Cesium Attenuation Correction of the Liver Dome Revealing Hepatic Lesion Missed With Computed Tomography Attenuation Correction Because of the Respiratory Motion Artifact

Abstract

Computed tomography (CT) attenuation-corrected FDG images are known to have particular artifacts, especially the respiratory artifact. The respiratory artifact may decrease the diagnostic value of the study around the diaphragm. Malpositioning of lesions, mismatches in location or size of organs, and constitution of an artifactual curvilinear cold area in the liver dome (the so-called “banana artifact”) or spleen have been reported. We report the case of a small liver metastasis in the hepatic dome, which was absolutely not seen on CT attenuation-corrected FDG images, but was clearly demonstrated on cesium transmission attenuation-corrected images. This case emphasizes the risk of the false-negative diagnosis of a liver metastasis in relation to a respiratory artifact and illustrates the usefulness of completing, if technically possible, the positron emission tomography (PET)/CT examination with a short conventional transmission acquisition centered on the diaphragm.