Quantitative cardiac CT perfusion: physiologically-inspired model and identifying microvascular disease from discordant CTA CAD-RADS

Figures

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  Figure 1. Pipeline of combinatory CCTP&CCTA analysis. In (A, B), a highly automatic prototype software analyzed the CCTP data and produced a polar map then mapped to AHA segments. Vessel-wised CAD-RADS were measured in CCTA (C). Patients were then separated into different subgroups and analyzed based on different conditions (D, E).

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  Figure 2. CCTA and CCTP analysis of a 47-year-old male patient with typical angina chest pain. CCTA (a–c) showed no luminal stenosis for all arteries. CCTP showed a normal stress MBF for all territories (d–i). The AHA sectors in (i) had a stress MBF of 320 ± 30 mL/min−100 g. The map between AHA segments and the corresponding coronary artery is shown in (j).

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  Figure 3. A 60-year-old male patient with typical angina chest pain. CCTA (a–c) showed >70% luminal narrowing of the LAD (1-vessel disease). CCTP showed a perfusion defect with an abnormal stress MBF of 178 mL/min−100 g in the territory supplied by the LAD (d–i). The map between AHA segments and the corresponding coronary artery is shown in (j).

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  Figure 4. Polar maps of myocardial blood flow (MBF) for 104 patients, divided into five groups based on diabetes status and the number of arteries with obstructive stenosis. (a) No diabetes, no obstructive stenosis (CAD-RADS < 3). (b) Diabetes, no obstructive stenosis (DM-CAD-RADS < 3). (c) No diabetes, obstructive stenosis in one vessel (1-vessel-CAD-RADS ≥ 3). (d) No diabetes, obstructive stenosis in multiple vessels (multi-vessel-CAD-RADS ≥ 3). (e) Diabetes, obstructive stenosis (DM-CAD-RADS ≥ 3). The green dashed line indicates the abnormal MBF threshold (200 mL/min−100 g). Polar maps are consistent with patient groupings. (See text for details.).

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  Figure 5. Polar map distribution of diabetic patients. Diabetic patients without and with obstructive disease are in green and purple, respectively. Ischemia is indicated when MBF distribution falls below the red dashed line. Patients 9, 11, and 14 showed normal MBF, while patients 1, 5, and 17 had local ischemia. The remaining 12 patients exhibited diffuse ischemia. Polar maps allow easy visual interpretation.

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  Figure 6. MBF distribution of individual territories without obstructive stenosis and with obstructive stenosis before and after excluding territories from diabetic patients. The red dashed line is the optimal MBF cutoff (200 mL/min−100 g). The blue asterisk is the median value of each distribution. The blue solid line is the mean value of each distribution.

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  Figure 7. Association of stress MBF and CAD-RADS, analyzed per territories. (a) There is a moderate Spearman's rank correlation between absolute MBF and CAD-RADS score (ρ = −0.53, p < 0.05). (b) There is a weaker Spearman's rank correlation between relative MBF and CAD-RADS (ρ = −0.43, p < 0.05). The relative MBF was calculated by normalizing each AHA segment with the territory with the highest average MBF. Between groups, t-tests are performed with an asterisk indicating P < 0.05.