Pitfalls in the interpretation of multidetector-row helical CT images at window width and level setting for lung...

This article describes pitfalls in the interpretation of multidetector-row helical CT (MDCT) images at the window width and level settings for lung parenchyma. On MDCT, linear artifacts, which look like black and white linear densities and are called "hurricane artifacts," radiate out from objects that have very different densities from their neighbors. For the evaluation of fine parenchymal details, a low table speed/slice collimation should be used. In fact, axial (step and shoot) scanning may be more effective for the evaluation of fine details. Since artifacts from vessels highly enhanced by contrast medium cause data blackout in the surrounding areas at high table speed/slice collimation, pulmonary parenchyma in such situations should be evaluated with unenhanced CT. Although multidetector-row helical CT is a promising tool for the evaluation of lung parenchyma, it is important to identify its shortcomings due to artifacts when interpreting images at the window width and level settings for lung parenchyma and to apply the appropriate methods for eliminating such artifacts.