Value of Contrast-Enhanced Ultrasound in the Differential Diagnosis of Focal Splenic Lesions

Purpose: To identify and validate contrast-enhanced ultrasound (CEUS) features for differentiating malignant from benign splenic lesions. Patients and Methods: Splenic lesions in 123 patients who underwent conventional ultrasound (B-mode US) and CEUS were included in this study. Two radiologists evaluated the sonograms of B-mode and CEUS. Statistical analysis was performed to identify significant imaging predictors for splenic malignant lesions. Two other radiologists independently reviewed B-mode and CEUS sonograms and diagnosed the lesions based on proposed criteria as 1) benign, 2) probably benign, 3) probably malignant or 4) malignant. The diagnostic efficiency between B-mode US and CEUS was compared. Results: Common imaging findings of malignant lesions included hypoechoic, ill-defined margin, absence of cystic/necrotic portion, presence of splenomegaly on B-mode US, and hypoenhancement, rapid washout and presence of intralesional vessels on CEUS (P < 0.05). Among them, three independent features were identified using multivariate logistic regression analysis: hypoechoic pattern, hypoenhancement pattern and intralesional vessels. When three of these findings were combined as a predictor for splenic malignant lesions, 22 (55.0%) of 40 malignant splenic lesions were identified with a specificity of 100%. The diagnostic performance of two readers using receiver operating characteristic curve analysis was 0.622 and 0.533, respectively, for B-mode US, which was significantly improved to 0.908 and 0.906 for CEUS (P < 0.001). The degree of other diagnostic efficiency and interreader agreement also increased with CEUS compared to B-mode US. Conclusion: CEUS may provide more useful information than B-mode US and improve the diagnosis efficiency for distinguishing malignant from benign splenic lesions.

Automated summary

The study aimed to identify and validate CEUS features for distinguishing malignant from benign splenic lesions. Results showed that CEUS had significantly higher diagnostic efficiency in distinguishing splenic lesions compared to B-mode US, improving the ability to differentiate malignant lesions.