[Imaging-anatomic study of diaphragmatic sternocostal triangle with double-phase 16-row MDCT]

This study was aimed to determine the effects of respiratory phase, age, sex and body mass indexes (BMI) on the visibility and morphological characteristics of the diaphragmatic sternocostal triangle in normal adults shown by multi-detector computed tomography (MDCT). A total of 100 normal adults were consecutively recruited and scanned with 16-row MDCT at the end of deep expiration and inspiration. The visibility and morphological characteristics of diaphragmatic sternocostal triangle were observed. All cases were grouped according to the respiratory phase, age, sex and BMI, respectively. The visibility rates by MDCT among different types of sternocostal triangles at the inspiratory or the expiratory phases were calculated and compared, and the visibility rate was correlated with age, sex, and BMI, respectively. In addition, the CT features of diaphragmatic hernia (n=2) were recorded and analyzed. The visibility rate of trigonum sternocostal was 43% at the end of inspiration and 32% at the end of expiration. No difference was found in regard to age, gender and BMI (P > 0.05). Rupture of diaphragm and the features of adjacent abdominal organs into thoracic cavity were revealed clearly on multiplanar reformation (MPR) images of MDCT in 2 patients with diaphragmatic hernia. The visibility rates of diaphragmatic sternocostal triangle were associated with the respiratory movement. MPR on MDCT could be useful for revealing the anatomic structure of diaphragm and the radiological features of diaphragmatic hernia. Furthermore, double-phase scanning of MDCT provides feasible method for studying the physiologic information of diaphragm movement in normal status and abnormal status.