MDCT demonstration of intraarticular gas in the glenohumeral joint and sternoclavicular joint with reference to arm position.

Purpose: Our purpose was to investigate the frequency of intraarticular gas in the glenohumeral joint and sternoclavicular joint, along with the influence of the patient's arm position.

Materials and methods: Multidetector-row computed tomography (MDCT) scan on a total of 104 healthy subjects was investigated retrospectively. Raised-arm and lowered-arm positions were used sequentially, and the presence of intraarticular gas was investigated.

Results: While the arms were in a raised position, intraarticular gas was observed in the glenohumeral joint about 9% of all subjects and in the sternoclavicular joint about 20% of all subjects. Intraarticular gas in the most subjects disappeared when the arms were lowered.

Conclusion: When scanning with the arms in a raised position, intraarticular gas was seen in the glenohumeral and/or and sternoclavicular joint, and disappeared in most cases when the body position was changed. Such intraarticular gas is thought to result from traction of the limbs and is considered clinically insignificant.