Pancreatic imaging with ultra-high-resolution photon-counting computed tomography: Preliminary assessment of image...

To evaluate the advantage of combining ultra-high-resolution (UHR) mode with virtual monoenergetic image (VMI) reconstruction in photon-counting CT (PCCT) to assess pancreatic ductal adenocarcinoma (PDAC) and peripancreatic vasculature.

From September 2024 to April 2025, participants with suspected PDAC were prospectively enrolled and underwent pancreatic multiphase contrast-enhanced CT in UHR scanning mode. Six image series were reconstructed: (a) 0.2-mm slice thickness, threshold three-dimensional images; (b) 1-mm slice thickness, VMIs at 70 keV; and (c-f) 0.4-mm slice thickness, VMIs at 40, 45, 50, and 55 keV. For quantitative analysis, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured in tumors and peripancreatic vessels. For qualitative analysis, two blinded observers evaluated image quality for tumors, peripancreatic vessels, and fine pancreatic anatomy using 5-point Likert-type scales.

Seventy-four participants (39 male; mean age, 65.7 ± 10.7 years) with histologically confirmed PDAC were included. The CNR and SNR for tumors and peripancreatic vessels declined with increasing monoenergetic levels during pancreatic parenchymal and portal venous phases (PVP), peaking at 40 keV (all P < 0.001, except for SNR_lesion). Image noise was lowest in 1-mm-70-keV series (all P < 0.001). Qualitative assessment favored 1-mm-70-keV, 0.4-mm-45-keV, and 0.4-mm-50-keV images for overall image quality across phases (all P < 0.05), except between 1-mm-70-keV and 0.4-mm-55-keV images during PVP. For fine anatomical details, 0.4-mm-45-keV and 0.4-mm-50-keV images received higher ratings relative to other series.

In PCCT, combining 0.4-mm slice thickness with low-keV VMI reconstruction (particularly at 45 keV) provides better image quality for preoperative evaluation of PDAC.