ABSTRACT
A prospective study was undertaken to compare MR imaging of the knee obtained with low-field and high-field systems. In 10 subjects, MR imaging of the knee was performed on a 0.2 T permanent magnet and on a 1.5 T superconductive system. Similar spin echo (SE) and 3D-FISP (3D Fourier transform with steady state precession) acquisitions were obtained. Comparative image analysis was performed independently by four radiologists. Results show that the image quality and diagnostic performance delivered by state-of-the-art 0.2 T and 1.5 T systems is equivalent. Advantages of the 1.5 T system included: better signal-to-noise ratio, shorter scan times, better visualization of asymptomatic grade 1 meniscal degeneration on SE images. Advantages of 0.2 T images were: decreased chemical shift, susceptibility and flow artifacts, improved evaluation of subchondral bone on 3D-FISP images, slightly better patient tolerance. We conclude that, for MR imaging of the knee, a low-field system is a cost-effective alternative to more expensive superconducting units.
Subject(s)
Knee Joint/anatomy & histology , Knee/anatomy & histology , Magnetic Resonance Imaging/methods , Adult , Artifacts , Cost-Benefit Analysis , Female , Fourier Analysis , Humans , Joint Diseases/diagnosis , Magnetic Resonance Imaging/economics , Male , Middle Aged , Prospective Studies , Signal Processing, Computer-AssistedABSTRACT
Two families are described which appear to contain examples of multiple epiphyseal dysplasia. In both families a striking incidence of severe osteochondritis of the knees was encountered. It is suggested that this was caused by the fragmented and maldeveloped epiphyses characteristic of epiphyseal dysplasia.
