title: A prospective evaluation of contrast and radiation dose and image quality in cardiac CT in children with complex congenital heart disease using low-concentration iodinated contrast agent and low tube voltage and current.
abstract: OBJECTIVE
  To the assess image quality, contrast dose and radiation dose in cardiac CT in children with congenital heart disease (CHD) using low-concentration iodinated contrast agent and low tube voltage and current in comparison with standard dose protocol.
  
  
  METHODS
  110 patients with CHD were randomized to 1 of the 2 scan protocols: Group A (n = 45) with 120 mA tube current and contrast agent of 270 mgI/ml in concentration (Visipaque™; GE Healthcare Ireland, Co., Cork, UK); and Group B (n = 65) with the conventional 160 mA and 370 mgI/ml concentration contrast (Iopamiro®; Shanghai Bracco Sine Pharmaceutical Corp Ltd, Shanghai, China). Both groups used 80 kVp tube voltage and were reconstructed with 70% adaptive statistical iterative reconstruction algorithm. The CT value and noise in aortic arch were measured and the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. A five-point scale was used to subjectively evaluate image quality. Contrast and radiation dose were recorded.
  
  
  RESULTS
  There was no difference in age and weight between the two groups (all p > 0.05). The iodine load and radiation dose in Group A were statistically lower (3976 ± 747 mgI vs 5763 ± 1018 mgI in iodine load and 0.60 ± 0.08 mSv vs 0.77 ± 0.10 mSv in effective dose; p < 0.001). However, image noise, CT value, CNR, SNR and subjective image quality for the two groups were similar (all p > 0.05), and with good agreement between the two observers. Comparing the surgery results, the diagnostic accuracy for extracardiac and intracardiac defects for Group A was 96% and 92%, respectively, while the corresponding numbers for Group B were 95% and 93%.
  
  
  CONCLUSIONS
  Compared with the standard dose protocol, the use of low tube voltage (80 kVp), low tube current (120 mA) and low-concentration iodinated contrast agent (270 mgI/ml) enables a reduction of 30% in iodine load and 22% in radiation dose while maintaining compatible image quality and diagnostic accuracy. Advances in knowledge: The new cardiac CT scanning protocol can largely reduce the adverse effects of radiation and contrast media to children. Meanwhile, it also can be used effectively to examine complex CHD.
authors.affiliation: 1 Diagnostic Imaging Center, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Qiao-Ru
authors.initials: QR
authors.lastname: Hou
authors.affiliation: 2 Department of Pediatric Cardiology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Gao
authors.affiliation: 1 Diagnostic Imaging Center, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Ai-Min
authors.initials: AM
authors.lastname: Sun
authors.affiliation: 1 Diagnostic Imaging Center, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.affiliation: 1 Diagnostic Imaging Center, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Hai-Sheng
authors.initials: HS
authors.lastname: Qiu
authors.affiliation: 3 Department of Radiology, Wuhan Medical and Healthcare Center for Woman and Children, Hubei, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.affiliation: 1 Diagnostic Imaging Center, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Li-Wei
authors.initials: LW
authors.lastname: Hu
authors.affiliation: 4 CT Research Center, GE Healthcare, Shanghai, China.
authors.forename: Jian-Ying
authors.initials: JY
authors.lastname: Li
authors.affiliation: 1 Diagnostic Imaging Center, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Yu-Min
authors.initials: YM
authors.lastname: Zhong
mesh_terms: D000293:Adolescent; D000465:Algorithms; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media; D005260:Female; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011446:Prospective Studies; D011829:Radiation Dosage; D059629:Signal-To-Noise Ratio; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000592:standards; D014283:Triiodobenzoic Acids
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids; C044834:iodixanol