Analysis of coronary computed tomography angiography-derived pericoronary fat attenuation index characteristics in the diagnostic assessment of patients with Takayasu arteritis

Figures

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  Figure 1. The flowchart of patient recruitment and study design. TAK, Takayasu arteritis; CTA, computed tomography angiography; CAI, coronary artery involvement.

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  Figure 2. A 28-year-old female TAK patient underwent coronary CTA examination due to chest tightness and pain. MPR of the coronary artery showed diffuse thickening of the left main artery and left anterior descending branch, narrowing of the lumen, and concentric signs of blood vessels, namely, TAK-CAI. The white arrow indicates a concentric circle sign of the left main artery vascular wall thickening in the transverse section image. TAK, Takayasu arteritis; CTA, computed tomography angiography; MPR, multiplanar reformation; CAI, coronary artery involvement.

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  Figure 3. A 28-year-old female TAK patient underwent coronary artery CTA examination due to chest tightness and pain. The coronary CTA image and MPR of the coronary artery showed no thickening of the left main artery and left anterior descending branch walls, no stenosis of the lumen, and unobstructed artery lumen, indicating a healthy coronary artery. TAK, Takayasu arteritis; CTA, computed tomography angiography; MPR, multiplanar reformation.

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  Figure 4. Perivascular FAI analysis around epicardial coronary vessels of the LAD coronary artery in an age- and gender-matched normal coronary control individual. (A) Axial view and range of HU to detect pericoronary fat [PCAT colour map ranging from bright yellow (−190 HU) to dark red (−30 HU)]. (B) Curved multiplane review of PCAT measurement. (C) Cross-sectional and longitudinal view of PCAT measurement. The software automatically tracked the ROI within the set fat threshold (from −190 to −30 HU), ROI: the length of FAI measurement was 0–40 mm to the proximal LAD, and the radial distance was equal to the diameter of the vessel. FAI of LAD was measured as −109 HU. Perivascular fat was defined as fat within a radial distance equal to the diameter (d) of the vessel. FAI, fat attenuation index; LAD, left anterior descending artery; HU, Hounsfield unit; PCAT, pericoronary adipose tissue; ROI, region of interest.

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  Figure 5. Perivascular FAI analysis around epicardial coronary vessels of the RCA in a TAK-CAI patient. (A) Axial view and range of HU to detect pericoronary fat [PCAT colour map ranging from bright yellow (−190 HU) to dark red (−30 HU)]. (B) Curved multiplane review of PCAT measurement. (C) Cross-sectional and longitudinal view of PCAT measurement. The software automatically tracked the ROI within the set fat threshold (from −190 to −30 HU), ROI: the length of FAI measurement was 10–50 mm to the proximal RCA, and the radial distance was equal to the diameter of the vessel. FAI of RCA was measured as −59 HU. FAI, fat attenuation index; RCA, right coronary artery; TAK, Takayasu arteritis; CAI, coronary artery involvement; HU, Hounsfield unit; PCAT, pericoronary adipose tissue; ROI, region of interest.

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  Figure 6. Comparison of perivascular FAI parameters between TAK-nonCAI and coronary healthy controls. FAI/HU levels in the TAK-nonCAI group were significantly higher than those in the healthy control group. P<0.001 for all comparisons. TAK, Takayasu arteritis; CAI, coronary artery involvement; FAI, fat attenuation index; HU, Hounsfield unit.

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  Figure 7. Comparison of perivascular FAI parameters between active and inactive inflammation. Five parameters were used for evaluating the attenuation of PCAT values, including FAI/HU, 10th percentile, 90th percentile, MEAN and MEDIAN, which were significantly higher in the active inflammation group than those in the inflammation control group (P<0.001 for all comparisons). FAI, fat attenuation index; HU, Hounsfield unit; PCAT, pericoronary adipose tissue.