Atlas of Signs in Musculoskeletal Radiology is approved by the ARRS (American Roentgen Ray Society) and is included in AJR Webreview

A. Gentili,MD, M. Beller, MD, S. Masih, MD, L.L. Seeger, MD

Diagnosis:

Ankylosing Spondylitis

Discussion:

Single radiograph of the lumbar spine with linear vertical increased density along the spinous processes. This single central radiodense line on frontal radiographs is related to ossification of supraspinous and interspinous ligaments. In addition, there are two more lateral vertical linear lines, which represent ossification of the apophyseal joint capsules. The three vertical ossified lines together make up the trolley-track sign.

References:

Atlas of Signs in Musculoskeletal Radiology is approved by the ARRS (American Roentgen Ray Society) and is included in AJR Webreview

A. Gentili,MD, M. Beller, MD, S. Masih, MD, L.L. Seeger, MD