Pseudocyst formation in acute pancreatitis: ultrasonographic evaluation of 99 cases.

A total of 99 patients admitted with a diagnosis of acute pancreatitis were studied by abdominal A- and B-mode ultrasonography in an effort to detect pseudocyst formation. Positive ultrasonic scans were noted in 52 cases. In three patients with positive sonography, surgical exploration did not demonstrate pseudocysts, giving a false positive rate of 8.3%. Of the negative studies four were proven incorrect at surgery or autopsy , yielding a false negative rate of 8.5%. Approximately one-fifth with cystic lesions underwent spontaneous resolution. Three additional patients with pseudocysts had spontaneous cyst-enteric fistulization demonstrated by radiography. The sensitivity and accuracy of pancreatic ultrasound demonstrated by this study established ultrasonography as the procedure of choice in detecting pseudocyst formation in patients with acute pancreatitis.