Sonographic assessment of renal size in healthy adults

Normal sonographic measurements for kidney dimensions in Saudi adult population: A cross-sectional prospective study

BACKGROUND

The use of ultrasound-based measurements to determine renal size has proven valuable in the diagnosis of renal function and associated disorders. The dimensions of the abdominal organs are affected by an individual's body age, height, sex, and weight. The objective of this study was to establish the standard sonographic parameters for renal dimensions and to determine the correlation between body measurements and renal dimensions in a population of healthy adults residing in Jazan City, Saudi Arabia.

METHODS

The present study was a prospective study conducted at a single center located in Jazan City from February to August 2022. Ninety-five participants underwent abdominal ultrasonography. The process of measuring renal size through sonography entails the measurement of various dimensions of the kidney, such as renal length, width, and thickness. The demographic information of the participants, including their sex, age, height, and weight, was documented. All analyses were performed using Statistical Package for the Social Sciences v27 software.

RESULTS

The dimensions of the right kidney, specifically the length, width, and thickness, had mean value of 9.79 centimeters (cm), 5.09 cm, and 4.10 cm, respectively. The left kidney had mean dimensions of 10.1 cm, 5.09 cm, and 4.10 cm for length, width, and thickness, respectively. The left kidney was larger than the right kidney. Furthermore, male participants exhibited larger kidney measurements than their female counterparts did. A noteworthy positive correlation was observed between the thickness of the left kidney and sex, whereas no significant correlations were found with age, weight, or height.

CONCLUSION

The current study revealed that the kidney dimensions were observed to be larger in males as compared to females. The research findings indicate that there is no significant correlation between kidney dimensions and various demographic factors, such as age, height, weight, and sex. In addition, this study provides reference tables for further use.

Changes in renal volume post Percutaneous nephrolithotomy based on ultrasonography and its correlation with glomerular filtration rate (GFR)

INTRODUCTION

Percutaneous nephrolithotomy (PCNL) is considered to be the gold standard management for renal calculi. The purpose of this study is to comprehend the overall alterations in renal volume occurring after PCNL. The changes in the kidney's total volume in individual patients will be examined by ultrasonography pre and postoperatively, and it will be correlated with GFR.

MATERIALS AND METHODS

It was a prospective observational study performed over 70 participants, conducted at the department of Urology of a tertiary care hospital in Eastern India. Each patients were evaluated with pre and post PCNL USG for kidney volume and GFR. The data was statistically evaluated by SPSS software.

RESULTS

The preoperative and post operative calculated mean GFR was 96.030 ± 18.922 ml and 86.681 ± 16.938 ml,volume was 127.258 ± 25.705 and 123,678 ± 26.357 respectively . There was statistically significant decrease in GFR and volume following PCNL. It also shows that patients who underwent single puncture PCNL had significantly less decrease in GFR and kidney volume compared to multiple puncture PCNL. Moreover, the calculated mean change in GFR and volume were significantly less seen in single puncture-one step dilatation and single puncture-serial dilatation as compared to multiple puncture-one step dilatation and multiple puncture-serial dilatation.

CONCLUSION

Our study showed that there was significant changes in the renal volume and GFR following PCNL . So, a sonographic estimation of renal dimensions and GFR calculation after PCNL will help in the prognosis and further follow up of patients. A Single puncture had a better operative outcome and less adverse consequences with respect to GFR, volume change and for renal function as compared to multiple puncture.

Investigation of Kidney Morphology and Somatotype Components in Early-Stage Kidney Patients

Objectives

The aim of this study is to examine the kidney morphology and somatotype components of adult patients with early-stage chronic kidney disease (CKD).

Methods

The sample consisted of 46 individuals with early-stage CKD (26 men and 20 women, mean age=45.92±16.53 years). The pathological subjects were compared with a control group consisting of 46 healthy subjects (28 men and 18 women, mean age=41.96±11.48 years). The Heath-Carter method was used to determine somatotype components. Abdominal computed tomography (CT) of patients with Stage 2 CKD and healthy volunteers taken within the past 3 months was scanned to determine kidney morphology. Kidney measurements were performed on CTs (length, width, depth, and volume of kidney).

Results

Kidney patients (mean somatotype: 6.33-5.37-0.6) were less ectomorphic and more endomorphic than the controls (mean somatotype: 4.35-4.40-3.02). Moderate effect size (ES) was found in endomorphy (ES=0.87; p=0.035) and ectomorphy (ES=1.08; p=0.012) between groups. No significant difference was observed in the kidney morphology (ES=0.04-0.19; p>0.05).

Conclusion

In the early-stage CKD, kidney morphology may not be the distinguishing factor. On the other hand, patients differed significantly in terms of endomorph components. Being overweight can also be one of the negative findings for kidney disease. Somatotype classification could be a suitable tool for monitoring kidney disease.

Ultrasound appearance of the kidney among radiology department attendees of a tertiary centre in Malawi

Background: Diagnostic and therapeutic decisions in nephrology in low-resource settings are frequently based on ultrasound assessment of kidney size. An understanding of reference values is critical, particularly given the rise of non-communicable disease and the expanding availability of point-of-care ultrasound. However, there is a paucity of normative data from African populations. We determined estimates of kidney ultrasound measures, including kidney size based on age, sex, and HIV status, among apparently healthy outpatient attendees of Queen Elizabeth Central hospital radiology department, Blantyre, Malawi. Methods: We performed a cross-sectional cohort study of 320 adults attending the radiology department between October 2021 and January 2022. Bilateral kidney ultrasound was performed on all participants using a portable Mindray DP-50 machine and a 5MHz convex probe. The sample was stratified by age, sex, and HIV status. Predictive linear modelling was used to construct reference ranges for kidney size estimating the central 95 percentiles of 252 healthy adults. Exclusion criteria for the healthy sample were known kidney disease, hypertension, diabetes, BMI > 35, heavy alcohol intake, smoking and ultrasonographic abnormalities. Results: There were 162/320 (51%) male participants. The median age was 47 (interquartile range [IQR] 34-59). Among people living with HIV 134/138 (97%) were receiving antiretroviral therapy. Men had larger average kidney sizes: mean 9.68 cm (SD 0.80 cm), compared to 9.46 cm (SD 0.87 cm) in women ( p = 0.01). Average kidney sizes in people living with HIV were not significantly different from those who were HIV-negative, 9.73 cm (SD 0.93 cm) versus 9.58 cm (SD 0.93 cm) ( p = 0.63). Conclusions: This is the first report of the apparently healthy kidney size in Malawi. Predicted kidney size ranges may be used for reference in the clinical assessment of kidney disease in Malawi.

Ultrasound appearance of the kidney among radiology department attendees of a tertiary centre in Malawi

Background: Diagnostic and therapeutic decisions in nephrology in low-resource settings are frequently based on ultrasound assessment of kidney size. An understanding of reference values is critical, particularly given the rise of non-communicable disease and the expanding availability of point-of-care ultrasound. However, there is a paucity of normative data from sub-Saharan Africa (SSA). We determined estimates of kidney ultrasound measures, including kidney size based on age, sex, and HIV status, among apparently healthy outpatient attendees of Queen Elizabeth Central hospital radiology department, Blantyre, Malawi. Methods: We performed a cross-sectional cohort study of 320 adults attending the radiology department between October 2021 and January 2022. Bilateral kidney ultrasound was performed on all participants using a portable Mindray DP-50 machine and a 5MHz convex probe. The sample was stratified by age, sex, and HIV status. Predictive linear modelling was used to construct reference ranges for kidney size estimating the central 95 percentiles of 252 healthy adults. Exclusion criteria for the healthy sample were known kidney disease, hypertension, diabetes, BMI > 35, heavy alcohol intake, smoking and ultrasonographic abnormalities. Results: There were 162/320 (51%) male participants. The median age was 47 (interquartile range [IQR] 34-59). Of those whose HIV status was known and positive, 138/308 (45%), 134/138 (97%) were receiving antiretroviral therapy. Men had larger average kidney sizes: mean 9.68 cm (SD 0.80 cm), compared to 9.46 cm (SD 0.87 cm) in women ( p = 0.01). Average kidney sizes in HIV-positive participants were not significantly different from those who were HIV-negative, 9.73 cm (SD 0.93 cm) versus 9.58 cm (SD 0.93 cm) ( p = 0.63). Conclusions: This is the first report of the apparently healthy kidney size in Malawi. Predicted kidney size ranges may be used for reference in the clinical assessment of kidney disease in Malawi.

Ultrasound Renal Score to Predict the Renal Disease Prognosis in Patients with Diabetic Kidney Disease: An Investigative Study

Renal disease associated with type 2 diabetes mellitus (T2DM) has become the leading cause of chronic kidney disease (CKD). Renal ultrasonography is an imaging examination required in the work-up of renal disease. This study aimed to identify the differences in renal ultrasonographic findings between patients with and without DM, and to evaluate the relationship between renal ultrasound findings and renal prognosis in patients with DM. A total of 252 patients who underwent renal ultrasonography at Chungnam National University Hospital were included. Kidney disease progression was defined as a ≥10% decline in the annual estimated glomerular filtration rate (eGFR), which, in this paper, is referred to as ΔeGFR/year, or the initiation of renal replacement therapy after follow-up. The renal scoring system was evaluated by summing up the following items: the value of renal parenchymal echogenicity (0: normal; 1: mildly increased; and 2: increased) and the shape of the cortical margin (0: normal and 1: irregular; right kidney length/height (RH-0 or 1), mean cortical thickness/renal length/height (CKH-0 or 1), and cortical thickness/parenchymal thickness (CK/PK-0 or 1) based on the median: 0-above median, and 1-below median). Patients with DM had thicker renal PKH than those without, despite having lower eGFRs (0.91 ± 0.15, 0.86 ± 0.14, p = 0.006). In the progression group, the renal scores were significantly higher than those from the non-progression group. In the multivariate logistic regression analysis, the higher renal scores, presence of DM, and younger age were independently predicted for renal disease progression after adjusting for confounding variables, such as the presence of hypertension, serum hemoglobin and albumin levels, and UPCR. In conclusion, patients with high renal scores were significantly associated with renal disease progression. Our results suggest that renal ultrasonography at the time of diagnosis provides useful prognostic information in patients with kidney disease.

A new threshold for kidney asymmetry improves association with abnormal renal-aortic ratio for diagnosis of renal artery stenosis

BACKGROUND

Renal artery stenosis (RAS) reflects more widespread atherosclerosis deposition and is associated with high morbidity and mortality. According to the guidelines, a discrepancy in the size of the kidneys of over 15 mm found in an ultrasound should initiate the RAS diagnostic algorithm. This study aims to find the optimal threshold for renal asymmetry that better reflects the frequency of a significantly abnormal renal-aortic ratio (RAR), justifying further RAS diagnostic workup, than the currently used cut-off of 15 mm difference in renal diameters.

METHODS

The analysis included 1175 patients (mean age: 52 years, IQR: 38-66, men/women: 597/578) who underwent Doppler ultrasonography screening of renal arteries with recorded kidney size and RAR calculation. Ultrasound features of RAS were defined as a RAR greater than 3.5 or signs of renal artery occlusion. Receiver operating characteristic (ROC) curves were created and analyzed for absolute differences in kidney size and abnormal RAR. We calculated the area under the curve (AUC) and optimal cut-off values for sensitivity and specificity analysis.

RESULTS

The final analysis included 169 patients with a significant difference in renal dimension. RAS features were met in 61 patients. According to ROC curve analysis, the optimal index of renal asymmetry was 12 mm. The sensitivity and specificity for this method were 82.0% and 83.3%, respectively, and AUC was 86.3%.

CONCLUSION

Changing the definition of a significant difference in kidney size from 15 mm to 12 mm increases sensitivity and specificity for abnormal RAR and this finding may accelerate the diagnosis of RAS.

Correlation of Sonographic Parameters with Renal Function in Patients with Newly Diagnosed Chronic Kidney Disease

AIMS

To correlate sonographic renal parameters (mean renal cortical thickness, length and volume) with renal functions in patients with newly diagnosed chronic kidney disease. To predict the best renal parameter correlating with renal functions in patients with newly diagnosed chronic kidney disease.

MATERIAL AND METHODS

A hospital-based prospective cross-sectional study was conducted in the Department of Radiodiagnosis, Indira Gandhi Medical College and Hospital, Shimla, in 78 adults with newly diagnosed chronic kidney disease visiting the hospital from December 2019 to November 2020.

RESULTS

A statistically significant positive correlation was found between eGFR and mean renal length, mean renal cortical thickness, and mean renal volume (p <0.001).The strongest correlation was shown between mean renal volume and eGFR (r = 0.90, r² = 0.82; p-value <0.001).

CONCLUSIONS

Renal volume and cortical thickness should be considered along with traditional renal parameters.

Effect of age and sex in renal function by ultrasound and serum chemistry in two primate species (Alouatta caraya and Sapajus apella)

BACKGROUND

Comparative studies of kidney morphophysiology in nonhuman primates can help us investigate interspecies differences in growth and aging patterns.

METHODS

We tested the effect of age and sex in renal morphophysiology in 21 Alouatta caraya and 21 Sapajus apella (age range = 0.5-26 years) by ultrasound, red blood cell (RBC) count, and kidney function tests.

RESULTS

A. caraya had greater growth rate and absolute renal volume than S. apella, but the latter showed a greater relative renal volume and RBC count. There was a negative relationship between RBC and age, a positive relationship between creatinine and body mass, and an apparent negative relationship between creatinine and age only in S. apella.

CONCLUSIONS

Our results indicate that A. caraya has a faster aging mechanism than S. apella, and the higher relative kidney volume in S. apella is suggestive of high metabolic demands in this species.

Measurement of renal cortical thickness using ultrasound in normal dogs: a reference range study considering bodyweight and body condition score

The renal cortical thickness (RCT) reflects the pathological condition of the kidney, and measuring this parameter can help diagnose renal fibrosis in dogs. The normal reference range of RCT in dogs is broad (3-8 mm) because of the extreme diversity in body size. Therefore, this retrospective, reference interval, and observational design study aimed to establish a normal reference range for RCT in dogs measured using ultrasound by considering bodyweight (BW), body surface area (BSA), body condition score (BCS), and abdominal aorta (Ao) diameter. A total of 60 dogs met the inclusion criteria, and abdominal ultrasound images and medical records of these dogs were analyzed. RCT was measured at 1-3 points where the renal capsule and broad base of the medullary pyramid were clearly observed. Ao diameter was measured caudal to the branch of the left renal artery in the mid-sagittal view. The RCT showed positive correlations with BW and BSA and a negative correlation with BCS, which can be described as follows: RCT (mm) = 0.131 × BW - 0.166 × BCS + 3.580. The RCT:Ao ratio was 0.70 ± 0.09 (mean ± standard deviation). No significant differences were found in the RCT:Ao ratio depending on BW or BCS. In conclusion, the RCT:Ao ratio and relative RCT considering both BW and BCS are potentially useful for evaluating the normality of the renal cortex on ultrasound examination in dogs with various physiques.

Evaluation of Normal Renal Size and its Influencing Factors: A Cross-Sectional Study on the Adult Population of Mashhad

BACKGROUND

The normal range of kidney size is a controversial issue among different populations given to its impressibility by multiple factors, therefore, this study aimed to provide valid reference ranges for kidney dimensions in the adult population of Mashhad. Also, we assessed the association of kidney size characteristics with some personal predisposing factors.

METHODS

This cross-sectional study was conducted on 938 healthy individuals. Ultrasound measurement, physical examination, and laboratory analysis were performed. Demographic, dietary, and anthropometric data were obtained. The variables were categorized into 5 groups each, and data analysis were performed using the following statistical tests: Pearson correlation test, variance analysis, t-test, and chi-square test. A value of p<0.05 was considered statistically significant.

RESULTS

Weight had the most association with kidney size followed to a lesser extent by height and age. Even after adjustment for other confounding variables, weight remained as an independent factor, while this effect was resolved for height and age. Also, all values for renal function, body bio-impedance, blood pressure components, and water intake were notably correlated with kidney size.

CONCLUSION

This study determined the normal kidney size in healthy adults. We also declared the normal range of kidney size is a dynamic concept and should be assessed for each individual separately according to their personal determinative factors.

Diagnostic performance of renal ultrasonography in detecting chronic kidney disease of various severity

Background

Association between early diagnosis of chronic kidney disease (CKD) and low morbidity and mortality rate has been proven. Thus, tools for early CKD diagnosis are vital. Ultrasonography has been widely used to diagnose and monitor the progression of CKD.

Objectives

To determine the performance of selected renal ultrasonographic parameters for the diagnosis of early CKD.

Methods

In a cohort of patients diagnosed with CKD (n = 100), diagnostic performance of ultrasonographically measured renal length (RL), renal cortical thickness (RCT), and parenchymal thickness (PT) was determined using receiver operating curve analysis; correlation of each parameter with the associated comorbidities and serum creatinine (Scr) levels was also determined. Severity of CKD was graded with estimated glomerular filtration rates (eGFR).

Results

Of all patient participants, 85 had severity grades 2 or 3. Mean (standard deviation) Scr was 1.88 (0.60) mg/dL; eGFR was 43.3 (11.85) mL/min/1.73 m2. RL was 9.01 (0.83) cm, PT was 1.32 (0.22) cm, and RCT was 6.0 (0.10) mm. PT and RCT were positively correlated with eGFR (P = 0.01 and 0.002, respectively). Early CKD was better predicted by PT (area under the curve (AUC) 0.735; 82% sensitivity; 30% specificity; 68% positive predictive value (PPV)) and RCT (AUC 0.741; 82% sensitivity; 48% specificity; 51% PPV); severe CKD was better predicted by RL (AUC 0.809; 67% sensitivity; 26% specificity, 45% PPV; 13% negative predictive value).

Conclusion

Index ultrasonic parameters show a diagnostic role in different stages of CKD. The index ultrasound and biochemical parameters showed a complementary role in predicting renal dysfunction.

Reference indices for evaluating kidney dimensions in children using anthropometric measurements

Background

Kidney pathologies often result in change in renal size. Knowledge of normal kidney sizes is important for screening, diagnosis, prognosis and follow-up management of paediatric renal diseases.

Objectives

The aim of this study was to establish the age-, height- and weight-matched kidney dimensions in apparently healthy Nigerian children.

Method

A descriptive, cross-sectional study of right and left kidney parameters (length, width, thickness and volume) of 1315 school-aged Nigerian children was conducted over 8 months. Ages ranged from 5 to 17 years. Parameters were obtained using a General Electric (GE) LOGIC 400CL ultrasound machine. Kidney dimensions were correlated with age, sex and anthropometric measurements.

Results

Normative values for all the kidney parameters for each age, height and weight groups and also gender were established for the study population. The left kidneys were noted to be longer and thicker, and of more volume than the right kidneys. The right kidneys were seen to be wider (p < 0.01). Length of the left kidneys in females was noted to be more than those of the males in the age- and weight-matched categories (p < 0.05). The width of both kidneys was higher in the males in all the categories (p < 0.05). Males showed higher values of thickness and volume in the height category. All the renal parameters significantly correlated with body size indicators, except for body mass index.

Conclusion

This study has established gender-, age-, weight- and height-specific range of values of the kidney parameters of apparently healthy children together with regression models.

Ultrasonographic Renal Dimensions Amongst Adult Nigerian Diabetics: Correlation with Clinical, Anthropometric and Metabolic Risk Factors

Diabetes is now becoming a major public health problem globally. It is increasingly associated with renal diseases, particularly chronic kidney disease worldwide. A simple, accurate, reproducible and non-invasive method of evaluation is necessary for early morphological assessment for timely intervention, diagnosis, treatment, and evaluation of renal diseases in diabetes mellitus. In this cross-sectional comparative study, among one hundred and four adult diabetic cases and fifty-three healthy controls, the ultrasonographic renal dimensions were determined and compared in both cases and controls. Correlations were sought between the renal dimensions and the clinical, anthropometric, and metabolic characteristics of the study population. The dimensions of the kidneys in diabetic cases versus controls were; lengths (9.94± 0.76cm vs 9.27 ± 0.90 and 10.28 ± 0.87cm vs 9.41± 1.02cm(p=<0.001), cortical thickness (1.77± 0.28cm vs 1.26± 0.49cm, p<0.001 and 1.89± 0.52cm vs 1.37± 0.78cm, p<0.001 and volumes (121.9± 39.50cm3 vs 107.8± 29.82cm, p=0.026 and 136.3± 45.09cm3 vs 118.8± 33.79cm3, (p=0.015) were significantly higher in Diabetes mellitus cases on the right and left respectively. The waist circumference, fasting blood sugar, postprandial blood sugar, cholesterol, and urinary albumin, all had correlations with the mean kidney length. Taking together, the ultrasonographic renal lengths, cortical thickness, and volumes are increased in diabetic disease without renal function compromise compared to age-, gender- and body mass index-matched non-diabetic controls. The clinical, anthropometric, and metabolic parameters of the diabetes cases also showed significant correlations with mean kidney length.

QUANTITATIVE MORPHO-FUNCTIONAL ANALYSIS OF SIMMETRY-ASIMMETRY CONDITION OF HUMAN NORMAL KIDNEY

The aim of the present research was to perform quantitative morpho-functional analysis of the symmetry-asymmetry condition of human normal autopsy and “live” kidneys using the complex of morphological and ultra-sonographic methods. METHODS: Morphometric study of 10 autopsy kidneys of healthy men 36 - 60 years of age was conducted; retrospective analysis of data obtained by vital ultra-sonographic study of 65 kidneys of men without renal diseases at the same age period was performed as well. All kidneys were with a single renal artery. RESULTS: The kidney length and width are statistically significantly greater on right, than on left, but there were no statistically significant differences between right and left kidneys in thickness of the kidney and size of its parenchyma. Results of morphometric study of autopsy renal glomeruli, as well as multislice computed tomographic angiography and doppler investigation of renal artery in color duplex scan mode did not show any statistically significant differences on right and on left. CONCLUSIONS: For determining of the standard quantitative indicators of kidney it is necessary to take into account the age and gender of the studied people, as well as the effect of side.

Reference ranges for ultrasonographic renal dimensions as functions of age and body indices: A retrospective observational study in Taiwan

An ethnicity-based reference range for normal renal size is fundamental for ultrasonographic assessment. Herein, we aimed to establish a Chinese renal reference by a large sample size, as well as to elucidate the relationship of renal dimension to age and body indices, with the aid of a comprehensive literature review. Records of 3707 healthy cases were obtained from health evaluation centers of Kaohsiung and Linkuo Chang Gung Memorial Hospitals. As a result, the mean right renal length was 10.62±0.69 cm, left renal length 10.76±0.70 cm, right renal width 4.78±0.75 cm, and left renal width 5.10±0.64 cm. Renal size was well-correlated curvilinearly to age, while linearly to body height, body weight, and body mass index. Renal size increases and then decreases with aging, and significant variations of renal size exist among different ethnicities. Our work provides a reliable reference range for renal size in the Chinese population, and valid relationships between renal dimensions and other parameters.

Automation of the kidney function prediction and classification through ultrasound-based kidney imaging using deep learning

Prediction of kidney function and chronic kidney disease (CKD) through kidney ultrasound imaging has long been considered desirable in clinical practice because of its safety, convenience, and affordability. However, this highly desirable approach is beyond the capability of human vision. We developed a deep learning approach for automatically determining the estimated glomerular filtration rate (eGFR) and CKD status. We exploited the transfer learning technique, integrating the powerful ResNet model pretrained on an ImageNet dataset in our neural network architecture, to predict kidney function based on 4,505 kidney ultrasound images labeled using eGFRs derived from serum creatinine concentrations. To further extract the information from ultrasound images, we leveraged kidney length annotations to remove the peripheral region of the kidneys and applied various data augmentation schemes to produce additional data with variations. Bootstrap aggregation was also applied to avoid overfitting and improve the model's generalization. Moreover, the kidney function features obtained by our deep neural network were used to identify the CKD status defined by an eGFR of <60 ml/min/1.73 m2. A Pearson correlation coefficient of 0.741 indicated the strong relationship between artificial intelligence (AI)- and creatinine-based GFR estimations. Overall CKD status classification accuracy of our model was 85.6% -higher than that of experienced nephrologists (60.3%-80.1%). Our model is the first fundamental step toward realizing the potential of transforming kidney ultrasound imaging into an effective, real-time, distant screening tool. AI-GFR estimation offers the possibility of noninvasive assessment of kidney function, a key goal of AI-powered functional automation in clinical practice.

Sonographic evaluation of kidney echogenicity and morphology among HIV sero-positive adults at Lagos University Teaching Hospital

AIM

To evaluate the role of kidney echogenicity and morphology in the diagnosis of human immunodeficiency virus-associated nephropathy (HIVAN).

SUBJECTS AND METHODS

In the cross-sectional study, a sample of 340 anti-retroviral therapy (ART)-naïve AIDS patients underwent laboratory CD4+ count, serum creatinine determination and sonographic renal echogenicity grading and size measurement. Rounded kidneys were described as bulbous while bean-shaped kidneys were described as reniform; echogenicity was categorized into grades 0, 1, 2 and 3. Kidney length, width, thickness and volume were measured in HIVAN and control groups.

RESULTS

Mean age of the population was 42.7 ± 9.4 years; 87.4% had HIVAN. Mean CD4+ count, serum creatinine and GFR for HIVAN patients were 153.1 ± 103.2 cells/mm3, 218.4 ± 147.4 mmol/L and 50.1 ± 23.6 mL/min/1.73 m2 for males and 121.9 ± 91.0 cells/mm3, and 222.0 ± 150.4 mmol/L and 39.3 ± 20.6 mL/min/1.73 m2 for females, respectively; control subjects and non-HIVAN patients had grade 0 renal echogenicity; 56.9% of HIVAN patients had echogenicity grade 3; 5.3% had kidney length < 10 cm; 73.9% had bulbous kidneys; the kidney was significantly wider and thicker in HIVAN (p < 0.05).

CONCLUSION

Sonographic evaluation of renal echogenicity and morphology can reliably predict HIVAN diagnosis. Apathy to screening and late presentation were high while HIV/AIDS remains an important public health problem in the city of Lagos. Unilateral reduction in kidney size could be a major sequela of AIDS while sonographic measurement of absolute kidney length appears inadequate in the evaluation of AIDS patients with nephropathy.

RENAL ARTERIAL DOPPLER VELOCIMETRIC INDICES AMONG HEALTHY SUBJCTS IN NORTH WEST NIGERIA

BACKGROUND

Doppler sonography is a non-invasive modality for evaluation of renal vascular anatomy and flow dynamics, causes of secondary hypertension and renal diseases.

AIM

To determine the normal reference values for the renal arterial Doppler velocimetric indices in healthy adults and correlate them with gender and age.

METHODOLOGY

The subjects consist of 36 males and 44 females. They were scanned using 3.5MHz transducer. After parenchymal assessment, the renal arteries were identified using colour mapping, followed by measurement of velocimetric indices on spectral Doppler tracings on each side.

RESULTS

The mean peak systolic velocity (PSV) was highest on the left side in males measuring 65.75 ± 28.41cm/sec and 60.7 ± 24.20cm/sec on the right. In females, it measured 61.83 ± 22.50cm/sec and 60.04 ± 24.67cm/sec on the right and left sides. The mean end diastolic velocity (EDV) was higher on the right side, measuring 23.59 ± 11.45cm/sec and 22.50 ± 8.37cm/sec in males and 25.19 ± 10.72cm/sec and 22.33 ± 8.47cm/sec in females. There was age related dependency on the mean resistive index (RI).

CONCLUSION

This study has shown that there was a statistical significant correlation between RI and systolic-diastolic ratio (S/D) with age. However, gender did not show significant correlation with these indices.

Clinical significance of renal cortical thickness in patients with chronic kidney disease

PURPOSE

The aim of this study was to evaluate the correlations between laboratory findings and ultrasonographic measurements of renal length and cortical thickness in patients receiving follow-up for chronic kidney disease (CKD).

METHODS

A total of 41 CKD patients (18 males and 23 females; mean age, 65.2 years; range, 42 to 85 years) with a low glomerular filtration rate who did not require renal replacement therapy were included in this prospective study. Patients were followed up with laboratory assays at bimonthly intervals and with ultrasonography performed twice a year. Renal cortical thickness, renal length, and estimated glomerular filtration rate (eGFR) values were compared using the paired-samples t test. Additionally, Pearson correlation analysis was conducted between renal length and cortical thickness measurements and eGFR values to assess kidney function.

RESULTS

At the beginning of the study and after 24 months, mean eGFR values of the 41 patients were 35.92 mL/min and 28.38 mL/min, respectively. The mean renal length was 91.29 mm at the beginning of the study and 90.24 mm at the end of the study. The mean cortical thickness was 5.76±2.05 mm at the beginning of the study and 5.28±1.99 mm at the end of the study. A statistically significant positive association was found between eGFR and mean renal length (r=0.66, P<0.01) and between eGFR and mean cortical thickness (r=0.85, P<0.01), with the latter being more prominent.

CONCLUSION

Our study suggests that ultrasonographic cortical thickness measurements may be an important imaging technique in the follow-up care of patients with CKD.

Population-based estimation of renal function in healthy young Indian adults based on body mass index and sex correlating renal volume, serum creatinine, and cystatin C

This population-based prospective study was undertaken in Mahatma Gandhi Medical College to estimate the renal function in young healthy Indian adults. A young healthy heterogeneous Indian cohort comprising 978 individuals, predominantly medical students, was assessed by a detailed questionnaire, and variables such as height, weight, body mass index (BMI), birth weight, and blood pressure were documented. Laboratory investigations included serum creatinine, serum cystatin C, blood sugar, urine protein, and imaging of the kidneys with ultrasound. The mean age of the cohort was 25±6 years, comprising 672 males and 306 females. The estimated glomerular filtration rates (eGFRs) by the Cockcroft–Gault formula for BMI <18.5 kg/m², 18.5–24.99 kg/m², 25–29.99 kg/m², and ≥30 kg/m² were 71.29±10.45 mL/min, 86.38±13.46 mL/min, 98.88±15.29 mL/min, and 109.13±21.57 mL/min, respectively; the eGFRs using cystatin C for the four groups of BMI were 84.53±18.14 mL/min, 84.01±40.11 mL/min, 79.18±13.46 mL/min, and 77.30±10.90 mL/min, respectively. This study attempts to establish a normal range of serum creatinine and cystatin C values for the Indian population and shows that in young healthy Indian adults, eGFR and kidney volume vary by BMI and sex.

7 T renal MRI: challenges and promises

The progression to 7 Tesla (7 T) magnetic resonance imaging (MRI) yields promises of substantial increase in signal-to-noise (SNR) ratio. This increase can be traded off to increase image spatial resolution or to decrease acquisition time. However, renal 7 T MRI remains challenging due to inhomogeneity of the radiofrequency field and due to specific absorption rate (SAR) constraints. A number of studies has been published in the field of renal 7 T imaging. While the focus initially was on anatomic imaging and renal MR angiography, later studies have explored renal functional imaging. Although anatomic imaging remains somewhat limited by inhomogeneous excitation and SAR constraints, functional imaging results are promising. The increased SNR at 7 T has been particularly advantageous for blood oxygen level-dependent and arterial spin labelling MRI, as well as sodium MR imaging, thanks to changes in field-strength-dependent magnetic properties. Here, we provide an overview of the currently available literature on renal 7 T MRI. In addition, we provide a brief overview of challenges and opportunities in renal 7 T MR imaging.