Usefulness of Ultrasonographic Superb Microvascular Imaging for Diagnosis and Management of Splenic Vein Thrombosis

A 68-year-old man was admitted to the hospital with acute onset of exertional chest pain. The patient had a history of a percutaneous coronary intervention and rheumatoid arthritis, for which he was taking aspirin (100 mg) and prednisolone (5 mg) on a daily basis. Coronary angiography did not reveal any coronary artery stenosis; however, contrast-enhanced computed tomography (CE-CT) revealed bilateral pulmonary emboli and bilateral deep venous thrombosis (DVT) involving the left popliteal vein and right soleal veins. In addition, splenic vein thrombosis was observed (Figure 1, Panel A-1, arrow). A vascular ultrasound examination was performed for the morphological evaluation of the splenic vein thrombosis. B-mode imaging revealed a poorly visualized structure with low brightness in the splenic vein (Figure 1, Panel A-2). Superb microvascular imaging (SMI) clearly showed a perfusion defect in the splenic vein (Figure 1, Panel A-3). Apixaban was administered to treat the multiple-site thrombosis. At the 1-month follow-up, CE-CT and vascular ultrasound examinations were repeated and confirmed the disappearance of the splenic vein thrombosis (Figure 2, Panel B-1, arrow; B-2, B-mode; and B-3, SMI). Vascular ultrasound has been widely used for assessing DVT. For splanchnic venous thrombosis, the usefulness of ultrasound evaluation in portal vein thrombosis has been reported.1 On the contrary, few studies have reported the use of ultrasound evaluation in splenic vein thrombosis.2 Superb microvascular imaging is a relatively new Doppler imaging technique which eliminates artifacts from tissue movement without reducing the vascular signal and enables better depiction of microvascularity and low-velocity blood flow compared with conventional ultrasonographic methods. Superb microvascular imaging can detect and display very slow blood flow signals in microvessels, which 1107705 JVUXXX10.1177/15443167221107705Journal for Vascular UltrasoundNawata et al research-article2022