The Quality Assessment of Virtual Unenhanced and Blending Images Derived from Dual-Energy CT for Detecting Colorectal...

This study aimed to evaluate the image quality of virtual unenhanced and blending images from dual-energy CT for detecting colorectal cancer (CRC).

A total of 72 patients with pathologically diagnosed CRC underwent abdominal dual-energy CT, following which virtual unenhanced, linear blending, and non-linear blending images were generated by post-processing reconstruction. Both subjective and objective evaluations were conducted on these images, with signal-to-noise (SNR) and contrast-to-noise ratio (CNR) calculations conducted for organs, such as the liver, pancreas, and spleen.

Virtual unenhanced images of CRC, extraserosal fat of the tumor, liver, pancreas, spleen, kidney, and subcutaneous fat showed a lower signal intensity than both linear and non-linear blending images (P < 0.05), while the CNR of virtual unenhanced images was higher than linear and nonlinear blending images (P < 0.05). Except for CRC lesions, the SNR of other organs in virtual unenhanced images was higher than in linear and non-linear blending images (P < 0.05). There were no significant differences in subjective image scores and the number of conventional lesions between virtual unenhanced image, linear, and non-linear blending (P ≥ 0.05). The Kappa coefficients for evaluating extraserosal invasion were 0.722, 0.584, and 0.584 for virtual unenhanced, linear blending, and non-linear blending images, respectively, with corresponding accuracies of 86.1%, 79.2%, and 79.2%.

Virtual unenhanced images of patients with CRC can provide high-quality images for diagnostic evaluation, potentially replacing linear blending and non-linear blending images in plain scans.