Table 4. Consensus statements of the ASCI-PT on the evaluation of stenosis grading and plaque characteristics of CCTA.

Issues	Degree of agreement	Consensus
1. Distal margin of LM	100% (17/17)	LM is defined as: ‘Ostium of LM to bifurcation of LAD and LCX’
		Lesions in the bifurcation towards LAD or LCX should be classified under LM
2. Proximal vs. mid LAD	64.7% (11/17)	Proximal LAD is defined as: ‘End of LM to the first large septal of D1 (D1 > 1.5-mm in size) whichever is most proximal, even though proximal LAD is extremely short’
				Arrow should be mid-LAD (if, D1 > 1.5-mm)
3. RI vs. OM1	76.4% (13/17)	RI is defined as: ‘Vessel originating from the LM between the LAD and LCX in case of a trifurcation’
				Arrow should be OM1
4. Categorization of coronary plaque	82.3% (14/17)	Noncalcified	Predominantly noncalcified	Predominantly calcified	Calcified
5. HRP morphology	100% (17/17)	2-FPP: Positive remodeling and low attenuation plaque
		Positive remodeling		Low attenuation plaque
		Outer vessel diameter (b) which is ≥ 10% greater than the mean of the diameter of the normal proximal and distal segments ([a + c]/2)		Presence of a central focal area within the plaque which has a low CT attenuation, which is usually defined as at least 1 voxel with < 30 HU
				Addendum: 30 HU could be used when tube voltage is 100 kVp – 120 kVp
6. Coronary stenosis evaluation	100% (17/17)	The maximal (percent diameter) stenosis is recommended in line with the SCCT 2014 interpretation guideline		Grade	Stenosis degree
				Normal	No stenosis
				Minimal	< 25%
		Minimal lumen area or percent area stenosis may be additive but is not required		Mild	25%–49%
				Moderate	50%–69%
				Severe	70%–99%
				Occluded	Occluded
7. Determining reference vessel for calculation of percent stenosis	100% (17/17)	Recommendations
		1. The most normal-appearing site immediately proximal to the plaque should be chosen
		2. If the proximal segment is not appropriate (e.g., ostial lesion) the closest distal reference should be chosen
		Options
		3. Similar to IVUS studies, the most normal-looking cross-section within 10 mm of the lesion without an intervening side branch should be chosen
		4. Averaging proximal and distal reference diameter or area could be applied similarly to previous IVUS or quantitative CCTA studies (if there is a significant intervening branch at the area with plaque)
		5. For comparison to quantitative angiography, an interpolated reference diameter (area) should be chosen using dedicated analysis software
8. Determining diameter on a cross sectional image of CCTA	66.7% (10/15)	Reference diameter		Lesion diameter
		Reference Average of a and b		Minimal lumen Average of a and b

ASCI-PT = Asian Society of Cardiovascular Imaging-Practical Tutorial, CCTA = coronary CT angiography, LM = left main artery, LAD = left anterior descending artery, LCX = left circumflex artery, RCC = right coronary cusp, LCC = left coronary cusp, pLAD = proximal LAD, pLCX = proximal LCX, D1 = the first diagonal artery, RI = ramus intermedius, OM1 = first obtuse marginal artery, HRP = high-risk plaque, 2-FPP = 2-feature-positive plaques, HU = Hounsfield unit, SCCT = Society of Cardiovascular Computed Tomography, IVUS = intravascular ultrasonography