Quantitation of differential renal blood flow and renal function using dynamic contrast-enhanced MRI in rats.
A first-pass upslope approach was used to estimate differential renal blood flow (DRBF) and a Patlak-Rutland approach was used to estimate differential renal function (DRF) using Gd-DTPA-BMA-enhanced MRI. DRBF and DRF were estimated in rat kidneys under three different experimental conditions: 1) transient renal artery occlusion (TRAO); 2) partial unilateral ureteric obstruction (PUO); and 3) sham-operated control rats (SHAM). A bolus of Gd-DTPA-BMA was given intravenously during a dynamic single slice T1-weighted gradient echo sequence, which allowed calculation of concentration from signal intensity values. Calculations based on the raw signal intensity showed that DRBF was decreased in both PUO (44 +/- 1%; P < 0.05) and in TRAO (38 +/- 1%; P < 0.05) compared with SHAM (52 +/- 1%). Converting the signal intensity into a measure of Gd-DTPA-BMA concentration did not substantially alter these findings (PUO: 40 +/- 3%, P < 0.05; TRAO: 35 +/- 2%, P < 0.05; SHAM 49 +/- 1%). Likewise, DRF decreased in both PUO (43 +/- 4%; P < 0.05) and TRAO (39 +/- 3%; P < 0.05) compared with SHAM (48 +/- 2%). Converting the signal intensity into measurements of Gd-DTPA-BMA concentration revealed similar findings (PUO: 41 +/- 5%, P < 0.05; TRAO: 34 +/- 5%, P < 0.05; SHAM: 49 +/- 2%). Our results suggest that renal damage in rats may be demonstrated by an observed reduction of DRBF and DRF as estimated from single-slice Gd-DTPA-BMA enhanced signal intensity using time-activity curves with and without quantitation of Gd-concentration.
MR Research Centre, Aarhus University Hospital, Aarhus, Denmark.
Michael
M
Pedersen
Yimin
Y
Shi
Peter
P
Anderson
Hans
H
Stødkilde-Jørgensen
Jens Christian
JC
Djurhuus
Isky
I
Gordon
Jørgen
J
Frøkiaer
D000704:Analysis of Variance; D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage; D019786:Gadolinium DTPA / Q000008:administration & dosage; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D007275:Injections, Intravenous; D007668:Kidney / Q000098:blood supply / Q000378:metabolism / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D016555:Matched-Pair Analysis; D051381:Rats; D017208:Rats, Wistar; D012078:Renal Artery Obstruction / Q000503:physiopathology; D012079:Renal Circulation / Q000502:physiology*; D014517:Ureteral Obstruction / Q000503:physiopathology
D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA