ULTRASOUND VERSUS PLAIN FILM IN THE DETECTION OF PNEUMOPERITONEUM

To evaluate ultrasound (US) versus conventional plain film radiography (CPF) in the detection of pneumoperitoneum, 30 patients with postsurg ical pneumoperitoneum and a control group of 22 patients were studied using US and CPF. Sonograms and radiograms were obtained while patient s were supine and in left lateral decubitus. The two orthogonal plain films of the abdomen were acquired with a horizontal X-ray beam. The e pigastric region and right hypochondrium were investigated with ultras onography. Four experienced, blinded radiologists examined 160 sonogra ms and 104 radiograms. Statistical analysis yielded a sensitivity of 7 5.7% for radiography versus 86% for ultrasonography, a specificity of 89.2% versus 83.5%, an accuracy of 81.5% versus 85%, a positive, predi ctive value of 90.2% versus 87%, and a negative predictive value of 76 .2% versus 83.5%, respectively. US could therefore be considered a rel iable alternative imaging technique in the detection of pneumoperitone um.