Dynamic CT Myocardial Perfusion Imaging in Patients without Obstructive Coronary Artery Disease: Quantification of Myocardial Blood Flow according to Varied Heart Rate Increments after Stress

Figures

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  Fig. 1. Flow chart of inclusion and exclusion criteria. CCTA = coronary CT angiography, CT = computed tomography, MPI = myocardial perfusion imaging

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  Fig. 2. Representative case of high-quantified MBF derived from a subject with maximal increase in HR after stress (HR increased by 24 beats/min). CPR image shows normal coronary arteries without atherosclerosis or stenosis. Short-axis views of CT-MPI from the apical to basal segments reveal high MBF values from 224 mL/100 mL/min to 262 mL/100 mL/min. CPR = curved planar reformation, HR = heart rate, LAD = left anterior descending, LCX = left circumflex, MBF = myocardial blood flow, RCA = right coronary artery

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  Fig. 3. Representative case of low-quantified MBF derived from a subject with minimal increase in HR after stress (HR increased by 9 beats/min). CPR image shows coronary arteries with atherosclerosis and minimal stenosis (< 25%) at the proximal LAD and middle RCA. Short-axis views of CT-MPI from the apical to basal segments reveal low MBF values from 121 mL/100 mL/min to 132 mL/100 mL/min.

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  Fig. 4. Global MBF values of subgroups with different HR increments after stress. The lowest MBF was found in the subgroup with minimal increase in HR, whereas the highest MBF was observed in the subgroup with maximal increase in HR.

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  Fig. 5. MBF values of all myocardial segments based on the 17-segment model. Segment #3 (basal inferoseptal) had significantly lower MBF compared to any other segments (all p < 0.01). This difference was not significant between all other segments.