The Role of Linear and Convex Probes to Determine the Normal Range of Splenic and Liver Stiffness in Healthy Children Assessed by Point Shear Wave Elastography

Background: Elastography is used to determine tissue stiffness. Objectives: The aim of the study was (i) to determine the normal values of liver and splenic stiffness in a pediatric population, (ii) to assess if these values are comparable or not when the linear probe is used, and finally (iii) to assess the impact of potential confounding factors such as age, and gender. Patients and Methods: This prospective study consists of 97 healthy volunteers between 6 months and 14 years of age. These volunteers were divided into four groups based on age. The shear wave velocities (SWVs) were obtained from each hepatic lobe and splenic parenchyma by each transducer (linear 9L4 and convex 4C1). Results: Splenic parenchyma values were significantly higher than the liver parenchyma regardless of the probe used (P = 0.001). There was no statistically significant differences obtained when using the 9L4 probe for both hepatic lobes and the splenic parenchyma under the age of 2 years (P = 0.352, 0.898 and 0.876). The variance was similar in both lobes with the 4C1 probe (t = 0.6471, non-significant). Whereas, with the 9L4 probe, the variance was slightly higher in the left lobe (t = -4.16, P = 0.01). Gender had no effect on SWV (P ≥ 0.1 for all sites). Conclusion: The velocity values obtained from the different parts of the liver and spleen could be used as reference values to enlighten further studies. For children under the age of 2 years, a linear probe could be a better choice for assessing liver and splenic parenchymal tissue stiffness.