CT appearance of unfused ossicles in the lumbar spine.

The computed tomographic (CT) appearance of unfused ossicles in the lumbar spine has had little attention. Unfused ossicles result from accessory ossification centers near the tip of the vertebral processes. Their main importance lies in distinguishing them from fractures. The CT appearance of unfused ossicles in the lumbar spine was correlated with that of the corresponding surface anatomy from a cadaver specimen. Thereafter, 100 consecutive CT studies were reviewed and two cases of presumedly unfused ossicles were found. The CT appearance of unfused ossicles and their differential diagnosis is discussed.