title: Intracoronary transluminal attenuation gradient in coronary CT angiography for determining coronary artery stenosis.
abstract: Coronary computed tomography angiography (CTA) assessment of calcified or complex coronary lesions is frequently challenging. Transluminal attenuation gradient (TAG), defined as the linear regression coefficient between luminal attenuation and axial distance, has a potential to evaluate the degree of coronary stenosis. We examined the value of TAG in determining the stenosis severity on 64-slice coronary CTA. The value of TAG of 370 major coronary arteries was measured from 7,263 intervals of 5-mm length. Compared with coronary CTA and invasive coronary angiography, TAG decreased consistently and significantly with maximum stenosis severity on a per-vessel basis, from -1.91 ± 4.25 Hounsfield units/10 mm for diameter stenosis of 0% to 49% to -13.37 ± 9.81 Hounsfield units/10 mm for diameter stenosis of 100% (p < 0.0001). Adding TAG to the interpretation of coronary CTA improved diagnostic accuracy (p = 0.001), especially in vessels with calcified lesions (N = 127; net reclassification improvement 0.095; p = 0.046). TAG appears to be able to contribute to improved classification of coronary artery stenosis severity in coronary CTA, especially in severely calcified lesions.
authors.affiliation: Department of Medicine, Cardiovascular Imaging Center, Cardiac and Vascular Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jin-Ho
authors.initials: JH
authors.lastname: Choi
authors.forename: James K
authors.initials: JK
authors.lastname: Min
authors.forename: Troy M
authors.initials: TM
authors.lastname: Labounty
authors.forename: Fay Y
authors.initials: FY
authors.lastname: Lin
authors.forename: Dorinna D
authors.initials: DD
authors.lastname: Mendoza
authors.forename: Dae Hee
authors.initials: DH
authors.lastname: Shin
authors.forename: Nikki S
authors.initials: NS
authors.lastname: Ariaratnam
authors.forename: Sunaina
authors.initials: S
authors.lastname: Koduru
authors.forename: Juan F
authors.initials: JF
authors.lastname: Granada
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Gerber
authors.forename: Jae K
authors.initials: JK
authors.lastname: Oh
authors.forename: Hyeon-Cheol
authors.initials: HC
authors.lastname: Gwon
authors.forename: Yeon Hyeon
authors.initials: YH
authors.lastname: Choe
mesh_terms: D000368:Aged; D016009:Chi-Square Distribution; D017023:Coronary Angiography / Q000379:methods*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted; D015203:Reproducibility of Results; D056910:Republic of Korea; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed; D061205:Vascular Calcification / Q000000981:diagnostic imaging*