MR imaging of the hip: normal anatomic variants and imaging pitfalls

MR imaging of the hip is one of the most common musculoskeletal MR imaging studies performed today to assess for occult fractures, acetabular labral tears, hyaline cartilage loss, and musculotendinous injuries. Several developmental variations are seen in the hip, which can be mistaken for disease or potentially even contribute to the development of a pathologic condition. As in any imaging study, it is important to be cognizant of these variations as well as associated findings that help distinguish between true abnormality and developmental variation when interpreting an MR image of the hip. This article describes the numerous variants of the hip that are frequently seen on arthrographic and nonarthrographic MR imaging examinations.