title: A Simplified Whole-Organ CT Perfusion Technique with Biphasic Acquisition: Preliminary Investigation of Accuracy and Protocol Feasibility in Kidneys.
abstract: OBJECTIVE
  To determine the feasibility and accuracy of a protocol for calculating whole-organ renal perfusion (renal blood flow [RBF]) and regional perfusion on the basis of biphasic computed tomography (CT), with concurrent dynamic contrast material-enhanced (DCE) CT perfusion serving as the reference standard.
  
  
  METHODS
  This prospective study was approved by the institutional review board, and written informed consent was obtained from all patients. Biphasic CT of the kidneys, including precontrast and arterial phase imaging, was integrated with a first-pass dynamic volume CT protocol and performed and analyzed in 23 patients suspected of having renal artery stenosis. The perfusion value derived from biphasic CT was calculated as CT number enhancement divided by the area under the arterial input function and compared with the DCE CT perfusion data by using the paired t test, correlation analysis, and Bland-Altman plots. Correlation analysis was made between the RBF and the extent of renal artery stenosis. All postprocessing was independently performed by two observers and then averaged as the final result.
  
  
  RESULTS
  Mean ± standard deviation biphasic and DCE CT perfusion data for RBF were 425.62 mL/min ± 124.74 and 419.81 mL/min ± 121.13, respectively (P = .53), and for regional perfusion they were 271.15 mL/min per 100 mL ± 82.21 and 266.33 mL/min per 100 mL ± 74.40, respectively (P = .31). Good correlation and agreement were shown between biphasic and DCE CT perfusion for RBF (r = 0.93; ±10% variation from mean perfusion data [P < .001]) and for regional perfusion (r = 0.90; ±13% variation from mean perfusion data [P < .001]). The extent of renal artery stenosis was negatively correlated with RBF with biphasic CT perfusion (r = -0.81, P = .012).
  
  
  CONCLUSIONS
  Biphasic CT perfusion is clinically feasible and provides perfusion data comparable to DCE CT perfusion data at both global and regional levels in the kidney. Online supplemental material is available for this article.
authors.affiliation: From the Department of Radiology, the 309th Hospital of Chinese People's Liberation Army, 17 Heishanhu Rd, Haidian District, Beijing 100091, P.R. China.
authors.forename: XiaoDong
authors.initials: X
authors.lastname: Yuan
authors.affiliation: From the Department of Radiology, the 309th Hospital of Chinese People's Liberation Army, 17 Heishanhu Rd, Haidian District, Beijing 100091, P.R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: From the Department of Radiology, the 309th Hospital of Chinese People's Liberation Army, 17 Heishanhu Rd, Haidian District, Beijing 100091, P.R. China.
authors.forename: ChangBin
authors.initials: C
authors.lastname: Quan
authors.affiliation: From the Department of Radiology, the 309th Hospital of Chinese People's Liberation Army, 17 Heishanhu Rd, Haidian District, Beijing 100091, P.R. China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Tian
authors.affiliation: From the Department of Radiology, the 309th Hospital of Chinese People's Liberation Army, 17 Heishanhu Rd, Haidian District, Beijing 100091, P.R. China.
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.affiliation: From the Department of Radiology, the 309th Hospital of Chinese People's Liberation Army, 17 Heishanhu Rd, Haidian District, Beijing 100091, P.R. China.
authors.forename: GuoKun
authors.initials: G
authors.lastname: Ao
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D005260:Female; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D007668:Kidney / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012078:Renal Artery Obstruction / Q000000981:diagnostic imaging*; D012079:Renal Circulation; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide