Abstract:

Objective

To measure spleen stiffness using two-dimensional shear wave elastography（2D-SWE） in children with splenomegaly of varying etiologies by Young’s modulus values and explore its differences and clinical application value.

Methods

A total of 93 children meeting the diagnostic criteria for splenomegaly （case group） and 45 healthy children （control group） were enrolled from outpatient or inpatient departments of Wuhan Children’s Hospital between January 2022 and May 2024. The case group was further divided into subgroups： infectious disease group （IDG， n=23）， hematological disease group （BDG，n=19）， and portal venous system disease group （PVDG， n=51）. Based on ultrasound-diagnosed cirrhosis， they were classified into a cirrhosis subgroup （n=32） or non-cirrhosis subgroup （n=61）. All participants underwent conventional ultrasound and 2D-SWE examinations. Conventional 2D ultrasound parameters （spleen length and thickness） and Young’s modulus values of the splenic parenchyma were measured. Independent samples t-test was used to compare elasticity between the control and case groups. Point-biserial correlation analysis was applied for elasticity between the cirrhosis and non-cirrhosis subgroups. The Kruskal-Wallis test was used to assess elasticity differences among etiological subgroups. Receiver operating characteristic （ROC）curves were plotted for different etiological subgroups to determine the optimal cutoff values （via Youden index）， area under the curve （AUC）， sensitivity， and specificity. Spearman correlation was used to analyze the relationship between spleen size and stiffness in the case group.

Results

Spleen length， thickness， and Young’s modulus values were higher in the case group than in controls ［（11.24±2.76）cm vs （8.08±1.43）cm， （2.94±0.83）cm vs （2.18±0.39）cm， and （24.75±8.23） kPa vs （16.11±2.66） kPa， t=7.197， 5.809， and 6.863， respectively； all P＜0.001］. The cirrhosis subgroup had higher Young’s modulus values than the non-cirrhosis subgroup ［（30.72±5.82） kPa vs （21.62±7.57） kPa； r=0.529， P＜0.001］. Among etiological subgroups， Young’s modulus value was higher in the PVDG， followed by the BDG and IDG ［（28.86±5.75）kPa， （23.90±10.13） kPa， and （16.34±3.18） kPa， respectively， H=46.353， P＜0.001］. ROC analysis showed optimal cutoff values of 20.46 kPa （sensitivity 63.16%， specificity 91.30%） for distinguishing IDG from BDG and 23.80 kPa （sensitivity 80.39%， specificity 73.68%） for BDG vs PVDG.

Conclusion

2D-SWE is feasible for assessing spleen stiffness in children with splenomegaly， with significantly higher stiffness observed in cirrhotic patients. Stiffness varies by etiology （PVDG ＞ BDG ＞ IDG）. 2D-SWE has potential clinical value in the etiological diagnosis of splenomegaly in children， as well as in the disease assessment and long-term follow-up of pediatric patients with splenomegaly complicated by liver cirrhosis.

Key words: Children, Splenomegaly, Two-dimensional shear wave elastography, Spleen stiffness