Ultrasonographic demonstration of inner tube sign: a tropical dilemma.INTRODUCTION
 Ultrasonographic demonstration of intra biliary parallel lines or "inner tube sign" is considered diagnostic for biliary ascariasis in regions where ascariasis is endemic.


 In most, diagnosis was confirmed by ultrasonographic demonstration of restitution of normal appearance of bile duct with passage of round worms in vomitus or faeces.



Ultrasonographic demonstration