Does vessel length impact transluminal attenuation gradient in 320-slice coronary CT angiography? Correlation with invasive angiography
This study aimed to investigate the influence of vessel length on transluminal attenuation gradient (TAG) and establish a new index, VLN-TAG (VLN-TAG (HU/100 mm2) = TAG (HU/10 mm)/vessel length (10 mm)), to estimate the diagnostic value using 320-slice computed tomography (CT).
A total of 150 coronary arteries from 52 patients who underwent single-beat scanning using 320-slice CT and invasive coronary angiography (ICA) within 2 weeks were retrospectively enrolled. TAG was obtained from the major three epicardial vessels, and its interrelation with the measured length of the vessels was evaluated by Pearson correlation and regression analyses. The changes in TAG and VLN-TAG were compared with the corresponding stenosis severities ascertained by ICA using repeated measures ANOVA.
TAG had a significant interrelation with the measured length of the vessels (r = 0.644, p < 0.001). Neither TAG nor VLN-TAG with different stenosis degrees of < 50, 50–70, and 70–99% on ICA had significant difference among the three groups. Plaque composition had no influence on VLN-TAG in all groups. The combined TAG or VLN-TAG and coronary computed tomography angiography (CCTA) assessment did not significantly change the area under the curve compared with using CCTA only. In the calcified vessels group, adding VLN-TAG to CCTA improved the specificity (92.86 vs 85.71%).
Vessel length is an important factor impacting TAG. TAG does not offer an incremental diagnostic value compared with CCTA only for detecting coronary stenosis.
• Transluminal attenuation gradient (TAG) does not improve the diagnostic value of CCTA. Vessel length impacts TAG, but VLN-TAG does not improve the diagnostic value of CCTA.
• Plaque composition had no influence on VLN-TAG in all groups of stenosis degrees. There may be a minimal improvement in specificity when VLN-TAG is applied to the calcified vessels group.
KeywordsCoronary stenosis Multidetector computed tomography Angiography
Body mass index
Coronary artery disease
Coronary computed tomography angiography
Fractional flow reserve
Invasive coronary angiography
Left anterior descending coronary artery
Left circumflex coronary artery
Negative predictive value
Positive predictive value
Right coronary artery
Transluminal attenuation gradient
Transluminal diameter gradient
This study has received funding from the Foundation of Shanghai Municipal Commission of Health and Family Planning (201540232) and Shanghai Science and Technology Commission, International Cooperation and Exchange Project (16410722200).
Compliance with ethical standards
The scientific guarantor of this publication is Guangyu Tang.
Conflict of interest
The authors declare that they have no conflict of interest.
Statistics and biometry
No complex statistical methods were necessary for this paper.
Written informed consent was waived by the Institutional Review Board.
Institutional Review Board approval was obtained.
• diagnostic or prognostic study
• performed at one institution
- 2.Hamm CW, Bassand JP, Agewall S et al (2011) ESC guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation: the task force for the management of acute coronary syndromes (ACS) in patients presenting without persistent ST-segment elevation of the European Society of Cardiology (ESC). Eur Heart J 32(23):2999–3054CrossRefGoogle Scholar
- 9.Wong DT, Ko BS, Cameron JD et al (2013) Transluminal attenuation gradient in coronary computed tomography angiography is a novel noninvasive approach to the identification of functionally significant coronary artery stenosis: a comparison with fractional flow reserve. J Am Coll Cardiol 61:1271–1279CrossRefGoogle Scholar
- 11.Nakanishi R, Matsumoto S, Alani A et al (2015) Diagnostic performance of transluminal attenuation gradient and fractional flow reserve by coronary computed tomographic angiography (FFR(CT)) compared to invasive FFR: a sub-group analysis from the DISCOVER-FLOW and DeFACTO studies. Int J Cardiovasc Imaging 31:1251–1259CrossRefGoogle Scholar
- 12.Yoon YE, Choi JH, Kim JH et al (2012) Noninvasive diagnosis of ischemia-causing coronary stenosis using CT angiography: diagnostic value of transluminal attenuation gradient and fractional flow reserve computed from coronary CT angiography compared to invasively measured fractional flow reserve. JACC Cardiovasc Imaging 5:1088–1096CrossRefGoogle Scholar
- 13.Choi JH, Koo BK, Yoon YE et al (2012) Diagnostic performance of intracoronary gradient-based methods by coronary computed tomography angiography for the evaluation of physiologically significant coronary artery stenoses: a validation study with fractional flow reserve. Eur Heart J Cardiovasc Imaging 13:1001–1007CrossRefGoogle Scholar
- 15.Ko BS, Wong DT, Nørgaard BL et al (2016) Diagnostic performance of transluminal attenuation gradient and noninvasive fractional flow reserve derived from 320-detector row CT angiography to diagnose hemodynamically significant coronary stenosis: an NXT substudy. Radiology 279:75–83CrossRefGoogle Scholar
- 26.Ko BS, Seneviratne S, Cameron JD et al (2016) Rest and stress transluminal attenuation gradient and contrast opacification difference for detection of hemodynamically significant stenoses in patients with suspected coronary artery disease. Int J Cardiovasc Imaging 32(7):1131–1141CrossRefGoogle Scholar
- 27.Yin WH, Lu B, Gao JB et al (2015) Effect of reduced X-ray tube voltage, low iodine concentration contrast medium, and sinogram-affirmed iterative reconstruction on image quality and radiation dose at coronary CT angiography: results of the prospective multicentre REALISE trial. J Cardiovasc Comput Tomogr 9(3):215–224CrossRefGoogle Scholar