title: Arterial Transit Time-corrected Renal Blood Flow Measurement with Pulsed Continuous Arterial Spin Labeling MR Imaging.
abstract: OBJECTIVE
  The importance of arterial transit time (ATT) correction for arterial spin labeling MRI has been well debated in neuroimaging, but it has not been well evaluated in renal imaging. The purpose of this study was to evaluate the feasibility of pulsed continuous arterial spin labeling (pcASL) MRI with multiple post-labeling delay (PLD) acquisition for measuring ATT-corrected renal blood flow (ATC-RBF).
  
  
  METHODS
  A total of 14 volunteers were categorized into younger (n = 8; mean age, 27.0 years) and older groups (n = 6; 64.8 years). Images of pcASL were obtained at three different PLDs (0.5, 1.0, and 1.5 s), and ATC-RBF and ATT were calculated using a single-compartment model. To validate ATC-RBF, a comparative study of effective renal plasma flow (ERPF) measured by99mTc-MAG3 scintigraphy was performed. ATC-RBF was corrected by kidney volume (ATC-cRBF) for comparison with ERPF.
  
  
  RESULTS
  The younger group showed significantly higher ATC-RBF (157.68 ± 38.37 mL/min/100 g) and shorter ATT (961.33 ± 260.87 ms) than the older group (117.42 ± 24.03 mL/min/100 g and 1227.94 ± 226.51 ms, respectively; P < 0.05). A significant correlation was evident between ATC-cRBF and ERPF (P < 0.05, r = 0.47). With suboptimal single PLD (1.5 s) settings, there was no significant correlation between ERPF and kidney volume-corrected RBF calculated from single PLD data.
  
  
  CONCLUSIONS
  Calculation of ATT and ATC-RBF by pcASL with multiple PLD was feasible in healthy volunteers, and differences in ATT and ATC-RBF were seen between the younger and older groups. Although ATT correction by multiple PLD acquisitions may not always be necessary for RBF quantification in the healthy subjects, the effect of ATT should be taken into account in renal ASL-MRI as debated in brain imaging.
authors.affiliation: Department of Radiology, Faculty of Medical Sciences, University of Fukui.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Shimizu
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kosaka
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Fujiwara
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Matsuda
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Tsuchida
authors.forename: Katsuki
authors.initials: K
authors.lastname: Tsuchiyama
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Oyama
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Kimura
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D007668:Kidney / Q000098:blood supply* / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012079:Renal Circulation / Q000502:physiology*; D015203:Reproducibility of Results; D013113:Spin Labels; D013995:Time; D055815:Young Adult
chemical_list: D013113:Spin Labels