Poorly Enhanced Areas of Pancreatic Adenocarcinomas on Late-Phase Dynamic Computed Tomography

Objectives: The aim of the study was to retrospectively compare image findings of poorly enhanced areas (PEAs) of pancreatic adenocarcinomas that show almost no enhancement or obviously hypoattenuating area relative to the surrounding carcinoma on late-phase dynamic computed tomography (CT) with pathological findings. Methods: Thirty-nine patients with pancreatic adenocarcinoma underwent dynamic CT and surgery. Poorly enhanced areas were classified according to their size, attenuation value, position, and border on CT imaging and signal intensity on magnetic resonance imaging. Results: Of the 33 PEAs, 12 showed neoplastic duct-like structure that contained both large tumor gland and dilated pancreatic duct with atypia, 11 showed necrosis, 4 showed retention cyst, 2 showed dilated pancreatic duct without atypia or with limited invasion, 1 showed mucin, and 3 showed no remarkable differences in characteristics compared with surrounding tissue. Neoplastic duct-like structures tended to be well defined (P < 0.01). Necrotic portions tended to show a high attenuation value (P < 0.01) and central position (P < 0.01) and were ill defined (P < 0.01). Retention cysts tended to show a peripheral position (P < 0.01). Conclusions: Poorly enhanced areas corresponded to cystic, necrotic, and mucinous components. Image findings demonstrated these characteristics. Necrotic component can be visualized and distinguished with other components and can be a prognostic factor.