ABSTRACT
Magnetic resonance imaging (MRI) of the hip has been valuable in the diagnosis of
occult osseous abnormalities and of periarticular soft tissue disorders. MRI has been
less useful in the evaluation of acetabular labral tears and other intra-articular
abnormalities. Image optimization is more technically challenging in the hip than
in smaller joints because the overlying soft tissues are thicker, resulting in decreased
spatial and contrast resolutions that may not be adequate to distinguish the acetabular
labrum from subchondral bone, articular cartilage, and joint capsule. MR arthrography
(MRA) extends the capabilities of conventional MRI because contrast solution separates
intra-articular structures and outlines abnormalities. In hips with suspected acetabular
labral injury, arthrographic MR images demonstrate the location and length of tears
and the presence of associated capsular defects. Arthrographic MR images may also
enable the accurate diagnosis of cartilage lesions and intra-articular loose bodies.
This article illustrates normal arthrographic MR features of the hip as well as pathologic
disorders of the acetabular labrum, capsule, and articular cartilage.
KEYWORDS
Hip arthrography - hip injuries - magnetic resonance imaging of the hip