Biliary Ascariasis: MR Cholangiography Findings in Two Cases

Abstract

We describe the imaging features of two cases of biliary ascariasis. Ultrasonography and CT showed no specific abnormal findings, but MR cholangiography clearly demonstrated an intraductal linear filling defect that led to the correct diagnosis. MR cholangiography is thus a useful technique for the diagnosis of biliary ascariasis.he migration of Ascaris lumbricoides into the biliary tree is an uncommon but well-known complication of intestinal ascariasis and often results in biliary colic. The radiologic findings of biliary ascariasis have been described sporadically in the literature (1 3), which has stated that ultrasonography (US) is useful in identifying worms inside the biliary tree (3). We describe two cases of biliary ascariasis undetected by both US and CT but correctly diagnosed after magnetic resonance (MR) cholangiography. CASE REPORTS Case 1A 44-year-old woman was admitted with a history of epigastric pain which had started ten days prior to admission and had increased in intensity, and associated anorexia, nausea, and fever. Physical examination revealed tenderness in the epigastrium, though liver function tests revealed nothing abnormal and serum bilirubin, amylase and lipase levels, as well as her blood leukocyte count, were within normal limits. US showed no abnormal findings, but contrast-enhanced CT scanning revealed showed dilation of the intrahepatic bile ducts in the left lobe and slightly hyperattenuating lesions within the dilated bile ducts (Fig. 1A). MR cholangiography involving projection imaging and single-shot rapid acquisition using the relaxation enhancement (RARE) technique (repetition time, msec; effective echo time, 1200 msec; echo spacing, 11.5 msec; echo train length, 240; flip angle, 150 ; slab thickness, 70 mm; field of view, 300 mm; number of signals acquired, one; matrix, 240 256; and acquisition time, 6.32 sec) showed a hypointense tubular filling defect in the left intrahepatic bile duct (Fig. 1B). Endoscopic retrograde cholangiography demonstrated a linear filling defect along the left intrahepatic and common bile duct (Fig. 1C).The worm was endoscopically removed through the ampulla of Vater (Fig. 1D), no additional treatment being undertaken. The patient's clinical symptoms subsequently subsided. Case 2A 41-year-old woman was admitted with a ten-day history of epigastric pain. Physical

Endoscopic Management of Biliary Parasitic Diseases

“…MR imaging and MRCP with 3-D MIP of the biliary tree are excellent non-invasive means of showing biliary ascariasis. ERCP show a long tubular filling defect in the bile duct or gallbladder [37]. ERCP may be mainly used for endoscopic removal of worms in an already diagnosed case [38].…”

“…After the ERCP procedure, all patients receive medical treatment. Pyrantel pamoate, mebendazole, albendazole, and levamisole are effective drugs and can be used for mass therapy to control ascariasis in endemic areas [37]. ES application is still controversial in patients with biliary ascariasis.…”

Ultrasonographic Diagnosis of Isolated Jejunal Ascaris Lumbricoides

“…An adult worm is typically 15-50 cm long and three-six millimeter (mm) thick (5). Life cycle in human infestation begins by ingestion of parasite's egg.…”

Ascariasis imaging: pictorial essay

“…On T1-weighted images, worms are seen as linear, slightly hyperintense tubular structures with a central hypointense area in dilated common bile duct. If there is massive biliary ascariasis, MR cholangiography shows intraductal worms as linear hypointense filling defects in the biliary tract [100].…”