What's the difference between ct scanning and pet scanning?

Radiation: Pt scan uses radioactive glucose that is injected. The glucose is taken up by organs for energy, and we measure how active the tissue is. Dead tissue, like a stroke takes up no glucose. Cancer takes up too much. Ct only takes a picture.

CT/PET: CT uses X-rays to produce images. The radiation passes through the body into detectors. With PET, a radioactive labelled substance, usually glucose, is injected into the body. Glucose is metabolically active, so PET forms functional images based on areas of high metabolic activity. CT images anatomic structure. Sometimes the 2 are combined, called PET/CT fusion imaging.

Here.: A computerised tomography (CT) scan uses X-rays and a computer to create detailed images of the inside of the body. Positron emission tomography (PET) scans are used to produce detailed three-dimensional images of the inside of the body. Before you have a PET scan, a radioactive substance (a radiotracer) will be passed into your body. This is usually by injection into a vein.

Anatomy / metabolism: CAT scan utilizes xrays for determination of anatomical structures in multiple planes coronal, sagittal, and transaxial. PET scan uses radioactivity with tracer FDG 18 a glucose metabolite to show metabolic areas . Usually malignant lesions are most active. Small metastatic lesions can be detected. Sometimes compared with anatomy with PT CT.