Compared to other imaging modalities, endoscopic ultrasound (EUS) has limitations in terms of image enhancement. However, with the availability of contrast agents in ultrasonography, EUS has evolved. Contrast-enhanced Doppler EUS (CD-EUS) enhances Doppler signals from vessels and is useful for characterizing lesions detected by EUS. Moreover, contrast-enhanced harmonic EUS (CH-EUS) with second-generation ultrasound contrast agents and a broad band transducer allows microvessels and parenchymal perfusion to be visualized. Vascularity can also be quantitatively analyzed during CH-EUS by generating a time-intensity curve. CE-EUS is useful for characterizing pancreatic lesions and can detect pancreatic adenocarcinomas with a sensitivity of 94%and a specificity of 89% as a result of the hypo-enhancement of these lesions. Indeed, CH-EUS is superior to multiple detector-computed tomography in terms of the differential diagnosis of small lesions that are ≤2 cm. CH-EUS complements EUS-guided fine-needle aspiration (EUS-FNA) as it identifies the EUS-FNA target and lesions with false-negative EUS-FNA findings. CH-EUS is also used to estimate the malignant potential of gastrointestinal stromal tumors and helps to differentiate between malignant and benign lymphadenopathy.
Keywords: contrast-enhanced endoscopic ultrasound; endoscopic ultrasound; ultrasound contrast.
© 2013 The Authors. Digestive Endoscopy © 2013 Japan Gastroenterological Endoscopy Society.