title: Non-enhanced low-tube-voltage high-pitch dual-source computed tomography with sinogram affirmed iterative reconstruction algorithm of the abdomen and pelvis.
abstract: OBJECTIVE
  To investigate the image quality, radiation dose and diagnostic value of the low-tube-voltage high-pitch dual-source computed tomography (DSCT) with sinogram affirmed iterative reconstruction (SAFIRE) for non-enhanced abdominal and pelvic scans.
  
  
  METHODS
  This institutional review board-approved prospective study included 64 patients who gave written informed consent for additional abdominal and pelvic scan with DSCT in the period from November to December 2012. The patients underwent standard non-enhanced CT scans (protocol 1) [tube voltage of 120 kVp/pitch of 0.9/filtered back-projection (FBP) reconstruction] followed by high-pitch non-enhanced CT scans (protocol 2) (100 kVp/3.0/SAFIRE). The total scan time, mean CT number, signal-to-noise ratio (SNR), image quality, lesion detectability and radiation dose were compared between the two protocols.
  
  
  RESULTS
  The total scan time of protocol 2 was significantly shorter than that of protocol 1 (1.4±0.1 seconds vs. 7.6±0.6 seconds, P<0.001). There was no significant difference between protocol 1 and protocol 2 in mean CT number of all organs (liver, 55.4±6.3 HU vs. 56.1±6.8 HU, P=0.214; pancreas, 43.6±5.9 HU vs. 43.7±5.8 HU, P=0.785; spleen, 47.9±3.9 HU vs. 49.4±4.3 HU, P=0.128; kidney, 32.2±2.3 HU vs. 33.1±2.3 HU, P=0.367; abdominal aorta, 44.8±5.6 HU vs. 45.0±5.5 HU, P=0.499; psoas muscle, 50.7±4.1 HU vs. 50.3±4.5 HU, P=0.279). SNR on images of protocol 2 was higher than that of protocol 1 (liver, 5.0±1.2 vs. 4.5±1.1, P<0.001; pancreas, 4.0±1.0 vs. 3.6±0.8, P<0.001; spleen, 4.7±1.0 vs. 4.1±0.9, P<0.001; kidney, 3.1±0.6 vs. 2.8±0.6, P<0.001; abdominal aorta, 4.1±1.0 vs. 3.8±1.0, P<0.001; psoas muscle, 4.5±1.1 vs. 4.3±1.2, P=0.012). The overall image noise of protocol 2 was lower than that of protocol 1 (9.8±3.1 HU vs. 11.1±3.0 HU, P<0.001). Image quality of protocol 2 was good but lower than that of protocol 1 (4.1±0.7 vs. 4.6±0.5, P<0.001). Protocol 2 perceived 229 of 234 lesions (97.9%) that were detected in protocol 1 in the abdomen and pelvis. Radiation dose of protocol 2 was lower than that of protocol 1 (4.4±0.4 mSv vs. 7.3±2.4 mSv, P<0.001) and the mean dose reduction was 41.4%.
  
  
  CONCLUSIONS
  The high-pitch DSCT with SAFIRE can shorten scan time and reduce radiation dose while preserving image quality in non-enhanced abdominal and pelvic scans.
authors.affiliation: Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Sun
authors.affiliation: Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China.
authors.forename: Hua-dan
authors.initials: HD
authors.lastname: Xue
authors.affiliation: Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China.
authors.forename: Zheng-yu
authors.initials: ZY
authors.lastname: Jin
authors.affiliation: Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China.
authors.forename: Yong-lan
authors.initials: YL
authors.lastname: He
authors.affiliation: Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China.
authors.forename: Da-ming
authors.initials: DM
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhu
mesh_terms: D000465:Algorithms; D006801:Humans; D010388:Pelvis / Q000473:pathology*; D011860:Radiography, Abdominal