Spectral Precise Image-Colon Cancer

This is a single-center, comparative, observational study. Datasets will be collected from patients with pathologically confirmed colon cancer who undergo abdomen-pelvis enhanced spectral CT scan at investigational center, including retrospective and prospective data. Based on the Dose Right Index (DRI) derived from CT image data, relevant data will be collected at a 1:1 ratio for the conventional radiation dose group (RD group, DRI = 21) and the low radiation dose group (LD group, DRI = 18). A total of 100 cases of datasets is expected to be collected. All CT raw data will be transmitted to Philips after the completion of the de-identification process. For the three-phase data of the LD group (plain scan, arterial phase and venous phase), offline reconstruction will be performed using the Spectral Precise Image algorithm to generate conventional images and VMI-40 keV images. A total of six image sequences will be quantitatively and qualitatively evaluated and compared. For both groups, conventional images and VMI-40 keV images will be reconstructed using iDose4.