抄録
Sentinel lymph nodes (SNs) are defined as the first nodes which receive lymph fluid from the primary tumor site. We aimed to detect SNs in vivo by using ultrasonography. In this study, contrast medium for ultrasonography, phospholipids-coated nanobubbles, was tried to be observed in the lymph node. Male Japan White rabbits were anesthetized with pentobarbital sodium (20 mg/kg iv.). Centripetal cannulation was performed in one of the popliteal afferent lymph vessels. Ultrasound contrast medium (2 mg/ml in physiological saline solution) was infused through the lymphatic cannula. A probe was fixed on the popliteal region of the rabbit. To evaluate a relationship between the amount of the contrast medium and degree of the enhancement, the infusion rate was increase in step from 0.74 ml/h to 14.7 ml/h. The contrast medium could be detected by Doppler ultrasonography at the region of the popliteal lymph node. Degree of the enhancement was increased in the infusion rate-dependent manner. When size of the contrast medium had been adjusted by passing through the polycarbonate membrane with 0.1 μm pores, efficiency of the enhancement was increased. These results suggest that development of efficient contrast medium enables to ultrasonographically detect sentinel lymph nodes in vivo. [J Physiol Sci. 2008;58 Suppl:S190]
