Indian Journal of Radiology and Imaging Indian Journal of Radiology and Imaging

: 1999  |  Volume : 9  |  Issue : 1  |  Page : 23-

Images : Biliary ascariasis

Rama Anand, Mahinder K Narula, Anuradha Gupta, Kamal Vig 
 Department of Radiology, Lady Hardinge Medical College and Associated, Smt. S.K. Hospital, New Delhi-110001, India

Correspondence Address:
Rama Anand
A-203, Meera Bagh, Outer Ring, Delhi-110087

How to cite this article:
Anand R, Narula MK, Gupta A, Vig K. Images : Biliary ascariasis.Indian J Radiol Imaging 1999;9:23-23

How to cite this URL:
Anand R, Narula MK, Gupta A, Vig K. Images : Biliary ascariasis. Indian J Radiol Imaging [serial online] 1999 [cited 2020 Jul 5 ];9:23-23
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Full Text

A six-years-old girl was admitted with a history of colicky pain in the abdomen of one month's duration. Sonography of the abdomen revealed distended bowel loops and an echogenic, linear, non- shadowing structure with a linear, central, tubular anechoic area within the gall-bladder lumen, suggestive of a roundworm showing an inner-tube sign [Figure 1]. The CBD and portal vein were normal.

Infestation with Ascaris lumbricoides (roundworm) is very common in the tropics. Adult worms can migrate through the biliary tract reaching the intra-hepatic ducts and the gall bladder, causing acute cholecystitis, cholangitis, biliary colic, obstructive jaundice and hepatic abscesses [1],[2],[3]. US of the abdomen has been advocated as a quick, safe, noninvasive and relatively inexpensive modality for suspected biliary ascariasis and various appearances of roundworms in the biliary tract and gallbladder have been described [3],[4].

The appearances described are as follows:

Inner-tube sign : The roundworm may be seen as a thick echogenic stripe with a central anechoic tube (gastrointestinal tract of the worm) in a gall bladder or CBD Stripe sign: Thin non-shadowing stripe without an inner tube, within the CBD or gall bladder. Spaghetti sign : Overlapping longitudinal interfaces in the main bile duct due to coiling of a single worm or several worms in the CBD.

Towards the end of the examination, the worm was seen neither in the gall bladder nor in the main bile duct as has been previously observed by Cerri et al [3] who reported free passage of a worm from the biliary tract to the intestine.


1Aggarwal SK, Aggarwal SP, Aggarwal DC. Demonstration of a round worm in the CBD. AJR 1964: 869-870.
2Cremin BJ. Biliary parasites. Br J Radiol 1969; 42: 506-508.
3Cerri GG, Leite GJ, Simoes JR et al . Ultrasonographic evaluation of Ascaris in the biliary tract . Radiology 1983; 146: 753-754.
4Schulman A, Loxton TA, Heydenrych JJ, Abdurahman EK. Sonographic diagnosis of biliary ascariasis. AJR 1982; 139: 485-489.