[Quantification of renal medullary perfusion with contrast-enhanced ultrasound: an experimental study].
OBJECTIVE
To quantitatively evaluate the effects of dopamine (DA) and noradrenaline (NE) on renal medullary perfusion and the differences in perfusion in the outer and inner medulla using contrast-enhanced ultrasound.


RESULTS
Contrast-enhanced ultrasound was performed in 10 dogs with simultaneous renal artery flow (RAF) measurement at the baseline level and during application of 3 different doses of DA and NE. During treatment with the 3 doses of DA, the changes of ultrasound-derived parameters (A, beta and A*beta) in the medulla were similar to the changes in the cortex. As compared with the baseline level, the ratios between the cortex and medulla exhibited no significant difference in A, beta and A*beta during DA treatment (P>0.05). No significant difference in ultrasound-derived medullar parameters was noted in dogs with NE treatment from the baseline level (P>0.05). However, a progressive decrease in the ratios of A, beta and A*beta between the cortex and medulla was noted during NE treatment in comparison with the baseline level (P<0.05). The velocity (beta) and perfusion (A*beta) of blood flow in the medulla decreased progressively from the outer medulla to the inner medulla at baseline (P<0.05), while the blood volume (A) remained unchanged (P<0.05).


CONCLUSIONS
The changes of blood flow in both the cortex and medulla are identical during DA treatment but different in the presence of NE. The progressive decrease in perfusion from the outer medulla to the inner medulla is attributed to the decrease in the velocity of blood flow.
Xie
Wen-jie
WJ
Department of Ultrasound, Women and Children's Hospital of Zhuhai, Zhuhai 519001, China. xyj404@163.com
Xing
Xiao-wen
XW
Bin
Jian-ping
JP
Xie
Jin-guo
JG
Zha
Dao-gang
DG
Liu
Yi-li
YL
D000818:Animals; D003287:Contrast Media; D004285:Dogs; D004298:Dopamine / Q000494:pharmacology; D007679:Kidney Medulla / Q000098:blood supply* / Q000000981:diagnostic imaging*; D009638:Norepinephrine / Q000494:pharmacology; D010743:Phospholipids; D012039:Regional Blood Flow; D013459:Sulfur Hexafluoride; D014463:Ultrasonography
D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D004298:Dopamine; D013459:Sulfur Hexafluoride; D009638:Norepinephrine