Partial Volume Correction Method for Improving Test-Retest Repeatability of In Vivo Human Brain 1H MRS and Quantification of Neurochemical Concentrations at 7T

Byeong-Yeul Lee¹, Xiao-Hong Zhu¹, Wei Chen¹, Melissa Terpstra¹

Human brain ultra-high field (7T) scanners are increasingly available in clinical settings and advantageous for sensitivity and specificity. Accurate quantification of metabolite concentrations from 1H MRS requires appropriate partial volume correction, especially when studying treatment effect or pathologies that alter brain morphometry. We developed a tissue segmentation method that remained reliable in the presence of inhomogeneous B1, which is typically encountered at ultra-high field. Utilization of T1/PD ratio images improved histogram based classification of tissue types. Using this approach to correct for partial volume effects, test-retest repeatability of metabolite concentrations quantified from single voxel in vivo 1H-MRS was improved.