title: Comparison of ASL and DCE MRI for the non-invasive measurement of renal blood flow: quantification and reproducibility.
abstract: OBJECTIVE
  To investigate the reproducibility of arterial spin labelling (ASL) and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) and quantitatively compare these techniques for the measurement of renal blood flow (RBF).
  
  
  METHODS
  Sixteen healthy volunteers were examined on two different occasions. ASL was performed using a multi-TI FAIR labelling scheme with a segmented 3D-GRASE imaging module. DCE MRI was performed using a 3D-FLASH pulse sequence. A Bland-Altman analysis was used to assess repeatability of each technique, and determine the degree of correspondence between the two methods.
  
  
  RESULTS
  The overall mean cortical renal blood flow (RBF) of the ASL group was 263 ± 41 ml min(-1) [100 ml tissue](-1), and using DCE MRI was 287 ± 70 ml min(-1) [100 ml tissue](-1). The group coefficient of variation (CVg) was 18 % for ASL and 28 % for DCE-MRI. Repeatability studies showed that ASL was more reproducible than DCE with CVgs of 16 % and 25 % for ASL and DCE respectively. Bland-Altman analysis comparing the two techniques showed a good agreement.
  
  
  CONCLUSIONS
  The repeated measures analysis shows that the ASL technique has better reproducibility than DCE-MRI. Difference analysis shows no significant difference between the RBF values of the two techniques.
  
  
  CONCLUSIONS
  Reliable non-invasive monitoring of renal blood flow is currently clinically unavailable. Renal arterial spin labelling MRI is robust and repeatable. Renal dynamic contrast-enhanced MRI is robust and repeatable. ASL blood flow values are similar to those obtained using DCE-MRI.
authors.affiliation: Imaging and Biophysics Unit, UCL Institute of Child Health, 30 Guilford Street, London, WC1N 1EH, UK, m.cutajar@ucl.ac.uk.
authors.forename: Marica
authors.initials: M
authors.lastname: Cutajar
authors.forename: David L
authors.initials: DL
authors.lastname: Thomas
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Hales
authors.forename: T
authors.initials: T
authors.lastname: Banks
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Clark
authors.forename: Isky
authors.initials: I
authors.lastname: Gordon
mesh_terms: D000328:Adult; D003287:Contrast Media; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods / Q000592:standards; D007668:Kidney / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards*; D008297:Male; D012077:Renal Artery / Q000502:physiology; D012079:Renal Circulation / Q000502:physiology*; D015203:Reproducibility of Results; D013113:Spin Labels; D055815:Young Adult
chemical_list: D003287:Contrast Media; D013113:Spin Labels