title: Image quality and radiation dose of lower extremity CT angiography at 70 kVp on an integrated circuit detector dual-source computed tomography.
abstract: BACKGROUND
  Despite the well-established requirement for radiation dose reduction there are few studies examining the potential for lower extremity CT angiography (CTA) at 70 kVp.
  
  
  OBJECTIVE
  To compare the image quality and radiation dose of lower extremity CTA at 70 kVp using a dual-source CT system with an integrated circuit detector to similar studies at 120 kVp.
  
  
  METHODS
  A total of 62 patients underwent lower extremity CTA. Thirty-one patients were examined at 70 kVp using a second generation dual-source CT with an integrated circuit detector (70 kVp group) and 31 patients were evaluated at 120 kVp using a first generation dual-source CT (120 kVp group). The attenuation and image noise were measured and signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Two radiologists assessed image quality. Radiation dose was compared.
  
  
  RESULTS
  The mean attenuation of the 70 kVp group was higher than the 120 kVp group (575 ± 149 Hounsfield units [HU] vs. 258 ± 38 HU, respectively, P < 0.001) as was SNR (44.0 ± 22.0 vs 32.7 ± 13.3, respectively, P = 0.017), CNR (39.7 ± 20.6 vs 26.6 ± 11.7, respectively, P = 0.003) and the mean image quality score (3.7 ± 0.1 vs. 3.2 ± 0.3, respectively, P < 0.001). The inter-observer agreement was good for the 70 kVp group and moderate for the 120 kVp group. The dose-length product was lower in the 70 kVp group (264.5 ± 63.1 mGy × cm vs. 412.4 ± 81.5 mGy × cm, P < 0.001).
  
  
  CONCLUSIONS
  Lower extremity CTA at 70 kVp allows for lower radiation dose with higher SNR, CNR, and image quality when compared with standard 120 kVp.
authors.affiliation: Department of Medical Imaging, Jinling Hospital, Clinical School of South Medical University, Nanjing, Jiangsu Province, PR China Department of Medical Imaging, Jinling Hospital, Clinical School of Nanjing University, Nanjing, Jiangsu Province, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Qi
authors.affiliation: Department of Medical Imaging, Jinling Hospital, Clinical School of South Medical University, Nanjing, Jiangsu Province, PR China Department of Medical Imaging, Jinling Hospital, Clinical School of Nanjing University, Nanjing, Jiangsu Province, PR China.
authors.forename: Yan'E
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Medical Imaging, Jinling Hospital, Clinical School of South Medical University, Nanjing, Jiangsu Province, PR China Department of Medical Imaging, Jinling Hospital, Clinical School of Nanjing University, Nanjing, Jiangsu Province, PR China.
authors.forename: Chang Sheng
authors.initials: CS
authors.lastname: Zhou
authors.affiliation: Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA.
authors.forename: James V
authors.initials: JV
authors.lastname: Spearman
authors.affiliation: Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA Department of Cardiology, Kerckhoff Heart and Thorax Center, Bad Nauheim, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Renker
authors.affiliation: Department of Medical Imaging, Jinling Hospital, Clinical School of South Medical University, Nanjing, Jiangsu Province, PR China Department of Medical Imaging, Jinling Hospital, Clinical School of Nanjing University, Nanjing, Jiangsu Province, PR China Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA.
authors.forename: U Joseph
authors.initials: UJ
authors.lastname: Schoepf
authors.affiliation: Department of Medical Imaging, Jinling Hospital, Clinical School of South Medical University, Nanjing, Jiangsu Province, PR China Department of Medical Imaging, Jinling Hospital, Clinical School of Nanjing University, Nanjing, Jiangsu Province, PR China kevinzhlj@163.com cjr.luguangming@vip.163.com.
authors.forename: Long Jiang
authors.initials: LJ
authors.lastname: Zhang
authors.affiliation: Department of Medical Imaging, Jinling Hospital, Clinical School of South Medical University, Nanjing, Jiangsu Province, PR China Department of Medical Imaging, Jinling Hospital, Clinical School of Nanjing University, Nanjing, Jiangsu Province, PR China.
authors.forename: Guang Ming
authors.initials: GM
authors.lastname: Lu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D035002:Lower Extremity / Q000098:blood supply* / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
keywords: Angiography; X-ray computed tomography (CT); low tube voltage; radiation dosage