Science behind Positron Emission Tomography

Principle

Positron Emission Tomography is a medical imaging procedure in nuclear medicine. A tomographic image is obtained after injecting a radioactive substance (typically containing Fluor-18) into the patient and tracing the substance inside the patient with a detector. The detector registers the signal of the particles that are emitted from radioactive decay (gamma rays).

Applications of PET

PET scanners are mainly used in medical applications. PET is used when e.g. staging the advancement of cancer in patients (clinical use) but also in medical research as it permits to reveal the functionality of the studied organs (preclinical use).

Properties of PET

The resolution of a PET scan is inferior to other medical imaging technologies e.g. MRI or CT. To the contrary of these procedures, PET does not show an anatomical but a functional view of the studied object, this means inactive structures do not appear on a PET scan.

Bimodal imaging devices

PET and MRI are two complementary imaging technologies, both well established and nowadays used in routine clinical and pre-clinical practice. In the past years combined PET/MRI systems received a lot of interest. The potential of this bi-modal approach is underlined by the fact that the major suppliers of clinical scanners (Siemens, Philips and General Electric) all offer a clinical PET/MRI system. Such combined methodology provides high-resolution morphological information, together with high-sensitivity molecular and metabolic/functional information. The annotation of the structural with the functional information is already very attractive: compared with PET/CT (CT: Computed Tomography), the two major advantages of PET/MRI are the higher soft tissue contrast of MRI and the removal of the CT induced radiation dose.

However, the full potential of combined PET and MRI lies in the fact that MRI can also provide significant functional data, which can be complemented or compared with those from PET. There is considerable added value from the simultaneous PET/MRI acquisition, far beyond the MRI being simply the anatomical counterpart of PET. Because of these reasons, and the large biomedical research potential, also the interest in pre-clinical hybrid PET/MRI systems - particularly those integrated into the same device for simultaneous co-registration - has significantly grown in recent years.

List of scientific materials

Posters, Talks, etc.