The use of SPET-CT and 99mTc sulphur colloid to image peritoneo-pleuric shunt and the thoracic duct in a patient with liver insufficiency and ascitis.

Technetium-99m sulphur colloid (99mTc-SC) scintigraphy is a commonly used method in the assessment of peritoneopleuric leak in cases of liver insufficiency [1-4]. A 40 years old patient with alcoholic cirrhosis liver insufficiency, ascitis and hepatic encephalopathy was severely dyspnoic due to large right sided pleural effusion. A 99mTc-SC peritoneo-pleuric scintigraphy was performed. A 1.5 inch 22 guage needle was inserted into the peritoneal cavity at the site of dullness, as identified by percussion and ascetic fluid was withdrawn. A dose of 185MBq of99mTc-SC was instilled into the peritoneal cavity through the same needle. The thoracic and abdominal planar images in anterior (A) and posterior (B) views were acquired 24h after tracer administration with the help of a SPET/CT-16 slices CT gamma camera (Siemens Symbia T, Germany), which showed diffuse tracer accumulation within the right hemithorax confirming communication between the ascitic fluid and pleural effusion (Fig. 1). A curvilinear track of intense tracer uptake was noted in the middle and left side of the thorax. Single photon emission tomography/CT (SPET/ CT) images of the thorax acquired at 24h demonstrated that this tracer activity was the thoracic duct (Fig. 2). The limited resolution of planar scintigraphy did not allow precise anatomical localization of the tracer activity but drainage to the thoracic duct was obvious on the SPET/CT scan. This case highlights the potential usefulness of SPET/CT in precise anatomical localization of tracer activity when planar imaging is inconclusive [5].