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.

scholarly journals Interrelationships Among Regional Cerebral Blood Flow, Mean Transit Time, Vascular Volume and Cerebral Vascular Resistance

Stroke ◽  
1974 ◽  
Vol 5 (6) ◽  
pp. 719-724 ◽  
Author(s):  
YOSHIHIRO KURIYAMA ◽  
TAKASHI AOYAMA ◽  
KUNIHIKO TADA ◽  
SHOTARO YONEDA ◽  
TADAATSU NUKADA ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Vascular Resistance ◽  
Transit Time ◽  
Regional Cerebral Blood Flow ◽  
Mean Transit Time ◽  
Regional Cerebral Blood ◽  
Vascular Volume ◽  
Cerebral Vascular Resistance ◽  
Cerebral Vascular

Distribution of Blood Flow in the Renal Cortex during Saline Loading

1970 ◽  
Vol 38 (6) ◽  
pp. 699-712 ◽  
Author(s):  
O. Munck ◽  
E. de Bono ◽  
I. H. Mills
Keyword(s):  
Blood Flow ◽  
Transit Time ◽  
Renal Cortex ◽  
Mean Transit Time ◽  
Control Period ◽  
Isotonic Saline ◽  
Saline Infusion ◽  
Cortical Blood Flow ◽  
Rapid Injection ◽  
Transit Times

1. The effect of infusion of isotonic saline on the circulation in the renal cortex in the dog was investigated by an external counting technique involving measurement of the transit times for 85Krypton and 131I-labelled albumin after rapid injection into the renal artery. 2. During saline infusion superficial renal cortical blood flow and overall cortical blood flow rose by 23 and 15%, respectively. There was a 6% rise in the ratio superficial cortical blood flow to overall cortical flow, which however, was not significant. 3. Resistance to flow through cortex decreased. 4. Mean transit time for plasma through cortex decreased from an average of 2·9 sec in the control period to 2·6 and 2·1 sec during saline infusion. 5. Renal cortical blood volume, as estimated from the cortical blood flow and the mean transit time for plasma, was virtually unchanged. 6. These studies indicate that the decrease in resistance to flow during acute isotonic saline infusion is probably caused by a dilatation of the resistance vessels only. No significant redistribution of blood flow in cortex takes place; this, however, does not exclude regional changes in glomerular filtration rate.

Microscope-Integrated Quantitative Analysis of Intraoperative Indocyanine Green Fluorescence Angiography for Blood Flow Assessment: First Experience in 30 Patients

2011 ◽  
Vol 70 (suppl_1) ◽  
pp. ons65-ons74 ◽  
Author(s):  
Marcel A. Kamp ◽  
Philipp Slotty ◽  
Bernd Turowski ◽  
Nima Etminan ◽  
Hans-Jakob Steiger ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Indocyanine Green ◽  
Transit Time ◽  
Rise Time ◽  
Fluorescence Angiography ◽  
Flow Index ◽  
Time To Peak ◽  
Transit Times ◽  
Blood Flow Index

Abstract BACKGROUND: Intraoperative measurements of cerebral blood flow are of interest during vascular neurosurgery. Near-infrared indocyanine green (ICG) fluorescence angiography was introduced for visualizing vessel patency intraoperatively. However, quantitative information has not been available. OBJECTIVE: To report our experience with a microscope with an integrated dynamic ICG fluorescence analysis system supplying semiquantitative information on blood flow. METHODS: We recorded ICG fluorescence curves of cortex and cerebral vessels using software integrated into the surgical microscope (Flow 800 software; Zeiss Pentero) in 30 patients undergoing surgery for different pathologies. The following hemodynamic parameters were assessed: maximum intensity, rise time, time to peak, time to half-maximal fluorescence, cerebral blood flow index, and transit times from arteries to cortex. RESULTS: For patients without obvious perfusion deficit, maximum fluorescence intensity was 177.7 arbitrary intensity units (AIs; 5-mg ICG bolus), mean rise time was 5.2 seconds (range, 2.9-8.2 seconds; SD, 1.3 seconds), mean time to peak was 9.4 seconds (range, 4.9-15.2 seconds; SD, 2.5 seconds), mean cerebral blood flow index was 38.6 AI/s (range, 13.5-180.6 AI/s; SD, 36.9 seconds), and mean transit time was 1.5 seconds (range, 360 milliseconds-3 seconds; SD, 0.73 seconds). For 3 patients with impaired cerebral perfusion, time to peak, rise time, and transit time between arteries and cortex were markedly prolonged (>20, >9 , and >5 seconds). In single patients, the degree of perfusion impairment could be quantified by the cerebral blood flow index ratios between normal and ischemic tissue. Transit times also reflected blood flow perturbations in arteriovenous fistulas. CONCLUSION: Quantification of ICG-based fluorescence angiography appears to be useful for intraoperative monitoring of arterial patency and regional cerebral blood flow.

Effect of levarterenol on renal blood flow and vascular volume in dogs

1959 ◽  
Vol 197 (5) ◽  
pp. 1115-1117 ◽  
Author(s):  
A. Mehrizi ◽  
W. F. Hamilton
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Transit Time ◽  
Mean Transit Time ◽  
Renal Vasculature ◽  
Peritubular Capillaries ◽  
Vascular Channels ◽  
Flowing Blood ◽  
The Mean ◽  
Renal Vascular

T-1824 was injected quickly into the renal artery of dogs and the renal vein stream was divided into samples every second. From the analysis of these timed samples a dye concentration curve was plotted and the flow and mean transit time were calculated. Since the flow calculated from the area of this curve agreed closely with the flow measured in the sampling tubes it was assumed that all the injected dye was recovered and that the mean transit time multiplied by the flow equaled the capacity of the active vascular channels. In seven animals the infusion of levarterenol produced an increase in renal vascular resistance without curtailing renal blood flow to such a degree that the dye curve could not be plotted. In these animals the arterial pressure rose, on the average from 109 to 176 mm Hg. This change in resistance reduced the renal blood flow from 120 to 84 cc/min., increased the mean transit time from 7.5 to 13.9 seconds and increased the volume of actively flowing blood from 15 to 17 cc (from 30 to 34 cc/100 gm of kidney). From these experiments it is concluded that the classical renal swelling from injection of epinephrine is the result of an increase in the resistance of post capillary segments of the renal vasculature and a distention of glomerular and possibly of peritubular capillaries.

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

An anatomic and physiological model of hepatic vascular system

1995 ◽  
Vol 79 (3) ◽  
pp. 1008-1026 ◽  
Author(s):  
D. R. Fine ◽  
D. Glasser ◽  
D. Hildebrandt ◽  
J. Esser ◽  
R. E. Lurie ◽  
...  
Keyword(s):  
Blood Flow ◽  
Transit Time ◽  
Vascular System ◽  
Model Parameters ◽  
Activity Time ◽  
Mathematical Relationship ◽  
Portal Flow ◽  
Splenic Blood Flow ◽  
Liver Activity ◽  
Transit Times

Hepatic function can be characterized by the activity/time curves obtained by imaging the aorta, spleen, and liver. Nonparametric deconvolution of the activity/time curves is clinically useful as a diagnostic tool in determining organ transit times and flow fractions. The use of this technique is limited, however, because of numerical and noise problems in performing deconvolution. Furthermore, the interaction of part of the tracer with the spleen and gastrointestinal tract, before it enters the liver, further obscures physiological information in the deconvolved liver curve. In this paper, a mathematical relationship is derived relating the liver activity/time curve to portal and hepatic behavior. The mathematical relationship is derived by using transit time spectrum/residence time density theory. Based on this theory, it is shown that the deconvolution of liver activity/time curves gives rise to a complex combination of splenic, gastrointestinal, and liver dependencies. An anatomically and physiologically plausible parametric model of the hepatic vascular system has been developed. This model is used in conjunction with experimental data to estimate portal, splenic, and hepatic physiological blood flow parameters for eight normal volunteers. These calculated parameters, which include the portal flow fraction, the splenic blood flow fraction, and blood transit times are shown to adequately correspond to published values. In particular, the model of the hepatic vascular system identifies the portal flow fraction as 0.752 +/- 0.022, the splenic blood flow fraction as 0.180 +/- 0.023, and the liver mean transit time as 13.4 +/- 1.71 s. The model has also been applied to two portal hypertensive patients. The variation in some of the model parameters is beyond normal limits and is consistent with the observed pathology.

scholarly journals The Effects of Changes in PaCO2Cerebral Blood Volume, Blood Flow, and Vascular Mean Transit Time

Stroke ◽  
1974 ◽  
Vol 5 (5) ◽  
pp. 630-639 ◽  
Author(s):  
ROBERT L. GRUBB ◽  
MARCUS E. RAICHLE ◽  
JOHN O. EICHLING ◽  
MICHEL M. TER-POGOSSIAN
Keyword(s):  
Blood Flow ◽  
Blood Volume ◽  
Transit Time ◽  
Mean Transit Time ◽  
Volume Blood ◽  
Volume Blood Flow

scholarly journals Aggregation in environmental systems: seasonal tracer cycles quantify young water fractions, but not mean transit times, in spatially heterogeneous catchments

2015 ◽  
Vol 12 (3) ◽  
pp. 3059-3103 ◽  
Author(s):  
J. W. Kirchner
Keyword(s):  
Transit Time ◽  
Mean Transit Time ◽  
Strong Nonlinearity ◽  
Isotopic Tracers ◽  
Water Fraction ◽  
Benchmark Tests ◽  
Environmental Systems ◽  
Transit Times ◽  
Event Based ◽  
The Relationship

Abstract. Environmental heterogeneity is ubiquitous, but environmental systems are often analyzed as if they were homogeneous instead, resulting in aggregation errors that are rarely explored and almost never quantified. Here I use simple benchmark tests to explore this general problem in one specific context: the use of seasonal cycles in chemical or isotopic tracers (such as Cl−, δ18O, or δ2H) to estimate timescales of storage in catchments. Timescales of catchment storage are typically quantified by the mean transit time, meaning the average time that elapses between parcels of water entering as precipitation and leaving again as streamflow. Longer mean transit times imply greater damping of seasonal tracer cycles. Thus, the amplitudes of tracer cycles in precipitation and streamflow are commonly used to calculate catchment mean transit times. Here I show that these calculations will typically be wrong by several hundred percent, when applied to catchments with realistic degrees of spatial heterogeneity. This aggregation bias arises from the strong nonlinearity in the relationship between tracer cycle amplitude and mean travel time. I propose an alternative storage metric, the young water fraction in streamflow, defined as the fraction of runoff with transit times of less than roughly 0.2 years. I show that this young water fraction (not to be confused with event-based "new water" in hydrograph separations) is accurately predicted by seasonal tracer cycles within a precision of a few percent, across the entire range of mean transit times from almost zero to almost infinity. Importantly, this relationship is also virtually free from aggregation error. That is, seasonal tracer cycles also accurately predict the young water fraction in runoff from highly heterogeneous mixtures of subcatchments with strongly contrasting transit time distributions. Thus, although tracer cycle amplitudes yield biased and unreliable estimates of catchment mean travel times in heterogeneous catchments, they can be used reliably to estimate the fraction of young water in runoff.

Vascular capacitance of dog intestine using mean transit time of indicator

1978 ◽  
Vol 234 (1) ◽  
pp. H7-H13 ◽  
Author(s):  
C. F. Rothe ◽  
B. L. Johns ◽  
T. D. Bennett
Keyword(s):  
Transit Time ◽  
Mean Transit Time ◽  
Venous Pressure ◽  
Control Flow ◽  
Constant Flow ◽  
Venous Capacitance ◽  
Vascular Volume ◽  
Norepinephrine Infusion ◽  
Percent Increase ◽  
Muscle Changes

Changes in vascular volume of dog jejunum caused by norepinephrine, isoproterenol, or acetylcholine at constant=flow perfusion, were compared to changes in volume caused by changes in blood flow or venous pressure. Vascular volume was measured by indicator dilution mean transit time, using a step input of indocyanine green (125 microgram/min). Venous pressure was held at 10 mmHg; control arterial pressure was about 110 mmHg. At a control flow of 521 ml/min.kg of tissue, the vascular volume was 104 +/- 14 (SD) ml/kg of tissue. Reducing flow by 75 percent caused the volume to decrease by 29 percent (--31 ml/kg); maximal norepinephrine infusion at constant flow and venous pressure decreased the vascular volume by 24 percent, and a 10-mmHg reduction in venous outflow pressure caused a 25 percent (--27 ml/kg) reduction. On the other hand, isoproterenol (100 microgram/liter) at constant flow caused a 245 percent increase in conductance and only a 12 percent increase in vascular volume. Thus, active venoconstriction, changes in venous pressure, or changes in flow independently may cause changes in vascular volume of the intestine. Active smooth muscle changes in the venous capacitance vessels are not necessarily correlated with changes in the arterial resistance vessels.

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