Contrast-enhanced ultrasound findings of gallbladder tuberculosis: a case report.

Preoperative diagnosis of gallbladder tuberculosis (TB) is difficult, and the contrast-enhanced ultrasound (CEUS) pattern has never been reported before. We present a case of TB in which CEUS had some special findings that were helpful for early diagnosis. The thickened gallbladder wall presented in the arterial phase of CEUS the "sandwich biscuit" sign with no enhancement in the middle layer and hyperenhancement in the inner and outer layers.