Positron emission tomography-computed tomography fusion scanning
Positron emission tomography-computed tomography fusion scanning (PET-CT) is a medical imaging technique that combines two complementary techniques, using cameras mounted on the same imaging gantry so the images are in the same anatomical plane. PET reveals information on the real-time metabolism of the tissues being imaged, but is not extremely precise in delineating structure. X-ray computed tomography gives no physiologic information, but is extremely detailed in its view of structure. Precise thickness measurements provided by CT also help correct attenuation in the CT scan.
While the CT and PET images usually are examined as a fusion, there are circumstances in which either the CT image alone, or even a CT scan in a different anatomical plane, may need to be examined to rule out artifacts generated by the fusion. 
Applications are widespread in cancer detection and scanning. It also reveals chronic infection in trauma. 
- Lale Kostakoglu, Ruth Hardoff, Rosna Mirtcheva, Stanley J. Goldsmith (September 2004), "PET-CT Fusion Imaging in Differentiating Physiologic from Pathologic FDG Uptake", RadioGraphics 24: 1411-1431, DOI:10.1148/rg.245035725
- Hossein Jadvar (14 March 2007), Expanding Applications for PET and PET/CT Scanning, Medscape