Spleen stiffness measurement by shear wave elastography using acoustic radiation force impulse in predicting the etiology of splenomegaly.

PURPOSE: To measure spleen stiffness by shear wave elastography (SWE) using acoustic radiation force impulse (ARFI) in patients with splenomegaly and to evaluate utility of elastography technique in identifying etiology of splenomegaly.
METHODS: Sixty-one treatment-naïve patients with splenomegaly were enrolled. The control group consisted of 20 healthy subjects without history of any disease including diabetes and hypertension, alcohol consumption, or biochemical or ultrasonographic findings indicating hepatic and renal diseases. B-mode ultrasonography and elastographic examinations were performed by a radiologist blinded to the participants. Spleen stiffness was measured by SWE using ARFI. Shear wave velocity (SWV) values were given in m/s.
RESULTS: Splenomegaly patients were assigned into three groups according to their etiologies as hepatoportal (n = 21), myeloproliferative (n = 23), and infectious (n = 17). Splenomegaly groups and control group were comparable regarding age and sex. Spleen size was higher in the splenomegaly groups than in the controls. Median SWV was significantly higher in the hepatoportal (3.85 m/s) and myeloproliferative (3.42 m/s) groups than in the infectious (2.66 m/s) and control (2.22 m/s) groups. The correlation between SWV and spleen size was not significant in any of the groups. The cut-off value was 3.42 (sensitivity 80.9%, specificity 56.5%) in distinguishing hepatoportal from myeloproliferative etiology; 3.02 (sensitivity 100%, specificity 100%) in distinguishing hepatoportal from infectious etiology; and 2.84 (sensitivity 91.3%, specificity 88.2%) in distinguishing myeloproliferative from infectious etiology.
CONCLUSION: Spleen stiffness measured by elastographic techniques in splenomegaly patients was higher than that in healthy subjects. SWV appeared to be beneficial in predicting the etiology of splenomegaly.