HIGH-RESOLUTION MAGNETIC-RESONANCE-IMAGING OF NORMAL PORCINE CARTILAGINOUS EPIPHYSEAL MATURATION

The aim of this study was to determine whether high-resolution magneti c resonance [MR] imaging could differentiate epiphyseal and articular cartilage in the cartilaginous epiphysis and demonstrate its developme ntal changes. T1- and TP-weighted (T1W and T2W) spin-echo sequences at 50-mm field of view (FOV) of hip joints were obtained from 14 piglets (newborn to 6 months), Subsequently, high-resolution MR images (15-mm FOV) of a biopsy core of the proximal femoral cartilaginous epiphysis were correlated with histology, Newborn cartilaginous epiphysis demon strated homogeneous signal intensity on T1W and T2W imaging with abund ant cartilage canals. From 2 weeks of age, the cartilaginous epiphysis showed a diminution of cartilage canals, with three zones evident on T2W imaging consisting of a low-signal middle zone separating two high er signal zones, Histologic evaluation demonstrated four distinct morp hologic laminas with a decrease in overall cartilage thickness with ag e, The laminas were not as well defined in the newborn compared with t he older piglets, No simple correlation was found between the MR zonal pattern and the morphological laminas on histology, No distinct demar cation between the articular cartilage and epiphyseal cartilage was pr esent, MR can visualize cartilage canals and demonstrate changes in th e cartilaginous epiphysis that occur with maturation. what component o f the cartilaginous epiphysis that accounts for the MR differences see n between newborn and older piglets remains unclear.