positron emission tomography

positron emission tomography
Name	Positron emission tomography
Specialty	Nuclear medicine
Invented by	Allan Cormack, Godfrey Hounsfield, Wilhelm Röntgen
Invention date	1970s
Location	United Kingdom, United States

Contents

positron emission tomography Positron emission tomography is a nuclear medicine imaging technique that produces three-dimensional functional images of physiological processes. It combines radiotracer pharmacology, detection hardware, and computational reconstruction to localize radiolabeled molecules in vivo, supporting diagnosis, staging, and research in Mount Sinai Hospital, Mayo Clinic, Massachusetts General Hospital, Johns Hopkins Hospital, and other centers. PET has been instrumental in studies at institutions such as Harvard Medical School, Stanford University School of Medicine, University of California, Los Angeles, University College London, and Karolinska Institutet.

History

The development of PET emerged from earlier work in radiology and particle physics by figures and institutions including Wilhelm Röntgen and laboratories at CERN, as well as medical engineering advances at General Electric and Siemens Healthineers. In the 1950s–1970s, pioneering scanners were built by teams at Washington University in St. Louis, Brookhaven National Laboratory, University of Pennsylvania, and University of California, Berkeley, leading to first human studies at Massachusetts General Hospital and University of Pennsylvania. Commercialization and clinical adoption accelerated through collaborations with companies such as Philips, Toshiba Medical Systems, and Hitachi, and were influenced by regulatory milestones at agencies like the Food and Drug Administration and health systems at National Health Service (England).

PET imaging relies on the physical process of positron emission from radionuclides produced in cyclotrons at facilities like Brookhaven National Laboratory, TRIUMF, and Paul Scherrer Institute. Positrons annihilate with electrons producing pairs of 511 keV gamma photons detected in coincidence by detector rings composed of scintillators developed by teams at Bell Labs, Saint-Gobain, and University of Pennsylvania. The line-of-response concept and tomographic reconstruction algorithms were advanced by mathematicians and engineers associated with University of Pennsylvania, University of Chicago, Massachusetts Institute of Technology, and influenced by computational methods from Los Alamos National Laboratory. Time-of-flight PET improvements trace to work at University of California, Berkeley and corporate research at GE Healthcare.

Radiotracer development has roots in radiochemistry and biochemistry research at institutions such as Brookhaven National Laboratory, Oak Ridge National Laboratory, Institut Laue–Langevin, and universities including University of Copenhagen and University of Oxford. Common PET radionuclides include fluorine-18 produced in cyclotrons at centers like University of Wisconsin–Madison and carbon-11 from facilities at McMaster University. Radiotracer examples include 2-[18F]fluoro-2-deoxy-D-glucose (FDG) synthesized in labs at University of Pennsylvania and neurotransmitter tracers developed at National Institute of Mental Health. Novel tracers for oncology, neurology, and cardiology emerged from collaborations among Memorial Sloan Kettering Cancer Center, Dana-Farber Cancer Institute, Imperial College London, and pharmaceutical companies such as Roche and Novartis.

PET scanner hardware and hybrid modalities evolved through engineering programs at Siemens Healthineers, GE Healthcare, Philips Healthcare, and research centers including Lawrence Berkeley National Laboratory. Detector technologies use scintillators like lutetium oxyorthosilicate developed via materials science research at Oak Ridge National Laboratory and silicon photomultipliers advanced by teams at Fondazione Bruno Kessler and Hamamatsu Photonics. Hybrid PET/CT and PET/MRI systems integrate components pioneered at Stanford University Medical Center, University of Pittsburgh Medical Center, and Brigham and Women's Hospital. Image acquisition protocols and motion correction methods were refined through clinical trials run at Cleveland Clinic, Vanderbilt University Medical Center, and multicenter networks coordinated by National Cancer Institute.

PET is used clinically in oncology at centers like Memorial Sloan Kettering Cancer Center, Mayo Clinic, and Royal Marsden Hospital for staging, restaging, and therapeutic response assessment; in cardiology at Cleveland Clinic and Cedars-Sinai Medical Center for myocardial viability; and in neurology at Massachusetts General Hospital and Charité – Universitätsmedizin Berlin for dementia and epilepsy localization. PET tracers support research into disorders studied at National Institute of Neurological Disorders and Stroke, Scripps Research Institute, and Max Planck Institute for Human Cognitive and Brain Sciences including Alzheimer’s disease, Parkinson’s disease, and psychiatric conditions. Multidisciplinary trials often involve cooperative groups such as European Organisation for Research and Treatment of Cancer and Children’s Oncology Group.

Quantitative PET relies on methods and software developed at academic centers and companies including Johns Hopkins University, University of Michigan, KIT (Karlsruhe Institute of Technology), Siemens Healthineers, and open-source projects from Lawrence Livermore National Laboratory. Kinetic modeling, standardized uptake value calculations, and arterial input function techniques stem from research at University of California, San Francisco, McGill University, and University of Toronto. Machine learning and radiomics integration involve collaborations with Google DeepMind, Microsoft Research, and computational neuroscience groups at MIT and ETH Zurich.

Radiation safety practice, dosimetry, and regulation are governed by standards and authorities including the International Atomic Energy Agency, Food and Drug Administration, European Medicines Agency, and professional bodies such as Society of Nuclear Medicine and Molecular Imaging and European Association of Nuclear Medicine. Cyclotron licensing, tracer GMP production, and clinical trial approvals are coordinated with national regulators and hospital radiation safety offices at institutions like Johns Hopkins Hospital and Mayo Clinic. Ethical and safety oversight in trials frequently involves institutional review boards at Harvard Medical School, Karolinska Institutet, and University of Oxford.