Armin Michael Huber MD, Presenter: Nothing to Disclose

Johannes Rieber MD, Abstract Co-Author: Nothing to Disclose

Marcus Hacker MD, Abstract Co-Author: Nothing to Disclose

Michael Schweyer, Abstract Co-Author: Nothing to Disclose

Maximilian Ferdinand Reiser MD, Abstract Co-Author: Nothing to Disclose

Stefan Oswald Schoenberg MD, Abstract Co-Author: Nothing to Disclose

Beneath morphological assessment by quantitative coronary angiography (CA) the pressure derived fractional flow reserve (FFR) is a well established method to invasively evaluate the functional severity of coronary lesions. The aim of our study was to compare MR Perfusion Imaging and SPECT for detection of flow limiting coronary stenoses compared to CA including FFR measurements..

43 Patients with suspected CAD received a CMRI and SPECT within two weeks of the scheduled CA. Signal intensity curves of the first pass of a Gadolineum–DTPA bolus at rest and during hyperemia (Adenosine 140µg/kg/min i.v.) were obtained. For each myocardial perfusion area using an 18 segment model, the myocardial perfusion reserve index (MPRI) was calculated as the ratio of US stress and US rest. Stenosis > 50% narrowing of the luminal diameter were evaluated by FFR measurements (Pressure Wire, Radi, SE) to assess their hemodynamic relevance. If FFR was <0.75 the lesion was defined as hemodynamically significant. Lesions < 50 % were considered as hemodynamically not significant.

129 perfusion areas (43 LAD; 43 LCx and 43RCA) were evaluated. 105 (81%) areas were normal by FFR and 24 (19%) areas showed hemodynamically significant stenoses. The mean for the MPRI was 1.7 (range 1.0-3.5). The mean MPRI was significantly different between the regions supplied by a normal coronary vessel (2.10.5) and significant stenosis (1.20.31) (p<.001). Using a cut-off value, determined by ROC analysis, a sensitivity of 88% (CI: 0.69-0.96) and a specificity of 90% (CI: 0.82-0.94) was determined for MRI. SPECT revealed a sensitivity of 71% (CI: 0.50-0.86) and a specificity of 91%(CI: 0.84-0.95).

The results demonstrate the ability of CMRI and SPECT to identify perfusion territories with hemodynamically significant coronary stenoses. The overall accuracy of CMRI is at least comparable to SPECT, the sensitivity is superior.

Compared to an invasive examination with assessment of morphology and functional relevance of coronary artery stenosis MR perfusion is at least equal to scintigraphy without radiation exposure.

Huber, A, Rieber, J, Hacker, M, Schweyer, M, Reiser, M, Schoenberg, S, Comparison of MR Perfusion Imaging and SPECT for the Detection of Hemodynamically Significant Coronary Stenoses Using Angiography and Fractional Flow Reserve as Reference Standard.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4432610.html