Computed tomography myocardial perfusion and myocardial blood flow by oxygen 15 positron emission tomography

Abstract

Introduction: Non-invasive computed tomography imaging has the potential to achieve comprehensive cardiac assessment in a rapid and low radiation dose assessment. We assessed computed tomography coronary angiography (CTCA) and computed tomography myocardial perfusion (CTP) compared to invasive coronary angiography (ICA) and fractional flow reserve (FFR). In addition we assessed myocardial blood flow using oxygen-15 labelled water positron emission tomography (PET). Methods: Contrast enhanced, electrocardiogram gated CTCA and adenosine stress CTP was performed in 31 patients (69% male) using a 320 multidetector scanner. Significant coronary disease was assessed on a per vessel basis as a stenosis greater than 50% with corresponding hypoperfusion on CTP. All patients underwent ICA and significant coronary artery disease was assessed as a stenosis greater than 70% and/or an FFR less than 0.8. Five patients underwent rest and adenosine stress oxygen-15 PET. The total coronary resistance (TCR) at rest and stress was calculated as the mean arterial pressured divided by myocardial blood flow. Results: The mean age was 63 years (95% CI 61, 66), body mass index 28 kg/m2 (27, 30) and radiation dose 564 mGy.cm (437, 692). The sensitivity, specificity, negative predictive value and positive predictive value of CTCA/CTP for detecting significant coronary artery disease as compared to ICA/FFR were 85%, 84%, 30% and 92% respectively. TCR at rest and stress were 80 (72, 87) and 31 (28, 33) for normal regions compared to 97 (43, 151) and 33 (32, 34) for regions with hypoperfusion on CTP. ![Figure][1] Figure 1. CTCA/CTP compared to ICA/FFR Conclusion: The diagnostic accuracy of CTCA/CTP imaging compares well with ICA/FFR. CTP may detect additional areas of hypoperfusion and oxygen-15 PET imaging will assist the assessment of these technologies. [1]: pending:yes