Five-phase high-resolution contrast-enhanced CT is associated with higher report-level concordance with pathology for pancreatic diseases.

BACKGROUND: This study aimed to investigate the diagnostic value of five-phase high-resolution contrast-enhanced CT (HR-CT) for pancreatic diseases. METHODS: A retrospective study involving 1886 patients with pathologically confirmed pancreatic disorders was performed with non-randomized protocol allocation according to clinical indications. All patients underwent preoperative contrast-enhanced CT scans, which were divided into two protocols: conventional four-phase CT (C-CT, including plain, pancreatic parenchymal phase, portal venous phase, and delayed phase; n = 346) and five-phase HR-CT (including plain, arterial phase, reduced field-of-view pancreatic parenchymal phase, portal venous phase, and delayed phase; n = 1540). Based on pathological findings, CT diagnostic results were categorized as accurate, erroneous, or ambiguous. Multivariate logistic regression and chi-square tests were used to compare the report-level concordance with pathology and sensitivity of the two CT protocols for pancreatic diseases. RESULTS: HR-CT was associated with a significantly higher report-level concordance with pathology for pancreatic diseases than C-CT, with an absolute increase of 11.2% (P < 0.001). Higher report-level concordance with pathology of HR-CT over C-CT was observed in both pancreatic ductal adenocarcinoma (PDAC) and non-PDAC subgroups (PDAC: 90.0% vs. 81.0%, P < 0.001; non-PDAC: 62.0% vs. 50.3%, P = 0.009). For small PDAC lesions (≤2 cm), the report-level concordance with pathology of HR-CT was 20.5% higher than that of C-CT (82.4% vs. 61.9%, P = 0.032). CONCLUSIONS: Five-phase HR-CT was associated with significantly higher report-level concordance with pathology for pancreatic diseases in this retrospective cohort, particularly for the detection of small PDAC (≤2 cm). Targeted use in selected patients, together with prospective multicenter validation, is warranted.