Computed tomographic differentiation between alcoholic and gallstone pancreatitis: Significance of distribution of infiltration or fluid collection

Abstract

Aim: To evaluate the usefulness of various computed tomography (CT) findings including distribution of infiltration or fluid collection in differentiating the major etiologies of acute pancreatitis.

Methods: We reviewed 75 relatively severe cases of acute pancreatitis of alcoholic (n = 43) or biliary stone (n = 32) etiology having infiltration or fluid collection on CT. We compared the pancreatic size, CT grading, presence or absence of biliary calculi, and dilatation of pancreatic or bile duct. We also evaluated degree and the distribution of infiltration and fluid collection in each group.

Results: The sizes of pancreas were not different between alcohol group and stone group. Alcohol group showed higher CT grading than stone group (P < 0.05). Presence of biliary stone and duct dilatation was statistically significant in differentiating etiology (P < 0.05). Alcohol group showed significantly prominent peripancreatic pathology than stone group only in left peritoneal compartment (P = 0.020).

Conclusion: Alcoholic pancreatitis tends to form more prominent peripancreatic changes than gallstone pancreatitis in relatively severe cases. This is evident on the anterior aspect of left abdomen. Although clinical history and some CT findings usually are a major determinant of the etiology, this pattern of peripancreatic pathology may have an ancillary role in determining the etiologies of acute pancreatitis in the equivocal cases.

Figure 1

Peripancreatic infiltration scores (1-3). A: Score 1 (Irregular peripancreatic infiltration without fluid collection). CT showing irregular strands of peripancreatic fat infiltrations in the compartment of RP (arrow), LP (open arrows), and LSR (arrowhead); B: Score 2 (Peripancreatic fluid collection with no or equivocal degree of mass effect). CT showing multiple fluid collections without mass effect in the compartment of RSR (arrows) and LSR (open arrows). Score 1 infiltrations in the compartment of RP and LP (arrowheads) are also seen; C: Score 3 (Peripancreatic fluid collection with definite mass effect to adjacent organs). CT showing score 3 fluid collection in the LP and LSR compartments (arrows) displacing or compressing adjacent bowels.

Figure 2

A 61-year old man with a clinical diagnosis of gallstone pancreatitis due to distal common bile duct stone. A and B: CT scans showing the peripancreatic infiltration or fluid collection predominantly in the right abdomen: score 1 infiltration in RP compartment (arrows), score 2 fluid collection in RSR compartment (open arrows). Distal common bile duct stone with bile duct dilatation also can be seen (arrowheads).

Figure 3

A 57-year old woman with score 1 infiltration in the RP and LP compartments (arrows) and score 2 fluid collections in the LP and LSR compartments (open arrows) is turned out to have a clinical diagnosis of alcoholic pancreatitis.