Quantitative Evaluation of Acute Pancreatitis Based on Dual-Energy Computed Tomography.

OBJECTIVE: To evaluate the value of dual-energy computed tomography (DECT) parameters for the quantitative diagnosis of acute pancreatitis (AP) and classification of its severity.

METHODS: Patients with AP underwent a plain CT scan and three contrast-enhanced DECT scans. We analyzed the group differences in iodine concentration (IC) and slope of the spectral Hounsfield unit curve (λ HU ) of the 3-phase enhanced scans (arterial, venous, and delayed phases).

RESULTS: The study included 60 AP patients (38 males and 22 females; mean age: 47.43±13.47 y). On the basis of the CT severity index (CTSI), the patients were divided into 2 groups: group A (mild AP, n=26) and group B (moderate/severe AP, n=34). IC and λ HU in the arterial and venous phases were all significantly higher in group A than in group B ( P <0.001) and could effectively differentiate the 2 groups. The areas under the curve were 0.753 (95% CI: 0.624-0.855), 0.799 (95% CI: 0.676-0.892), 0.774 (95% CI: 0.647-0.872), and 0.842 (95% CI: 0.724-0.923) for IC at arterial and venous phases and λ HU at arterial and venous phases, respectively. These parameters decreased with the increase of CTSI, showing significant negative correlations, with r were -0.512 (95% CI: -0.678 to -0.297), -0.492 (95% CI: -0.663 to -0.272), -0.552 (95% CI: -0.707 to -0.346), -0.569 (95% CI: -0.719 to -0.368) for IC at arterial and venous phases and λ HU at arterial and venous phases, respectively ( P <0.001).

CONCLUSIONS: DECT imaging can quantitatively analyze AP, and the IC and λ HU can be used to distinguish mild and severe cases, adding functional information to the CT morphology to determine the severity and prognosis of the disease.