LAUSR

OBJECTIVE This study aims to evaluate the value of multidetector computed tomography (MDCT) in detecting the location of gastroduodenal perforation. PATIENTS AND METHODS This cross-sectional descriptive study was conducted with 47 patients who underwent contrast-enhancing MDCT and were diagnosed with gastroduodenal perforation during surgery between July 2021 and June 2022. Radiologic findings included pneumoperitoneum (distribution and quantity) and analyzed the image findings for localizing the site of gastroduodenal perforation. RESULTS Pneumoperitoneum was the most common finding [95.74% (45 out of 47 patients)]. Regarding air distribution, the sensitivity (Se) and negative predictive value (NPV) of abdominal free air and supramesocolic free air were the highest (100% for both). The accuracy (Acc) of supramesocolic free air was the highest (93.6%), followed by abdominal free air (89.4%). Subphrenic free air also had a high Acc value (89.4%), with Se, specificity (Sp), and positive predictive value (PPV) being 90%, 85,7%, and 97.3%, respectively. The Sp PPV of falciform ligament/ligamentum teres sign, and periportal free air were also high (100% for both). In contrast, retroperitoneal free air was valuable in determining retroperitoneal duodenal perforation with an Sp, Se of 100%, and Acc of 89.4%. The thickness of abdominal free air was ≥5.5 mm, suggesting gastroduodenal perforation with a Se, Sp, PPV, NPV, and Acc of 82.5%, 100%, 100%, 50%, and 85.1%, respectively. CONCLUSIONS Subphrenic free air, periportal free air, falciform ligament sign, and the air above transverse mesocolon were correlated to gastric and duodenal bulb perforation. Retroperitoneal air indicates the perforation at the retroperitoneal duodenum. The thickness of abdominal free air ≥5.5 mm indicates gastric and duodenal bulb perforation.