Measurement of arterial transit time and renal blood flow using pseudocontinuous ASL MRI with multiple post-labeling delays: Feasibility, reproducibility, and variation

2017 ◽  
Vol 46 (3) ◽  
pp. 813-819 ◽  
Author(s):  
Dong Won Kim ◽  
Woo Hyun Shim ◽  
Seong Kuk Yoon ◽  
Jong Yeong Oh ◽  
Jeong Kon Kim ◽  
...  
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Transit Time ◽  
Arterial Transit Time

Chronic renal blood flow measurement in dogs by transit-time ultrasound flowmetry

1997 ◽  
Vol 38 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Roger G. Evans ◽  
Kathleen M. Stevenson ◽  
Simon C. Malpas ◽  
Sharyn M. Fitzgerald ◽  
Amany Shweta ◽  
...  
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Transit Time ◽  
Flow Measurement ◽  
Blood Flow Measurement

Comparison of Renal Blood Flow and Transit Times Measured by Means of 99mTc-Labelled Erythrocytes and Indocyanine Green in Humans with Normal and Diseased Kidneys

1976 ◽  
Vol 51 (2) ◽  
pp. 151-159
Author(s):  
F. C. Reubi ◽  
C. Vorburger ◽  
Gertrud Pfeiffer ◽  
S. Golder
Keyword(s):  
Blood Flow ◽  
Indocyanine Green ◽  
Renal Blood Flow ◽  
Transit Time ◽  
Mean Transit Time ◽  
Common Mechanism ◽  
Dilution Method ◽  
Appearance Time ◽  
Vascular Volume ◽  
Transit Times

1. In nineteen patients with normal or diseased kidneys, renal blood flow, transit times and vascular volume were determined by means of an indicator-dilution method. Two different indicators, plasma-bound Indocyanine Green (IG) and 99mTc-labelled erythrocytes, were used simultaneously. 2. Comparison of the results indicates that IG slightly overestimates renal blood flow, appearance time, mean transit time and vascular volume, as the erythrocyte/IG ratios averaged 0·972, 0·903, 0·93 and 0·921 respectively. Overestimation of the mean transit time was less apparent when it was prolonged. In patients with reduced renal function, the average blood flow values obtained with the two indicators were in good agreement. 3. It is unlikely that axial streaming of erythrocytes accounts for their shorter mean transit time, because the individual erythrocyte/IG mean transit time ratios were independent of the rate of blood flow and the peripheral packed cell volume. 4. Since the erythrocyte/IG mean transit time ratios correlated significantly with the erythrocyte/IG ratios for appearance time and renal blood flow, the common mechanism leading to a depression of all erythrocyte/IG ratios is presumably extravascular circulation and delayed recovery of a small fraction of IG.

Validation of miniature ultrasonic transit-time flow probes for measurement of renal blood flow in rats

1995 ◽  
Vol 268 (1) ◽  
pp. F175-F178 ◽  
Author(s):  
W. J. Welch ◽  
X. Deng ◽  
H. Snellen ◽  
C. S. Wilcox
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Transit Time ◽  
Ex Vivo ◽  
High Flow ◽  
Flow Rates ◽  
Time Flow ◽  
Wide Range ◽  
Transit Time Flowmeter

This study validates the accuracy of miniature ultrasonic transit-time flow probes for measuring renal blood flow (RBF) in the rat. Probes for 1-mm and 2-mm vessels were calibrated ex vivo using excised arteries at varying flow rates and hematocrit (Hct). Correlation between measured and true flow rates for the 2-mm probe were identical (r = 1.0) at both normal and subnormal Hct values. Correlation for the 1-mm probe was high (r = 0.994) at normal Hct, but varied at both high flow rates and subnormal Hct values. In vivo correlation of RBF measurements using the 1-mm probe with the clearance and extraction of p-aminohippuric acid showed a high correlation (r = 0.84; n = 72, P < 0.0001) over a wide range of flow rates (0.5-21 ml/min) and Hct (36-74%). Zero flow levels remained steady, averaging -0.2 +/- 0.2 ml/min during occlusion in the living animal and -0.1 +/- 0.3 ml/min after exsanguination. This study shows that the ultrasonic transit-time flowmeter (1-mm and 2-mm probes) is a reasonably accurate and reliable method with which to measure RBF in the anesthetized, acute-instrumented rat.

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