Detection of ischaemic myocardial lesions with coronary CT angiography and adenosine-stress dynamic perfusion imaging using a 128-slice dual-source CT: diagnostic performance in comparison with cardiac MRI

Abstract

Detection of ischaemic myocardial lesions with coronary CT angiography and adenosine-stress dynamic perfusion imaging using a 128-slice dual-source CT: diagnostic performance in comparison with cardiac MRI. Br J Radiol 2013;86: 20130481. FULL PAPER Detection of ischaemic myocardial lesions with coronary CT angiography and adenosine-stress dynamic perfusion imaging using a 128-slice dual-source CT: diagnostic performance in comparison with cardiac MRI Objective: We assessed the diagnostic performance of adenosine-stress dynamic CT perfusion (ASDCTP) imaging and coronary CT angiography (CCTA) for the detection of ischaemic myocardial lesions using 128-slice dual-source CT compared with that of 1.5 T cardiac MRI.Methods: This prospective study included 33 patients (6168 years, 82% male) with suspected coronary artery diseases who underwent ASDCTP imaging and adenosine-stress cardiac MRI. Two investigators independently evaluated ASDCTP images in correlation with significant coronary stenosis on CCTA using two different thresholds of 50% and 70% diameter stenosis. Hypoattenuated myocardial lesions on ASDCTP associated with significant coronary stenoses on CCTA were regarded as true perfusion defects. All estimates of diagnostic performance were calculated and compared with those of cardiac MRI.Results: With use of a threshold of 50% diameter stenosis on CCTA, the diagnostic estimates per-myocardial segment were as follows: sensitivity, 81% [95% confidence interval (CI): 70-92%]; specificity, 94% (95% CI: 92-96%); and accuracy 93% (95% CI: 91-95%). With use of a threshold of 70%, the diagnostic estimates were as follows: sensitivity, 48% (95% CI: 34-62%); specificity, 99% (95% CI: 98-100%); and accuracy, 94% (95% CI: 92-96%). Conclusion: Dynamic CTP using 128-slice dual-source CT enables the assessment of the physiological significance of coronary artery lesions with high diagnostic accuracy in patients with clinically suspected coronary artery disease. Advances in knowledge: Combined CCTA and ASDCTP yielded high accuracy in the detection of perfusion defects regardless of the threshold of significant coronary stenosis.It is important to evaluate not only anatomical information about coronary arteries but also physiological information about myocardial perfusion for the precise assessment of coronary artery disease (CAD) [1]. Myocardial perfusion imaging (MPI) can provide haemodynamic information during exercise-induced or pharmacological stress. Singlephoton emission tomography (SPECT), cardiac MRI or positron emission tomography (PET) has been extensively used for MPI [2,3]. Moreover, a normal MPI determined using these techniques carries an excellent prognosis with a low rate of cardiac events [4][5][6].SPECT and PET are limited in their ability to evaluate coronary artery morphology and cardiac structures. By contrast, CT MPI with coronary CTangiography (CCTA) can evaluate not only anatomical structure, including coronary artery morphology, but also myocardial perfusion status. Although radiation dose associa...

On the use of computed tomography in cardiac imaging

“…At a later stage, the vendor made available a prototype software with this functionality, which greatly simplified the process. Thus, our focus was different to that of most other studies comparing dynamic CTP with SPECT or cMR, as the most common approach is that of visual detection of perfusion defects (58)(59)(60). However, a study by Wang et al (103) did a similar type of comparison albeit with a different patient group.…”

“…With dynamic CTP, myocardial perfusion is visualised through repeated imaging during the first pass contrast inflow in the myocardium. The change in myocardial attenuation during this period is detected and forms the basis for a quantitative estimation of myocardial blood flow (57)(58)(59)(60)(61). There are a number of critical pre-requisites for this approach: the scanning of the left ventricle must be fast to be able to detect the short-lived phase of increase in attenuation that comes with the wash-in of contrast, and the x-ray detector has to be large enough to allow coverage of the entire heart.…”

“…Although none of the patients were described as having three-vessel disease, the possibility of a general decrease in SPECT signal intensity due to extensive CAD must be taken into consideration. However, Wang et al (103) describe a mean CTP blood flow of 142.9 ± 30.6 mL/100 mL tissue/min in normal segments (on SPECT) in a population with suspected CAD, while Ho et al (58) describe 121±31 mL/100 mL tissue/min and Kim et al (59) 113.2±26 in normal segments, thus placing our corresponding results of 131±38 and 141±40 mL/100 mL tissue/min for manual and automated segmentation well into the normal range as defined by these three studies. Also, in a relatively recent study by Bamberg et al (60), the cut-off point for differentiation between normal and ischemic myocardium was determined to be 0.88 mL/100 mL tissue/min.…”

“…Most other comparative studies (58)(59)(60)103) have used a qualitative approach, with focus on the visual detection of perfusion defects as compared to the reference method. The results of these studies have also been more encouraging, with sensitivity and specificity for perfusion defects in relation to SPECT of 0.83-0.85 and 0.78-0.92 respectively (58,103).…”

CAD-RADS – a new clinical decision support tool for coronary computed tomography angiography

“…Advancements in image quality have facilitated development of various new scanning and post-processing techniques (i.e. perfusion imaging, computed tomography-derived fractional flow reserve (CT-FFR)), which have substantially improved the initially moderate specificity of the CTA [9, 10]. Meanwhile, a high level of expertise is mandatory for the image interpretation to allow appropriate clinical management decision-making and to avoid unnecessary additional downstream testing.…”