Liver spontaneous hypoattenuation on CT is an imaging biomarker of the severity of acute pancreatitis.

PURPOSE: The purpose of this study was to evaluate the relationship between liver spontaneous attenuation (LSA) on computed tomography (CT) reflecting the degree of steatosis, and the severity of acute pancreatitis (AP). MATERIALS AND METHODS: All consecutive patients admitted from December 2014 to September 2020 for an episode of AP were retrospectively reviewed. LSA was evaluated on early CT examination and all abdominal CT examinations were reviewed by two abdominal radiologists. Severity of AP was categorized using Atlanta classification and CT severity index. Univariable and multivariable statistical analyses were performed. RESULTS: A total of 467 patients were included. There were 297 men and 170 women, with a mean age of 57 ± 19 (SD) years (range: 18-98 years). Among them, 236 patients (51%) had acute biliary pancreatitis, 134 (29%) had acute alcoholic pancreatitis and 97 (20%) had AP due to other etiologies. A total of 44 (9%) patients had severe AP and 423 (91%) had non severe AP. Median LSA was significantly lower in patients with severe AP (36 Hounsfield units [HU]; interquartile range [IQR]:18; 54) than in patients with non-severe AP (45 HU; IQR: 35; 51) (P < 0.001). In patients with alcoholic AP, median LSA was significantly lower in patients with severe AP (29 HU; IQR: 3; 43) than in those with non-severe AP (42 HU; IQR: 27; 50) (P = 0.022). At multivariable analysis, the third and fourth quartiles of liver spontaneous attenuation values (i.e., < 45 HU/>30 HU and < 30 HU) were independently associated with severe AP (OR, 3.23; 95% CI: 1.33-51.2; P = 0.038 and OR, 8.82; 95% CI: 1.91-69.7; P = 0.014; respectively). CONCLUSION: LSA on CT is associated with clinical severity of AP and may be used as an additional marker of disease severity.

Early Prediction of Acute Biliary Pancreatitis Using Clinical and Abdominal CT Features.

Background Assessment of the biliary origin of acute pancreatitis (AP) is crucial because it affects patient treatment to avoid recurrence. Although CT is systematically performed to determine severity in AP, its usefulness in assessing AP biliary origin has not been evaluated. Purpose To assess abdominal CT features associated with acute biliary pancreatitis (ABP) and to evaluate the predictive value of a combination of CT and clinical data for determining a biliary origin in a first episode of AP. Materials and Methods From December 2014 to May 2019, all consecutive patients who presented with a first episode of AP and with at least 6 months of follow-up were retrospectively reviewed. Evidence of gallstones was mandatory for a clinical diagnosis of ABP. Abdominal CT images were reviewed by two abdominal radiologists. Univariable and multivariable statistical analyses were performed, and a nomogram was constructed on the basis of the combination of clinical and CT features. This nomogram was validated in a further independent internal cohort of patients. Results A total of 271 patients (mean age ± standard deviation, 56 years ± 20; 160 men) were evaluated. Of these, 170 (63%) had ABP. At multivariable analysis, age (odds ratio [OR], 1.06; 95% CI: 1.03, 1.09; P < .001), alanine aminotransferase level (OR, 1.00; 95% CI: 1.00, 1.01; P = .009), gallbladder gallstone (OR, 15.59; 95% CI: 4.61, 68.62; P < .001), choledochal ring sign (OR, 5.73; 95% CI: 2.11, 17.05; P < .001), liver spontaneous attenuation (OR, 1.07; 95% CI: 1.04, 1.11; P < .001), and duodenal thickening (OR, 0.17; 95% CI: 0.03, 0.61; P = .01) were independently associated with ABP. The matching nomogram combining both clinical and CT features displayed an area under the curve of 0.94 (95% CI: 0.91, 0.97) in the study sample (n = 271) and 0.91 (95% CI: 0.84, 0.99) in the validation cohort (n = 51). Conclusion Abdominal CT provided useful features for diagnosis of acute biliary pancreatitis (ABP). Combining CT and clinical features in a nomogram showed good diagnostic performance for early diagnosis of ABP. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Chang in this issue.