Abstract

The combination of PET (positron emission tomography) with CT (computed tomography) has considerably enhanced the clinical application of PET. PET-CT combines the high resolution of CT with the high sensitivity of PET. As PET and CT results are obtained with one machine during one investigation, an optimal fusion of both procedures is possible. The accuracy of PET can be increased by about 15% by PET-CT, compared to conventional fusion of PET and CT images. The potential of PET-CT can only be fully used if contrast agents -either orally or intravenously- are applied. The Xrays of CT may also be used for attenuation correction. This article focuses mainly on PET-CT in lung cancer, malignant melanoma, head and neck tumors, thyroid tumors, and colorectal cancer, with illustrations of some cases documenting the potentials of PET-CT.