In 78 patients with likely pancreatitis, we used laparotomy, computerized tomography, ultrasonography and other information to make an objective diagnosis of pancreatitis. Laboratory studies included serum amylase, amylase isoenzymes and lipase. We found that both amylase and lipase are highly sensitive tests and P3 amylase by electrophoresis on agarose to be specific; a combination of these tests is recommended to assist in the diagnosis of pancreatitis. The frequent occurrence of an abnormal amylase and lipase in patients without pancreatitis is suggested as the cause of overdiagnosis of this disorder. A markedly increased amylase or lipase was always associated with pancreatic disease.

The abdominal radiographs of 74 patients with calcific pancreatitis were reviewed to assess the distribution, density and patterns of calcification. These characteristics were compared with the results of endoscopic retrograde cholangiopancreatography and ultrasonography. There was a decreasing gradient of calcification from head to tail in most patients. Foci of calcification greater than 5 mm in diameter were almost always associated with pancreatic duct obstruction. Endoscopic retrograde cholangiopancreatography did not provide additional diagnostic information and is unnecessary in calcific pancreatitis except when a precise map is required before operation.

Ultrasonography, computed tomography (CT), and an oral pancreatic function test were evaluated prospectively in 107 consecutive patients suspected of having pancreatic disease, the final diagnosis being made independently of these tests. Seventeen patients proved to have either chronic pancreatitis or a pancreatic neoplasm. Five had an unfused ventral pancreas and 10 had "minimal change" pancreatograms. Seventy five patients did not have pancreatic disease. Among the 17 patients with pancreatic disease the sensitivities of ultrasound, CT, and the pancreatic function test were 70%, 71%, and 76% respectively; among those without disease values of specificity of the three tests were 75%, 87%, and 72%. All three tests failed to detect most of the patients with unfused ventral pancreases or minimal change pancreatograms. The predictive values of a positive result for the three tests were 43%, 67%, and 34%. The predictive value of a negative result was greater than 90% for all the tests. Results improved when CT was combined with either of the two other tests. These findings show that CT is the most accurate of the three tests in diagnosing pancreatic disease but that a combination of ultrasound and the oral pancreatic function test offers a more widely applicable and almost as accurate alternative.

A tubeless pancreatic function test (BTP test) using N-benzoyl-l-tyrosyl-p-aminobenzoic acid was used to assess exocrine function from urinary recovery of p-aminobenzoic acid produced by hydrolysis of the peptide by chymotrypsin. Patients with acute pancreatitis were studied at various time intervals after the acute attack and compared with controls with abdominal pain that was not pancreatic in origin. The initial BTP test carried out in the convalescent period was abnormal in all of 30 patients with acute pancreatitis but normal in 10 patients with non-pancreatic abdominal pain and also in 8 patients who had recovered from an attack of acute pancreatitis 2-6 years previously. Results were improved or normal in 12 of 15 patients re-tested 1 year after the attack of pancreatitis, but 4 out of 6 still had abnormal results 2-6 months after the attack. The data suggest that an attack of acute pancreatitis may impair exocrine pancreatic function for several months.

Grey scale ultrasound scanning has been performed within 1 week of admission in 114 patients with acute pancreatitis in order to establish its reliability in detecting gallstones and to document early pancreatic changes. When the gallbladder was identified (69.4 per cent of patients), grey scale ultrasound was 96.1 per cent accurate in predicting the presence of gallstones. Of 85 patients (74.5 per cent), in whom adequate pancreatic imaging was achieved on the initial scan, 35 were reported within normal limits, 28 had generalized pancreatic swelling and 22 a localized pancreatic mass of cystic collection. These ultrasound findings did not correlate significantly with the objective assessment of severity of disease. However, all 9 patients (8.1 per cent) who developed a pseudocyst were in the group shown to have early localized pancreatic swelling. Grey scale ultrasound is a useful method of detecting gallstones in patients with acute pancreatitis, thus permitting early accurate biliary surgery. However, in almost one-third of our patients ultrasound failed to outline the gallbladder on the initial scan. While ultrasound scanning of the pancreas will detect the formation of pseudocysts and accurately chart their subsequent progress, we doubt whether an early scan is required to achieve this purpose. Although generalized pancreatic swelling is frequently reported, this finding was of no major clinical importance and did not relate to the severity of disease.

Despite the lack of precise knowledge as to its exact mechanism of causation, acute pancreatitis continues to engage the clinician's attention. The world medical literature is replete with publications on the subject and the numerous Australian studies attest to the continuing clinical interest (Hennessy, 1965; Bennett and Jepson, 1966; Kune, 1968; Barraclough and Coupland, 1972; Battersby and Chapuis, 1977 and Reid and Kune, 1978). The majority of these reviews concentrate on the supposed aetiology and clinical features of acute pancreatitis and cover well trodden ground. It is the purpose of this paper to review the problems in the diagnosis and management of acute pancreatitis in the light of present knowledge and to relate these to 494 patients with acute pancreatitis admitted to St Vincent's Hospital, Melbourne, during the period 1968 to 1979. The diagnosis of acute pancreatitis in these 494 cases was made at operation, autopsy or by the demonstration of an elevation in the serum amylase above 1200 International units (I.U.) per litre in patients with compatible symptoms and signs.

In this paper, recent advances in the diagnosis of pancreatic disease are reviewed, together with older methods currently in use. The clinical role of these techniques in the diagnosis of pancreatic disease is discussed with particular reference to symptomatology and prognosis of the various pancreatic disorders. Likely future developments in this field are considered.