Quantitative parameters of contrast-enhanced ultrasonography for assessment of renal pathology: A preliminary study in chronic kidney disease

Value of conventional ultrasound and contrast-enhanced ultrasound for the assessment of renal allograft dysfunction and prognosis

BACKGROUND

Ultrasound (US) is the primary imaging modality for the assessment of transplanted kidneys. This study aims to investigate the ability of conventional US and contrast-enhanced US (CEUS) in assessing renal allograft function and prognosis.

METHODS

A total of 78 consecutive renal allograft recipients were enrolled. Patients were classified as normal allograft function (n = 41) and allograft dysfunction (n = 37) groups. All patients underwent US and parameters were measured. The independent-samples t-test or Mann-Whitney U test, logistic regression analysis, Kaplan-Meier survival plots, and Cox regression analysis were used.

RESULTS

In multivariable analysis, cortical echo intensity (EI) and cortical peak intensity (PI) were determinant US parameters for renal allograft dysfunction (p = .024 and p = .003, respectively). The combination of cortical EI and PI showed an area under the receiver operating characteristic curve (AUROC) of .785 (p < .001). Of 78 patients (median follow-up: 20mo), 16 (20.5%) exhibited composite end points. Cortical PI had a general prediction accuracy with an AUROC of .691, sensitivity of 87.5%, and specificity of 46.8% at the threshold of 22.08 dB in predicting prognosis (p = .019). The combination of estimated-glomerular filtration rate (e-GFR) and PI in predicting prognosis showed an AUROC of .845 with a cut-off value of .836, sensitivity of 84.0%, and specificity of 67.3% (p < .001).

CONCLUSION

This study indicates that cortical EI and PI are useful US parameters for evaluating renal allograft function and e-GFR combined with PI may provide a more accurate predictor of survival.

Noninvasive evaluation of IgA nephropathy fibrosis using Doppler ultrasound

In this study, we aimed to explore the clinical value of routine color ultrasound parameters in the evaluation of tubular atrophy and interstitial fibrosis (TA/IF) in IgA nephropathy (IgAN). We enrolled 725 patients with IgAN who underwent renal biopsy at the First Affiliated Hospital of Anhui Medical University between January 2019 and May 2022. Examinations were performed to measure the routine ultrasound renal parameters and renal biopsy was done within next three days. Univariate and multivariate analyses were used to determine the correlates and the independent predictors of TA/IF. Simultaneously, a nomogram based on risk indicators was created to predict TA/IF. Univariate and multivariate analyses showed that sex (p < 0.001, OR = 2.538, 95%CI: 1.739–3.734), renal length (p < 0.001, OR = 0.927, 95%CI: 0.905–0.95), resistive index of main renal artery (p = 0.037, OR = 1.891, 95%CI: 1.027–3.426), peak systolic velocity of segmental renal artery (p = 0.58, OR = 0.975, 95%CI: 0.399–0.841), and cortex echogenicity (p < 0.001, OR = 3.448, 95%CI: 2.382–5.018) were independent predictors of TA/IF in IgAN nomograms, with a good C-index of 0.765 (95%CI = 0.727–0.803). Analyses of the calibration charts show that nomograms have good performance and clinical applicability. In our study, renal color ultrasound parameters correlated well with TA/IF in IgAN. By establishing a conventional color ultrasound prediction model, we can accurately gauge the extent of TA/IF in patients with IgAN for clinical applications.

Nomogram model for predicting early onset of chronic kidney disease using color Doppler region of interest technique

PURPOSE

The risk factors of chronic kidney disease were analyzed by using the region of interest quantitative technology of color Doppler combined with QLab software, and a Nomogram was established to conduct an individualized assessment of patients with chronic kidney disease.

METHODS

A total of 500 patients with chronic kidney disease diagnosed in our hospital from June 2019 to March 2021 were selected as the chronic kidney disease group, and 300 healthy patients during the same period were selected as the control group. Univariate analysis was performed on the test indexes and the vascularity index, flow index, and vascularization flow index measured by the color doppler region of interest quantitative technique. The above meaningful indicators were included in the Logistics regression analysis to obtain the independent risk factors of early chronic kidney disease. The independent risk factors were imported into R software to draw a Nomogram model for predicting early chronic kidney disease and evaluate the model.

RESULTS

Single factor analysis results suggest age, hypertension, diabetes, hyperlipidemia, disease of heart head blood-vessel, body mass index, vascularity index, flow index, and vascularization flow index, fasting blood sugar, triglyceride, total cholesterol, urea nitrogen, creatinine, uric acid, glomerular filtration rate differences statistically significant (P < 0.05). Logistics regression analysis showed that hypertension, diabetes, flow index, and vascularization flow index, urea nitrogen, and albumin were independent risk factors for the early occurrence of chronic kidney disease. The C-index of this Nomogram using independent risk factors is 0.896 (95%CI 0.862-0.930), which indicates that the Nomogram has good discriminant power. The receiver operating curve of the histograph was area under the curve (AUC) 0.884 (95%CI 0.860-0.908). The receiver operator characteristic curve (ROC) of urea nitrogen, albumin, flow index, and vascularization flow index were evaluated. The results indicated that the best cutoff value of urea nitrogen was 5.9 mmol/L, flow index was 14.67, vascularization flow index was 4.6, and albumin was 40.26 g/L.

CONCLUSION

In the prediction of chronic kidney disease I-II stage, the quantitative technique of color Doppler region of interest has certain diagnostic value. The model established in this study has good discriminative power and can be applied to clinical practice, giving certain indicative significance.

Advances of Contrast-Enhanced Ultrasonography and Elastography in Kidney Transplantation: From Microscopic to Microcosmic

Kidney transplantation is the best choice for patients with end-stage renal disease. To date, allograft biopsy remains the gold standard for revealing pathologic changes and predicting long-term outcomes. However, the invasive nature of transplant biopsy greatly limits its application. Ultrasound has been a first-line examination for evaluating kidney allografts for a long time. Advances in ultrasound in recent years, especially the growing number of studies in elastography and contrast-enhanced ultrasonography (CEUS), have shed new light on its application in kidney transplantation. Elastography, including strain elastography and shear wave elastography, is used mainly to assess allograft stiffness and, thus, predict renal fibrosis. CEUS has been used extensively in evaluating blood microperfusion, assessing acute kidney injury and detecting different complications after transplantation. Requiring the use of microbubbles also makes CEUS a novel method of gene transfer and drug delivery, enabling promising targeted diagnosis and therapy. In this review, we summarize the advances of elastography and CEUS in kidney transplantation and evaluate their potential efficiency in becoming a better complement to or even substitute for transplant biopsy in the future.

Somatic Mutation Profiling of Papillary Thyroid Carcinomas by Whole-exome Sequencing and Its Relationship with Clinical Characteristics

The incidence of papillary thyroid carcinomas (PTCs) has increased rapidly during the past several decades. Until now, the mechanisms underlying the tumorigenesis of PTCs have remained largely unknown. Next-generation-sequencing (NGS) provides new ways to investigate the molecular pathogenesis of PTCs. To characterize the somatic alterations associated with PTCs, we performed whole-exome sequencing (WES) of PTCs from 23 Chinese patients. This study revealed somatic mutations in genes with relevant functions for tumorigenesis, such as BRAF, BCR, CREB3L2, DNMT1, IRS2, MSH6, and TP53. We also identified novel somatic gene alterations which may be potentially involved in PTC progression. Gene set enrichment analysis revealed that the cellular response to hormone stimulus, epigenetic modifications, such as protein/histone methylation and protein alkylation, as well as MAPK, PI3K-AKT, and FoxO/mTOR signaling pathways, were significantly altered in the PTCs studied here. Moreover, Protein-Protein Interaction (PPI) network analysis of our mutated gene selection highlighted EP300, KRAS, PTEN, and TP53 as major core genes. The correlation between gene mutations and clinicopathologic features of the PTCs defined by conventional ultrasonography (US) and contrast-enhanced ultrasonography (CEUS) were assessed. These analyses established significant associations between subgroups of mutations and respectively taller-than-wide, calcified, and peak time iso- or hypo-enhanced and metastatic PTCs. In conclusion, our study supplements the genomic landscape of PTCs and identifies new actionable target candidates and clinicopathology-associated mutations. Extension of this study to larger cohorts will help define comprehensive genomic aberrations in PTCs and validate target candidates. These new targets may open methods of individualized treatments adapted to the clinicopathologic specifics of the patients.

State-of-the-Art Renal Imaging in Children

Imaging modalities for diagnosing kidney and urinary tract disorders in children have developed rapidly over the last decade largely because of advancement of modern technology. General pediatricians and neonatologists are often the front line in detecting renal anomalies. There is a lack of knowledge of the applicability, indications, and nephrotoxic risks of novel renal imaging modalities. Here we describe the clinical impact of congenital anomalies of the kidneys and urinary tract and describe pediatric-specific renal imaging techniques by providing a practical guideline for the diagnosis of kidney and urinary tract disorders.

Predicting cervical lymph node metastasis in patients with papillary thyroid cancer (PTC) - Why contrast-enhanced ultrasound (CEUS) was performed before thyroidectomy

The objective of this research was to investigate the clinical value of contrast-enhanced ultrasound (CEUS) for prediction of cervical lymph node metastasis (CLNM) in papillary thyroid cancer (PTC).One hundred and eighty-six patients with PTC confirmed by fine needle aspiration (FNA) were preoperatively performed CEUS.A multivariate analysis was performed to predict CLNM by 15 independent variables. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic performance.There were totally 37 patients with CLNM confirmed by pathology. Multivariate analysis demonstrated that intensity at peak time, capsule contact and size on CEUS were the three strongest independent predictors for CLNM. ROC analyses of these characteristics showed the areas under the curve (Az), sensitivity, and specificity were 0.650, 48.6 %, 79.8 %; 0.586, 67.6%, 49.7%; and 0.612, 56.8%, 64.4% for intensity at peak time, capsule contact, and size, respectively.The CEUS patterns of PTC are relative to not only the size of PTC but also the possibility of CLNM after thyroidectomy. CEUS seem to be a tool to predict CLNM in PTC patients.

Multiparametric ultrasound in the evaluation of kidney disease in elderly

After the age of 30 years, GFR progressively declines at an average rate of 8 mL/min/1.73 m/decade. A problem of advanced age is that the evaluation of renal function on the basis of indicators valid in young adults, such as creatininemia, is unreliable. In fact, many patients with chronic renal failure may have serum creatinine levels within the normal range even if they have a significant reduction in renal function. Ultrasound has become a routine method of investigation in renal disease: kidney size and parenchymal echogenicity are considered markers of renal function, so US is useful in assessing the presence and degree of renal failure. CEUS is useful in the evaluation of kidney disease in the elderly: the increased hemodynamic resistance of renal microvessels reduces perfusion in the renal cortex, so fewer microbubbles enter the renal cortex. EcoColor and EcoDoppler are also useful in the evaluation of senile alterations: here, the distribution of color-signals, as compared to that in the young adult population, appears more attenuated, limited to intersegmental and interlobar districts. Among the ecoDoppler parameters, the resistance index can be considered a marker of renal damage progression, with attention needing to paid to possible concomitant confounding factors. Ultrasonography, color-Doppler and CEUS are a non-invasive and convenient modality for managing kidney disease; their integration with anamnestic, objective and laboratory data permits fast and reliable clinical, diagnostic, and therapeutic classification. It also allows early therapeutic intervention and, ultimately, improvements in patient management.