Left Renal Cortical Thickness Measured by Ultrasound Can Predict Early Progression of Chronic Kidney Disease

Abstract

Aims: The kidney becomes atrophic in advanced chronic kidney disease, and renal size and parenchymal volume correlate with renal function. However, alterations in renal parenchymal volume have not been adequately studied in terms of the renal cortex and medulla. We investigated the relationship between the changes in the renal cortex and medulla and renal function. Methods: Renal ultrasound (US) parameters including renal length, parenchymal thickness, cortical thickness and medullary thickness were assessed in 176 subjects, who were categorized into 4 groups based on the estimated glomerular filtration rate (ml/min/1.73 m²): group 1, ≥90; group 2, ≥60 but <90; group 3, ≥30 but <60; and group 4, <30. Renal US parameters in both kidneys were compared among the 4 groups. Results: We found stepwise associations in renal length, cortical thickness and parenchymal thickness with decreased renal function. Medullary thickness showed no changes among groups 1-3. Multiple linear regression analysis including sex, age and renal US parameters showed that only renal length was an independent predictor of renal function. When analyzed in groups 1-3, cortical thickness was the strongest associated parameter. Lower cortical left/right ratio (left cortical thickness/right cortical thickness) showed a stepwise association with a decrease in renal function. Conclusion: Renal length and cortical thickness measured by US were correlated with renal function. In particular, left cortical thickness could help to detect early changes in renal function.

Predictive Value of Cortical Thickness Measured by Ultrasonography for Renal Impairment: A Longitudinal Study in Chronic Kidney Disease

“…Morphological parameters including length, cortical thickness and medullary thickness could be measured from all the patients, except that volumetric calculations were impossible in six patients. In order to eliminate influence from sex and body size, kidney morphological parameters were adjusted by height and body surface area as previously reported [15]. Referencing kidney morphological parameters to height diminished the sex differences, thus height-adjusted values were used thereafter in this study (Table 2).…”

“…Despite that kidney structure is associated with renal function, little attention has been paid to the potential utility of morphological assessment for detecting earlier stages of CKD until recently. Small number of cross-sectional studies with enhanced computed tomography [7] or ultrasonography [15] suggested thinning of cortical thickness precedes that of medulla or length.…”

“…All kidney ultrasonography was performed using standard grayscale B-mode imaging on an Aplio 500 Ultrasound System (Toshiba Medical Systems, Tochigi, Japan) with a 3.5-MHz convex transducer by one experienced physician (T.T., 8 years of clinical experience and ultrasound examination). Morphological measurements were performed as previously reported [15]. Briefly, kidney length, cortical thickness and medullary thickness were measured from the longitudinal images.…”

Consensus-based technical recommendations for clinical translation of renal ASL MRI

“…Several imaging studies have shown that a lower cortical thickness is associated with reduced renal function as measured by eGFR [88][89][90][91]. In the case of advanced disease, the reduction in cortical thickness can be severe enough such that it approaches the typical dimensions of the ASL voxels, significantly reducing the number of pure cortex voxels from which cortical RBF can be estimated.…”

Profiling and bioinformatic analysis reveal differential microRNA expression in the left and right kidneys in normal mice

“…Moreover, a meta‐analysis suggests that, in five different unilateral anomalies: multicystic dysplastic kidney, renal agenesis/aplasia, renal ectopia, pelviureteral junction obstruction, and nonobstructive nonrefluxing megaureter, the left side was affected in 53%, 57%, 56.9%, 63.2%, and 62.5% of patients, respectively, which were significantly different from the anticipated 50% anomalies . Moreover, left cortical thickness, but not right cortical thickness could help to detect early changes in renal functions . The right kidney–liver echogenicity ratio but not the left kidney–spleen echogenicity ratio showed a close relationship with decreased renal function when increased .…”