Ultrasound can detect and grade renal surface nodularity (RSN), and RSN grade shows a dose-response association with renal damage in hypertensive adults; RSN was frequently present in patients whose eGFR and urinalysis remained within normal limits, suggesting it may reflect structural change accompanying subclinical decline in renal function.
Renal surface nodularity was common among hypertensive adults undergoing routine health screening, detected in 47.1% of 871 patients.
The ultrasound-based RSN grading system showed good-to-excellent reproducibility.
Hypertension grade, hypertension duration, cortical echo intensity, and lower eGFR were independently associated with RSN.
The prevalence of renal damage rose with increasing RSN grade, showing a dose-response pattern.
Grade 2 RSN remained associated with renal damage after adjustment for covariates, including continuous eGFR, though the association was weaker after eGFR adjustment.
In a sensitivity analysis restricted to the non-eGFR components of the endpoint and adjusted for continuous eGFR, the association between grade 2 RSN and renal damage was no longer significant.
RSN was frequently present in patients without threshold-defined renal damage, and eGFR declined progressively across RSN grades in this group.
The authors conclude that RSN may reflect structural change accompanying subclinical decline in renal function.
This study looked at ultrasound scans of the kidneys in 871 adults with high blood pressure who had routine health check-ups. The researchers created a three-level scale for the roughness of the kidney surface (renal surface nodularity): smooth, mildly undulating, or severely serrated. Nearly half of the patients (47.1%) had some degree of surface roughness, and two radiologists' readings agreed well with each other and with their own repeat readings. A rougher kidney surface was linked to longer and more severe hypertension, brighter kidney cortex on ultrasound, and lower kidney filtration function (eGFR). Signs of kidney damage (reduced eGFR or protein in the urine) were found in 5.2% of people with a smooth surface, 8.0% with mild roughness, and 27.2% with severe roughness. The link with severe roughness held up after accounting for age, sex, hypertension severity, diabetes, and even eGFR, but it was no longer significant when the analysis looked only at urine protein and was adjusted for eGFR. Notably, among patients whose kidney tests were still in the normal range, about 17% had severe surface roughness, and their average eGFR was lower with each higher grade. This research suggests that kidney surface roughness on ultrasound might reflect early structural change that accompanies subtle loss of kidney function. However, because this was a single-time-point study, it cannot show that roughness predicts later kidney disease, and further follow-up studies would be needed.
Wang X, Chen Y, Zhu H, Xu Q. (2026). Ultrasound-detected renal surface nodularity and renal damage in hypertensive adults undergoing routine health screening: a cross-sectional study.. Frontiers in endocrinology. https://doi.org/10.3389/fendo.2026.1934293