Abstract #3532

T2* of the Osteochondral Junction Measured by VTE at 7T and Correlated with Histology

Vladimir Juras¹, Maria Isabel Menedez², Jochen Hofstaetter³, Martin Brix³, Sonja M. Walzer³, Pavol Szomolanyi¹, Oliver Bieri⁴, Xeni Deligianni⁴, Siegfried Trattnig¹

¹MR Centre of Excellence, Department of Radiology, Medical University of Vienna, Vienna, Austria; ²The Wright Center of Innovation in Biomedical Imaging, The Ohio State University Wexner Medical Center, Columbus, OH, United States; ³Department of Orthopaedics, Medical University of Vienna, Vienna, Austria; ⁴Department of Radiology, Division of Radiological Physics, University of Basel Hospital, Basel, Switzerland

This study shows that vTE-GRE is suitable tool for measuring the thickness of osteochondral junction; however, the measured values from MR images probably combine the signal from deep and calcified layer (it is not purely calcified cartilage) which would explain the discrepancy with histologically obtained values. The optimization of the two TE combinations for the best contrast is necessary. Low TEs in VTE sequence allow accurate calculation of T2* of osteochondral junction (in the range of ~5-10ms). Histological grading of the cartilage condition corresponds to changes in T2* in osteochondral junction which may suggest the changes in collagen matrix and calcified cartilage front in different OA stages. It was shown that lead accumulates in the tidemark which may significantly contribute to T2* alteration. Relatively low number of samples does not allow generating conclusive statements; in the future, it needs to be validated in the higher number of subjects.