Health Information

Nuclear Imaging and PET/CT

Cardiac nuclear imaging uses small amounts of radioactive material to diagnose or treat a variety of heart diseases. Generally the radiotracer is injected into a vein. It accumulates in the organ or area being evaluated, such as the heart and blood vessels, where it gives off energy in the form of gamma rays. The energy is detected by the positron emission tomography (PET) scanner, which creates images that detail the structure and function of the heart.

UC San Diego Health System specialists combine nuclear medicine images with CT or MRI images, allowing the images to be correlated and interpreted. This improves the assessment of anatomy, function and blood flow.

Nuclear imaging can be performed alone, with the heart muscle at rest, or in conjunction with exercise. The latter is known as a stress test, since it measures the heart’s function while its is beating harder and faster due to exercise or a medication that mimics the effects of exercise on the heart.

Applications of Nuclear Imaging

PET/CT

A PET/CT scanner combines two imaging techniques: positron emission tomography (PET) and computed tomography (CT). Positron Emission Tomography (PET) scans show the chemical functioning of the heart and arteries,  while the CT scan shows the structure. This combination makes it possible to merge anatomic information furnished by the CT scan with molecular imaging information provided by the PET imaging.

The technology allows abnormal function to be detected and then mapped, leading to more accurate diagnosis and better outcomes.

Applications of PET/CT