Magnetic resonance microscopic images with 50-mm field-of-view of the medial aspect of the knee

Abstract

To demonstrate the utility of microscopic images with field-of-view of 50 mm in delineation of the medial aspect of the knee, including fascial plane, superficial and deep layers of the medial collateral ligament (MCL), and the medial meniscus. Using a phantom, the signal-to-noise ratio (SNR) of a magnetic resonance (MR) microscopy coil with a diameter of 47 mm was calculated and compared with that of a regular coil. Four cadaveric knees were imaged by microscopy and resected to confirm the morphologies. Sixty-nine patients with internal derangement were examined by routine and microscopic imaging. Comparing the paired images for delineation of the above-mentioned structures, a qualitative image analysis was performed. SNRs of the MR microscopy coil were higher than those of the regular coil. MR microscopy readily demonstrated the multilayered appearance of the fascial plane and both layers of the MCL in cadavers and patients. In cases with MCL tears, ruptured stumps were identified by microscopy. MR microscopy delineated tiny cleavages in cases with meniscal tears. The mean values of qualitative evaluation of the MR microscopy were significantly higher than those of the routine imaging. High-resolution imaging delineated fine structures of the medial aspect of the knee.