A PET-CT scanner merges both PET and CT capabilities into one machine to identify abnormal tissue and its location. However, standard scanners of the past often overlooked small lesions because of motion caused by the respiratory cycle, the beating heart, or patient movement.
New technology allows a PET-CT scanner to detect lesions down to 2.0 mm and to better delineate boundaries, thus finding cancerous tissue earlier and saving viable tissue from radiation exposure. These scanners also have respiratory gating capabilities, adding detail and clarity to areas that are subject to motion, such as the heart and lungs.
During this procedure, the patient will first receive a radiopharmaceutical injection, which takes about 60 to 90 minutes to distribute itself throughout the body.
The patient then lies on a table that moves slowly through a ring-like scanner as it acquires the information it needs to generate PET and CT images. The patient should not feel anything during the scan, which can last from 15 to 60 minutes.
The motion-free platform of the scanner allows physicians to accurately identify multiple small lesions in areas affected by movement. The physician can review these detailed images after the scan is completed. In addition, the scanner has software that memorizes and overlays lesions so differences can be detected from appointment to appointment.