MR study of normal joint function using a low field strength system

A functional MR study was performed using a 0.064 T permanent magnet MR system. The shoulder joints, elbow joints, hip joints, and knee joints of three volunteers (mean height and weight, 176 cm and 71 kg, respectively) were examined at incremental joint angles in three to eight stages during flexion-extension, abduction-adduction, or pronation-supination movement. Each set of 16 images was obtained in 4 min, 49 s using three-dimensional Fourier transformation methods with gradient echo pulse sequences. The images were evaluated in static mode and sometimes in cine mode. The findings obtained about the physiology of these normal joints was generally compatible with findings previously accumulated in the field of kinesiology. The study suggests that this method can be useful for in vivo study of kinesiology and pathogenesis of diseases and that patients with most types of contracture or deformity can be examined by MR imaging.