Increased Radioisotope Accumulation Around Pulmonary Arteriovenous Fistula Illustrated by Tc-99m-macroaggregated Albumin Scintigraphy and SPECT/CT in a Patient with Osler-Weber-Rendu Syndrome

Tc-99m-MAA scintigraphy was performed in a patient with pulmonary hypertension to confirm the presence of a Right-to-LEFT (R-L) shunt due to the pulmonary Arteriovenous (AV) fistula. Both planar imaging and SPECT/CT showed multiple decreased or increased RI accumulation in both lung fields, and the R-L shunt ratio was high, indicating the presence of an R-L shunt. We considered that the decreased RI accumulated lesions were caused by pulmonary hypertension due to the pulmonary AV fistula. Osler-Weber-Rendu syndrome was proposed and genetic diagnosis was done. However, we speculated that the increased RI accumulated lesions were attributable to localized bleeding or a venous telangiectasia around the pulmonary AV fistula.