Effect of ultrasound contrast medium in color Doppler and power Doppler visualization of blood flow in canine kidneys.
OBJECTIVE
To examine the effect of an ultrasound contrast medium (UCM) in the visualization of parenchymal blood flow by means of color Doppler and power Doppler sonography.


METHODS
Nonenhanced and UCM-enhanced Doppler images of canine kidneys were obtained in a transversal plane during various states of flow reduction in the anterior branch of the renal artery. The UCM consisted of air-filled shell-stabilized microballoons (half-life approximately 2 min). The images were evaluated blindly by 4 observers who rated the amount of flow signal in the cortex and medulla, and categorized the flow state (normal, reduced or no flow) in the anterior part of the kidney.


RESULTS
The UCM increased the area of Doppler signals in the cortex and outer medulla during normal or reduced blood flow. The border between nonperfused and normally perfused parenchyma was more distinct with the UCM. The categorization of the regional flow state was more correct with the UCM. Improvement with the UCM was greatest when the nonenhanced Doppler images had suboptimal intensity, but positive effects with the UCM were also seen in recordings with adequate precontrast intensity. Color blooming artifacts sometimes occurred on the side of the kidney facing away from the transducer.


CONCLUSIONS
The UCM improved the color Doppler and power Doppler visualization of the parenchymal blood flow in the canine kidney, and allowed a more correct categorization to be made of the regional blood flow state.
Abildgaard
A
A
Department of Radiology, National Hospital, Oslo, Norway.
Kløw
N E
NE
Jakobsen
J A
JA
Egge
T S
TS
Eriksen
M
M
D000388:Air; D000818:Animals; D016477:Artifacts; D003287:Contrast Media; D004285:Dogs; D006207:Half-Life; D007089:Image Enhancement; D007668:Kidney / Q000098:blood supply* / Q000000981:diagnostic imaging; D007672:Kidney Cortex / Q000098:blood supply; D007679:Kidney Medulla / Q000098:blood supply; D008863:Microspheres; D015588:Observer Variation; D012039:Regional Blood Flow; D012077:Renal Artery; D012078:Renal Artery Obstruction / Q000000981:diagnostic imaging / Q000503:physiopathology; D012079:Renal Circulation; D016037:Single-Blind Method; D014159:Transducers; D018608:Ultrasonography, Doppler / Q000379:methods*; D018615:Ultrasonography, Doppler, Color
D003287:Contrast Media