Ultrashort Echo Time Quantitative Conductivity Mapping (UTE-QCM) in The Knee: A Feasibility Study

Motivation: Conductivity reflects ionic composition (sodium), providing critical insights into various diseases. QCM can offer this information, but there is currently no effective technique for MSK tissues with short T2. Goal(s): The aim of this study is to develop UTE-QCM using UTE-DESS and validate its feasibility. Approach: S+ and S- images from UTE-DESS were utilized to estimate the B1+ phase. Two QCM methods (parabolic fitting and integral-based methods) were investigated. Results: Integral-based QCM demonstrated improved noise-robustness. In a sodium phantom, the estimated conductivity showed high linearity with sodium concentrations. In the knee, the generated conductivity map detected both long and short T2 tissues. Impact: UTE-QCM has the potential to provide a new quantitative imaging tool targeting short T2 tissues in the MSK system, facilitating the diagnosis and prognosis of joint disorders such as osteoarthritis and tumors such as osteosarcoma.