[Biphasic liver diagnosis with multiplanar-detector spiral CT].

PURPOSE: Scan protocol optimization and value of a multi-row-detector helical CT (MS-CT) in comparison to a single-row-detector spiral CT (SS-CT) for imaging of focal liver lesions.
MATERIALS AND METHODS: The ability of a MS-CT with different scan parameters (slice thickness, scan mode, table-speed, reconstruction interval) for the detection of low-contrast objects was evaluated with a liver phantom and compared to a SS-CT. The clinical value (detection and characterization) of MS-CT with various slice thicknesses (3.75, 5, 7.5 mm) was compared intraindividually in 20 patients with a total of 43 benign and malignant lesions.
RESULTS: In the experimental study the MS-CT reached the same detection rates for low-contrast objects despite a three-times faster scan-time compared to a SS-CT. The slice thicknesses of 3.75 and 5 mm proved to be optimal and were superior to a thickness of 7.5 mm for the detection and characterization of liver lesions. A distinct separation between arterial and portal venous phase was achieved by this protocol.
CONCLUSION: The MS-CT allows a reliable acquisition of the entire liver parenchyma in defined perfusion phases. It improves the detection and characterization of focal liver lesions with optimized scan parameters with a significantly faster scan time than with the SS-CT.