Fig. 5From: Value of contrast-enhanced ultrasound in diagnosis and differential diagnosis of polypoid lesions of gallbladder ≥ 1 cmDiagram shows ultrasound (US) appearance of gallbladder (GB) with low-frequency transducer and high-frequency transducer. Low-frequency transducer may depict a single or two layers of gallbladder wall and high-frequency transducer can depict three layers of gallbladder wall: the innermost hyperechoic layer (mucosa), the middle thin hypoechoic layer (muscular) and the outermost hyperechoic layer (serosa)Back to article page