Which of the following radiopharmaceuticals is typically administered intravenously?

The radiopharmaceutical 99mTc macroaggregated albumin is typically administered intravenously due to its specific application in nuclear medicine for imaging and evaluating blood flow in organs, particularly the lungs. When injected intravenously, it aggregates in the small blood vessels, which allows for gamma camera imaging to assess pulmonary perfusion. This property of macroaggregated albumin is crucial for conducting lung scans, such as ventilation-perfusion (V/Q) studies.

The intravenous route is preferred to ensure rapid distribution within the circulatory system and immediate visualization of the pulmonary vasculature. This allows for accurate diagnosis and assessment of conditions like pulmonary embolism, where you need to see how well blood is flowing to the lung tissues.

Other radiopharmaceuticals listed may have varying routes of administration based on their specific medical applications, but 99mTc macroaggregated albumin's usage aligns directly with intravenous administration for effective imaging outcomes.