjects had low myelin water fraction (MWF) in the lateral funiculi compared to HC. RRMS subject MWF was heterogeneous within the cord. The PPMS subject showed no trends in ROI results but had a region of low MWF Z score corresponding to a focal lesion. The NMO subject with a longitudinally extensive transverse myelitis lesion had low values for whole cord mean MWF of 12.8% compared to 24.3% (standard deviation 2.2%) for HC. The NMO subject without lesions also had low MWF compared to HC. DTI and qT₁ metrics showed similar trends, corroborating the MWF results and providing complementary information.

Conclusion: GRASE is sufficiently sensitive to detect decreased myelin within MS spinal cord plaques, NMO lesions, and PLS diffuse spinal cord injury. Decreased MWF in PLS is consistent with demyelination secondary to motor neuron degeneration. GRASE MWI is a feasible method for rapid assessment of myelin content in the cervical spinal cord and provides complementary information to that of DTI and qT₁ measures.

Keywords: Diffusion tensor imaging; Mri; Myelin water imaging; Quantitative T(1); Spinal cord.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Cervical Cord / diagnostic imaging*
Cervical Cord / pathology
Diffusion Tensor Imaging / methods*
Diffusion Tensor Imaging / standards
Feasibility Studies
Female
Humans
Male
Middle Aged
Motor Neuron Disease / diagnostic imaging*
Motor Neuron Disease / pathology
Multiple Sclerosis / diagnostic imaging*
Multiple Sclerosis / pathology
Myelin Sheath* / pathology
Neuromyelitis Optica / diagnostic imaging*
Neuromyelitis Optica / pathology
Sensitivity and Specificity