What is the administration method for Tc sulfur colloid in liver/spleen scans?

• A. Intravenous
• B. Subcutaneous
• C. Inhalation
• D. Oral ingestion

Answer: (A)

The administration method for Technetium (Tc) sulfur colloid in liver/spleen scans is intravenous. This route is commonly used because it allows for optimal distribution of the radiopharmaceutical throughout the bloodstream, facilitating its uptake by the reticuloendothelial system, which includes the liver and spleen.

When Tc sulfur colloid is administered intravenously, it is rapidly taken up by the macrophages in the liver and spleen, where it then emits gamma radiation that can be detected by a gamma camera during imaging. This is crucial for providing clear and accurate diagnostic images of these organs, helping to identify conditions such as liver disease or splenic abnormalities.

Other routes of administration such as subcutaneous, inhalation, and oral ingestion would not provide the same level of efficacy or localization necessary for accurate imaging of the liver and spleen. Each of those methods is suited for different types of examinations and would not achieve the specific targeting required for scintigraphy in this context.