AbstractBackground and AimPancreatic ductal adenocarcinoma (PDAC) is a lethal cancer, partly because its early detection is difficult. This study aimed to identify computed tomography (CT) findings associated with PDAC prior to diagnosis.MethodsPast CT images were retrospectively collected from the PDAC group (n = 54) and the control group (n = 90). The following imaging findings were compared: pancreatic mass, main pancreatic duct (MPD) dilatation with or without cutoff, cyst, chronic pancreatitis with calcification, partial parenchymal atrophy (PPA), and diffuse parenchymal atrophy (DPA). In the PDAC group, CT findings were examined during the pre‐diagnostic period and 6–36 months and 36–60 months before diagnosis. Multivariate analyses were performed using logistic regression.ResultsMPD dilatation with cutoff (P < 0.0001) and PPA (P = 0.023) were identified as significant imaging findings 6–36 months before diagnosis. DPA was identified as a novel imaging finding at 6–36 months (P = 0.003) and 36–60 months (P = 0.009) before diagnosis.ConclusionDPA, MPD dilatation with cutoff, and PPA were identified as imaging findings associated with pre‐diagnostic PDAC.