Relationship of renal morphology on 3-dimensional ultrasonography with renal pathologic findings and outcome in biopsy-proven nephropathy.

Kidney morphology has been used to estimate renal functions. The present study investigated the usefulness of kidney length and renal parenchymal volume (RPV) measured using three-dimensional ultrasonography (3-D USG) in estimating renal pathological findings, and the outcome in patients with nephropathy who underwent renal biopsy. In this study, 94 adult patients who had native kidney biopsy with 3-D USG results were included. The mean kidney length and RPV were independent factors of, and positively correlated to the estimated glomerular filtration rate (eGFR). The mean kidney length and RPV had inverse associations with the percentage of global glomerulosclerosis. Higher mean RPV, other than longer kidney length, indicated a lower prevalence of tubular atrophy. During 63.3±19.3 months of follow-up, a mean RPV of <125 ml increased the risk of composite outcome by 4.287 fold (95% confidence interval, 1.133-16.227) as compared with a mean RPV of ≥125 ml (P=0.032). In conclusion, kidney size was inversely associated with certain nephronal damage and positively associated with eGFR in nephropathy. Furthermore, smaller RPVs predicted worse outcomes of nephropathy.