Comparison Between Resistivity Index of Renal Artery in Normal Kidney and Calculi Obstructed Kidney

2020 ◽  
pp. 23-26
Author(s):  
OJS Admin
Keyword(s):  
Blood Flow ◽  
Renal Disease ◽  
Renal Artery ◽  
Vascular Resistance ◽  
Doppler Ultrasonography ◽  
Renal Stone ◽  
Resistive Index ◽  
Normal Kidney ◽  
Doppler Measurement ◽  
Resistivity Index

Doppler ultrasonography has been informed to be able to differentiate between obstructive and non-obstructive renal disease. It has also been suggested that severe urinary obstructions may cause decrease in blood flow and increase in vascular resistance. Doppler measurement of the resistive index can detect these changes. Doppler ultrasound can determine intrarenal resistivity index (RI) in renal stone obstruction. RIvalues provide reliable cutoff values to compare the normal and obstructed kidney resistivity index.

scholarly journals Resistive index of retinal arterial blood flow in type-II diabetics without retinopathy

2015 ◽  
Vol 47 (1-2) ◽  
pp. 7-11
Author(s):  
Mashah Binte Amin ◽  
Khaleda Parvin Rekha ◽  
Farzana Shegufta ◽  
Md Towhidur Rahman ◽  
Nafisa Abedin ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Velocity ◽  
Doppler Ultrasonography ◽  
Resistive Index ◽  
Diabetic Patients ◽  
Type Ii ◽  
Type Ii Diabetics ◽  
Healthy Control ◽  
Retinal Artery ◽  
The Mean

Diabetic retinopathy is a vascular disorder affecting the microvasculature of retina. It is caused by changes in the blood vessels of retina. If untreated, it may lead to blindness. Therefore if diagnosed and treated promptly, blindness is usually preventable. In ophthalmology, Colour Doppler Imaging is a new method that enables us to assess the orbital vasculature. Duplex color Doppler ultrasonography is the investigation of choice to assess retinal arterial flow velocities very quickly without any invasive procedure for qualitative and quantitative assessment of blood flow velocities. This study was performed to observe the difference between Doppler flow velocity indices of retinal artery in Type-II Diabetics subjects without retinopathy and those of normal control subjects. This case-control study was carried out in the Radiology department, BIRDEM for two years. All the selected subjects underwent Duplex Doppler ultrasonography of both eyes using 5 to 7.5 MHz linear phase transducer. Findings included spectral analysis, those were PSV, EDV and RI. Unpaired ttest was done to compare blood flow velocity indices of retinal artery in type-II diabetic patients without retinopathy and that of healthy control adult subjects and a P value <0.05 was taken as significant. Majority (42.5%) of patients were in 4th decade in diabetic subjects with male predominant, which was 58.7%. The mean duration of diabetes was 4.56 + 2.1 years. In the current study, it was found that the mean resistive index (RI) in 80 diabetic patients without retinopathy was (0.75 + 0.04) ranging 0.66-0.81. And that of 80 healthy subjects was (0.64 + 0.02) ranging 0.600.70.1n this study the mean differences of retinal arterial RI in diabetic eyes without retinopathy and healthy control eyes was statistically significant (p<0-05) in unpaired 't' test. From the result of present study it can be concluded that, there is statistically significant increased retinal arterial resistivity index of type-II diabetic patients without retinopathy. Higher RI in type-II diabetics may predict the early haemodynamic changes in the retinal artery of these patients before the clinical onset of retinopathy. DOI: http://dx.doi.org/10.3329/bmjk.v47i1-2.22555 Bang Med J (Khulna) 2014; 47 : 7-11

Pre- and postglomerular resistance changes in the isolated perfused kidney

1960 ◽  
Vol 199 (5) ◽  
pp. 923-926 ◽  
Author(s):  
Lerner B. Hinshaw ◽  
Robert D. Flaig ◽  
Curtis H. Carlson ◽  
Nguyen K. Thuong
Keyword(s):  
Blood Flow ◽  
Renal Artery ◽  
Renal Blood Flow ◽  
Vascular Resistance ◽  
Combined Effects ◽  
Peritubular Capillary ◽  
Tissue Pressure ◽  
Capillary Pressures ◽  
Resistance Data ◽  
Ureteral Occlusion

The objective of the present study was to evaluate the relative roles of pre- and postglomerular vascular resistance changes in the autoregulation phenomenon. Experiments were performed on isolated dog kidneys perfused during ureteral occlusion. Ureteral pressures were assumed to approximate Bowman capsule extravascular pressure. As renal artery pressure was progressively elevated through the autoregulatory range, ureteral, intrarenal venous, and tissue pressures were measured; glomerular and peritubular capillary pressures were estimated, and pre- and postglomerular resistances were calculated. Results indicate that autoregulation of renal blood flow is brought about by the combined effects of increased tissue pressure and Bowman capsule extravascular pressure. Progressive increases in postglomerular resistance are responsible for the rise in ‘over-all’ renal resistance. Data provide evidence for the absence of the ‘myogenic reflex’ as a causal factor in autoregulation. Results are in agreement with previous reports of Winton and Gómez regarding glomerular pressure estimations and renal segmental resistance calculations.

The use of intrarenal Doppler ultrasonography as predictor for positive outcome after renal artery revascularization

Vascular ◽  
2016 ◽  
Vol 25 (1) ◽  
pp. 63-73 ◽  
Author(s):  
Jeroen JWM Brouwers ◽  
Rob C van Wissen ◽  
Hugo TC Veger ◽  
Joris I Rotmans ◽  
Bart Mertens ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Renal Function ◽  
Prediction Model ◽  
Renal Artery ◽  
Renal Artery Stenosis ◽  
Doppler Ultrasonography ◽  
Resistive Index ◽  
Artery Stenosis ◽  
Renal Revascularization ◽  
Ultrasound Parameters

Whether patients with renal artery stenosis should undergo therapeutic revascularization is controversial. In this retrospective study, we evaluated prognostic intrarenal Doppler ultrasound parameters that might have a predictive value for a beneficial response after renal revascularization. From January 2003 until December 2012, all renovascular interventions for renal artery stenosis were analyzed. The resistive index and the maximal systolic acceleration were determined by Doppler ultrasonography prior to intervention. Thirty-two patients who underwent a renal revascularization procedure were included: 13 combined positive responders and 19 combined non-responders. The combined positive responders had a significant lower resistive index than the combined non-responders (0.5 vs. 0.6, P = 0.001) and a significant lower maximal systolic acceleration (1.0 vs. 3.8, P = 0.001) before revascularization. A prediction model (RI ≤ 0.5 and ACCmax ≤ 1.3 m/s2) was formulated to identify a subgroup that benefits from renal revascularization. This model has an expected sensitivity of 69% and specificity of 89% for improvement in renal function and/or blood pressure after revascularization. The non-invasive intrarenal Doppler ultrasound parameters resistive index and maximal systolic acceleration can be used as tools to predict improvement in renal function and/or blood pressure after revascularization of renal artery stenosis. The clinical value of this prediction model should be evaluated in a prospective trial.

scholarly journals Role of renal Duplex ultrasonography in evaluation of hepatorenal syndrome

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohamad Sherif Mogawer ◽  
Sahar Abdel Rahman Nassef ◽  
Samah Mohamad Abd Elhamid ◽  
Shaimaa Elkholy ◽  
Nahla Emad Abd El Aziz ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Liver Disease ◽  
Renal Artery ◽  
Hepatorenal Syndrome ◽  
Resistive Index ◽  
Duplex Ultrasonography ◽  
Renal Resistive Index ◽  
Resistivity Index ◽  
Function Tests

Abstract Background Hepatorenal syndrome is a potentially fatal complication of advanced liver disease. Markers for early diagnosis and identification of high-risk patients are lacking. Our aim was to evaluate the role of renal Duplex ultrasonography in the diagnosis and early prediction of hepatorenal syndrome. This study included 50 patients. Clinical assessment, liver function tests, hepatitis C virus antibody, kidney function tests, and abdominal and renal color Duplex ultrasound were done to all subjects. Results Univariate regression analysis for hepatorenal syndrome showed a statistically significant positive correlation with the Model For End-Stage Liver Disease score (p-value <0.0001) and renal artery hilum resistivity index (p-value = 0.0017). Logistic multivariable regression analysis proved that the renal artery hilum resistivity index was an independent predictor of hepatorenal syndrome. Renal artery hilum resistivity index can be used as a predictor of hepatorenal syndrome with 100% sensitivity and 66.7% specificity with a cut-off value > 0.77. Conclusion The renal resistive index could be a good predictor of hepatorenal syndrome.

scholarly journals Dopplerfluxometria da artéria femoral de cães adultos hígidos (Canis lupus familiaris)

2018 ◽  
Vol 46 (1) ◽  
pp. 5
Author(s):  
Ivan Felismino Charas Dos Santos ◽  
Letícia Rocha Inamassu ◽  
Sheila Canevese Rahal ◽  
Maria Jaqueline Mamprim ◽  
David José De Castro Martins ◽  
...  
Keyword(s):  
Blood Flow ◽  
Femoral Artery ◽  
Pulsatility Index ◽  
Normal Values ◽  
Peak Systolic Velocity ◽  
Resistive Index ◽  
Resistivity Index ◽  
Diastolic Velocity ◽  
Healthy Dogs ◽  
The Right

Background: In Veterinary Medicine, there are several methods for early and accurate assessment of blood flow dynamics. The Dopplerfluxometry can access the peak systolic velocity, mean velocity and end diastolic velocity, including Resistive Index and Pulsatility Index. Normal values of Dopplerfluxometry in healthy dogs allow the identification of vascular abnormalities and authors’ knowledge there are no reference regarding the values of Dopplerfluxometry of the femoral artery in healthy dogs. The aim of the study was to assess the femoral Dopplerfluxometry of adult healthy dogs by Resistive Index, Pulsatility Index, systolic and diastolic velocities, and femoral artery diameter.Materials, Methods & Results: Eighteen healthy intact beagle dogs, male and female, aging from 2 to 4 years old (mean ± SD: mean 3 ± 0.8 years), weighing from 10.1-17.9 kg [22.3-39.5 lb] [mean ± SD: 14.3 ± 2.7 kg (31.5 ± 5.96 lb)] were used. The dogs underwent to physical examination, complete blood cell count, serum biochemistry examination urinalysis, and radiographs examination, muscular and cardiac evaluation. Females had to be in anestrous. All dogs were submitted to right femoral artery Dopplerfluxometry. The dogs were positioned in dorsal recumbency by one person without any chemical restraint. A high definition ultrasound device equipped with a 3 - 13 MHz multi-frequency linear transducer was used. The right femoral artery was identified with the transducer positioned transversely on the right triangle femoral area. Peak systolic velocity, end-diastolic velocity was measured. The Resistivity Index and Pulsatility Index were calculated automatically by the ultrasound machine software. Three measurements were obtained with the Doppler spectrum. The values of peak systolic velocity, end-diastolic velocity, Resistivity Index, Pulsatility Index and femoral artery diameter were expressed as Mean ± Standard Deviation (SD).Discussion: No studies regarding to femoral artery Dopplerfluxometry in healthy dogs were found in the literature. These results can be used as normal reference values of Dopplerfluxometric parameters for adult dogs. The literature cited only Dopplerfluxometric values of renal arteries, abdominal aorta and of the internal thoracic artery. The normal values of arterial Dopplerfluxometry is necessary to identify the spectral quantitative characteristics of the blood flow for diagnosis and prognosis of vascular diseases. Authors referred to changes in blood perfusion by Dopplerfluxometry examination, but no changes in B-mode ultrasonography. The femoral Resistivity Index values can be used to correlate the postoperative evolution in dogs submitted to femoral bone, hip and knee surgeries, since Dopplerfluxometry allows blood flow assessment in the femoral region muscles. Changes in the heart rate, blood pressure, stress, exercise, and diseases as hypotension, renal lesion, hepatic diseases, diabetes, hyperadrenocorticism can change the Dopplerfluxometric parameters. All dogs which used in this study were clinically healthy, and were used beagle dogs due to lowest variations within breed. Sedation was avoid due to possible changes in Dopplerfluxometric parameters since the use of sedation or tranquilization in animals is strongly discussed due to possible hemodynamic changes that may occur during the examination. In conclusion, the mean values of the right femoral artery Dopplerfluxometry in male and female adult healthy dogs is Resistivity Index (0.887); Pulsatility Index (1.599); peak systolic velocity (124.41 cm/s), end-diastolic velocity (14.12 cm/s), femoral artery diameter (3.9 mm).

Inner medullary blood flow in postischemic acute renal failure in the rat

1989 ◽  
Vol 256 (3) ◽  
pp. F456-F461 ◽  
Author(s):  
Y. Yagil ◽  
M. Miyamoto ◽  
R. L. Jamison
Keyword(s):  
Blood Flow ◽  
Renal Artery ◽  
Renal Blood Flow ◽  
Vascular Resistance ◽  
Renal Ischemia ◽  
Renal Vascular Resistance ◽  
Left Renal Artery ◽  
Vasa Recta ◽  
Renal Vascular ◽  
Total Renal Blood Flow

To study the effect of renal ischemia on the circulation in the inner medulla, blood flow in descending and ascending vasa recta was determined by fluorescence videomicroscopy in the exposed papilla of the uninephrectomized rat after clamping of the renal artery for 45 min. Total renal blood flow was determined in parallel studies with an electromagnetic flowmeter. Animals were studied 90 min (group 1E) and 24 h (group 2E) after right nephrectomy and release of the left renal artery clamp. Control rats were studied 90 min (group 1C) and 24 h (group 2C) after right nephrectomy alone. In groups 1E and 2E, total renal blood flow was reduced to 70 and 80% of that in their respective controls; renal vascular resistance increased by 50 and 73%, respectively. In striking contrast, blood flow was markedly elevated in descending and ascending vasa recta in groups 1E and 2E compared with the values in their respective uninephrectomized controls. These results indicate that the circulation in the inner medulla is rapidly restored after 45 min of total renal ischemia and that vasa recta blood flow rises above normal after 90 min and 24 h, despite a reduction in total renal blood flow and an increase in renal vascular resistance.

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