Multiplanar volume rendering and maximum intensity projection of mul-tislice computed tomography data allow for robust evaluation of the hepatic parenchyma, with early detection of neovascularity and tumor stain, and enable better assessment of the tumor burden compared with routine axial images. Lesion characterization can also potentially improve. This is in addition to accurate delineation of the hepatic vascular anatomy, which allows for segmental localization and assists in surgical and nonsurgical planning.
Hypervascular liver lesions may be primary or meta-static tumors. These lesions are characteristically hyper-vascular and hyperattenuating on arterial phase imaging. These include focal nodular hyperplasia, hepatic adenoma, hepatocellular carcinoma, metastatic melanoma, and neuroendocrine tumors. Detection of these lesions requires dual-phase imaging to improve lesion conspicuity.
The introduction of multislice computed tomography (CT) resulted in increased speed of volumetric acquisitions, allowing optimization of the dual-phase images. The advantages of multislice CT include faster scanning, improved spatial resolution in the z-axis, less respiratory misregistration, improved temporal resolution, better contrast bolus utilization, and volumetric data acquisition of the entire liver in a single breath-hold.3"5 These factors have significantly improved the diagnostic accuracy of CT, particularly in hepatic imaging.
Multislice CT generates a large volume of data, and the full potential for data utilization has recently been explored. To take full advantage of the data generated, it became necessary to find alternative techniques for the visualization and analysis of the volumetric data acquired.67 New commercially available workstations with efficient real-time editing offer high-quality image processing and facilitate the analysis and interpretation of the large volumetric data sets.
The purpose of this study was to determine the incremental value of image processing techniques, including multiplanar volume rendering and maximum intensity projection, over axial images of multislice CT data for the evaluation of hepatic hypervascular lesions.