UCSF

Colorectal cancer (CRC) is a very common malignancy that affects 1 in 20 Americans. Screening has been shown to reduce both incidence and mortality. When screening for CRC, identifying the polyp masses along the colon is key for the appropriate follow-up and treatment. To screen for CRC, Computer Tomographic Colonography (CTC) can be performed with a conventional 120kVp CT scan. However, a potentially sensitive approach to CTC, using dual energy CT (DECT) is emerging. The focus of this study was to create a colon phantom and use it to compare the performance of DECT to conventional CT in CTC. In creating the colon phantom, the attenuation spectral properties for DECT were matched to the real human abdomen, which included fat, iodine tagged stool and soft tissue (similar to polyps). The abdomen geometry was also simulated. The final colon phantom was scanned in conventional CT mode and in DECT at 40 keV, and the sensitivity, specificity and reading confidence were compared. Overall, DECT showed to have a higher sensitivity and increased reading confidence compared to conventional CT.