Frequency of sternal variations and anomalies in living individuals evaluated by MDCT

The aim of this retrospective study was to present the frequency and MDCT appearances of sternal variations and anomalies, as well as to highlight their clinical significance.

This retrospective study was carried out on 1150 patients, who underwent chest MDCT. Axial planes, multiplanar and curved-planar reconstructed images were studied. Age and sex distribution of the variations was evaluated.

Anatomical variations of the sternum were found in 74.1%. The most frequent variation was the double-ended xiphoid process (36.9%), followed by the single xiphoidal foramen (25.8%) and the sternal sclerotic band (12.8%). Other variations observed were: sternal notch (10.1%), xiphoidal ligament calcification (8.3%), sternal foramen (4.9%), complete manubriosternal fusion (4.1%) and sternoxiphoidal fusion (4.1%), triple-ended xiphoid process (3.7%), sternal cleft (1.5%), whereas the rest of the variations including sternoxiphoidal junction pseudoforamen, suprasternal bone, pseudocleft, suprasternal tubercle and absence of xiphoid process were in less than 1%. In our subjects, sternal and xiphoidal foramina were adjacent to: the pericardium (37.14%), the diaphragm (22.9%), the mediastinal fat (17.1%), the liver (11.4%), the lung (8.5%) and to the stomach (2.9%).

Sternal variations are frequent, asymptomatic, detected incidentally at cross-sectional imaging and may be confused with pathologic conditions. Radiologists should be familiar with these variations in order to discriminate them from pathologies and avoid complications during interventional procedures.

This study presents thoroughly the sternal variations' MDCT appearance, detected in a Greek population, correlates them with age and gender and discuss their clinical significance in detail.