Noninvasive assessment of coronary stenoses by myocardial perfusion imaging during pharmacologic coronary vasodilation. VIII. Clinical feasibility of positron cardiac imaging without a cyclotron using generator-produced Rubidium-82

Abstract

The purpose of this study was to determine the clinical feasibility of diagnosing significant coronary artery disease by positron imaging of myocardial perfusion without a cyclotron, using generator-produced rubidium-82 (82Rb). Fifty patients underwent positron emission tomography of the entire heart using a multislice positron camera and intravenous 82Rb or nitrogen-13 ammonia (13NH3) before and after intravenous dipyridamole combined with handgrip stress. Images were read by two observers blinded as to clinical or arteriographic data. Automated quantitative coronary arteriography was obtained for the arteriographic determination of coronary flow reserve, previously demonstrated to be a single integrated measure of stenosis severity accounting for all its geometric dimensions of length, absolute diameter, percent narrowing and asymmetry by quantitative analysis of cine films. Significant coronary artery disease was defined as an arteriographically determined coronary flow reserve of less than 3.0 based on all stenosis dimensions. Any single geometric measure of stenosis severity alone was an inadequate reference standard for comparison with perfusion images. Sensitivity of identifying patients with coronary artery disease having an arteriographically determined coronary flow reserve of less than 3.0 was 95% by positron imaging with a specificity of 100%. The single case that was missed, studied with 13NH3, had a 43% diameter narrowing of a small ramus intermedius off the left coronary artery with no significant narrowing of the major coronary arteries. Positron emission tomography of myocardial perfusion before and after intravenous dipyridamole combined with handgrip stress utilizing generator-produced 82Rb provides sensitive and specific diagnosis of reduced coronary flow reserve due to coronary artery disease in humans.

Impact of Myocardial Perfusion Imaging with PET and 82Rb on Downstream Invasive Procedure Utilization, Costs, and Outcomes in Coronary Disease Management

“…In a meta-analysis of 44 studies published between January 1990 and October 1997, the sensitivity of exercise SPECT was found to be 87% (95% confidence interval ½CI, 86%-88%) with specificity of 64% (95% CI, 60%-68%) (19). In contrast, both sensitivity and specificity of CAD detection with PET is at least 95% in populations with an intermediate pCAD (20)(21)(22)(23)(24). This is due largely to high-energy-photon coincidence detection, attenuation correction, a doubling of image resolution to 10-mm full width at half maximum for cardiac PET, which is depth independent, and markedly improved image contrast associated with 20-30 times as many acquired counts in PET compared with SPECT images.…”

High Prevalence of Myocardial Perfusion Abnormalities on Positron Emission Tomography in Asymptomatic Persons With a Parent or Sibling With Coronary Artery Disease

“…8 -11 Cardiac PET has a diagnostic accuracy of ՆϷ95%, even in asymptomatic subjects. 5,[12][13][14][15][16][17] In patients with abnormal coronary arteriograms, coronary flow reserve on PET is reduced in myocardial regions without arteriographic stenoses 18,19 due to diffuse disease that is not apparent on the arteriogram, [3][4][5][6][7] which, however, may cause perfusion abnormalities on dipyridamole PET. 20 Accordingly, we tested the hypothesis that significant myocardial perfusion defects on dipyridamole PET are common in asymptomatic persons with a parent or sibling with CAD either with or without other risk factors or lipid disorders.…”

Changes in Myocardial Perfusion Reserve after PTCA: Noninvasive Assessment with Positron Tomography

“…Differences in uptake could be due to differences in extraction between ["N]ammonia and 82Rb. Despite this potential limitation, the approach can detect a >50% diameter narrowing (10,21). As with all radionuclide imaging studies, partial volume errors can also affect measured activity (72).…”