Hepatobiliary SPECT•CT Study in a Patient with Suspicion of Biliary Leak
Author: Deepanjan Mitra, MD, North City Hospital & Diagnostics, Kolkata, India
A 40-year-old female had a history of choledochal cyst treated with surgical excision, along with cholecystectomy and choledocho-duodenostomy. The surgery was complicated with an anastomotic leak, which was eventually controlled. Subsequently, the patient presented with abdominal pain and fever. In view of the suspicion of a recurrence of biliary leak, the patient underwent a dynamic 99mTc HIDA hepatobiliary scintigraphy followed by a SPECT•CT study on a Symbia™ T2 system.
Scanner Symbia T2 Scan dose 5 mCi (185 MBq) 99mTc HIDA Scan delay 20 min post injection CT 110 kV, 245 eff mAs 3 mm slice thickness SPECT 64 frames 20 sec/frame Flash 3D recon
Dynamic planar images, acquired for initial 30 minutes following injection, show normal hepatic uptake of tracer with normal transit into the bilateral hepatic ducts and the common bile duct. There is accumulation of tracer at the lower end of CBD (blue arrow) at the level of the choledocho-duodenostomy anastomotic site, as well as stasis in the left hepatic duct. There is normal clearance of tracer into the duodenum and, subsequently, into the small bowel with gradual increase in the gastric region (red arrow). Delayed images show progressive accumulation of tracer in the anastomotic site with stasis in the left hepatic duct. A significant amount of tracer is visible in the right flank, which appears to be in the bowel.
Clinical impression from dynamic planar and SPECT•CT images was of normal biliary transit through anastomosis without evidence of obstruction. The biliary stasis in the dilated hepatic ducts, as well as the tracer hold up in the anastomotic site and adjacent duodenal loop, reflects post surgical bowel stasis and lack of peristaltic activity. Duodenogastric reflux is common in post-biliary and duodenal surgery.
SPECT•CT was instrumental in localization of tracer within the duodenal lumen confirming anastomotic stasis. Thin-slice CT performed on Symbia T2 with SureView, which enables increased pitch for faster acquisition without degradation of image quality, was instrumental in CT acquisition coverage of liver and upper abdomen without excessive breath-hold time. Symbia T2 also aided in visualization of tracer within the gastric lumen and bowel lumen in the right flank, which helped confirm absence of anastomotic leak inspite of significant biliary stasis at the anastomotic junction.