More interestingly, there is uptake in the thyroid gland. Additional images of the neck and head show the uptake in the thyroid gland (arrow) and in the brain (thin arrow).
Thyroid activity is often associated with free technetium pretechnetate; however, thyroid activity was seen on three previous studies. Free technetium pretechnetate shows the brain as a negative defect, whereas macroaggregated albumin shows the brain with positive uptake. Therefore, this patient has a right-to-left shunt. The increased right heart pressure due to chronic lung disease resulted in shunting across a patent foramen ovale.
