Evaluation of renal blood perfusion: analysis of time-density curve with contrast-enhanced color Doppler

Jianhua LIU; Jingguang HE; Hong RAN; Zhuopeng LUO; Daogang ZHA; Yili LIU

ABSTRACT

BACKGROUND:

By using ultrasound examination, renal function was conventionally assessed through measuring the blood flow parameters of large renal arteries in all levels and the rate of the color flow area in arter ies on the cross section of kidneys, in which method great errors have been induced.

OBJECTIVE:

This study was designed to assess the renal blood perfusion with use of the image analysis software package in the color Doppler system.

DESIGN:

It was an experimental study on animals.

SETTING:

This study was conducted in the Department of Functional Examination of Guangzhou First People' s Hospital.MATERIALS The study had been accomplished at the Animal Laboratory of the General Hospital of Guangzhou Military Area Command of Chinese PLA from January 1999 to Aprial 2000. Eight healthy New Zealand rabbits were selected, 4 females and 4 males and weighing 2.5-3.5 kg.Sixteen kidneys of them were examined. A self-made contrast medium, with prevailing ingredient of albumin shelled and CsF8 gas-filled microbubbles,was used in this study.

METHODS:

After intravenous bolus injection of a fluorocarbon contrast medium, a color Doppler energy mapping, a color flow mapping and a power Doppler harmonic imaging of renal blood flow were collected successively and a time-density curve were created with system's standard software.MAIN OUTCOME

MEASURES:

The time-density curve of renal blood perfusion with contrast-enhanced color Doppler was a main outcome measurement in the study.

RESULTS:

All of the 8 rabbits entered the analysis procedure. The contrast-enhanced time-density curve of renal blood perfusion was singlepeaked, with a rapid incline and a subsequent slow decline. Quantitative analysis of interested sections could be performed by replaying the corresponding contrast-enhanced color Doppler images at a certain time after injection.

CONCLUSION:

The time-density curve of color flow mapping and color Doppler energy mapping is capable of reflecting the features of renal blood perfusion effectively. It can display not only the general renal perfusion but also the segmental regions with low perfusion, and thus to delineate the functional lesions in the kidneys.