title: [Non-contrast magnetic resonance angiography for renal arteries using breath held inflow inversion recovery-fan shaped inward outward view ordering: impact on image quality by changing wait recovery time after data acquisition].
abstract: OBJECTIVE
  We assessed the wait time of non-contrast renal artery magnetic resonance (MR) angiography with a single breath hold using inflow inversion recovery-fan shaped inward outward view ordering technique in normal volunteers.
  
  
  METHODS
  The wait time (WT)-the duration between the data acquisition and the following inversion recovery pulse-was varied from 10 ms to 2000 ms, and the contrast ratio between the renal artery and the background structures for each WT was assessed quantitatively. A simulation was also performed.
  
  
  RESULTS
  The contrast ratio between the renal artery and each background structure with 2000 ms of WT was higher than that with 10 ms of WT. The contrast ratio between the renal artery and renal cortex with 1500 ms of WT was also higher than that with 10 ms of WT. In the simulation, when WT lengthened, the residual longitudinal magnetization of each background structure lowered.
  
  
  CONCLUSIONS
  The WT affects contrast; adjustment of WT should be added to the assessment of the imaging parameter.
authors.affiliation: Department of Radiological Technology, Tokyo University Hospital.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Koichi
authors.initials: K
authors.lastname: Motoyoshi
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Takei
authors.forename: Masaaki
authors.initials: M
authors.lastname: Akahane
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Imae
authors.forename: Jiro
authors.initials: J
authors.lastname: Sato
authors.forename: Masaki
authors.initials: M
authors.lastname: Katsura
authors.forename: Seigyoku
authors.initials: S
authors.lastname: Tei
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Takero
authors.initials: T
authors.lastname: Sarashina
authors.forename: Keiichi
authors.initials: K
authors.lastname: Yano
authors.forename: Kuni
authors.initials: K
authors.lastname: Ohtomo
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012077:Renal Artery / Q000033:anatomy & histology*; D013997:Time Factors