Fifty-one patients were studied to determine the relative accuracy of sonography and computed tomography (CT) in the evaluation of hilar cholangiocarcinoma. Both sonography and CT permitted detection of intrahepatic bile duct dilatation in all patients. Nonunion of right and left intrahepatic bile ducts was identified with sonography in 90% and with CT in 94% of patients. The tumor per se was depicted by sonography in 21% and by CT in 40% of patients. Forty tumors (78%) were of the infiltrating type, seven (14%) were exophytic, and four (8%) were polypoid. With sonography, infiltrating and exophytic tumors were difficult to depict, whereas polypoid tumors were well identified. With CT, infiltrating tumors were more difficult to depict than were exophytic or polypoid tumors. On CT scans, depicted tumors of the infiltrating type showed high attenuation and an indistinct margin, whereas exophytic and polypoid tumors showed low attenuation and a well-defined margin. Sonography and CT were comparably accurate in determining the level of obstruction in hilar cholangiocarcinoma even when no mass was depicted. CT was superior to sonography in depicting tumor per se and in demonstrating associated findings.
ObjectiveTo evaluate the feasibility of coronary artery calcium scoring based on three virtual noncontrast-enhanced (VNC) images derived from single-source spectral dual-energy CT (DECT) as compared with true noncontrast-enhanced (TNC) images.Materials and MethodsThis prospective study was conducted with the approval of our Institutional Review Board. Ninety-seven patients underwent noncontrast CT followed by contrast-enhanced chest CT using single-source spectral DECT. Iodine eliminated VNC images were reconstructed using two kinds of 2-material decomposition algorithms (material density iodine-water pair [MDW], material density iodine-calcium pair [MDC]) and a material suppressed algorithm (material suppressed iodine [MSI]). Two readers independently quantified calcium on VNC and TNC images. The Spearman correlation coefficient test and Bland-Altman method were used for statistical analyses.ResultsCoronary artery calcium scores from all three VNC images showed excellent correlation with those from the TNC images (Spearman's correlation coefficient [ρ] = 0.94, 0.88, and 0.89 for MDW, MDC, and MSI, respectively; p < 0.001 for all pairs). Measured coronary calcium volumes from VNC images also correlated well with those from TNC images (ρ = 0.92, 0.87, and 0.91 for MDW, MDC, and MSI, respectively; p < 0.001 for all pairs). Among the three VNC images, coronary calcium from MDW correlated best with that from TNC. The coronary artery calcium scores and volumes were significantly lower from the VNC images than from the TNC images (p < 0.001 for all pairs).ConclusionThe use of VNC images from contrast-enhanced CT using dual-energy material decomposition/suppression is feasible for coronary calcium scoring. The absolute value from VNC tends to be smaller than that from TNC.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.