Diagnosis and grading of chronic pancreatitis by morphological criteria derived by ultrasound and pancreatography.

The most commonly used modalities in the diagnosis of chronic pancreatitis are ultrasonography, computed tomography (CT) and endoscopic retrograde pancreatography (ERP). Computed tomography scanning is only of value in severe chronic pancreatitis. Both ultrasound and pancreatography are capable of showing ductal changes in mild forms of the disease, but comparison of the two methods has been difficult. A scheme of morphological criteria and descriptive terminology of pancreatitis was applied to 58 out of 85 patients with a firm clinical diagnosis of chronic pancreatitis. Twenty-seven patients were excluded from the study, four with a faulty clinical diagnosis and 23 with non-diagnostic pancreatograms. There was an exact classification into normal, equivocal, mild, moderate or marked chronic pancreatitis in 50 out of 58 patients (86%) and an almost perfect correlation (+ or - one grade) in 54 out of 58 (93%). There were four discrepancies. Ultrasound examination missed focal pancreatitis in the tail, a small cavity in the uncinate process and a variant of chronic pancreatitis. One ultrasound scan was of poor quality. Morphological grading by different techniques is feasible and use of this scheme can reduce diagnosis to a simple and specific set of rules.