Incremental Value of Adenosine-induced Stress Myocardial Perfusion Imaging with Dual-Source CT at Cardiac CT Angiography

Abstract

Purpose:First, to assess the feasibility of a protocol involving stressinduced perfusion evaluated at computed tomography (CT) combined with cardiac CT angiography in a single examination and second, to assess the incremental value of perfusion imaging over cardiac CT angio graphy in a dual-source technique for the detection of obstructive coronary artery disease (CAD) in a high-risk population. Materials and Methods:Institutional review board approval and informed patient consent were obtained before patient enrollment in the study. The study was HIPAA compliant. Thirty-fi ve patients at high risk for CAD were prospectively enrolled for evaluation of the feasibility of CT perfusion imaging. All patients underwent retrospectively electrocardiographically gated (helical) adenosine stress CT perfusion imaging followed by prospectively electrocardiographically gated (axial) rest myocardial CT perfusion imaging. Analysis was performed in three steps: (a) Coronary arterial stenoses were scored for severity and reader confi dence at cardiac CT angiography, (b) myocardial perfusion defects were identifi ed and scored for severity and reversibility at CT perfusion imaging, and (c) coronary stenosis severity was reclassifi ed according to perfusion fi ndings at combined cardiac CT angiography and CT perfusion imaging. The sensitivity, specifi city, negative predictive value (NPV), and positive predictive value (PPV) of cardiac CT angiography before and after CT perfusion analysis were calculated. Results:With use of a reference standard of greater than 50% stenosis at invasive angiography, all parameters of diagnostic accuracy increased after CT perfusion analysis: Sensitivity increased from 83% to 91%; specifi city, from 71% to 91%; PPV, from 66% to 86%; and NPV, from 87% to 93%. The area under the receiver operating characteristic curve increased signifi cantly, from 0.77 to 0.90 ( P , .005). Conclusion:A combination protocol involving adenosine perfusion CT imaging and cardiac CT angiography in a dual-source technique is feasible, and CT perfusion adds incremental value to cardiac CT angiography in the detection of signifi cant CAD.q RSNA, 2010

Stress Dual-Energy Computed Tomography-Myocardial Perfusion Imaging to Identify Coronary Artery Stenoses Causing Ischemia: A Direct Comparison between Invasive Coronary Angiography and Cardiac Magnetic Resonance-Myocardial Perfusion Imaging

“…Accordingly, combined ICA/ CMR-MPI is sufficient as a reference standard for collecting anatomical and physiological information regarding coronary stenosis. CTP has been widely investigated using various CT scanners, acquisition protocols, study populations, and reference standards and is considered a promising method for imaging myocardial ischemia, comparable to SPECT and CMR-MPI [7][8][9][10][11][12][13][14]. Bettencourt et al [14] demonstrated that CTP is globally inferior to CMR-MPI; however, integrating CTP and CCTA showed similar diagnostic performance to CMR-MPI using FFR as the reference standard for detecting hemodynamically significant CAD.…”

“…Furthermore, less than half of high-grade stenoses identified using CCTA physiologically cause myocardial ischemia, and concerns have arisen that the use of CCTA-identified coronary artery disease (CAD) may precipitate high rates of unnecessary ICA [5,6]. To address these limitations, pharmacological CT myocardial perfusion imaging (MPI) has emerged as an additional CT method for diagnosing myocardial ischemia and showed satisfactory diagnostic performance compared with single photon emission computed tomography (SPECT)-MPI, fractional flow reserve (FFR), a combination of ICA and SPECT-MPI, and a combination of ICA and cardiac magnetic resonance (CMR)-MPI [7][8][9][10][11][12][13][14]. However, these investigations have been largely limited to the use of single-energy CT, which relies on relative Hounsfield unit density measurements to detect myocardial perfusion deficits.…”

Coronary CT Angiography in Coronary Artery Disease: from Diagnosis to Prevention

“…Although recent studies suggest that cardiac CT myocardial perfusion is feasible and provides functional significance of CAD, the diagnostic accuracy suffers from high false positive findings. [21][22][23] This has been overcome with the use of hemodynamic analysis of blood flow to coronary artery based on numerical simulation using computational fluid dynamic techniques.…”

Commentary on: delayed enhancement imaging of myocardial viability: low-dose high-pitch CT versus MRI

“…Rocha et al [14] observed incremental value of CTperfusion over CT-angiography to define hemodynamic relevance of a coronary stenosis.…”

“…Adenosine stress-perfusion imaging [11][12][13][14][15] is feasible and several studies show promising results. The clear advantage of CT in this setting is the complementary evaluation of coronary artery anatomy and myocardial function, which overcomes current shortcomings of CTA.…”