Diagnostic value of real-time shear wave elastography in children with chronic kidney disease

Quantitative analysis of contrast-enhanced ultrasound and superb microvascular imaging for the evaluation of disease activity in inflammatory bowel disease

OBJECTIVE

To evaluate the effectiveness of conventional US (ultrasound), SMI (superb microvascular imaging), and CEUS (contrast-enhanced ultrasound) features for the assessment of the activity of inflammatory bowel disease.

METHODS

Conventional US, CEUS and SMI features of 76 patients were retrospectively analyzed. Patients were categorized into two groups: active group (n = 57) and inactive group (n = 19), with endoscopic results as reference standard. Results in the active group and inactive group were compared using an independent t-test, Mann-Whitney U test, chi-square test, and receiver operating characteristic curve (ROC) analysis. Cut-off values were determined using ROC analysis, and sensitivity and specificity were calculated. US quantitative and TIC-based quantitative parameters were analyzed, and each patient was scored based on the parameters that are statistically significant and immediately available in the clinic to evaluate the diagnostic ability of conventional US, SMI, and CEUS features for active IBD patients.

RESULTS

Qualitative parameters such as CEUS enhancement pattern I/II, LimbergIII/IV, and lost bowel stratification were reliable indicators of active patients. Quantitative parameters such as bowel thickness and VI of mSMI were reliable indicators of active patients. Patients scored based on these statistically significant parameters with a score ≥3, were highly suspected to be active patients. For TIC-based quantitative parameters, PE, WiAUC, WoAUC, WiWoAUC, WiR, WiPI, and WoR were statistically significant in the differentiation of active IBD from inactive IBD.

CONCLUSIONS

Conventional US, SMI, and CEUS features may help in the differentiation of active IBD from inactive IBD and have potential application value in the choice of treatment options.

Obesity and Body Composition in Relation to Liver and Kidney Ultrasound Elastography in Paediatric Patients with Either Hypertension or Chronic Kidney Disease

(1) Background: Ultrasound elastography is a novel ultrasound technique for evaluating tissue elasticity. One of the key factors influencing the measurement in children is excess weight. This study aimed to evaluate the effect of body composition, namely, fat mass, on liver and kidney ultrasound elastography in paediatric patients. (2) Methods: 114 participants, in whom bioimpedance, along with liver and kidney ultrasound elastography, were performed, were included (37 patients with chronic kidney disease, 46 patients with hypertension, and 31 healthy subjects). (3) Results: Bioimpedance analysis showed a significant correlation between liver elastography parameters and the phase angle (p = 0.002), fat-free mass (p = 0.001), body cell mass (p = 0.001), total body water (p = 0.001), extracellular water (p = 0.006), and, to lesser extent, fat mass (p = 0.041). On the contrary, kidney elastography parameters strongly correlated only with fat mass (p < 0.001 for both kidneys). (4) Conclusions: Liver and kidney stiffness increased in overweight participants and showed significant correlation with fat mass, particularly in the case of kidney elastography.

Diagnostic utility of two-dimensional shear wave elastography in nephropathic dogs and its correlation with renal contrast-enhanced ultrasound in course of acute kidney injury

Aims of our study were to evaluate the feasibility and diagnostic value of two-dimensional shear wave elastography in dogs with acute kidney injury, chronic kidney disease, and acute on chronic kidney disease, its correlation with renal functional (creatinine, urea), and prognostic parameters (serum calcium-phosphorus product, urinary output), and with contrast-enhanced ultrasound (qualitative and quantitative evaluation). The study was prospective. A group of healthy (Group A) and a group of nephropathic dogs (Group B) were included. Shear wave elastography was performed on the left kidney of the subjects of both groups; contrast-enhanced ultrasound was performed only in dogs with acute kidney injury and acute on chronic kidney disease. Sixty-four dogs were included (Group A, n=24; Group B, n=40). The renal stiffness values were significantly higher in Group B than Group A; optimal cut-off stiffness values for detection of renal pathology were: ≥1.51 m/sec (area under the curve, 0.84; 95% confidence interval 0.74-0.94) and ≥6.75 kPa (area under the curve, 0.84; 95% confidence interval 0.73-0.94). For contrast-enhanced ultrasound, a significant positive correlation was found between renal stiffness, area under the curve, and wash-out area under the curve values of cortex quantitative analysis. No correlations were found between renal stiffness and renal functional and prognostic parameters. Shear wave elastography showed diagnostic utility to detect renal abnormalities in dogs with acute kidney injury, chronic kidney disease and acute on chronic kidney disease, however, it could not differentiate between these different nephropathies.

Diagnostic assessment of two-dimensional shear wave elastography in relation to dimethyl arginine levels in dogs with chronic kidney disease

BACKGROUND

In veterinary medicine, previous studies regarding the diagnostic performance of shear wave elastography (SWE) in chronic kidney disease (CKD) are not consistent with each other. Moreover, there has been no study evaluating the relationship between symmetric dimethyl arginine (SDMA) concentration and renal shear wave velocity (SWV) using two-dimensional SWE (2D SWE) in dogs with CKD.

OBJECTIVES

This study aimed to evaluate the diagnostic capability of 2D SWE in dogs with CKD and to assess the relationship between renal SWV and SDMA concentration.

METHODS

Dogs with healthy kidneys and dogs with CKD underwent 2D SWE and SDMA assay. Renal stiffness was estimated as renal SWV in m/s.

RESULTS

SDMA concentration had a weak positive correlation with the left (r = 0.338, p = 0.022) and right renal SWV (r = 0.337, p = 0.044). Renal SWV was not significantly different between healthy kidney and CKD groups in the left (p = 0.085) and right (p = 0.171) kidneys.

CONCLUSIONS

2D SWE may could not distinguish between dogs with healthy kidney and dogs with early stage of CKD, but it would be useful for assessing the serial change of renal function in dogs.

Diagnostic performance of renal cortical elasticity by supersonic shear wave imaging in pediatric glomerular disease

PURPOSE

To explore the diagnostic performance of renal cortical elasticity expressed by Young's modulus (YM) using the supersonic shear wave imaging (SSI) technique in pediatric glomerular disease.

MATERIALS AND METHODS

Seventy-one children with glomerular disease confirmed by renal biopsy and sixty healthy volunteers were enrolled in this study. Conventional and SSI ultrasound examinations were performed in all individuals for both kidneys. We measured renal length, renal width, renal thickness, parenchyma thickness, interlobar arterial resistive index (RI) and the YM of the middle and lower pole.

RESULTS

Regardless of which pole and which side of the kidney, the YM in the disease group was significantly higher than that in the control group (P < 0.001). The YM of the middle pole in the left kidney demonstrated the largest AUC (0.936, P < 0.001), and the corresponding cut-off value was 15.48 kPa with a sensitivity of 87.3% and a specificity of 86.7%. There was no significant difference in the YM among different pathological types of pediatric glomerular disease in the disease group, and the same in different grades of patients with Immunoglobulin A (IgA) nephropathy by Lee classification and the Oxford Classification as well as Henoch-Schonlein purpura nephritis (HSPN) by International Study of Kidney Disease in Children (ISKDC) classification (P > 0.05). We found positive but weak correlations between the YM and renal length (r = 0.299, P = 0.001), renal width (r = 0.408, P < 0.001), renal thickness (r = 0.299, P = 0.001), and parenchyma thickness (r = 0.212, P = 0.015), whereas the YM had no significant correlations with age, sex, BMI, interlobar arterial RI, and laboratory findings (P > 0.05).

CONCLUSIONS

SSI technology is a non-invasive and feasible method for the diagnosis of pediatric glomerular disease. However, SSI did not show good performance in distinguishing different pathological types and disease grades in our study.

The value of shear wave elasticity and shear wave dispersion imaging to evaluate the viscoelasticity of renal parenchyma in children with glomerular diseases

BACKGROUND

To study the value of shear wave elasticity and shear wave dispersion imaging to evaluate the viscoelasticity of renal parenchyma in children with glomerular diseases.

METHODS

Forty-three children with glomerular diseases were prospectively evaluated by shear wave elasticity (SWE) and shear wave dispersion imaging (SWD); 43 healthy volunteers served as the control group. The shear wave velocities (SWV) and the dispersion slopes were measured at the upper, middle, and lower poles of both kidneys. The analysis of mean SWV and mean dispersion slope in control and patient groups was used to further evaluate the value of SWE and SWD in the viscoelasticity of renal parenchyma in children with glomerular disease.

RESULTS

The mean SWV in children with glomerular disease was higher than that in the healthy control group (1.61 ± 0.09 m/s vs. 1.43 ± 0.07 m/s, p < 0.001). Compared with healthy group, the mean dispersion slope in children with glomerular disease was significantly increased (13.5 ± 1.39 (m/s)/kHz vs. 12.4 ± 1.40 (m/s)/kHz, p < 0.001). Correlation analysis showed absence of correlation between the SWV and dispersion slope of occult blood, serum creatinine, 24-h urine protein, blood albumin, BMI and ROI box depth of children with glomerular disease.

CONCLUSIONS

The present study shows that it is feasible to use SWE and SWD to evaluate the difference of viscoelasticity of the renal parenchyma between healthy children and those with glomerular disease.

2D Shear wave elastography for evaluation of renal cortex and medulla: stiffness values in healthy children

PURPOSE

To evaluate renal cortical and medullary stiffness using 2D Shear-wave elastography (SWE) in healthy children.

METHODS

In this IRB approved prospective study, we measured the stiffness of cortex and medulla of children (4 months-17 years) at the upper pole, mid pole, and lower pole in bilateral kidneys.

RESULTS

The median (IQR) values of renal cortex in <1 year age group was 8.7 (5.7-11.7) kPa for right and 8.7 (4.2-14.1) kPa for the left side. For 1-5 years age group, it was 7.3 (5.3-10) kPa for the right and 8.9 (6-12.3) kPa for the left side. For >5 years, it was 7.4 (5.3-11.2) kPa for the right and 9.6 (6.2-12.7) kPa for the left side. The median (IQR) values of renal medulla in <1 year age group was 7.1 (5.1-12.5) kPa for right and 6.8 (4-10.6) kPa for the left side. For 1-5 years age group, it was 7.2 (4.9-9.7) kPa for the right and 6.9 (5.6-9.9) kPa for the left side. For >5 years, it was 6.8 (5.1-9.6) kPa for the right and 7 (5-10.2) kPa for the left side. The differences in the elasticity values amongst these groups were statistically insignificant (p>0.05). There was a significant correlation between SWE values of cortex and medulla of right kidney (ρ=0.64) and of left kidney (ρ=0.61), respectively.

CONCLUSION

SWE values of renal cortical and medullary stiffness in healthy children do not correlate with age. There is a significant correlation between SWE values of cortex and medulla of the kidneys in healthy children.

Liver and kidney ultrasound elastography in children and young adults with hypertension or chronic kidney disease

BACKGROUND

Ultrasound elastography is a research method increasingly used to measure tissue elasticity. The aim of the study was to assess its usability in pediatric patients with either chronic kidney disease (CKD) or hypertension.

METHODS

A total of 46 patients with CKD (group 1), 50 patients with hypertension (group 2), and 33 healthy participants as the control group were included. In all, we performed studies assessing their cardiovascular risk along with liver and kidney elastography.

RESULTS

Liver elastography parameters were increased compared to those in the control group (1.49 m/s, p = 0.007, in group 1 and 1.52 m/s, p < 0.001, in group 2, vs. 1.41 m/s among controls). Kidney elastography parameters were significantly higher in group 2 (1.9 m/s, p = 0.001, and 1.9 m/s, p = 0.003, in each kidney) when compared to group 1 (1.79 m/s and 1.81 m/s). Additionally, all participants were divided according to overweight/obesity and normal weight status, where both liver (1.53 m/s vs. 1.45 m/s, p < 0.001) and kidney parameters (1.96 m/s and 1.92 m/s vs. 1.81 m/s and 1.84 m/s, p = 0.002) were significantly higher in the group of overweight/obese subjects.

CONCLUSIONS

Ultrasound elastography of the liver and kidney is feasible in pediatric patients with either CKD or hypertension, showing increased liver stiffness parameters in both groups, further aggravated by obesity. In obese patients with CKD, kidney stiffness also increased indicating a negative effect of clustering cardiovascular risk factors leading to decreased kidney elasticity. Further research is warranted. A higher resolution version of the Graphical abstract is available as Supplementary information.

Ultrasound Elastography in Children

Ultrasound elastography is a novel ultrasound technique, being extensively researched in children in the last decade. It measures tissue elasticity with the observation of tissue response after an external stimulus. From research to clinical practice, ultrasound elastography has evolved significantly in liver fibrosis evaluation in children; however, several other applications of the technique are available in both clinical practice and research environments. Practically, in children any organ can be assessed, including the brain in early ages, along with muscle and connective tissue elasticity evaluation, spleen, kidney, skin, lymphatic tissue, etc. The elastography method, age, body mass index and technical points should be considered when performing ultrasound elastography. This review highlights its vast potential as a diagnostic tool in the pediatric population, where ultrasound is a dominant imaging tool; however, the indications and exam protocol for its clinical use in several fields in pediatrics have yet to be elucidated.

Shear wave elastography using high-frequency linear probe for transplant kidney monitoring: A methodological study

OBJECTIVES

To investigate the influencing factors of the image quality of shear wave elastography (SWE) performed using a high-frequency probe and its reproducibility for renal allografts.

METHODS

A total of 211 patients with transplanted kidneys who underwent SWE examination performed using high-frequency or low-frequency probes were recruited for the study. The reproducibility of inter- and intraobserver agreements were analysed by using the intraclass correlation coefficient (ICC). According to the colour filling of the area of interest and imaging noise when conducting SWE, the image quality was classified as three grades: "good", "common", and "poor". A logistic regression was used to analyse the independent factors for SWE quality.

RESULTS

In the comparative analysis, high frequency, transection measurement and middle pole were selected as the appropriate measurement methods. Regarding reproducibility, the ICCs) of the intra- and interobserver agreements were 0.85 and 0.77, respectively. Multivariate analysis indicated that only the skin allograft distance and kidney width were independent variables for SWE quality. In the subgroup analysis of the skin-allograft distance, the "good" and "common" rates of images decreased as the distance increased, but the CV (coefficients of variation) showed the opposite trend. The SWE quality of kidney width <5.4 cm was significantly better than that of kidney width ≥5.4 cm.

CONCLUSIONS

High-frequency SWE can be used in the evaluation of transplanted kidneys due to its good repeatability and high successful measurement rate, but we should pay attention to the influence of the skin-allograft distance and kidney width on SWE quality.

Evaluation of renal parenchyma stiffness in children with nephropathy by shear wave elastography: A systematic review and meta-analysis

BACKGROUND

The role of shear wave elastography (SWE) in assessing renal parenchymal stiffness in children with nephropathy is obscure. This systematic review and meta-analysis investigated this issue.

MATERIALS AND METHODS

PubMed, Embase, Web of Science, and the Cochrane Library databases were searched for studies evaluating renal parenchyma stiffness in children with nephropathy by SWE from inception to October 2021. The search was not limited by language. Two investigators independently screened the literature and extracted data. Any discrepancies were resolved via discussion with the senior professor. Study quality was assessed by the Newcastle-Ottawa Scale and the standardized mean difference of shear wave velocity (SWV) for the evaluation of renal parenchyma stiffness was determined.

RESULTS

Eight studies involving a total of 496 children with nephropathy and 353 healthy children were selected. Eight studies used SWV as parameters of renal parenchyma stiffness. The SWV was not significantly different in children with renal lesion than in those without renal lesion, with a standardized mean difference of 0.49 (95% confidence level, -0.40 to 1.39, p = 0.28). There was a high heterogeneity between studies.

CONCLUSION

Although there was significant difference in SWE of renal parenchyma between controls and patients in each study we included, statistical differences were not seen after results of all research were amalgamated due to different diseases with different pathomechanisms. SWE could be used to evaluate renal parenchymal stiffness in children with kidney disease after more well-designed and high-quality studies with a large sample size will be performed in the future.

Application value of shear-wave elastography combined with monochrome superb microvascular imaging in renal allograft chronic rejection

BACKGROUND

Conventional ultrasound (US), which include gray scale US and Doppler US, is the first-line imaging modality for the evaluation of renal allograft; however, conventional US indicators have limitations.

OBJECTIVE

To explore the application value of shear-wave elastography (SWE) combined with monochrome superb microvascular imaging (mSMI) in renal allograft chronic rejection (CR).

METHODS

From November 2021 to February 2022 in the Lanzhou University Second Hospital, the US features of 54 patients with renal allograft were retrospectively analyzed. Patients were categorized into two groups: stable group(n = 44) and CR group(n = 10), with clinical diagnosis as reference standard. The vascular index (VI) on mSMI and parenchymal stiffness were measured in the middle cortex of all renal allografts and receiver operating characteristic (ROC) curves were drawn to evaluate the feasibility of differentiation. Statistically significant US features and biochemical indicators such as creatinine were scored, and the results of the scores were analyzed by ROC curve.

RESULTS

The VI on mSMI of the stable group (49.5±2.0) was significantly greater than that of the CR group (33.8±5.9) (P = 0.028). There was a statistically significant difference in parenchymal stiffness between stable group (16.2kPa±1.2) and CR group (33.9kPa±6.6) (P = 0.027). The sensitivity was 90% and specificity was 81.8% of the scores in the differentiation of stable group from CR group (cut-off value, 2; P = 0.000).

CONCLUSION

SWE combined with mSMI may help differentiate stable renal allograft from renal allograft CR and have the potential application value in the diagnosis of renal allograft CR.

Predicting Progression of Kidney Injury Based on Elastography Ultrasound and Radiomics Signatures

Background: Shear wave elastography ultrasound (SWE) is an emerging non-invasive candidate for assessing kidney stiffness. However, its prognostic value regarding kidney injury is unclear. Methods: A prospective cohort was created from kidney biopsy patients in our hospital from May 2019 to June 2020. The primary outcome was the initiation of renal replacement therapy or death, while the secondary outcome was eGFR < 60 mL/min/1.73 m2. Ultrasound, biochemical, and biopsy examinations were performed on the same day. Radiomics signatures were extracted from the SWE images. Results: In total, 187 patients were included and followed up for 24.57 ± 5.52 months. The median SWE value of the left kidney cortex (L_C_median) is an independent risk factor for kidney prognosis for stage 3 or over (HR 0.890 (0.796−0.994), p < 0.05). The inclusion of 9 out of 2511 extracted radiomics signatures improved the prognostic performance of the Cox regression models containing the SWE and the traditional index (chi-square test, p < 0.001). The traditional Cox regression model had a c-index of 0.9051 (0.8460−0.9196), which was no worse than the machine learning models, Support Vector Machine (SVM), SurvivalTree, Random survival forest (RSF), Coxboost, and Deepsurv. Conclusions: SWE can predict kidney injury progression with an improved performance by radiomics and Cox regression modeling.

Shear Wave Elastography in the Evaluation of Renal Parenchymal Stiffness in Patients With Chronic Kidney Disease: A Meta-Analysis

Background

Chronic kidney disease (CKD) is a progressive loss of renal function, mainly due to hypertension, diabetes, and primary kidney disease. The histopathological findings are that of glomerulosclerosis, tubulointerstitial fibrosis and loss of renal parenchyma characterized. Therefrom, CKD can lead to higher morbidity and mortality. Patients with CKD have multiple risk factors, and the prevention work is complicated and arduous. Therefore, it is important to quantify the severity of CKD. The aim of this study is to investigate the value of shear wave elastography (SWE) in the evaluating renal parenchymal stiffness in patients with CKD.

Methods

We carried out the systematic search of databases for publications in PubMed, Embase and Cochrane Library on SWE evaluating renal fibrosis in patients with CKD. The Endnote X9, STATA 16, Review Manager 5.3 and other software were used to sort out documents, extract, integrate and analyze data.

Results

The outcomes were utilized to appraise the diagnostic accuracy of SWE and diagnose the CKD with renal fibrosis. A total of 405 patients were enrolled and their data analysis results were as follows: summary of sensitivity (S-SEN) 84% (95% confidence interval (CI): 80-87%); specificity (S-SPE) 80% (95% CI: 76-84%); summary of DLR (digital light radiography) positive (DLR-P) 4.29 (95% CI: 3.43 - 5.37); and DLR negative (DLR-N) 0.20 (95% CI: 0.16 - 0.25). The corresponding areas under the curves of diagnostic odds ratio (DOR) and summary receiver operating characteristic curve (SROC) were 21.50 (95% CI: 14.69 - 31.46) and 89% (95% CI: 86-92%), respectively.

Conclusions

SWE is highly accurate and has clinical significance for evaluating renal fibrosis, especially when the shear modulus value is used as the threshold.

Liver stiffness assessed by shear-wave elastography declines in parallel with immunoregulatory proteins in patients with chronic HCV infection during DAA therapy

BACKGROUND

A rapid decline of liver stiffness (LS) was detected by non-invasive methods in patients with chronic hepatitis C (HCV) infection during treatment with direct-acting antivirals (DAA).

OBJECTIVE

To investigate the influence of inflammation on LS.

METHODS

We prospectively examined LS by sonographic shear-wave elastography in 217 patients during DAA therapy from treatment initiation (BL) to 12 weeks after end of therapy (SVR12). Demographic data, laboratory findings and serum levels of cytokines were determined.

RESULTS

Values of LS decreased from 1.86 m/s to 1.68 m/s (p = 0.01) which was most pronounced in patients who had F4 fibrosis at BL (3.27 m/s to 2.37 m/s; p <  0.001). Initially elevated values of aminotransferases, ferritin, IgG (p <  0.001 each) and international normalized ratio (p <  0.003) declined, thrombocyte count (p = 0.007) increased. Correlations of these laboratory parameters with BL levels of LS measurement (LSM) were most apparent in patients with F1-F3 fibrosis. Tumor necrosis factor (TNF)-α (p = 0.031), interleukin (IL)-10 (p = 0.005) and interferon y inducible protein (IP)-10 (p <  0.001) decreased in parallel with LSM under DAA therapy and corelated with BL values.

CONCLUSION

Decrease of systemic inflammatory parameters correlated with LSM under DAA therapy. We conclude that regression of LSM is attributable to the decline of inflammation rather than reflecting fibrosis.