Contrast harmonic enhanced EUS: technique and clinical outcome

The use of ultrasound contrast agents is widespread in transabdominal ultrasound bringing a relevant clinical impact. Endoscopic ultrasound is very accurate but some limitations exist. For this reason, image enhancement with ultrasound contrast agents is expected to bring significant results also to endoscopic ultrasound. Contrast enhanced endoscopic ultrasound is performed at a high technical level with a dedicated harmonic echo; for this purpose radial and linear echoendoscopes can be used with a dedicated software. This new technique detects strong echosignals from microbubbles in vessels with very slow flow, without artifacts. In clinical experiences, the finding of a hypoenhancing mass with inhomogeneous pattern is a sensitive and accurate parameter to identify patients affected from adenocarcinoma. On the other hand, the finding of a hyperenhanced mass tends to rule out adenocarcinoma and is more suggestive of neuroendocrine tumor. Contrast harmonic enhanced endoscopic ultrasound can be used to select the lesions and/or areas within the lesion to puncture with fine needle aspiration in order to maximize the diagnostic yield.