Diagnosis of gallbladder polypoid lesions using contrast enhanced ultrasound

Purpose Effectiveness of differential diagnosis of gallbladder polypoid lesions using contrast enhanced ultrasound (CEUS) examination by perflubutane (Sonazoid®:Daiichi-Sankyo, Tokyo). Material & Methods CEUS was performed on 183 patients with gallbladder polypoid lesions.It consists of 10 adenocarcinomas, 2 adenomas, 129 benign polyps and 42 adenomyomatosis (fundal type). For benigndiseases, we examined cases where the size was 6 mm or more and could be observed for more than one year. Ultrasound was performed using TUS-A500 (Aplio 500) (Canon MedicalSystems. Tokyo) and prosound alpha10 (Hitachi Aloka Medical,Ltd.Tokyo). First, the largest cross section of a lesion was visualized using B-mode and infusion of Sonazoid. The characteristics and behavior of blood flow in the lesion in the early vascular phase were examined over approximately 30 sec. Thereafter, observation was continued accordingly for about 3 min. Sonazoid infusion using contrast harmonic imaging and real-time perfusion Imaging. Results Gallbladder carcinoma showed hypervascular staining and “eruption sign” was apparent in 60%. The “eruption sign” showed an image of a vigorously boiling water that was splashing up from the entire lesion. Blood flow imaging revealed irregular size and buckling, including tortuous vessels and erratic blood flow in 70%. Gallbladder adenoma showed “eruption sign” was apparent in 50%. The irregular size, tortuous vessels and eruption signs of blood flow imaging were 83.3% as an index of neoplastic. Gallbladder benign polyp, staining was scattered within them, and “flicker sign” was observed in 93.8%. The “flicker sign” showed an image of bubbling pre-boiled hot water. Five cases (3.9%) showed a diffused and hypervascular staining pattern. The staining time was shorter than gallbladder carcinoma. Blood flow image showed normal vessels without buckling. Linear blood flow of the stalk of gallbladder polyp was also characteristic. Gallbladder adenomyomatosis (fundal type), staining was scattered and mild flicker signs were observed in 85.7%. Blood flow at the surface of the prominence and internal Rokitansky-Aschoff sinus was observed clearity. Conclusions CEUS can clarify the hemodynamics and blood flow images and are useful for the differential diagnosis of gallbladder polypoid lesions.