title: Evaluation of Plaque Morphology by 64-Slice Coronary Computed Tomographic Angiography Compared to Intravascular Ultrasound in Nonocclusive Segments of Coronary Arteries.
abstract: Although intravascular ultrasound (IVUS) is the current gold standard for plaque characterization, noninvasive coronary computed tomographic angiography (CCTA) requires further evaluation. The ability to detect plaque morphology by CCTA remains unclear. The purpose of this study was to evaluate the diagnostic accuracy of CCTA for plaque detection and morphology.
  
  
  
  Thirty-one patients underwent cardiac catheterization with IVUS and CCTA. The presence of plaque was evaluated by both modalities in nonocclusive segments (<50% stenosis) of the left anterior descending artery, left circumflex artery, and right coronary artery. Plaque morphology was classified as (1) normal, (2) soft or fibrous, (3) fibrocalcific, or (4) calcific. Results by IVUS and CCTA were compared blindly on a segment-to-segment basis with subgroup analysis based on CCTA tube voltage.
  
  
  
  Among the 31 patients (mean age 56.2 ± 8.6 years, 27% female), 152 segments were analyzed. Of these segments, 42% were in the left anterior descending artery, 32% were in the left circumflex artery, and 26% were in the right coronary artery. Plaque morphology by IVUS identified 103 segments as fibrous (68%), 31 as fibrocalcific (20%), and 6 as calcific (4.0%); 12 segments were normal (8.0%). To evaluate for the presence of plaque, CCTA had an overall sensitivity and specificity of 99% and 75%, respectively. In patients who underwent CCTA with a tube voltage of 100 kV, both sensitivity and specificity were 100%. The sensitivity and specificity of CCTA to identify plaque as calcified (fibrocalcific or calcific) vs noncalcified (soft or fibrous) were 87% and 96%, respectively. Overall, the accuracy of CCTA to detect the presence of plaque was 97%; the accuracy to detect plaque calcification was 94%.
  
  
  
  CCTA offers excellent sensitivity and accuracy for plaque detection and morphology characterization in nonocclusive coronary segments. In addition, diagnostic accuracy is preserved with a reduced tube voltage protocol.
authors.affiliation: Division of Cardiology, University of Washington School of Medicine, Seattle, Washington.
authors.forename: Manoj
authors.initials: M
authors.lastname: Kesarwani
authors.affiliation: Division of Cardiology, Los Angeles Biomedical Research Center, Harbor-UCLA Medical Center, 1124 W Carson St, Torrance, CA 90502.
authors.forename: Rine
authors.initials: R
authors.lastname: Nakanishi
authors.affiliation: Division of Cardiology, Los Angeles Biomedical Research Center, Harbor-UCLA Medical Center, 1124 W Carson St, Torrance, CA 90502.
authors.forename: Tae-Young
authors.initials: TY
authors.lastname: Choi
authors.affiliation: Division of Cardiovascular Medicine, Los Angeles County/USC Medical Center, Keck School of Medicine, University of Southern California, Los Angeles, California.
authors.forename: David M
authors.initials: DM
authors.lastname: Shavelle
authors.affiliation: Division of Cardiology, Los Angeles Biomedical Research Center, Harbor-UCLA Medical Center, 1124 W Carson St, Torrance, CA 90502. Electronic address: mbudoff@labiomed.org.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Budoff
mesh_terms: D000072226:Computed Tomography Angiography; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D019160:Endosonography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D018084:Ultrasonography, Interventional; D061205:Vascular Calcification / Q000000981:diagnostic imaging
keywords: Coronary plaque; coronary computed tomographic angiography; intravascular ultrasound; radiation reduction