Bradley Schott

Introduction. Multiple Sclerosis (MS) is a chronic autoimmune disease that targets the central nervous system¹. The damage to the CNS is caused by two main agents, the demyelination of neuronal axons, and the resulting inflammation due to this breakdown. Despite all the work going on and the public awareness of MS, it remains one of the top five causes of neurological disability in the United States². The disease affects women more than men and has both genetic and environmental factors that influence the progression and development of MS^2,3. MS is categorized into four phenotypes; however, there is significant overlap between these categories which makes classification and targeted treatment difficult¹. Currently 3-Tesla (3T) Magnetic Resonance Imaging (MRI) is used to detect white tract lesions, but limited sensitivity makes it difficult to characterize and quantify the lesions^4,5. Treatment options include attempts at modifying the immune system, increasing the myelination process, and managing symptoms with medications^2,3. Methods and Results. The use of 7T MRI has increased the signal-to-noise ratio(SNR) which allowed for better classification of lesions associated with MS⁴. In the past, utilization of 3T has resulted in misclassification with several lesions being mistaken as neoplasms. In addition to the more typical white matter tract lesions, gray matter lesions are also visible and quantifiable with 7T imaging⁶. The best way to visualize these gray matter lesions is through a method called quantitative magnetization transfer(qMT) which further increases the SNR. One study found that up to 26% of MS lesions are gray matter lesions. These chronic lesions expand and mutate making characterization nearly impossible, but use of 7T has improved the identification and quantification of these chronic rim lesions which correlates to better outcome measures. MS also causes cognitive dysfunction as well as motor and sensory deficits, which is believed to stem from cortical gray matter health. The use of selective inversion recovery has also shown a correlation between MS chronic lesions and cognitive performance^6,8,9. In addition, MS causes lower urinary tract symptoms (LUTS) despite increased brain activation as seen on functional MRI (fMRI)^9,10. Conclusions. MS is an active disease the progresses and changes over time. MRI is the best predictor of symptomatology and progression of the disease and while 3T is decent at detecting lesion burden, 7T is vital for better understanding of the disease. Furthermore, classification is essential to develop a treatment plan that gives the best outcome for the patient.

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6. McKeithan L, Lyttle B, Box B, et al. 7T quantitative magnetization transfer (qMT) of cortical gray matter in multiple sclerosis correlates with cognitive impairment. NeuroImage. https://pubmed.ncbi.nlm.nih.gov/31525497/.
7. Absinta M, Sati P, Masuzzo F, et al. Association of Chronic Active Multiple Sclerosis Lesions With Disability In Vivo. JAMA neurology. https://pubmed.ncbi.nlm.nih.gov/31403674/.
8. Harrison DM, et al. Association of Cortical Lesion Burden on 7-T Magnetic Resonance Imaging With Cognition and Disability in Multiple Sclerosis. JAMA neurology. https://pubmed.ncbi.nlm.nih.gov/26192316/.
9. Shi Z, Tran K, Karmonik C, Boone T, Khavari R. High spatial correlation in brain connectivity between micturition and resting states within bladder-related networks using 7 T MRI in multiple sclerosis women with voiding dysfunction. World journal of urology. https://pubmed.ncbi.nlm.nih.gov/33512570/.

Khavari R., et al. Functional Magnetic Resonance Imaging with Concurrent Urodynamic Testing Identifies Brain Structures Involved in Micturition Cycle in Patients with Multiple Sclerosis. The Journal