Contrast-enhanced ultrasonography with SonoVue: differentiation between benign and malignant lesions of the spleen.

ABSTRACT

OBJECTIVE: We investigated the ability of contrast-enhanced ultrasonography with SonoVue (Bracco SpA, Milan, Italy), a sulfur hexafluoride microbubble contrast agent, to reveal differences between benign and malignant focal splenic lesions. METHODS: In a prospective study we investigated 35 lesions in 35 patients (24 male and 11 female; mean age +/- SD, 54 +/- 15 years) with focal splenic lesions detected by B-mode ultrasonography. After intravenous injection of 1.2 to 2.4 mL of SonoVue, the spleen was examined continuously for 3 minutes using low-mechanical index ultrasonography with contrast-specific software. The final diagnosis was established by histologic examination, computed tomography, or magnetic resonance imaging. RESULTS: In 14 patients, the splenic lesions were malignant (metastasis, n = 6; non-Hodgkin lymphoma, n = 6; and Hodgkin lymphoma, n = 2). In 21 patients, the focal splenic lesions were benign (ischemic lesion, n = 6; echogenic cyst, n = 5; abscess, n = 4; hemangioma, n = 3; hematoma, n = 1; hemophagocytosis syndrome, n = 1; and splenoma, n = 1. Typical findings for benign lesions were 2 arrival patterns no contrast enhancement (neither in the early nor in the parenchymal phase; P < .05) and the beginning of contrast enhancement in the early phase followed by contrast enhancement in the parenchymal phase 60 seconds after injection. In contrast, the combination of contrast enhancement in the early phase followed by rapid wash-out and demarcation of the lesion without contrast enhancement in the parenchymal phase (60 seconds after injection) was typical for malignant lesions (P < .001). CONCLUSIONS: Contrast-enhanced ultrasonography is helpful in the differentiation between benign and malignant lesions of the spleen.