Vascular pattern and diagnostic accuracy of contrast-enhanced ultrasound (CEUS) in spleen alterations.

Background: Contrast-enhanced ultrasound (CEUS) has been used as an additional imaging technique in order to clarify rare focal splenic lesions (FSL). CEUS is a safe and cost-effective modality for assessment of perfusion.

Objective: To validate contrast enhancement pattern and evaluate the diagnostic accuracy of CEUS in unclear FSL.

Methods: CEUS examinations of the spleen in 50 patients between 2012 and 2018 were included in the study. Examinations were performed using B-mode, colour-coded Doppler ultrasound (CCDS) and CEUS after injection of sulphur hexafluoride microbubbles and interpreted in consensus by two experienced radiologists. Reference standard was defined as histopathological report and clinical course (treatment response, long term follow up).

Results: All patients were successfully examined by CEUS without an adverse reaction. CEUS presented the correct differentiation of benign and malignant alterations in 49/50 (98%). Lesion washout was found in all malignant but also 16.7% of all benign lesions. Matched to the histopathological report and clinical follow up, CEUS represented a sensitivity of 100% (95% -CI, 57-100), a specificity of 98% (95% -CI, 88-100), a positive predictive value (PPV) of 83% (95% -CI, 44-97) and a negative predictive value (NPV) of 100% (95% -CI, 92-100).

Conclusion: CEUS may provide additional information by visualization of dynamic contrast enhancement pattern to differentiate benign and malignant lesions. Nevertheless, established criteria for malignancy (early enhancement or washout) in FSL should be considered with caution since they are also found in benign lesions.