Characterization of nontraumatic focal splenic lesions using contrast-enhanced sonography.

PURPOSE To compare contrast-enhanced sonography (CEUS) with contrast-enhanced CT in the assessment of nontraumatic focal lesions of the spleen. METHODS CEUS and CT findings in 22 patients with fever of unknown origin and ultrasound-detected splenic focal lesions were analyzed retrospectively. CEUS was performed using an ultrasound unit equipped with a 3.6-MHz probe and contrast-specific software. A 4-ml bolus of second-generation contrast medium was used. The CEUS examinations included a 4-minute recording following injection of the contrast medium. MRI, splenic biopsy, or ultrasound follow-up were used if findings from CT were inconclusive. RESULTS The final diagnoses were as follows: seven splenic infarcts, five hemangiomas, three lacerations, two benign cysts, one lymphoma, one granuloma, one abscess, and two lesions of unknown etiology. CEUS and CT had the same specificity (77.2%). Both CEUS and CT failed to characterize nodular hypovascular lesions with a hypoenhancing pattern. CONCLUSIONS CEUS is as effective as CT for characterizing nontraumatic focal lesions of the spleen. If CEUS findings are consistent with a benign splenic lesion, CT seems to be of limited additional value.