Quantitative and qualitative evaluation of pancreatic cancer on photon-counting detector CT and dual-energy CT using...

To compare the depiction performance of photon-counting detector CT (PCD-CT) and dual-energy CT (DE-CT) quantitatively and qualitatively for pancreatic cancer under reference conditions equivalent to 120 kVp, used in clinical practice.

For this retrospective single-center study, 124 patients with pathologically proven pancreatic cancer who had undergone initial dynamic contrast-enhanced upper abdominal CT between January 2023 and October 2024 were included (PCD-CT: n = 62; DE-CT: n = 62). Reference images were 70 keV virtual monoenergetic images for PCD-CT and 80/Sn150 kVp linearly blended images for DE-CT. The tumor-to-pancreas ratio (TPR) and contrast-to-noise ratio (CNR) were calculated in the pancreatic and equilibrium phases. After two radiologists rated tumor visibility independently using a five-point scale, the mean visibility score was analyzed. Group differences were assessed using Welch's t test and linear regression adjusted for age, body mass index (BMI), tumor size, and tumor location. A predefined subgroup analysis was conducted for tumors ≤ 20 mm (pancreatic phase).

In the equilibrium phase, the visibility score was higher with PCD-CT than with DE-CT (3.065 vs. 2.548; p < 0.001) and remained significant after adjustment (β = +0.305; p = 0.032). TPR and CNR were similar in both phases (pancreatic: TPR 0.495 vs. 0.537, p = 0.088; CNR 13.789 vs. 12.231, p = 0.246; equilibrium: TPR 1.027 vs. 1.017, p = 0.868; CNR 0.901 vs. 0.110, p = 0.597), as was pancreatic-phase visibility (4.250 vs. 4.065; p = 0.136). Results for tumors ≤ 20 mm were consistent with the main analysis.

Under 120 kVp-equivalent conditions, PCD-CT and DE-CT showed comparable quantitative performance for pancreatic cancer, whereas PCD-CT provided superior subjective tumor visibility in the equilibrium phase, suggesting improved visual detectability without loss of quantitative image quality.