Adenosine Stress High-Pitch 128-Slice Dual-Source Myocardial Computed Tomography Perfusion for Imaging of Reversible Myocardial Ischemia

Abstract

Background-Coronary computed tomography angiography (CTA) enables accurate anatomic evaluation of coronary artery stenosis but lacks information about hemodynamic significance. The aim of this study was to evaluate 128-slice myocardial CT perfusion (CTP) imaging with adenosine stress using a high-pitch mode, in comparison with cardiac MRI (CMR). Methods and Results-Thirty-nine patients with intermediate to high coronary risk profile underwent adenosine stress 128-slice dual source CTP (128ϫ0.6 mm, 0.28 seconds). Among those, 30 patients (64Ϯ10 years, 6% women) also underwent adenosine stress CMR (1.5T). The 2-step CTP protocol consisted of (1) adenosine stress-CTP using a high-pitch factor (3.4) ECG-synchronized spiral mode and (2) rest-CTP/coronary-CTA using either high-pitch (heart rate Ͻ63 bpm) or prospective ECG-triggering (heart rate Ͼ63 bpm). Results were compared with CMR and with invasive angiography in 25 patients. The performance of stress-CTP for detection of myocardial perfusion defects compared with CMR was sensitivity, 96%; specificity, 88%; positive predictive value (PPV), 93%; negative predictive value (NPV), 94% (per vessel); and sensitivity, 78%; specificity, 87%; PPV, 83%; NPV, 84% (per segment). The accuracy of stress-CTP for imaging of reversible ischemia compared with CMR was sensitivity, 95%; specificity, 96%; PPV, 95%; and NPV, 96% (per vessel). In 25 patients who underwent invasive angiography, the accuracy of CTA for detection of stenosis Ͼ70% was (per segment): sensitivity, 96%; specificity, 88%; PPV, 67%; and NPV, 98.9%. The accuracy improved from 84% to 95% after adding stress CTP to CTA. Radiation exposure of the entire stress/rest CT protocol was only 2.5 mSv. Conclusions-Adenosine-induced stress 128-slice dual-source high-pitch myocardial CTP allows for simultaneously assessment of reversible myocardial ischemia and coronary stenosis, with good diagnostic accuracy as compared with CMR and invasive angiography, at a very low radiation exposure. (Circ Cardiovasc Imaging. 2011;4:540-549.)

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

“…Even though stress DECT-MPI is potentially superior to routine CTP for detecting perfusion defects, the diagnostic performance and increased value of stress DECT-MPI for detecting perfusion defects are limited and mainly involve only small pilot studies. Compared to the study by Feuchtner et al [11], the diagnostic performance of stress CVIA DECT-MPI is similar in the per-segment analysis but lower in the per-vessel analysis compared with routine CTP against CMR-MPI, particularly the lower specificity and PPV. Our results differ from Bettencourt et al [14], who reported that routine CTP showed 67% sensitivity and 95% specificity at the patient level and 55% sensitivity and 95% specificity at the vessel level compared with CMR-MPI for detecting perfusion defects.…”

“…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.…”

“…Myocardial perfusion on routine or single-shot CTP is assessed using semi-quantitative metrics such as the transmural perfusion ratio and visual perfusion assessment [7][8][9][10][11][12][13][14]. Mapping the iodine distribution within the left ventricular myocardium is possible with DECT.…”

“…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.…”

Myocardial CT perfusion imaging for ischemia detection

“…Many single and multicenter studies have validated the results of myocardial CTP against other modalities such as SPECT, CMR, PET, invasive coronary angiography (ICA) and invasive fractional flow reserve (FFR) (34)(35)(36)(37)(38)(39)(40)(41)(42). Most of these were performed in a limited number of patients and using different scanner generations, showing high sensitivity and negative predictive value, and moderate specificity and positive predictive value.…”