title: Coronary Computed Tomographic Angiography at Low Concentration of Contrast Agent and Low Tube Voltage in Patients with Obesity:: A Feasibility Study.
abstract: OBJECTIVE
  Using lower tube voltage can reduce the exposure to radiation and the dose of contrast agent. However, lower tube voltage is often linked to more noise and poor image quality, which create a need for more effective technology to resolve this problem. To explore the feasibility of coronary computed tomographic angiography (CCTA) in patients with obesity at low tube voltage (100 kV) and low contrast agent concentration (270 mg/mL) using iterative reconstruction.
  
  
  METHODS
  A total of 48 patients with body mass index greater than 30 kg/m(2) were included and randomly divided into two groups. Group A received a traditional protocol (iopromide 370 mg/mL + 120 kV); group B received a protocol with low tube voltage (100 kV), low contrast agent concentration (270 mg/mL), and iterative reconstruction. The effective dose (ED), average attenuation values, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), the figure of merit (FOM), image quality scores, and the total iodine intake were compared.
  
  
  RESULTS
  No significant differences in average CT attenuations, SNR, CNR, and subjective scores were noticed between the two groups (P > 0.05), whereas the FOM of group B was significantly higher than that of group A. Effective radiation dose, total iodine, and iodine injection rate in group B were lower than those of group A (P <0.01).
  
  
  CONCLUSIONS
  In patients with obesity, isotonic contrast agent with low iodine concentration and low-dose CCTA were feasible. Substantial reduction in radiation dose and the iodine intake could be achieved without compromising the image quality.
authors.affiliation: Department of Radiology, Ningbo First Hospital, Ningbo Hospital, Zhejiang University, Ningbo, Zhejiang, China; Ningbo University School of Medicine, No. 818 Fenghua Road, Jiangbei District, Ningbo, Zhejiang 315211, China.
authors.forename: Yu-Ning
authors.initials: YN
authors.lastname: Pan
authors.affiliation: Department of Radiology, Ningbo No.2 Hospital, Ningbo, Zhejiang, China.
authors.forename: Ai-Jing
authors.initials: AJ
authors.lastname: Li
authors.affiliation: Department of Cardiology, Ningbo First Hospital, Ningbo Hospital, Zhejiang University, Ningbo, Zhejiang, China.
authors.forename: Xiao-Min
authors.initials: XM
authors.lastname: Chen
authors.affiliation: Department of Cardiology, Ningbo First Hospital, Ningbo Hospital, Zhejiang University, Ningbo, Zhejiang, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Radiology, Ningbo First Hospital, Ningbo Hospital, Zhejiang University, Ningbo, Zhejiang, China; Ningbo University School of Medicine, No. 818 Fenghua Road, Jiangbei District, Ningbo, Zhejiang 315211, China.
authors.forename: Da-Wei
authors.initials: DW
authors.lastname: Ren
authors.affiliation: Department of Radiology, Ningbo First Hospital, Ningbo Hospital, Zhejiang University, Ningbo, Zhejiang, China; Ningbo University School of Medicine, No. 818 Fenghua Road, Jiangbei District, Ningbo, Zhejiang 315211, China. Electronic address: hqlpyn@163.com.
authors.forename: Qiu-Li
authors.initials: QL
authors.lastname: Huang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000150:complications / Q000000981:diagnostic imaging*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D059629:Signal-To-Noise Ratio; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide
keywords: Obesity; X-ray computer; contrast media; coronary vessels; radiation dosage; tomography