Figure 3. Lung and spleen. Also present: salivary glands, thyroid, kidney, stomach and heart.

A 61-year-old female with metastatic neuroendocrine cancer, carcinoid syndrome, and no prior radioembolization, was injected with ^99mTc-MAA via right groin access into the right hepatic artery and imaged 73 minutes after injection. Calculated lung shunt fraction was 26%. She did not undergo subsequent ⁹⁰Y-radioembolization.

Axial, coronal, and MIP SPECT (Row A), axial and coronal fused SPECT/CT (Row B), axial and coronal CT (Row C), and anterior planar (D) images demonstrate radiotracer uptake in the lungs, consistent with hepatopulmonary shunting. The lung shunt fraction in this case was 26%, and ⁹ Y radioembolization was not performed. Radiotracer uptake was also seen in the renal cortices, which is a common site of extrahepatic uptake of radiotracer during hepatic artery perfusion studies, and is hypothesized to relate to breakdown of ^99mTc-MAA over time, with lodging of smaller aggregates in renal capillaries. Anterior planar and MIP images also demonstrate radiotracer uptake in the salivary glands, thyroid gland, and stomach, consistent with the distribution of free pertechnetate.