Diagnosis of pancreatic cancer by contrast-harmonic endoscopic ultrasound (EUS): Complementary and not competitive with EUS-guided fine-needle aspiration

摘要

Contrast-harmonic endoscopic ultrasound (CH-EUS) is a relatively new technique, based on observation of a specific tissue harmonic after intravenous injection of an ultrasound contrast agent [1]. SonoVue (sulfur hexafluoride microbubbles; Bracco Imaging, Milan, Italy), the most widely adopted contrast agent, acts as a pure intravascu-lar enhancer; intraprocedural observation of the microvasculature of the lesion of interest is achieved and compared with that of the surrounding parenchyma and vessels. Researchers have identified different patterns of SonoVue uptake in pancreatic tumors, and classified them into three broad categories: hypoenhanced, iso-enhanced, and hyperenhanced. Further classification can be derived by analyzing the network of vessels (homogeneous or inhomogeneous) and the timing of contrast washout (fast washout during the arterial phase or slow washout during the venous phase).