Shear wave elastography of the spleen using elastography point quantification: stiffness values in healthy children

Shear Wave Ultrasonographic Elastography in Pediatric Spleens and Its Role in Differential Diagnosis

Shear wave elastography (SWE) has become popular in clinical practice for many diseases. However, there is not adequate research on spleen-related diseases. This study aimed to investigate the potential of quantitative values obtained through SWE in evaluating spleen pathologies in the pediatric population and to demonstrate its performance to differentiate splenomegaly-related diseases. The research group retrospectively included children with pathological diagnoses related to the spleen from November 2016 to April 2021, and they were categorized into three groups, including portal hypertension (PH), benign lymphoid hyperplasia (BLH), and malignant infiltration (MI). Spleen sizes and parenchymal stiffness were also calculated for each group. Subsequently, mean spleen stiffness in each group was compared with normal values within the same age group. In total, 2781 children (1379 children for the study group; 1402 children for the control group) were enrolled in the study. The highest stiffness was observed in the PH group, which is statistically higher than others (p < 0.05). Although the mean spleen stiffness in the group with BLH was higher than the control and MI group, the difference was not statistically significant (p = 0.08). The mean stiffness in the group with MI was significantly lower than both the control group (p = 0.005) and PH (p = 0.01). In conclusion, using SWE in the differential diagnosis of etiologies causing splenomegaly could make an important contribution.

Shear wave elastography of kidneys in children: utility in distinguishing steroid-resistant and steroid-sensitive nephrotic syndrome

PURPOSE

To assess the renal elasticity values using (SWE) and correlate the values with steroid sensitivity to distinguish between steroid-resistant nephrotic syndrome (SRNS) and steroid-sensitive nephrotic syndrome (SSNS) in children.

METHODS

In this IRB-approved cross-sectional study, 83 children (4-14 years) diagnosed with nephrotic syndrome were included from July 2021 to December 2022. SWE measurements were done for each kidney's upper pole, interpolar region, and lower pole. Mean as well as median SWE were calculated. Correlation of the renal stiffness values was done with different laboratory findings (blood urea, serum creatinine, 24 h urine protein, serum albumin, and serum cholesterol), the grayscale findings (cortical echogenicity, and corticomedullary differentiation), and the final diagnosis of SRNS and SSNS. The statistical tests were done at a significance level of α = 0.05.

RESULTS

The median (IQR) overall SWE of kidneys was higher in SRNS group 12.64 (8.4-19.68) kPa than SSNS group 9.87 (8.20-12.56) kPa. The difference was significant (p = 0.004). At a cut-off of ≥ 10.694 kPa (AUROC- 0.641), the overall SWE predicted SRNS group with a sensitivity of 70% and a specificity of 63%. A significant correlation (p < 0.05) was found between the SWE and 24-h urine protein, cortical echogenicity, and corticomedullary differentiation in SSNS, while only between SWE and corticomedullary differentiation in SRNS.

CONCLUSION

The mean SWE was higher in children with SRNS. While SWE has potential to differentiate SSNS from SRNS, a different study design where SWE is performed at presentation is needed for confirmation.

2D Shear wave elastography for evaluation of renal cortex and medulla: stiffness values in healthy children

PURPOSE

To evaluate renal cortical and medullary stiffness using 2D Shear-wave elastography (SWE) in healthy children.

METHODS

In this IRB approved prospective study, we measured the stiffness of cortex and medulla of children (4 months-17 years) at the upper pole, mid pole, and lower pole in bilateral kidneys.

RESULTS

The median (IQR) values of renal cortex in <1 year age group was 8.7 (5.7-11.7) kPa for right and 8.7 (4.2-14.1) kPa for the left side. For 1-5 years age group, it was 7.3 (5.3-10) kPa for the right and 8.9 (6-12.3) kPa for the left side. For >5 years, it was 7.4 (5.3-11.2) kPa for the right and 9.6 (6.2-12.7) kPa for the left side. The median (IQR) values of renal medulla in <1 year age group was 7.1 (5.1-12.5) kPa for right and 6.8 (4-10.6) kPa for the left side. For 1-5 years age group, it was 7.2 (4.9-9.7) kPa for the right and 6.9 (5.6-9.9) kPa for the left side. For >5 years, it was 6.8 (5.1-9.6) kPa for the right and 7 (5-10.2) kPa for the left side. The differences in the elasticity values amongst these groups were statistically insignificant (p>0.05). There was a significant correlation between SWE values of cortex and medulla of right kidney (ρ=0.64) and of left kidney (ρ=0.61), respectively.

CONCLUSION

SWE values of renal cortical and medullary stiffness in healthy children do not correlate with age. There is a significant correlation between SWE values of cortex and medulla of the kidneys in healthy children.

Ultrasound Elastography in Children

Ultrasound elastography is a novel ultrasound technique, being extensively researched in children in the last decade. It measures tissue elasticity with the observation of tissue response after an external stimulus. From research to clinical practice, ultrasound elastography has evolved significantly in liver fibrosis evaluation in children; however, several other applications of the technique are available in both clinical practice and research environments. Practically, in children any organ can be assessed, including the brain in early ages, along with muscle and connective tissue elasticity evaluation, spleen, kidney, skin, lymphatic tissue, etc. The elastography method, age, body mass index and technical points should be considered when performing ultrasound elastography. This review highlights its vast potential as a diagnostic tool in the pediatric population, where ultrasound is a dominant imaging tool; however, the indications and exam protocol for its clinical use in several fields in pediatrics have yet to be elucidated.

Two-dimensional Shear Wave Elastography: Utility in Differentiating Gallbladder Cancer From Chronic Cholecystitis

OBJECTIVE

To study the utility of 2D shear wave elastography (SWE) and ascertain cut-off values of shear wave elasticity (SWe) to differentiate benign and malignant thickening of the gallbladder wall.

METHODS

This study was a prospective study of patients with symptomatic gallstone disease (GSD, n = 51) and gallbladder cancer (GBC, n = 46) and controls without any biliary disease (n = 46). All the participants underwent 2D USG and SWE of the gallbladder. Grey-scale ultrasound and SWE were done in the different regions in the gallbladder.

RESULTS

The median age of the patients with GSD was 49 years (interquartile range [IQR]: 33-55), GBC was 55 years (IQR: 46-65), and controls was 37 years (IQR: 27-48.25). In patients with GBC, asymmetrical mural thickening was the predominant imaging pattern (n = 24, 52.2%). The mean SWe of the abnormal area in GBC (34.99 ± 17.77 kPa [n = 46]) was significantly higher than that of the uninvolved region (18.27 ± 8.12 kPa [n = 35]; P < .01). The mean SWe of the uninvolved region in GBC (18.27 ± 8.12 kPa [n = 35]) was also significantly higher (P < .01) than that of GSD (12.27 ± 4.13 kPa [n = 51]) and controls (10.52 ± 3.75 kPa [n = 46]). On ROC analysis, AUC of 0.927, at a cut-off of 20 kPa, sensitivity was 91.3%, specificity was 83.5%, positive likelihood ratio was 5.54, and negative likelihood ratio was 0.10 to diagnose GBC.

CONCLUSION

The 2D SWE is a reliable adjunctive tool to grey-scale USG in differentiating the malignant from benign gallbladder wall and may help to pick up early malignancy in GSD.