Color Doppler ultrasound (CDU) in the diagnosis of obstructive hydronephrosis in pregnant women

Imaging in Urolithiasis

Urolithiasis has high incidence in industrialized countries (0.5% in Europe and North America). Its high incidence along with the severity of clinical symptoms makes nephrolithiasis an important consideration in patients with acute abdominal pain. Imaging has a pivotal role and non-contrast computed tomography scan is the gold standard examination in both the diagnosis and follow-up of patients with urolithiasis. Ultrasound and kidneys, ureters, and bladder radiography are also essential tools in the follow-up of this pathology given its high recurrence rates while MRI can be used in special patient populations such as pregnant women.

ACR Appropriateness Criteria® Hydronephrosis on Prior Imaging-Unknown Cause

Initial imaging evaluation of hydronephrosis of unknown etiology is a complex subject and is dependent on clinical context. In asymptomatic patients, it is often best conducted via CT urography (CTU) without and with contrast, MR urography (MRU) without and with contrast, or scintigraphic evaluation with mercaptoacetyltriglycine (MAG3) imaging. For symptomatic patients, CTU without and with contrast, MRU without and with contrast, MAG3 scintigraphy, or ultrasound of the kidneys and bladder with Doppler imaging are all viable initial imaging studies. In asymptomatic pregnant patients, nonionizing imaging with US of the kidneys and bladder with Doppler imaging is preferred. Similarly, in symptomatic pregnant patients, US of the kidneys and bladder with Doppler imaging or MRU without contrast is the imaging study of choice, as both ionizing radiation and gadolinium contrast are avoided in pregnancy. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Development and validation of a simple-to-use nomogram for predicting minimal change disease based on quantification of color Doppler sonography data from a region of interest

OBJECTIVES

To establish a simple-to-use nomogram based on quantification of color Doppler sonography data from a region of interest (ROI) to diagnose minimal change disease (MCD) promptly and non-invasively, and to evaluate the prediction capability of the nomogram.

METHODS

We recruited 564 patients with pathology-proven renal disease who were admitted to our hospital from July 2020 to July 2021 (388 patients in the training dataset and 176 patients in the validation dataset), and their color Doppler sonography data were acquired from a ROI and underwent ipsilateral renal biopsy. The collected clinical features and ultrasonic features were imported into Rstuido and statistically significant features were selected by stepwise regression using the forward-backward method. Multivariate Logistic regression analysis was combined with clinical analysis to obtain the final modeling features. General and dynamic nomogram models were constructed with the selected features, depending on whether they were MCD or not. Bootstrapping and internal validation were used for internal and external validation of the nomogram, respectively. The performance of the nomogram was assessed by C-index, calibration curve, and receiver operating characteristic (ROC) curve.

RESULTS

Age and VI were independent factors in predicting MCD. The value of Age (Best cut-off value: 33.5 years) combined with VI (Best cut-off value: 40.50 points) in the diagnosis of MCD was significantly higher than that of single diagnosis (AUC 0.901, 95% CI 0.863-0.938). The C-index of the nomogram constructed with age and VI in the training and validation datasets was 0.915 [95% confidence interval (CI) 0.874-0.956 and 0.875 95% CI 0.783-0.967], respectively. Calibration curves were fitted well. The sensitivity, specificity, and accuracy were 76.1%, 95.6%, and 78.3%, respectively, in the training dataset, and 74.1%, 94.4%, and 76.1% in the validation dataset, respectively.

CONCLUSION

The nomogram constructed with age and VI showed a satisfactory degree of differentiation and accuracy, which is of great significance for early, non-invasively, and individually analysis of the risk of MCD.

Treatment for complete bilateral duplex kidneys with severe hydronephrosis and ureterectasis of the upper moiety in a child: A case report and literature review

Aim

To explore the treatment experience of the duplex kidney.

Method

A case of the complete bilateral duplex kidney with severe hydronephrosis and ureterectasis in the upper moiety of the kidney diagnosed in the Department of Urology of Kunming Children's Hospital from 2021 to 2022 was retrospectively analyzed and relevant literature was reviewed.

Results

A 2-month-old baby girl was admitted to the hospital because of hydronephrosis of bilateral kidneys found by prenatal ultrasound for 3 months and fever for 3 days. After being given the relevant examinations, the girl was diagnosed with complete bilateral duplex kidneys with severe hydronephrosis and ureterectasis in the upper moiety, and urinary tract infection. The patient's urinary tract infection was poorly controlled after positive anti-infective therapy, so a bilateral ureterostomy was performed. After the surgery, urinary tract infection was soon cured. A bilateral ureteroureterostomy was performed 13 months later, and the patient recovered after 7 days.

Conclusion

Cutaneous ureterostomy combined with late ureteroureterostomy for children with complete bilateral duplex kidneys with severe hydronephrosis in the upper moiety and ureter are not only beneficial to caregivers’ nursing after the operation, but also have significance for salvaging renal function.

The internist and the renal resistive index: truths and doubts

The renal resistive index (RRI) is measured by Doppler sonography in an intrarenal artery, and is the difference between the peak systolic and end-diastolic blood velocities divided by the peak systolic velocity. The RRI is used for the study of vascular and renal parenchymal renal abnormalities, but growing evidence indicates that it is also a dynamic marker of systemic vascular properties. Renal vascular resistance is only one of several renal (vascular compliance, interstitial and venous pressure), and extrarenal (heart rate, aortic stiffness, pulse pressure) determinants that combine to determine the RRI values, and not the most important one. RRI cannot always be considered a specific marker of renal disease. To summarize from the literature: (1) hydronephrosis, abdominal hypertension, renal vein thrombosis and acute kidney injury are all associated with an acute increase in interstitial and venous pressure that determine RRI values. In all these conditions, RRI is a reliable marker of the severity of renal damage. (2) The hemodynamic impact of renal artery stenosis can be assayed by the RRI decrease in the homolateral kidney by virtue of decreasing pulse pressure. However, renal diseases that often coexist, increase renal vascular stiffness and hide the hemodynamic effect of renal stenosis. (3) In transplant kidney and in chronic renal disease, high RRI values (>0.80) can independently predict renal and clinical outcomes, but systemic (pulse pressure) rather than renal hemodynamic determinants sustain the predictive role of RRI. (4) Higher RRI detects target renal organ damage in hypertension and diabetes when renal function is still preserved, as a marker of systemic atherosclerotic burden. Is this the fact? We attempt to answer.