title: Coronary CT Angiography: Variability of CT Scanners and Readers in Measurement of Plaque Volume.
abstract: Purpose To determine reader and computed tomography (CT) scan variability for measurement of coronary plaque volume. Materials and Methods This HIPAA-compliant study followed Standards for Reporting of Diagnostic Accuracy guidelines. Baseline coronary CT angiography was performed in 40 prospectively enrolled subjects (mean age, 67 years ± 6 [standard deviation]) with asymptomatic hyperlipidemia by using a 320-detector row scanner (Aquilion One Vision; Toshiba, Otawara, Japan). Twenty of these subjects underwent coronary CT angiography repeated on a separate day with the same CT scanner (Toshiba, group 1); 20 subjects underwent repeat CT performed with a different CT scanner (Somatom Force; Siemens, Forchheim, Germany [group 2]). Intraclass correlation coefficients (ICCs) and Bland-Altman analysis were used to assess interreader, intrareader, and interstudy reproducibility. Results Baseline and repeat coronary CT angiography scans were acquired within 19 days ± 6. Interreader and intrareader agreement rates were high for total, calcified, and noncalcified plaques for both CT scanners (all ICCs ≥ 0.96) without bias. Scanner variability was ±18.4% (coefficient of variation) with same-vendor follow-up. However, scanner variability increased to ±29.9% with different-vendor follow-up. The sample size to detect a 5% change in noncalcified plaque volume with 90% power and an α error of .05 was 286 subjects for same-CT scanner follow-up and 753 subjects with different-vendor follow-up. Conclusion State-of-the-art coronary CT angiography with same-vendor follow-up has good scan-rescan reproducibility, suggesting a role of coronary CT angiography in monitoring coronary artery plaque response to therapy. Differences between coronary CT angiography vendors resulted in lower scan-rescan reproducibility.©RSNA, 2016 Online supplemental material is available for this article.
authors.affiliation: From the Department of Radiology and Imaging Sciences, National Institutes of Health Clinical Center, 10 Center Dr, Bldg 10, Room 1C355, Bethesda, MD 20892 (R.S., J.Z.M., A.P., M.A.A., M.M., V.S., D.A.B.); Office of Biostatistics Research (C.O.W.) and Cardiovascular and Pulmonary Branch (M.Y.C.), National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Md; and Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Md (J.A.C.L.).
authors.forename: Rolf
authors.identifier: http://orcid.org/0000-0001-7889-6773
authors.initials: R
authors.lastname: Symons
authors.affiliation: From the Department of Radiology and Imaging Sciences, National Institutes of Health Clinical Center, 10 Center Dr, Bldg 10, Room 1C355, Bethesda, MD 20892 (R.S., J.Z.M., A.P., M.A.A., M.M., V.S., D.A.B.); Office of Biostatistics Research (C.O.W.) and Cardiovascular and Pulmonary Branch (M.Y.C.), National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Md; and Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Md (J.A.C.L.).
authors.forename: Justin Z
authors.initials: JZ
authors.lastname: Morris
authors.affiliation: From the Department of Radiology and Imaging Sciences, National Institutes of Health Clinical Center, 10 Center Dr, Bldg 10, Room 1C355, Bethesda, MD 20892 (R.S., J.Z.M., A.P., M.A.A., M.M., V.S., D.A.B.); Office of Biostatistics Research (C.O.W.) and Cardiovascular and Pulmonary Branch (M.Y.C.), National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Md; and Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Md (J.A.C.L.).
authors.forename: Colin O
authors.initials: CO
authors.lastname: Wu
authors.affiliation: From the Department of Radiology and Imaging Sciences, National Institutes of Health Clinical Center, 10 Center Dr, Bldg 10, Room 1C355, Bethesda, MD 20892 (R.S., J.Z.M., A.P., M.A.A., M.M., V.S., D.A.B.); Office of Biostatistics Research (C.O.W.) and Cardiovascular and Pulmonary Branch (M.Y.C.), National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Md; and Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Md (J.A.C.L.).
authors.forename: Amir
authors.identifier: http://orcid.org/0000-0001-7149-5424
authors.initials: A
authors.lastname: Pourmorteza
authors.affiliation: From the Department of Radiology and Imaging Sciences, National Institutes of Health Clinical Center, 10 Center Dr, Bldg 10, Room 1C355, Bethesda, MD 20892 (R.S., J.Z.M., A.P., M.A.A., M.M., V.S., D.A.B.); Office of Biostatistics Research (C.O.W.) and Cardiovascular and Pulmonary Branch (M.Y.C.), National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Md; and Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Md (J.A.C.L.).
authors.forename: Mark A
authors.initials: MA
authors.lastname: Ahlman
authors.affiliation: From the Department of Radiology and Imaging Sciences, National Institutes of Health Clinical Center, 10 Center Dr, Bldg 10, Room 1C355, Bethesda, MD 20892 (R.S., J.Z.M., A.P., M.A.A., M.M., V.S., D.A.B.); Office of Biostatistics Research (C.O.W.) and Cardiovascular and Pulmonary Branch (M.Y.C.), National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Md; and Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Md (J.A.C.L.).
authors.forename: João A C
authors.initials: JA
authors.lastname: Lima
authors.affiliation: From the Department of Radiology and Imaging Sciences, National Institutes of Health Clinical Center, 10 Center Dr, Bldg 10, Room 1C355, Bethesda, MD 20892 (R.S., J.Z.M., A.P., M.A.A., M.M., V.S., D.A.B.); Office of Biostatistics Research (C.O.W.) and Cardiovascular and Pulmonary Branch (M.Y.C.), National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Md; and Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Md (J.A.C.L.).
authors.forename: Marcus Y
authors.initials: MY
authors.lastname: Chen
authors.affiliation: From the Department of Radiology and Imaging Sciences, National Institutes of Health Clinical Center, 10 Center Dr, Bldg 10, Room 1C355, Bethesda, MD 20892 (R.S., J.Z.M., A.P., M.A.A., M.M., V.S., D.A.B.); Office of Biostatistics Research (C.O.W.) and Cardiovascular and Pulmonary Branch (M.Y.C.), National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Md; and Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Md (J.A.C.L.).
authors.forename: Marissa
authors.initials: M
authors.lastname: Mallek
authors.affiliation: From the Department of Radiology and Imaging Sciences, National Institutes of Health Clinical Center, 10 Center Dr, Bldg 10, Room 1C355, Bethesda, MD 20892 (R.S., J.Z.M., A.P., M.A.A., M.M., V.S., D.A.B.); Office of Biostatistics Research (C.O.W.) and Cardiovascular and Pulmonary Branch (M.Y.C.), National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Md; and Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Md (J.A.C.L.).
authors.forename: Veit
authors.initials: V
authors.lastname: Sandfort
authors.affiliation: From the Department of Radiology and Imaging Sciences, National Institutes of Health Clinical Center, 10 Center Dr, Bldg 10, Room 1C355, Bethesda, MD 20892 (R.S., J.Z.M., A.P., M.A.A., M.M., V.S., D.A.B.); Office of Biostatistics Research (C.O.W.) and Cardiovascular and Pulmonary Branch (M.Y.C.), National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Md; and Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Md (J.A.C.L.).
authors.forename: David A
authors.initials: DA
authors.lastname: Bluemke
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000072226:Computed Tomography Angiography / Q000592:standards; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008875:Middle Aged; D015588:Observer Variation; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging* / Q000473:pathology; D015898:Tomography Scanners, X-Ray Computed / Q000592:standards