Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, regional chemical composition, and absorption. Different tracers are used for various imaging purposes, depending on the target process within the body. For example, 18
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-FDG is commonly used to detect cancer, NaF18
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is widely used for detecting bone formation, and oxygen-15 is sometimes used to measure blood flow.
Radiology is the medical discipline that uses medical imaging to diagnose diseases and guide their treatment, within the bodies of humans and other animals. It began with radiography, but today it includes all imaging modalities, including those that use no electromagnetic radiation, as well as others that do, such as computed tomography (CT), fluoroscopy, and nuclear medicine including positron emission tomography (PET). Interventional radiology is the performance of usually minimally invasive medical procedures with the guidance of imaging technologies such as those mentioned above.
Nuclear medicine or nucleology is a medical specialty involving the application of radioactive substances in the diagnosis and treatment of disease. Nuclear imaging, in a sense, is "radiology done inside out" because it records radiation emitting from within the body rather than radiation that is generated by external sources like X-rays. In addition, nuclear medicine scans differ from radiology, as the emphasis is not on imaging anatomy, but on the function. For such reason, it is called a physiological imaging modality. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) scans are the two most common imaging modalities in nuclear medicine.
Scintigraphy, also known as a gamma scan, is a diagnostic test in nuclear medicine, where radioisotopes attached to drugs that travel to a specific organ or tissue (radiopharmaceuticals) are taken internally and the emitted gamma radiation is captured by external detectors to form two-dimensional images in a similar process to the capture of x-ray images. In contrast, SPECT and positron emission tomography (PET) form 3-dimensional images and are therefore classified as separate techniques from scintigraphy, although they also use gamma cameras to detect internal radiation. Scintigraphy is unlike a diagnostic X-ray where external radiation is passed through the body to form an image.
Molecular imaging is a field of medical imaging that focuses on imaging molecules of medical interest within living patients. This is in contrast to conventional methods for obtaining molecular information from preserved tissue samples, such as histology. Molecules of interest may be either ones produced naturally by the body, or synthetic molecules produced in a laboratory and injected into a patient by a doctor. The most common example of molecular imaging used clinically today is to inject a contrast agent into a patient's bloodstream and to use an imaging modality to track its movement in the body. Molecular imaging originated from the field of radiology from a need to better understand fundamental molecular processes inside organisms in a noninvasive manner.
The American College of Radiology (ACR), founded in 1923, is a professional medical society representing nearly 40,000 diagnostic radiologists, radiation oncologists, interventional radiologists, nuclear medicine physicians and medical physicists.
Michel Matthew Ter-Pogossian was an American medical physicist. He was professor of radiology at the Washington University School of Medicine for over 30 years. A pioneer in nuclear medicine, he is best known for his research on the positron emission tomography (PET). He is considered one of its creators and often referred to as the "father of PET."
Mallinckrodt Pharmaceuticals is an American-Irish domiciled manufacturer of specialty pharmaceuticals, generic drugs and imaging agents. In 2017 it generated 90% of its sales from the U.S. healthcare system. While Mallinckrodt is headquartered in Ireland for tax purposes, its operational headquarters are in the U.S. Mallinckrodt's 2013 tax inversion to Ireland drew controversy when it was shown Acthar was Medicaid's most expensive drug.
Michael Edward Phelps is a professor and an American biophysicist. He is known for being one of the fathers of positron emission tomography (PET).
Evarts Ambrose Graham (1883–1957) was an American academic, physician, and surgeon.
Abass Alavi is an Iranian-American physician-scientist specializing in the field of molecular imaging, most notably in the imaging modality of positron emission tomography (PET). In August 1976, he was part of the team that performed the first human PET studies of the brain and whole body using the radiotracer [18F]Fluorodeoxyglucose (FDG). Alavi holds the position of Professor of Radiology and Neurology, as well as Director of Research Education in the Department of Radiology at the University of Pennsylvania. Over a career spanning five decades, he has amassed over 2,300 publications and 60,000 citations, earning an h-index of 125 and placing his publication record in the top percentile of scientists.
Nuclear medicine physicians, also called nuclear radiologists or simply nucleologists, are medical specialists that use tracers, usually radiopharmaceuticals, for diagnosis and therapy. Nuclear medicine procedures are the major clinical applications of molecular imaging and molecular therapy. In the United States, nuclear medicine physicians are certified by the American Board of Nuclear Medicine and the American Osteopathic Board of Nuclear Medicine.
David Edmund Kuhl was an American scientist specializing in nuclear medicine. He was well known for his pioneering work in positron emission tomography. Dr. Kuhl served as the Chief of the Division of Nuclear Medicine at the University of Michigan for 20 years and retired in June 2011.
Zang-Hee Cho, Ph.D., is a Korean neuroscientist who developed the first Ring-PET scanner and the scintillation detector BGO. More recently, Cho developed the first PET-MRI fusion molecular imaging device for neuro-molecular imaging.
Richard L. Wahl, a nuclear medicine physician, is the Elizabeth Mallinckrodt Professor and Chairman of Radiology, and Director of the Mallinckrodt Institute of Radiology at Washington University School of Medicine. He is known for his work in PET/CT imaging.
The Alvin J. Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine is a cancer treatment, research and education institution with six locations in the St. Louis area. Siteman is the only cancer center in Missouri and within 240 miles of St. Louis to be designated a Comprehensive Cancer Center by the National Cancer Institute (NCI). Siteman is also the only area member of the National Comprehensive Cancer Network, a nonprofit alliance of 32 cancer centers dedicated to improving the quality and effectiveness of cancer care.
Radiopharmaceuticals, or medicinal radiocompounds, are a group of pharmaceutical drugs containing radioactive isotopes. Radiopharmaceuticals can be used as diagnostic and therapeutic agents. Radiopharmaceuticals emit radiation themselves, which is different from contrast media which absorb or alter external electromagnetism or ultrasound. Radiopharmacology is the branch of pharmacology that specializes in these agents.
Samuel Achilefu is a Nigerian-born scientist and medical researcher who has pioneered both fundamental and applied research in science, engineering, and medicine. Dr. Samuel Achilefu is the Michel M. Ter-Pogossian Professor of Radiology and Vice Chair for Innovation and Entrepreneurship at the Mallinckrodt Institute of Radiology, Washington University School of Medicine. He holds joint appointments as a professor of medicine, biochemistry and molecular biophysics, and biomedical engineering. He currently serves as the Director of the Washington University Molecular Imaging Center and the privately funded Theranostic Innovation Program. He is co-director of the Center for Multiple Myeloma Nanotherapy and co-Leader of the Oncologic Imaging Program of the Alvin J. Siteman Cancer Center at Washington University.
Jason S. Lewis is a British radiochemist whose work relates to oncologic therapy and diagnosis. His research focus is a molecular imaging-based program focused on radiopharmaceutical development as well as the study of multimodality small- and biomolecule-based agents and their clinical translation. He has worked on the development of small molecules as well as radiolabeled peptides and antibodies probing the overexpression of receptors and antigens on tumors.
Christine O. "Cooky" Menias, M.D., is an American radiologist, Mayo Clinic College of Medicine and Science professor, and editor designate of RadioGraphics, one of the leading educational journals in radiology.
