Fluidothorax on lung perfusion scintigraphy

Overview

77-y-old patient was sent to our department for a lung scintigraphy due to a dyspnea. He was been treated for a chronic myeloid leukemia, he had a recurrent fluidothorax in his history. Lung perfusion scintigraphy revealed non-segmental perfusion defect in the lower part of the right lung (Fig. 1), so SPECT/CT imaging was performed. It confirmed bilateral fluidothorax, more severe on the right side, which corresponded with the perfusion defect (Fig. 2). Lateral images in the upright position were then performed to assess if the fluid is free or encapsulated and to improve interpretation towards an embolism. The perfusion defect partially changed its position and both lungs changed their shape – dorsal borders changed from linear to convex – it is more apparent on the right side (Fig. 3). It confirmed partially free fluid. Fluidothorax can mimic both segmental and non-segmental perfusion defects and it cannot be visible on chest X-ray sometimes. Pulmonary embolism can be one of its causes. SPECT/CT is a useful imaging method to assess the role of fluidothorax or other parenchymal changes on detected perfusion abnormalities. If it is not available, lateral views performed in an upright position can solve this problem. We excluded pulmonary embolism and further clinical course confirmed our conclusion. Patient dyspnea disappeared after subsequent thoracocentesis.

Key words:
fluidothorax, pulmonary embolism, scintigraphy, body position