Accuracy of ultrasound in diagnosing abdominal masses.

B-mode ultrasonography was performed in 246 patients with suspected abdominal masses over a seven-year period. In 105 (40 percent), the accuracy of ultrasonic diagnosis was evaluated surgically. Sonography was proven correct in 60 (57 percent) patients who had undergone operation. Among 141 patients who had not undergone operation and whose diagnoses were established by other means, ultrasonography agreed with the clinical diagnosis in 69 (31 percent). Ultrasound accuracy, as confirmed by operation, was highest for splenic masses (100 percent) and for aortic aneurysm (88 percent). Liver masses were correctly identified in 56 percent of patients and gallbladder lesions in 38 percent. While only a 48 percent accuracy was obtained in diagnosing pancreatic disease, 64 percent of all pseudocysts were localized. Ultrasonography correlated positively with operative findings in 56 percent of renal masses. Intraperitoneal abscess was accurately diagnosed in 61 percent of patients but retroperitoneal adenopathy in only 33 percent. Abdominal ultrasonography, while accurately diagnosing splenic and aortic masses, failed to identify approximately half of other mass lesions. Improved techniques hold promise of improving this diagnostic accuracy.