title: Low-concentration contrast medium for 128-slice dual-source CT coronary angiography at a very low radiation dose using prospectively ECG-triggered high-pitch spiral acquisition.
abstract: OBJECTIVE
  To assess the impact of low-concentration contrast medium on vascular enhancement, image quality, and radiation dose of coronary computed tomography (CT) angiography (CCTA) by using prospectively electrocardiography (ECG)-triggered high-pitch spiral acquisition with low tube voltage in combination with iterative reconstruction.
  
  
  METHODS
  One hundred patients (body mass index ≤ 25 kg/m(2), heart rate ≤ 65 beats per minute) were prospectively randomized to two groups, with 50 patients each, which were differed by contrast medium. All patients underwent prospectively ECG-triggered high-pitch spiral acquisition CCTA (2 × 128 × 0.6 mm, 300 mAs). Group A patients received iopromide 370 (370 mg I/mL), were scanned using 100 kVp, and reconstructed with filtered back projection. Group B patients received Iodixanol 270 (270 mg I/mL), were scanned using low tube voltage of 80 kVp, and reconstructed with iterative reconstruction techniques (IRT). CT attenuation was measured in coronary artery and other anatomic regions. Image quality score, noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and radiation dose were calculated and compared.
  
  
  RESULTS
  The iodixanol 270 group showed no significant difference in image quality score (1.61 ± 0.69 vs 1.57 ± 0.66; P > .05), CT attenuation (P > .05), noise (P > .05), SNR (47.89 ± 14.03 vs 44.37 ± 12.79; P > .05), and CNR (42.38 ± 12.67 vs 38.13 ± 11.38; P > .05) in comparison to the iopromide 370 group but at a significantly lower radiation dose (0.26 ± 0.05 vs 0.57 ± 0.10; P < .001), which reflects dose saving of 54.4%.
  
  
  CONCLUSIONS
  Combining IRT with high-pitch spiral acquisition mode and low-tube-voltage technique, a low-concentration contrast medium of 270 mg I/mL can still maintain the contrast enhancement in coronary arteries without impairing image quality and significantly lower the radiation dose.
authors.affiliation: Department of Radiology, Xijing Hospital, Fourth Military Medical University, No. 169, West Changle Road, Xi'an, Shaanxi Province 710032, China. Electronic address: zhengmw2007@163.com.
authors.forename: Minwen
authors.initials: M
authors.lastname: Zheng
authors.affiliation: Department of Radiology, Xijing Hospital, Fourth Military Medical University, No. 169, West Changle Road, Xi'an, Shaanxi Province 710032, China.
authors.forename: Yongjie
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Radiology, Xijing Hospital, Fourth Military Medical University, No. 169, West Changle Road, Xi'an, Shaanxi Province 710032, China.
authors.forename: Mengqi
authors.initials: M
authors.lastname: Wei
authors.affiliation: Department of Radiology, Xijing Hospital, Fourth Military Medical University, No. 169, West Changle Road, Xi'an, Shaanxi Province 710032, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Radiology, Xijing Hospital, Fourth Military Medical University, No. 169, West Changle Road, Xi'an, Shaanxi Province 710032, China.
authors.forename: Hongliang
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Department of Radiology, Xijing Hospital, Fourth Military Medical University, No. 169, West Changle Road, Xi'an, Shaanxi Province 710032, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Li
mesh_terms: D000328:Adult; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods*; D003287:Contrast Media / Q000008:administration & dosage; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D016247:Information Storage and Retrieval / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D011835:Radiation Protection / Q000379:methods; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014283:Triiodobenzoic Acids / Q000008:administration & dosage
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids; C044834:iodixanol
keywords: Coronary computed tomography angiography; contrast medium; high-pitch iterative reconstruction; radiation dose