Role Of Ultrasonography In The Diagnosis Of Focal Splenic Lesions

Spleen is a special organ for its immunity function and abundant blood supply.It restrains and destroys tumor cells,so focal splenic lesions are rare relative to those in the other abdominal organs.The poor correlation between ultrasound appearances and splenic pathology causes difficulty in clinical diagnosis.Difficulties in differential diagnosis are not uncommon,especially with small lesions.Color Doppler flow imaging(CDFI) is usually of limited additional value.These years Contrast-enhanced ultrasonography(CEUS) has improved diagnostic accuracy in the lesions of liver, gallbladder,breast and so on.SonoVue is regarded as spleen-specific enhancement that lasts longer than liver parenchyma.So the spleen is optimally suited for CEUS. Till now few data described CEUS of focal splenic lesions.Part One:Conventional ultrasonography of focal splenic lesionsOne hundred and two patients were observed,including 28 cases of lymphoma, 16 cases of hemangioma,14 cases of metastases,10 cases of lympho-hemangioma,9 cases of infarct,9 cases of cyst,4 cases of sclerosing angiomatoid nodular transformation(SANT),3 cases of tuberculosis,3 cases of inflammatory pseudo tumor(IPT),3 cases of lymphangioma,2 cases of leukemia metastases and 1 case of pancreas cystadenocarcinoma infiltration.A conventional ultrasound exploration is performed,eventually including the use of color Doppler mode.The results showed that conventional ultrasound could reveal whether the splenic lesions were cystic or solid,and CDFI could make out if the lesions have blood supply.Conventional ultrasonography can approximately distinguish benign and malignant lesions. However it is difficult to diagnose metastases without clinical history.Part Two:Contrast-enhanced ultrasonography of focal splenic lesionsThirty-six patients were examed,including 8 cases of metastases,7 cases of lymphoma,7 cases of hemangioma,5 cases of lympho-hemangioma,2 cases of infarct,2 cases of SANT,2 cases of IPT,1 case of leukemia metastases,1 case of genuine cyst and 1 case of pseudo cyst.CEUS was performed with Technos DU8 or Philips IU22.Both of them were equipped with a probe at the frequency of 2.0～5.0MHz.A sulfur hexafluoride-based microbubble contrast agent(Sonovue,Bracco) was injected intravenously at a dose of 1.2ml.We used a low ultrasonic beam pressure (mechanical index:0.070～0.097).Sound beam was focused at deeper aspect of interest region.The contrast agent extincted more quickly in malignant lesions than in benign ones.We detected more lesions after CEUS.But we still haven't searched out the rule of perfusion between benign and malignant lesions.Part Three:Comparative study of contrast-enhanced ultrasonography and contrast-enhanced CT in diagnosing focal splenic lesionsSeventeen patients with focal splenic lesions were studied,including 5 cases of hemangioma,4 cases of lympho-hemangioma,4 cases of metastases,3 cases of lymphoma and 1 case of IPT.The result showed the vascular displaying rates of contrast-enhanced sonography and contrast-enhanced CT were 100%.The perfusion of the lesions has no difference between CEUS and CT images.In conclusion,CEUS can display vascularity in focal splenic lesions sensitively. The conventional ultrasonography combined with CEUS has provided a helpful means in diagnosing focal splenic lesions.