Utility of kidney ultrasonography during initial evaluation of pediatric nephrotic syndrome

Current guidelines note a gap in high-quality evidence regarding utility of kidney ultrasonography (KUS) during initial evaluation of nephrotic syndrome (NS) due to presumed minimal change disease (pMCD). However, KUS is frequently obtained at our institution. This retrospective chart review assessed incidence and impact of abnormal sonographic findings in these patients.

Patients 1-18 years, newly diagnosed at our institution with NS from pMCD between 2011 and 2021, were identified. Hypertension, urinalysis, kidney function, and steroid responsiveness data were collected. Imaging findings were abstracted from radiology reports. Clinical impact of KUS was defined by actions taken in response to KUS.

A total of 173 patients identified with new NS; 98 met inclusion criteria. Of these, 54% had KUS during the initial encounter. Demographic and laboratory data did not differ between those with and without KUS. KUS were abnormal in 70% of studies: increased kidney echogenicity (39.6%) and nephromegaly (35.8%) were the most common abnormal findings. Other findings included decreased corticomedullary differentiation, lobular kidney contour, solitary simple kidney cyst, and mild unilateral hydronephrosis. Steroid resistance was not associated with either nephromegaly or abnormal echogenicity.

Our data showed no clinically relevant ultrasound findings causing deviations from the standard of care for pMCD. There was no association between KUS findings and steroid resistance. These data suggest there is little to no benefit from routine KUS imaging in patients with pMCD upon initial presentation. A higher resolution version of the Graphical abstract is available as Supplementary information.