Uniform-MT CEST to Isolate GagCEST Contrast from Asymmetric MT Effects: First in vivo Study on Human Knees at 7 T

Jae-Seung Lee¹, ², Prodromos Parasoglou¹, Ding Xia¹, Alexej Jerschow², Ravinder R. Regatte¹

The in-vivo quantification of glycosaminoglycan (GAG) concentration is important for the early diagnosis of osteoarthritis. One promising method to measure GAG content in articular cartilage is chemical exchange saturation transfer (CEST). However, the CEST measurement may be interfered with the magnetization transfer (MT) effects resulting from the background extracelluar matrix. Recently, we have proposed a new strategy to disentangle CEST effects from asymmetric MT effects by using a simultaneous two-frequency RF irradiation technique to make the MT effects uniform. For the first time, this uniform-MT CEST method is applied in an in vivo human knee MRI study.