Quantification of renal perfusion using an intravascular contrast agent (part 1): results in a canine model.
In this work absolute values of regional renal blood volume (rRBV) and flow (rRBF) are assessed by means of contrast-enhanced (CE) MRI using an intravascular superparamagnetic contrast agent. In an animal study, eight foxhounds underwent dynamic susceptibility-weighted MRI upon injection of contrast agent. Using principles of indicator dilution theory and deconvolution analysis, parametric images of rRBV, rRBF, and mean transit time (MTT) were computed. For comparison, whole-organ blood flow was determined invasively by means of an implanted flow probe, and the weight of the kidneys was evaluated postmortem. A mean rBV value of 28 ml/100 g was found in the renal cortex, with a corresponding mean rBF value of 524 ml/100 g/min and an average MTT of about 3.4 s. Although there was a systematic difference between the absolute blood flow values determined by MRI and the ultrasonic probe, a significant correlation (r(s) = 0.72, P < 0.05) was established. The influence of the arterial input function (AIF), T(1) relaxation effects, and repeated measurements on the precision of the perfusion quantitation is discussed.
Aumann
Silke
S
Department of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
Schoenberg
Stefan O
SO
Just
Armin
A
Briley-Saebo
Karen
K
Bjørnerud
Atle
A
Bock
Michael
M
Brix
Gunnar
G
D000818:Animals; D001810:Blood Volume; D003287:Contrast Media / Q000008:administration & dosage*; D003911:Dextrans; D004285:Dogs; D052203:Ferrosoferric Oxide; D007091:Image Processing, Computer-Assisted; D007262:Infusions, Intravenous; D007501:Iron / Q000008:administration & dosage; D008279:Magnetic Resonance Imaging; D058185:Magnetite Nanoparticles; D010087:Oxides / Q000008:administration & dosage; D012079:Renal Circulation
D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; C097921:ferumoxtran-10; D007501:Iron; D052203:Ferrosoferric Oxide