Relaxation-compensated CEST MRI in the spinal cord of multiple sclerosis patients at 3T

Motivation: Clinical MR imaging is insensitive to underlying biochemical changes that may precede inflammatory multiple sclerosis (MS) lesions. Detecting tissue changes in early disease pathology could be significant for diagnosis and prognosis. Goal(s): Evaluate AREX (apparent exchange-dependent relaxation rate) sensitivity to alternative amide chemical exchange saturation transfer (CEST) methods in the spinal cord of MS patients. Approach: 32 healthy controls and 36 MS patients were imaged, and differences between amide CEST contrasts (both uncorrected and magnetization transfer (MT) corrected) were explored. Results: Removing MT contributions and T1-relaxation decreases the heterogeneity in the healthy spinal cord and shows variation in the cord of MS patients. Impact: Initial results suggest that AREX shows improvement over alternative methods and could offer increased sensitivity to biochemical changes in the spinal cord of MS patients.