title: Low concentration contrast medium for dual-source computed tomography coronary angiography by a combination of iterative reconstruction and low-tube-voltage technique: feasibility study.
abstract: OBJECTIVE
  To assess the impact of low-concentration contrast medium on vascular enhancement, image quality and radiation dose of coronary CT angiography (cCTA) by using a combination of iterative reconstruction (IR) and low-tube-voltage technique.
  
  
  METHODS
  One hundred patients were prospectively randomized to two types of contrast medium and underwent prospective electrocardiogram-triggering cCTA (Definition Flash, Siemens Healthcare; collimation: 128 mm × 0.6mm; tube current: 300 mAs). Fifty patients received Iopromide 370 were scanned using the conventional tube setting (100 kVp or 120 kVp if BMI ≥ 25 kg/m(2)) and reconstructed with filtered back projection (FBP). Fifty patients received Iodixanol 270 were scanned using the low-tube-voltage (80 kVp or 100 kVp if BMI ≥ 25 kg/m(2)) technique and reconstructed with IR. CT attenuation was measured in coronary artery and other anatomical regions. Noise, image quality and radiation dose were compared.
  
  
  RESULTS
  Compared with two Iopromide 370 subgroups, Iomeprol 270 subgroups showed no significant difference in CT attenuation (576.63 ± 95.50 vs. 569.51 ± 118.93 for BMI< 25 kg/m(2), p=0.647 and 394.19 ± 68.09 vs. 383.72 ± 63.11 for BMI ≥ 25 kg/m(2), p=0.212), noise (in various anatomical regions of interest) and image quality (3.5 vs. 4.0, p=0.13), but significantly (0.41 ± 0.17 vs. 0.94 ± 0.45 for BMI< 25 kg/m(2), p<0.001 and 1.14 ± 0.24 vs. 2.37 ± 0.69 for BMI ≥ 25 kg/m(2), p<0.001) lower radiation dose, which reflects dose saving of 56.4% and 51.9%, respectively.
  
  
  CONCLUSIONS
  Combined IR with low-tube-voltage technique, a low-concentration contrast medium of 270 mg I/ml can still maintain the contrast enhancement without impairing image quality, as well as significantly lower the radiation dose.
authors: Department of Radiology, Xijing Hospital, Fourth Military Medical University, 127# West Changle Road, Xi'an 710032, Shaanxi Province, China. Electronic address: zhengmw2007@163.com.
authors: Minwen
authors: M
authors: Zheng
authors: Department of Radiology, Xijing Hospital, Fourth Military Medical University, 127# West Changle Road, Xi'an 710032, Shaanxi Province, China. Electronic address: yingyinglyly@126.com.
authors: Ying
authors: Y
authors: Liu
authors: Department of Radiology, Xijing Hospital, Fourth Military Medical University, 127# West Changle Road, Xi'an 710032, Shaanxi Province, China. Electronic address: weimengqi2008@163.com.
authors: Mengqi
authors: M
authors: Wei
authors: Department of Radiology, Xijing Hospital, Fourth Military Medical University, 127# West Changle Road, Xi'an 710032, Shaanxi Province, China. Electronic address: wu18291988526@163.com.
authors: Yongjie
authors: Y
authors: Wu
authors: Department of Radiology, Xijing Hospital, Fourth Military Medical University, 127# West Changle Road, Xi'an 710032, Shaanxi Province, China. Electronic address: zhaohl1980@163.com.
authors: Hongliang
authors: H
authors: Zhao
authors: Department of Radiology, Xijing Hospital, Fourth Military Medical University, 127# West Changle Road, Xi'an 710032, Shaanxi Province, China. Electronic address: xjyylj@yeah.net.
authors: Jian
authors: J
authors: Li
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media / Q000008:administration & dosage; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D004305:Dose-Response Relationship, Drug; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007455:Iodine / Q000008:administration & dosage*; 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
chemical_list: D003287:Contrast Media; D007455:Iodine
keywords: Contrast medium concentration; Coronary CT angiography; Image quality; Iterative reconstruction; Radiation dose