resistivity index
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2021 ◽  
Anjali Rani ◽  
Madhu Jain ◽  
RC Shukla ◽  
Ishan Ishan ◽  
TB Singh ◽  

Abstract ObjectivePreeclampsia and eclampsia are one of major cause of maternal mortality. Various parameters like pulsatility index (PI) and resistivity index (RI) of color Doppler are helpful in detection of preeclampsia and intrauterine growth restriction. The reference ranges of the various parameters like uterine artery PI and RI are mainly from western countries. The reference range for Indian Population is lacking. So the objective of the study is to construct reference range of uterine artery for women from eastern India.Material and MethodIn this study, total 201 pregnant patients were included. Color Doppler of normal pregnant women was done at 18 to 22 weeks and then followed up at 28 to 32 weeks gestation. The uterine artery PI and RI was measured during pregnancy. The obtained data were tabulated and 5th, 25th, 50th, 75th, 90th and 95th percentile was calculated. The reference range was constructed according to gestational age starting from 18 to 22 weeks and then from 28 to 34 weeks. Statistical analysis was performed using SPSS.ResultThe main parameter observed are pulsatility and resistivity index of left and right uterine arteries first at 18 to 22 weeks and then followed up at 28 to 34 weeks. Our data suggests that as the gestational age increases both pulsatility and resistivity index decreases. The cut off value for reference range was taken up to 95th percentile. Anything above 95th percentile is abnormal. The reference range for left uterine artery pulsatility index was found to be 1.19 to 1.16 at 18 to 22 weeks, 1.09 at 28 weeks while 0.89 at 34 weeks. Similarly, the reference range for resistivity index was found to be 0.61 at 18 to 22 weeks while it decreases to 0.54 at 28 to 34 weeks.ConclusionReference range of uterine artery doppler indices for the local population is very useful tool to early prediction of Preeclampsia and IUGRs of that population and can aid in timely treatment of mother and baby. Our data shows decrease in pulsatility and resistivity index with increase in the gestational age.

Ginika N. Iyizoba ◽  
Adekunle A. Adeyomoye ◽  
Omodele A. Olowoyeye ◽  
Ozoemena S. Oboke ◽  
Rasheed A. Arogundade ◽  

Background: Diabetes mellitus is a metabolic disease characterized by elevated blood glucose level due to impaired insulin secretion, insulin action or both with diabetic retinopathy being the most common microangiopathic complication. A comparative, cross- sectional study aimed at evaluating Doppler blood flow indices in the ophthalmic artery in diabetic retinopathy and non-retinopathy patients when compared to normal controls in a Nigerian tertiary hospital.Methods: Data were collected over 7 months (April 2017-October 2017) in Lagos University Teaching Hospital, Idi-Araba Lagos, Nigeria. Sixty-five diabetic retinopathy patients, 65 diabetic patients without retinopathy and 65 non-diabetic controls had their ophthalmic artery Doppler indices assessed for comparison.Results: The end diastolic velocity (EDV) of the ophthalmic arteries in the diabetic patients were significantly lower than those of control group (EDV=5.84±2.59 cm/s, p<0.001 bilaterally). In diabetic patients with retinopathy, the end diastolic velocity of the ophthalmic arteries was significantly lower than those of diabetic patients without retinopathy (EDV=5.84±2.59 cm/s right eye, EDV=5.75±2.39 left eye, p<0.001 bilaterally). The resistivity index (RI) of the ophthalmic arteries was significantly higher in both diabetic patients with retinopathy and those without retinopathy compared to control group (RI=0.92±0.07 right eye, p=0.044 right eye, p<0.001 left eye) with resistivity index of diabetic retinopathy respondents significantly higher than the diabetic patients with no retinopathy.Conclusions: The study showed that Doppler is a useful screening parameter in identifying eyes at risk of developing sight threatening proliferative disease in diabetic patients. Significant differences exist in ophthalmic artery Doppler flow indices of diabetics with retinopathy compared to the healthy controls. 

2021 ◽  
Vol 124 ◽  
pp. 104240
Ying Wang ◽  
Lisa Burris ◽  
Christopher R. Shearer ◽  
Douglas Hooton ◽  
Prannoy Suraneni

2021 ◽  
Abubakar Isah ◽  
Abdulrauf Rasheed Adebayo ◽  
Mohamed Mahmoud ◽  
Lamidi O. Babalola ◽  
Ammar El-Husseiny

Abstract Capillary pressure (Pc) and electrical resistivity index (RI) curves are used in many reservoir engineering applications. Drainage capillary pressure curve represents a scenario where a non-wetting phase displaces a wetting phase such as (i) during gas injection (ii) gas storage in reservoirs (e.g. aquifer or depleted hydrocarbon reservoirs). The gas used for injection is typically natural gas, N2, or CO2. Gas storage principally used to meet requirement variations, and water injection into oil-wet reservoirs are drainage processes. Resistivity index (RI) curve which is used to evaluate the potential of oil recovery from a reservoir, is also an important tool used in log calibration and reservoir fluid typing. The pore drainage mechanism in a multimodal pore system is important for effective recovery of hydrocarbon reserves; enhance oil recovery (EOR) planning and underground gas storage. The understanding of pore structure and drainage mechanism within a multimodal pore system during petrophysical analysis is of paramount importance to reservoir engineers. Therefore, it becomes inherent to study and establish a way to relate these special core analyses laboratory (SCAL) methods with quick measurements such as the nuclear magnetic resonance (NMR) to reduce the time requirement for analysis. This research employed the use of nuclear magnetic resonance (NMR) to estimate saturation exponent (n) of rocks using nitrogen as the displacing fluid. Different rock types were used in this study that cover carbonates, sandstones, and dolomites. We developed an analytical workflow to separate the capillary pressure curve into capillary pressure curve for macropores and a capillary pressure curve for the micropores, and then used these pore scale Pc curves to estimate an NMR - capillary pressure - based electrical resistivity index - saturation (NMR-RI-Sw) curve for the rocks. We predicted the saturation exponent (n) for the rock samples from the NMR-RI-Sw curve. The NMR-based saturation exponent estimation method requires the transverse (T2) relaxation distribution of the rock - fluid system at various saturations. To verify the reliability of the new workflow, we performed porous plate capillary pressure and electrical resistivity measurements on the rock samples. The reliability of the results for the resistivity index curve and the saturation exponent was verified using the experimental data obtained from the SCAL method. The pore scale Pc curve was used to ascertain the drainage pattern and fluid contribution of the different pore subsystems. For bimodal rock system, the drainage mechanism can be in series, in parallel, or in series - parallel depending on the rock pore structure.

2021 ◽  
Vol 205 ◽  
pp. 108842
Cheng Feng ◽  
Jungui Feng ◽  
Ziyan Feng ◽  
Yuntao Zhong ◽  
Zhiqiang Mao ◽  

2021 ◽  
Vol 15 (3) ◽  
pp. 225-228
Aline de Sousa Alves ◽  
Fernanda Vieira Henrique ◽  
Sabrina Barros Araújo ◽  
Dayanny de Sousa Alencar ◽  
Higina Moreira Melo ◽  

This study aimed to evaluate the renal function of six bitches of various breeds and ages, with open pyometra, attended in the Small Animal Medical Clinic sector of the Veterinary Hospital from Federal University of Campina Grande, through the measurement of laboratory tests: urea and creatinine serum, dosage of the urinary Protein-Creatinine Ratio (PCR), urinary gamma-glutamyltransferase (GGT) and determination of the renal resistivity index (RI). The levels of urea and creatinine were elevated in 16.6% (1/6) of the female dogs; the urinary protein-creatinine ratio was increased in 66.6% (4/6), while the urinary gamma-glutamyltransferase value was elevated in 50% (3/6). The renal resistivity index was increased in the right and left kidneys by 66.6% (4/6) of bitches, with no statistical difference between them. It was concluded that the renal resistivity index was a practical and effective method to assist in the diagnosis of acute kidney injury, along with other early markers, such as PCR and urinary GGT.

2021 ◽  
Vol 2 (4) ◽  
pp. 44-53
David Guimolaire Nkouathio ◽  
Éric Donaldo Ntchambia Djeunou ◽  
Rachid Mohamed ◽  
Synthia Tengomo Nguimatsia ◽  
Marie Louise Chenyi Vohnyui

This work studies the characteristics of pyroclastic (materials) and evaluates the environmental impacts due to the opening of a pyroclastic quarry in the Tombel graben area saturated lime test, specific surface determination, mechanical resistivity index within long and short terms have been used to characterize pozzolan materials in the study area and it’s important to the cement industry while environmental impact was determined through soil permeability test and nuisance noise. From the results obtained, samples had very large specific surfaces (>3500 Cm2/g) and highly reactive with lime. The samples studied are in conformity with standard mechanical resistivity index SAI. For cement manufacture. The environmental impacts define an "absolute average" impacts relating to the opening of the quarry. Hence a particular attention is needed in this area of study and mitigation measures have been proposed.

Wenlian Xiao ◽  
Yubin Yang ◽  
Min Li ◽  
Xuefeng Yang ◽  

To further understand the relationship between the capillary pressure and resistivity index of tight reservoir sandstones, we measured these parameters using the semiporous plate method in four tight clayey sandstones from the Junggar Basin, China. To provide a benchmark for analyzing our results, we applied the same experimental procedures to four clay-free, tight Fontainebleau sandstones from the Paris Basin, France. We observed approximate power law relationships between the resistivity index and water saturation for Fontainebleau sandstones and Junggar Basin sandstones, in agreement with the Archie’s equation and Waxman-Smits equation, respectively. The capillary pressure and resistivity index data were differently related in the two types of sandstones. We observed a power law correlation for the Fontainebleau sandstones, whereas the Junggar sandstones showed a linear relationship. These differences in behavior appear to be primarily linked to the presence of clays in the Junggar sandstones but not in the Fontainebleau sandstone, and the difference in pore structure between the two types of sandstones.

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