Abstract
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Objectives: Multislice spiral computed tomography (MSCT) offers a valuable alternative for the diagnosis of coronary artery disease (CAD) avoiding the risks inherent with invasive diagnostic procedures. However, its value in the detection of functionally relevant coronary stenoses remains uncertain. We prospectively compared the accuracy of 64-slice CT angiography with myocardial perfusion imaging (MPI) using 99mTc-tetrofosmin-SPECT as gold standard for the detection of functionally relevant coronary lesions.
Methods: Electrocardiographically gated MPI and 64-slice CT were performed in 62 consecutive patients with suspected or known CAD. Fixed and reversible perfusion defects were allocated to their corresponding coronary artery territory. In MSCT images coronary arteries were visually assessed and relevant coronary stenoses with a luminal area narrowing ≧ 50 % and ≧ 75 % were characterized by two independent observers who were unaware of the MPI results.
Results: A total of 247 coronary arteries and 858 coronary segments (including 8 bypass grafts) in 62 patients were analyzed. Seventy-five segments (9 %) were excluded from the analysis because reliable luminal evaluation was not possible due to motion artifacts, calcifications or stent artifacts in small vessels. In the remainig 783 segments MSCT revealed stenoses ≧ 50 % in 40 of 226 coronary arteries (18 %) and ≧ 75 % in 18 (8 %) coronary arteries. Sensitivity, specificity, and negative and positive predictive value for MSCT to detect any perfusion defect on MPI were 75 %, 86 %, 98 %, and 23 % respectively for stenoses ≧ 50 % and 67 %, 95 %, 98 %, and 44 % respectively for stenoses ≧ 75 % .
Conclusions: 64-slice CT angiography yielded a low positive predictive value for the detection of any perfusion defect in a non-selected study population. However, sensitivity and particularly the negative predicitive value were high indicating that MSCT is a reliable tool for screening a low- to intermediate-risk population.
- Society of Nuclear Medicine, Inc.