Evaluating feline lower urinary tract disease: Doppler ultrasound of the kidneys

OBJECTIVES

Ultrasonography is used in the evaluation of urinary disorders, and the resistivity index (RI) and pulsatility index (PI) have been successfully used to detect early hemodynamic changes in the course of kidney diseases in humans and dogs. The aim of this study was to investigate RI and PI in cats with feline lower urinary tract disease (FLUTD).

METHODS

Twenty-nine client-owned cats were selected and divided into a control group (CG; n = 10), a group of animals with obstructive FLUTD (OG; n = 11) and non-obstructive FLUTD (nOG; n = 8). Clinical, laboratory and ultrasound evaluations were performed in all cats.

RESULTS

RI and PI values for cats in the CG were below the upper limit of normal suggested in other studies, while cats with FLUTD showed significantly higher values in the assessment of RI (P = 0.027 and P = 0.034, respectively) and PI (P = 0.044 and P = 0.048, respectively) of the right and left kidneys.

CONCLUSIONS AND RELEVANCE

Alteration in renal blood flow was observed in cats with lower urinary tract disorders, even in the nOG group. To the best of our knowledge, this is the first report of renal blood flow changes related to non-obstructive FLUTD.

Retrobulbar Short Posterior Ciliary Artery Hemodynamics in Patients with Pseudoexfoliation Glaucoma and Primary Open-Angle Glaucoma

Purpose

To investigate retrobulbar blood flow changes in the short posterior ciliary arteries (SPCAs) in patients with pseudoexfoliation glaucoma (PEG) and primary open-angle glaucoma (POAG).

Methods

In this prospective study, there were 22 eyes in the PEG group, 28 eyes in the POAG group, and 28 eyes with senile cataract in the control group. Peak systolic velocity (PSV), end-diastolic velocity (EDV), mean velocity (Vm), and resistivity index (RI) parameters of the temporal and nasal SPCAs were compared between the study groups.

Results

Mean temporal PSV, EDV, and Vm value were significantly lower in both the POAG group and the PEG group (P = 0.049, P = 0.004, P = 0.020), respectively. Temporal SPCA RI values were not significantly different between the groups (P = 0.115).

Conclusion

There are retrobulbar blood flow changes in glaucomatous compared to nonglaucomatous eyes. However, SPCAs blood flow characteristics are similar between PEG and POAG subtypes.

Correlation of optical coherence tomography and Doppler ultrasonography findings in pseudoexfoliation syndrome

PURPOSE

We aimed to investigate the correlation between the color Doppler imaging (CDI) results and parameters determined by spectral domain optical coherence tomography (SD-OCT) in cases with pseudoexfoliation syndrome (XFS).

METHODS

99 participants were included in this prospective study. Retinal nerve fiber layer (RNFL), ganglion cell complex (GCC), optic nerve head (ONH) measurements were recorded. Perfusions of the ophthalmic artery (OA) and central retinal artery (CRA) were determined and resistivity indices (RI) were calculated.

RESULTS

No statistically significant differences were determined between the groups regarding the RNFL and ONH parameters. Only the minimum GCC thickness value was determined to be reduced in XFS group (n = 49) when compared to the controls (n = 50) (p = 0.018). The OA-RI and CRA-RI values of XFS group were significantly higher than the control group (p < 0.001 and p = 0.001). In XFSs, negative correlations were present between OA-RI and the minimum, average, inferior and inferotemporal regions of GCC thickness (r = - 0.448 p = 0.001, r = - 0.275 p = 0.040, r = - 0.295 p = 0.027, r = - 0.304 p = 0.024, respectively), and also between CRA-RI and minimum GCC values (r = - 0.317, p = 0.017). While a significant relationship was present between age and OA-RI and CRA-RI values in controls, no such correlation was present in XFSs.

CONCLUSIONS

The vascular resistance increased with age in controls, whereas it was independent of age in XFS group. In XFSs, RIs correlated significantly with certain GCC values, but not with RNFL and ONH parameters. It would be beneficial to follow the XFS with CDI as it provides supportive parameters to GCC in order to recognize early changes in XFS.

Usefulness of Doppler ultrasound for the early diagnosis of diabetic nephropathy in type 1 diabetes mellitus

PURPOSE

Early diagnosis and management of diabetic nephropathy (DN) might prevent or delay its progression to end-stage renal disease. The purpose of this study was to investigate whether changes in the duplex Doppler resistivity index (RI) are useful for the early identification of renal involvement in children and adolescents with insulin-dependent diabetes mellitus and associated conditions.

MATERIALS AND METHODS

A total of 49 diabetic patients (two groups: 21 with DN and 28 without DN) were included in this study. DN was defined as 30-300 mg/l of albumin excretion in a random urine sample. The RI of the main renal arteries and their intrarenal branches (arcuate, interlobar) were evaluated with duplex Doppler ultrasound and correlated with age, renal length, duration of diabetes, and laboratory examinations.

RESULTS

The mean age did not significantly differ between the two groups. The patients with DN had a significantly longer duration of type 1 diabetes (p = 0.02). The majority of patients (90.5%) had mild renal involvement with microalbuminuria and normal renal function. The mean RI was normal in both groups of patients, with no significant difference between the two groups.

CONCLUSION

The RI did not increase in the early clinical stage of DN and was not a reliable marker for the screening of DN in patients with type 1 diabetes mellitus.

The comparison of the resistivity index values in the ultrasonographic evaluation of a unilateral atrophic/hypoplastic kidney

Background

In the study, we aimed to determine the sensitivity of the renal resistivity index (RI) in differentiating hypoplastic and atrophic kidneys in patients with small-sized kidneys, and to evaluate its capacity to predict the renal involvement confirmed by the DMSA scintigraphy.

Material and methods

We retrospectively reviewed the ultrasonography (US) and DMSA findings, and medical records of pediatric patients with unilateral diminutive kidneys followed between January 2017 and June 2018. The RI measurements were performed twice, and the mean RI was calculated for each kidney of all patients.

Results

Sixty-three (male/female, m/f = 28/35) pediatric patients aged 107.2 ± 49.4 months (range 14–206 months) were included in this study. The DMSA scintigraphy revealed abnormal changes to atrophic kidneys in 38 patients and hypoplastic kidneys in 25. There were no differences between the groups with atrophy and hypoplasia by age, gender, urine density, and creatinine. The patient group with atrophic kidneys had a mean RI of 0.55 ± 0.21, and patients with hypoplastic kidneys had a mean RI of 0.67 ± 0.03. The mean RI and systolic/diastolic rates of the patients with atrophy were significantly lower than of the patients with hypoplastic kidneys (p = 0.042 and p = 0.048, respectively). There was a positive correlation between RI and DFR in the group with atrophy (r = 0.461, p = 0.016), but this was not the case for the group with hypoplastic kidneys (r= −0.066, p = 0.889).

Conclusions

The resistivity index might be very useful for differentiating atrophy and hypoplasia in patients with unilateral small kidneys and can be used instead of scintigraphic evaluation.

Reference values for ductus venosus doppler indices of normal gestation at 22-37 weeks: A Vietnamese cohort study

Prenatal doppler ultrasound of the ductus venosus plays an important role in the evaluation of fetal circulation and fetal heart function. We aimed to establish the percentile of Resistivity Index (RI) and Pulsatility Index (PI) of the Ductus Venosus (DV) among normal Vietnamese fetuses with a gestation from 22 to 37 weeks in a cohort study. Normal Vietnamese fetuses with a gestation ranging from 22 to 37 weeks were examined in a cohort study. The PI and RI were recorded from the DV. We analyzed 640 participants who all fulfilled the inclusion and exclusion criteria of our study. Results: There was a significant correlation between RI, PI and gestational age as shown with the equations y = 0.077x - 0.003x² + 3.493e - 5x³ (r=0.97) and y = 0.106x - 0.004x² + 4.5e - 5x³ (r=0.94), respectively. A centile module was constructed for the DV RI and PI indices among normal Vietnamese fetuses with gestation from 22 to 37 weeks.

Doppler evaluation of maternal vessels in normal gestation and threatened abortion in canines

Background

Ultrasonographic monitoring of the pregnant bitch is an established routine in many veterinary clinics. In order to better assess foetal health and avoid pregnancy losses, Doppler ultrasonographic evaluation of the pregnant uterus is the need of the day. Investigations on the dynamics of maternal and foetal blood flow using Doppler ultrasound have been conducted in multiple species recently and it is invisaged that it would be a reliable diagnostic tool in future in monitoring pregnancy. The present study was designed to compare Doppler parameters systolic peak velocity (SPV), end diastolic velocity (EDV), pulsatility index (PI) and resistivity index (RI) of the uteroplacental (UPA) and umbilical arteries (UA) measured during 40 to 50 and 51 to 60 days in normal gestation and threatened abortion in canines.

Results

In total 40 pregnant bitches with known history of breeding; irrespective of age and parity belonging to different breeds were classified into normal gestation (NG) and threatened abortion (TA). Bitches with the history of greenish black discharge or expulsion of one foetus were included in the abortion group and bitches with no such symptoms were included in the normal gestation group. End diastolic velocity of uteroplacental vessels decreased while PI and RI increased significantly with decrease in body weight in threatened abortion cases during 40 to 50 and 51 to 60 days of gestation in canines. Systolic peak velocity and EDV of umbilical arteries increased while PI decreased significantly with decrease in body weight during 40 to 50 days of gestation in canine threatened abortions.

Conclusions

Doppler evaluation of uteroplacental and umbilical arteries is recommended as a diagnostic tool to monitor high risk pregnancy during 40 to 50 and 51 to 60 days of gestation in canines.

Assessment of Doppler flow parameters of the retrobulbar arteries and internal carotid artery in patients with glaucoma: the significance of ophthalmic artery peak ratio and the intima-media thickness of the internal carotid artery

PURPOSE

The objective of this study was to analyze flow parameters of the central retinal artery (CRA), ophthalmic artery (OA), and internal carotid artery (ICA) assessed by color Doppler ultrasound.

METHODS

Thirty-five patients with primary open-angle glaucoma (PAAG), 65 patients with normal-tension glaucoma (NTG), and 45 healthy controls, a total of 145 patients were included in this study and study participants were divided into three groups. All study participants underwent color Doppler ultrasound to assess blood flow parameters of CRA, OA and ICA.

RESULTS

Comparisons among three groups revealed that pulsatility index and resistive index of the OA were significantly higher and peak ratio and end-systolic volume were significantly lower in patients with NTG or PAAG compared to healthy controls (p < 0.001 for all). As with OA, resistive index of the CRA was statistically significantly higher in patients with glaucoma (PAAG and NTG) compared to healthy controls (p < 0.001). The peak systolic volume and intima-media thickness of the ICA were statistically significantly higher in patients with PAAG compared to the other two groups (p < 0.001). ROC curve analysis of the CRA resistive index, OA resistive index and OA peak ratio in patients with glaucoma (PAAG and NTG) revealed that the sensitivity and specificity were 89% and 88%; 86% and 84%; 84% and 82%, respectively, at cutoff values of 0.64, 0.78 and 0.59, respectively.

CONCLUSIONS

Ophthalmic artery peak ratio and ICA intima-media thickness may be useful parameters in the diagnosis of patients with glaucoma.

Vascular resistance of carotid and vertebral arteries is associated with retinal microcirculation measured by laser speckle flowgraphy in patients with type 2 diabetes mellitus

AIMS

Evaluation of the retinal microcirculation is key to understanding retinal vasculopathies, such as diabetic retinopathy. Laser speckle flowgraphy (LSFG) has recently enabled us to directly evaluate the vascular resistance in both retinal vessels and capillaries, non-invasively. We therefore assessed whether retinal vessel blood flow and/or the capillary microcirculation are associated with blood flow in the cervical arteries in diabetic patients without severe retinopathy.

METHODS

We enrolled 110 type 2 diabetes patients, with no or mild non-proliferative diabetic retinopathy, in this prospective cross-sectional study. We measured the resistivity indices (RIs) of the retinal vessel and capillaries by LSFG and those of cervical arteries by Doppler ultrasonography, followed by analyzing associations.

RESULTS

The RIs of not only the carotid but also vertebral arteries were associated with those of retinal vessel blood flow and the retinal capillary microcirculation. Multiple regression analyses revealed these associations to be independent of other explanatory variables including age and diabetes duration.

CONCLUSIONS

We obtained novel and direct evidence demonstrating a close association between the retinal microcirculation and cervical artery hemodynamics in diabetic patients. These findings suggest shared mechanisms to underlie micro- and macro-angiopathies. Thus, high vascular resistance of cervical arteries may be a risk of developing retinopathy.

Effect of Transdermal Nitroglycerine on Doppler Velocity Waveforms of the Uterine, Umbilical and Fetal Middle Cerebral Arteries in Patients with Chronic Placental Insufficiency: A Prospective RCT

INTRODUCTION

Increase in Nitric Oxide (NO) may be important in vascular adaptation needed to accommodate increased uteroplacental blood flow as pregnancy advances. Hence, in certain conditions like Pregnancy Induced Hypertension (PIH) and Fetal Growth Restriction (FGR), NO donors may play an effective role in increasing uteroplacental perfusion. Transdermal route appears to be a safe and effective route.

AIM

To evaluate the effect of nitroglycerine patch on Doppler velocity waveforms of the uterine, umbilical and fetal middle cerebral arteries in patients with chronic placental insufficiency.

MATERIALS AND METHODS

A prospective randomized controlled clinical trial was conducted on eighty consecutive pregnant women with FGR with or without PIH and having evidence of altered waveform velocimetry in uterine, umbilical and fetal middle cerebral artery. They were divided into two groups- study and control group. Transdermal nitroglycerine patch (10 mg per 24 hours) was applied in study group for three consecutive days. Changes in various Doppler indices were noted after three days of patch application and compared between the two groups. Analysis was carried out using SPSS (Statistical Package for Social Studies) for Windows version 20.0 and online GraphPad software (Prism 5 for Windows) version 5.01.

RESULTS

A significant fall in the systolic and diastolic ratio (S/D), Pulsatility Index (PI) and Resistivity Index (RI) of the uterine (3.07±0.52, 1.04±0.14 and 0.54±0.10 respectively, p<0.001) and umbilical artery (3.73±3.30, 1.18±0.21and 0.64±0.07 respectively, p<0.001) was noted after three days of patch application. No such significant change was observed in the middle cerebral artery indices.

CONCLUSION

The therapeutic approach of NO donor administration via transdermal route in pregnant patients with chronic placental insufficiency, apparently improved both maternal and fetoplacental haemodynamics, thus may help in improving perinatal outcome.

B-mode and Doppler ultrasound of chronic kidney disease in dogs and cats

Ultrasound is the imaging test of choice for renal evaluation, because it provides information about the position, size, shape, internal architecture and hemodynamics of the kidneys without harming the patient. In chronic kidney disease, the main findings observed in B-mode ultrasound images are increased cortical echogenicity, loss of corticomedullary differentiation, reduced renal volume and irregular renal contour, and when these changes are associated, they are indicative of end-stage renal disease. However, the cause of kidney disease cannot be determined by ultrasonography, but must be confirmed by means of biopsy, although the presence of ultrasonographic changes indicative of the end-stage of the disease may contraindicate this procedure. The Doppler ultrasound test complements the ultrasonic B-mode examination and enables the assessment of renal perfusion based on a calculation of the hemodynamic indices, which are increased in cases of chronic kidney lesions, with higher values ​​in the most severe cases. Thus, ultrasound examinations are not only useful in diagnostics but also play an important role in defining the prognosis of patients with chronic kidney disease.

Uterine artery pulsatility and resistivity indices in pregnancy: Comparison of MRI and Doppler US

OBJECTIVE

The aim of this work was to evaluate whether the uterine arteries (UtA) could be identified and their flow profiles measured during a fetal MRI examination. A comparison was performed against same day sonographic Doppler assessment.

METHODS

35 normal, healthy, singleton pregnancies at 28-32 weeks gestation underwent routine Doppler examination, followed by MRI examination. The resistivity index (RI) and pulsatility index (PI) of the left and right UtA were measured using phase contrast MRI. Bland Altman statistics were used to compare MRI and ultrasound results.

RESULTS

Sixty-nine comparable vessels were analysed. Six vessels were excluded due to artefact or technical error. Bland-Altman analysis demonstrated the ultrasound indices were comparable, although systematically lower than the MRI indices; Right UtA RI bias -0.03 (95% limits of agreement (LOA) -0.27 to +0.20), and left UtA RI bias -0.06 (95% LOA -0.26 to +0.14); Right UtA PI bias -0.06 (95% LOA -0.50 to +0.38), Left UtA PI bias -0.11 (95% LOA -0.54 to +0.32). The inter-rater agreement for the MRI derived PI and RI analysis was good.

CONCLUSION

This study demonstrates that in the majority of early third trimester pregnancies, the uterine arteries can be identified, and their flow profiles measured using MRI, and that the derived PI and RI values are comparable with Doppler ultrasound values.