Radial-sequence magnetic resonance imaging in evaluation of acetabular labrum.

We investigated the usefulness of a radial-sequence magnetic resonance imaging (MRI) technique in the visualization of the acetabular labrum, which surrounds the acetabulum. In 22 hip joints of 12 volunteers, T2-weighted images were obtained on 24 radial planes of the acetabular rim, set at 15 degrees -intervals, using the small tip angle gradient echo method. We examined 7 planes in the weight-bearing portion. The acetabular labrum in the weight-bearing portion was depicted in good contrast to the surrounding tissues. The shape of the labrum differed among individuals and also in the anterior and posterior portions of the labrum. The signal intensity of the labrum was low or partially moderate. There was a high signal intensity band on the base of the acetabular labrum in several portions, which should be carefully interpreted to avoid confusion with abnormality. We concluded that radial-sequence MRI could be a useful technique for evaluation of the condition of the acetabular labrum in the weight-bearing portion.