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Pharmacology / Nuclear Medicine

PET/CT improves patient management with precise diagnosis and evaluation of treatment


CU-Pet CT ImagingPET/CT (positron emission tomography/computed tomography) combines molecular imaging of disease biology with high-quality anatomical imaging in a single procedure. This provides accurate and comprehensive diagnosis to help physicians select the most appropriate treatments and assess the patient’s response to treatment. Physicians can use PET/CT to examine all tissues throughout the body for disease. The technology is based on PET imaging, which was invented by Dr. Michael E. Phelps, Norton Simon Professor and chair of the UCLA Department of Molecular and Medical Pharmacology. PET imaging has emerged as the state of the art in diagnostic imaging for cancer, neurological and cardiovascular disorders.

How it works

PET relies on imaging probes that selectively target the biology of diseases. In the case of cancer, PET images show increases in biological activity because tumors consume up to 30 times more sugar than normal tissues. Introducing a radiolabeled sugar in the patient’s body makes tumors clearly visible on PET images. In diseases like Alzheimer’s and Parkinson’s, the affected areas show decreases in biological activity due to declining functions of the brain.

PET images of disease biology sometimes lack exact location information. PET/CT overcomes this limitation by projecting the PET images onto the anatomical framework of the body provided by CT. This enables nuclear medicine specialists and radiologists to provide comprehensive and precise diagnoses, including the stage and spread of disease, to help referring physicians select the best treatment for individual patients. Follow- up PET/CT images can be used to assess the effectiveness of the treatment, helping physicians decide to either continue the current treatment or switch to an alternative therapy. This ability supports a personalized approach to diagnosis and treatment that is in keeping with UCLA’s mission to deliver leading-edge patient care.

CU-PET Limphoma ImagesIn PET/CT studies, a minute amount of a radiolabeled sugar — or another imaging probe that targets a different biological process — is injected into a vein of the arm. The amount is so small that the body is not even aware of the imaging probe. The PET/CT images take about 30 minutes for a whole body study and about 10 minutes for a specific organ study, such as the brain. Because the PET/CT is an open system, few patients complain of claustro-phobia. The radiation dose involved in these studies is well below the limits that are known to cause any harm. In about 20 million PET studies, there have been no reported complications.

Current clinical applications

PET/CT is currently used to diagnose cancer, stage the severity and extent of involvement in different organs and assess treatment responses. It is also used to provide early diagnosis of neurological diseases, including Alzheimer’s, Parkinson’s and seizure disorders, and to provide reassessment throughout the course of these disorders. PET/CT is also used to determine which patients with coronary artery disease would benefit from coronary artery bypass, angioplasty or heart transplant.


In addition to its clinical service, the Ahmanson Translational Imaging Division of the Department of Molecular and Medical Pharmacology conducts imaging research trials in many cancers using radiolabeled sugars as well as imaging probes that target other specific biological characteristics of cancer. UCLA researchers are also conducting trials in Alzheimer’s and other types of dementias.

Providing biological and anatomical information

PET/CT uniquely provides biological and anatomical information about disease in a single imaging session. For example, PET can be used to determine how actively tumor tissues grow by how much sugar they consume. This assessment of the rate of tumor glucose consumption provides unique information on the presence of a primary tumor and extent of its spread to other tissues (metastases), and the response to treatment.

According to Johannes Czernin, M.D., UCLA Professor of Molecular and Medical Pharmacology, “PET imaging provides accurate diagnostic information about the biology of diseases in tissues throughout the body. However, structural, anatomical information cannot be obtained with PET.” PET/CT scanners combine the unique biological examination of nuclear medicine with diagnostic-anatomical CT information to permit precise, comprehensive and informed diagnoses.

Participating Physicians

Johannes Czernin, M.D.
Professor, Molecular and Medical
Pharmacology/Nuclear Medicine
Chief, Ahmanson Translational Imaging Division

Martin Allen-Auerbach, M.D.
Associate Professor, Molecular and
Medical Pharmacology/Nuclear Medicine

Heinrich Schelbert, M.D., Ph.D.
Professor, Molecular and Medical
Pharmacology/Nuclear Medicine

Christiaan Schiepers, M.D., Ph.D.
Professor, Molecular and Medical
Pharmacology/Nuclear Medicine

Daniel Silverman, M.D., Ph.D.
Professor, Molecular and Medical
Pharmacology/Nuclear Medicine

Pawan Gupta, M.D. 
Visit Assistant Professor Molecular
and Medical Pharmacology/Nuclear Medicine

Edward Zaragoza, M.D.
Professor, Radiology
Chief of Acute Care Imaging
Clinical Director of Radiology IT

Jonathan Goldin, M.D., Ph.D.
Professor, Radiology & Biomedical Physics Program
Executive Chief of Clinical Care
Chief of Radiology Department, UCLA Medical Center, Santa Monica
Co-Director of Thoracic Research Imaging Laboratory

Cheryce Poon, M.D.
Assistant Professor, Radiology

Antonio Gutierrez, M.D.
Assistant Professor, Radiology

Laura Doepke, M.D.
Assistant Professor. RadiologyContact Information

(310) 794-1005 Referral and appointments
(310) 825-4829 Consultation and faculty contact
(310) 206-4899 Fax

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