QSM of epiphyseal cartilage neovascularization following femoral head ischemia: a retrospective 9.4T piglet model study

Motivation: Quantitative susceptibility mapping (QSM) can potentially allow detection of revascularization in Legg-Calvé-Perthes disease (LCPD), a childhood hip disorder, by characterizing changes in the epiphyseal cartilage vascular canals. Goal(s): To visualize and characterize regional neovascularization in the epiphyseal cartilage of ischemic femoral heads in an LCPD piglet model using a recently described QSM processing pipeline. Approach: 9.4T 3D GRE data sets of n=7 pairs of operated and control femoral heads were retrospectively analyzed with QSM. Vascular densities in quadrants of the epiphyseal cartilage were measured and compared. Results: Significant increases in vascular density were found in ischemic samples, particularly in medial and posterior quadrants. Impact: This work demonstrates improved visualization and characterization of neovascularization following ischemic injury and revascularization of epiphyseal cartilage using the recently described QSM processing pipeline. This tool may be useful for studying the pathogenesis of LCPD and related developmental joint disorders.