[Assessment of the distribution of renal cortical blood flow by contrast ultrasonography].
The importance of the distribution of intrarenal blood flow in the regulation of various renal functions, such as urine concentration and sodium excretion, has been well recognized. However, there have been no reliable methods to measure local flow in the kidney in vivo. The present study demonstrated the usefulness of contrast ultrasonography combined with injection of sonicated 5% albumin for assessment of the distribution of renal cortical blood flow in eleven mongrel dogs. The left kidney was displayed by tomographic echography, and microbubbles of sonicated albumin were injected into the abdominal aorta above the left renal artery. Video density time curves were generated and fitted to a time-intensity curve. Intrarenal infusion of acetylcholine (4.0 micrograms/kg/min) increased renal blood flow (RBF) from 2.5 +/- 0.3 to 4.6 +/- 1.0 ml/min/g kwt (p < 0.01), and norepinephrine (0.5 microgram/kg/min) decreased RBF from 2.5 +/- 0.3 to 1.2 +/- 0.5 ml/min/g kwt (p < 0.01). There were significant positive correlations between percent change in RBF and peak intensity and area under the curve, which were calculated with a time-intensity curve. Furthermore, the inner/outer renal cortex ratio of peak intensity significantly increased during acetylcholine infusion (0.72 +/- 0.11 vs 0.86 +/- 0.09; p < 0.01), whereas no significant change was observed during norepinephrine infusion. These results suggest that renal contrast ultrasonography may be useful for real-time assessment of the distribution of renal cortical blood flow in vivo.
Fujita
Y
Y
Second Department of Internal Medicine, Kagawa Medical School, Japan.
Yura
T
T
Fujioka
H
H
Uchida
K
K
Shoji
T
T
Takahashi
N
N
Sumikura
T
T
Yuasa
S
S
Matsuo
H
H
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D003287:Contrast Media; D004285:Dogs; D007672:Kidney Cortex / Q000098:blood supply* / Q000000981:diagnostic imaging*; D009638:Norepinephrine / Q000494:pharmacology; D012079:Renal Circulation / Q000187:drug effects; D014463:Ultrasonography / Q000379:methods
D003287:Contrast Media; D000109:Acetylcholine; D009638:Norepinephrine