From the RSNA refresher courses - Chronic adult hip pain: MR arthrography of the hip

This article describes the technique for performance and interpretation of magnetic resonance arthrography of the hip. A description of normal anatomy of the hip is presented, and the appearance of the abnormal labrum is discussed. Labral detachments and tears are the most common clinically significant abnormalities to be identified. These abnormalities are recognized on the basis of the presence of contrast material at the acetabular-labral interface or within the substance of the labrum. Many varied appearances of the labrum have been identified within the asymptomatic population, and the correlation of these appearances is contrasted with those of the abnormal labrum in symptomatic patients. To date, it is difficult to draw conclusions regarding the significance of an absent labrum or of a sulcus at the acetabular-labral junction. Experience suggests that an absent labrum. in a symptomatic individual is pathologic and that a sulcus at the anterosuperior acetabular-labral junction may be a normal variant.