Question

PET imaging and MRI

1. Are very similar in principle
2. The principle of PET imaging is completely different from the other modalities

Answer 1

A.MRI scans use a strong magnetic field to produce detailed images of internal structures of the body. They can also provide information about how well these structures are functioning.

PET scans use tracers to highlight abnormalities that indicate disease.

Until now, scientists could not integrate PET and MRI for simultaneous scanning because MRI’s powerful magnets interfered with the imaging detectors on the PET scanner.

PET and MRI scans have been conducted separately, and the separate images later merged. That merger, however, requires a complex computer process. At Stanford, our newly-available PET/MRI scanner can perform both types of scans at the same time to gather more information than merged PET and MRI scans.

B.The principle of positron emission tomography (PET) is that radiation emitted from a radiopharmaceutical injected intravenously into a patient is registered by external detectors positioned at different orientations.

PET differs from other nuclear medicine examinations in that PET detects metabolism within body tissues, whereas other types of nuclear medicine examinations detect the amount of a radioactive substance collected in body tissue in a certain location to examine the tissue's function.

Unlike MRIs, PET scans use positrons. A tracer is injected into your body that allows the radiologist to see the area scanned. An MRI scan can be used when your organ shape or blood vessels are in question, whereas PET scans will be used to see your body's function.