Ultrasound elastography correlations between anthropometrical parameters in kidney transplant recipients

Ultrasound elastography (USE) is a method to assess the stiffness of parenchymatous organs. Shear wave elastography (SWE) is considered to be the most suitable elastography method for the non-invasive kidney transplant (KTx) elasticity assessment. The aim of this study was to assess the implementability of SWE for the evaluation of kidney transplant elasticity measurement depending on the depth of an allograft, body mass index (BMI) and donor age. Secondly, to investigate the associations between SWE stiffness measurements and the clinical parameters. This cross-sectional prospective study involved consecutive 100 KTx patients were grouped according to time from transplantation and their BMI (in BMI<25 group the mean was 22.1±2.4, n=42 and in BMI≥25 group the mean BMI was 29.9±3.3, n=58). Mean estimated glomerular filtration rate was almost similar in both groups: <25 group 54.3 and ≥25 group 53.4 mL/min. Mean elastography results were found statistically different (p=0.006) BMI<25 (8.95±5.84 kPa) and BMI≥25 (5.95±3.16 kPa) groups. Significant correlation was found between SWE and the depth of the measurement (r=-0.4, p<0.05). The variations in USE stiffness values were smallest in patients group with lower BMI. In conclusion, we demonstrated that the non-invasive USE measurement stiffness result depends on a patient's BMI, the depth of renal allograft and donor age.