Positron Emission Tomography or PET uses radiation, ingested by the patient, to create 3-dimensional, color images of the functional or metabolic processes in the body.
The idea of emission tomography was introduced as early as the late 1950s. And the scintiscanner was the first instrument used to create images outlining radioactivity tracers in the body. During the 1970s, further development of radiopharmaceuticals, in particular, 2-fluorodeoxy-D-glucose (2FDG), was instrumental in expanding PET imaging. To fully appreciate 2FDG imaging, positron instrumentation was designed to utilize two-dimensional arrays. PC-I was the first instrument in 1968 to begin the process of capturing image data related to the use of ingested radiopharmaceuticals. In the early 1980s, as Computed Tomography (CT) arrived on the scene, providing cross-sectional views of the body, it inspired a core of scientists involved in PET development that a similar array of detectors could be used in PET imaging.
In the mid-1990s, Ronald Nutt, an electrical engineer, physicist David Townsend and oncology surgeon Dr. Rudy Egeli, were working together at the University of Geneva to create a machine. This machine would correlate a match between the data captured from PET imaging and CT scans for physicians to better determine the precise location of a tumor within an organ. A sudden epiphany occurred, which was to create a fusion between both PET and CT modalities. And the team of scientists built the first prototype of the modern PET/CT Scanner was born; patients were receiving imaging at the University of Pittsburgh Medical Center in 1998.
In comparison to CT, PET/CT scans have made it possible to detect small tumors not previously detected with CT alone. For example, when women, who were successfully treated for ovarian cancer in the past, received blood tests that began to show markers suggesting tumors were recurring somewhere in their bodies, they were subjected to both CT and PET/CT scans. CT scans were reflecting as negative, but PET/CT scanning revealed the location of small new tumors in the pelvis that surgeons could remove before they metastasized. PET operates on an entirely different principle to general anatomical imaging; it uses the body’s metabolic processes to differentiate between normal and abnormal functioning by using radionuclides adhering to biologically active molecules, such as glucose, which become concentrated in the organs of the body and begins to decay. When the nuclides decay, they emit positrons which the PET scanner turns into images. Cross-sectional imaging modalities such as CT and MR assist in determining where, in the organ or the tissue, the tumor resides. PET, is therefore used heavily in clinical oncology and is especially useful for diagnosis of specific brain diseases associated with dementia. It is an excellent research tool, especially for cancer, since it is better able to reveal the presence of cancers; exposing any tumors as they metabolize the radionuclide riding on a biologic molecule at a different rate than surrounding healthy tissues.
It is an exciting time for radiology imaging. PET/MR hybrid scanners and the development of new radiotracers will further the benefit of utilizing positron emission in the detection of the disease process in the body as well as monitoring the therapeutic progress of drugs used to treat patients. Being able to not only view the internal structures of the body but visualize how the body is absorbing treatment is essential to identifying treatment plans, for earlier intervention and halt of the progression of disease processes leading to longer and healthier lives.
Innovation in healthcare software further enables physicians to tap into the technology of radiology imaging promoting greater efficiency in image interpretation, results communication and ultimately patient care. RamSoft PowerServer™ PACS is equipped with an advanced multi-modality viewer which supports PET imaging. RamSoft PowerServer™ PACS features
- Tools for easy SUV display
- Fusion Opacity and Registration options
- Single click MIP/MPR display
- Versatile Viewing Protocols featuring PET Fusion
- Color mapping including ability to create custom mappings and modify existing ones
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