Positron Emission Tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques (e.g., X rays, ultrasound, magnetic resonance imaging), but pictures of physiological activity.

The first useable positron emission tomography (PET) instrument for human studies was developed in the early 1970s by a team of researches at Washington University's Mallinckrodt Institute of Radiology. The Clinical Positron Emission Tomography (PET) Center, located on the 7th floor of the Mallinckrodt Institute of Radiology at Barnes-Jewish Hospital's south campus, is one of the Midwest's leading PET imaging centers, offering comprehensive diagnostic testing for patient care, education in nuclear medicine, and leading-edge research.

The Clinical PET Center was opened in 1988, and was one of a few facilities in the world that pioneered the transition from research to medical practice. Acknowledged as a world leader in PET, the Center is part of the Mallincrodt Institute of Radiology's Division of Nuclear Medicine. It has served as the training ground for the foremost experts in the field.

Understanding Positron Emission Tomography (PET)

PET produces an image of function rather than form. This is different from an X-ray, MRI or CT scan, which produces an image of bone, tissue or organ structure. The PET image can show actual metabolic activity within different regions of organs and tissues, differentiate between normal and diseased tissue, detect viable versus dying tissue, and determine drug response in the patient.

The information gained from PET technology extends the physician's understanding of basic biological processes and improves the diagnosis of disease. PET is useful in diagnosing, staging, and re-staging many types of cancer (such as lung, colon, breast), as well as assessing tumor response to therapy.

It also is useful for evaluation of certain neurological disorders such as epilepsy and cardiac disease, including advanced coronary artery disease.

Treatment Approach

Most PET scans are done on an outpatient basis, lasting 1 ½ to 2 ½ hours, depending on the specific type of PET examination. Patients receive a radiopharmaceutical containing a substance that can be traced by radiation detectors in the PET machine.

The most commonly used radiopharmaceutical consists of the sugar glucose labeled with fluorine-18 (fluorodeoxyglucose or FDG). The radioisotopes used for PET scans are short-lived, so the amount of radiation exposure to the patient is small.

PET Physicians

The PET Center is staffed by Mallinckrodt Institute of Radiology nuclear medicine physicians, who collectively have more than 145 years of experience in nuclear medicine and PET. The PET specialists are full-time clinical physicians on staff at Barnes-Jewish Hospital and St. Louis Children's Hospital.

Barry Siegel, MD, Director
Professor, Radiology
Professor, Medicine
Director, Division of Nuclear Medicine
Mallinckrodt Institute of Radiology

Dr. Siegel received his medical degree from Washington University School of Medicine, St. Louis, completed residency training in diagnostic radiology and served a fellowship in nuclear medicine, both at the Mallinckrodt Institute of Radiology, Washington University, St. Louis. He is board certified in diagnostic radiology, nuclear medicine and nuclear radiology. His areas of clinical interest include: nuclear medicine, nuclear imaging, positron emission tomography (PET), radioiodine treatment, and radionuclide imaging.

Henry Royal, MD, Associate Director
Professor, Radiology
Associate Director, Nuclear Medicine, Mallinckrodt Institute of Radiology

Dr. Royal received his medical degree at St. Louis University, and completed residencies at Brown University, Providence, Rhode Island and Harvard Medical School. He is board certified in internal medicine and nuclear medicine. His areas of specialty and clinical interest include tumor imaging, pulmonary embolism, radiation injuries, nuclear medicine, positron emission tomography (PET).

Farrokh Dehdashti, MD
Keith Fischer, MD
Robert Gropler, MD
Tom Miller, MD, PhD
Jerold Wallis, MD

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