PET / CT with contrast
When is this exam indicated?
PET with CT scan is commonly used in oncology when both PET and CT scan with mdc are required. In particular it is commonly used to define the stage of the disease in patients with known primary lesions, to make differential diagnosis between relapse and outcome of radiotherapy treatment, to evaluate the response to chemo- and/or radiotherapy treatment, to search for disease in patients with increased tumor markers and negative or doubtful clinical-instrumental picture, to search for metastases from primary tumor at unknown locations, to diagnose the nature of expansive formations detected by other methods.
How is it performed?
Preparation and side effects: in order to book and perform the combined PET/CT cmc study, in addition to the specifics of PET preparation, it is necessary to notify at the time of booking the possible presence or suspected presence of allergic diathesis as the CT scan in this case must be performed at the O.U. of Radiodiagnostics and after appropriate desensitizing preparation. In other cases, blood tests for creatinine and plasma protein electrophoresis should be available no earlier than one month before the actual date of the PET/CT cmc study. A fasting of at least 6 hours is required before undergoing the PET and CT cmc examination. The duration of the PET examination depends on the radiopharmaceutical used. In case of the radiopharmaceutical FDG it is about two hours and 15 minutes (60-90 minutes waiting time after the delivery of the radiopharmaceutical and a total of 30 to 40 minutes of PET and CT cmc imaging). During the waiting time is required an adequate hydration with at least 2-3 glasses of water, available in the waiting room, to promote the elimination of PET tracer that is not metabolized by the body. At the end of the CT study with contrast medium it is necessary to drink 1-2 liters of water during the day and abundantly in the next couple of days.
Intravenous injection of contrast medium involves some risks, but those in use today (non-ionic mdc) are better tolerated and almost entirely free of side effects that will be explained to the patient at the time of anamnesis prior to the examination.