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

Abstract

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 inter-reader 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.

Keywords:

• spleen
• splenic diseases
• contrast-enhanced ultrasound
• conventional ultrasound

Acknowledgments

We greatly appreciate the financial supports by the 1.3.5 project for disciplines of excellence, West China Hospital, Sichuan University (ZYJC18008), National Science Foundation of China (NSFC) (81701797), Beijing Natural Science Foundation (7192200), Science and Technology Innovation Talent of Sichuan (20CXRC0065), Science and Technology Project of Chengdu (2019-YF05-00376-SN), Science and Technology Project of the Health Planning Committee of Sichuan (20PJ011).

Ethics

This is a single-center study and was approved by West China Hospital of Sichuan University Biomedical Research Ethics Committee. Written informed consent was waived because of the retrospective nature of clinical and imaging data collection. The study was conducted in accordance with the Declaration of Helsinki and the privacy of the participants data were protected.

Disclosure

The authors report that they have no conflicts of interest related to this work.