PET shows superior sensitivity, specificity for CAD detection

Source: GE Healthcare

CHICAGO, Nov. 30 – A meta-analysis of myocardial perfusion PET presented this week at the 93rd scientific assembly and annual meeting of the Radiological Society of North America (RSNA) demonstrated that the modality has excellent sensitivity and specificity for detecting coronary artery disease (CAD) compared with other non-invasive myocardial perfusion imaging technologies.

“Although myocardial perfusion PET using either cyclotron-produced nitrogen-13 ammonia or generator-produced rubidium 82, has reported excellent diagnostic capabilities in the detection of coronary artery disease in individual studies, the technique is not widely used in practice,” said Kiran Nandular, MD.

Nandular presented the results of research on published PET myocardial perfusion studies he conducted with colleagues at the William Beaumont Hospital in Royal Oak, Mich., and the University of Michigan Health System in Ann Arbor, Mich.

He speculated that PET may not be considered as a first-line modality for myocardial perfusion imaging because of the cost of the systems, their availability, or a lack of clinician knowledge about PET’s performance for this exam.

The researchers examined journal-based studies from January 1977 to March 2007 using the MEDLINE (ProQuest, Ann Arbor, Mich.) and EMBASE (Elsevier, New York City) biomedical and pharmacological databases. Nandular said a published study was included if it met the following two criteria:

• It used PET as a diagnostic test for CAD; and
• It used catheter x-ray angiography as the reference standard.

A study was excluded if it was a scientific meeting abstract, Nandular said. Analysis of the selected journal studies was performed on both a subject and coronary-territory level, he said.

Over the 10-year meta-analysis period, 17 studies (comprising 1,325 patients) met the researcher’s inclusion criteria. Nine of the studies used rubidium-82, seven studies were conducted with nitrogen-13 ammonia, and one study utilized one or the other agent, Nandular reported.

On a patient level, PET demonstrated a sensitivity of 92 and specificity of 90 for the detection of CAD. SPECT myocardial perfusion imaging showed a sensitivity of 86 and a specificity of 74, while stress echocardiography had a CAD detection sensitivity of 84 and a specificity of 82, Nandular said. On a coronary territory level, PET showed a sensitivity of 83 and specificity of 88.

“PET demonstrates excellent diagnostic properties in the diagnosis of coronary artery disease, especially at the patient level,” he said. “The capabilities appear superior to those reported in meta-analyses for perfusion imaging with thallium-201 and sestamibi, or anatomical imaging with coronary CT angiography or MR angiography.”

Nandular observed that previous studies have found PET to be cost-effective for myocardial perfusion imaging. He believes that with his team’s current findings of superior sensitivity and specificity for PET imaging, the modality should be more widely considered as an initial test in the diagnosis of CAD.

“PET is an underutilized modality in the diagnosis of coronary artery disease and should be more widely considered given its excellent sensitivity and specificity,” Nandular said.