Frequency of Sternal Variations and Anomalies Evaluated by MDCT

Abstract

OBJECTIVE. Our objective was to reveal the frequency and MDCT appearances of sternal variations and anomalies in subjects without sternal deformities. SUBJECTS AND METHODS. One thousand consecutive patients who underwent thoracic MDCT examination were enrolled in the study. All MDCT data, including multiplanar and curved-planar reconstructed images, were evaluated for detection of sternal variations and anomalies. Various kinds of sternal variations and anomalies, such as suprasternal bones and tubercles, manubriosternal and sternoxiphoidal fusions, sternal clefts and foramina, and sternal sclerotic bands were documented. RESULTS. In 1,000 subjects, the frequencies of main sternal variations and anomalies were as follows: suprasternal bone in 4.1%, suprasternal tubercle in 4%, complete manubriosternal fusion in 19.6%, complete sternoxiphoidal fusion in 30.3%, sternal foramen in 4.5%, and sternal sclerotic band in 37.1%. Xiphoidal foramen was seen in 27.4%, and the most common type was single foramen. Xiphoid process mostly ended as a single process (71%). Double-ended xiphoid process was also frequent (27.2%). Pseudocleft and pseudoforamen at the sternoxiphoidal junction were detected in 3.3% and in 3.6% of subjects, respectively. CONCLUSION. MDCT exhibited various sternal variations and anomalies. Sternal foramen is a frequent minor anomaly and generally associated with sternal sclerotic bands. Early manubriosternal and sternoxiphoidal fusions can be seen in early adulthood without osteodegeneration. Double-ended xiphoid process and single xiphoidal foramen are frequent sternal variations. Awareness of MDCT appearances of sternal variations and anomalies provides a better differential diagnosis with pathologic conditions.