Final answer:
Iodinated IV contrast agents are used in medical imaging and known to concentrate in the thyroid gland, liver, and some parts of the brain. They perfuse normal liver and brain tissues due to iodine's natural affinity for these areas. The perfusion in the thecal sac and lymph nodes is less clear and depends on specific conditions.
Step-by-step explanation:
Iodinated IV contrast agents are commonly used in medical imaging to enhance the visibility of internal structures in diagnostic procedures. These agents perfuse, or pass through, different types of tissues where their uptake can be imaged. The question pertains to which normal tissues iodinated IV contrast agents perfuse. It is known that iodine-131 concentrates in the thyroid gland, the liver, and some parts of the brain, according to medical diagnostics using radiopharmaceuticals. The reference also mentions the absorption of certain compounds by the liver, and that gallium-67 accumulates where there is rapid cell growth, as in lymph nodes. Hence, one can infer that iodinated contrast agents will perfuse normal liver and brain tissues due to the affinity of iodine for these tissues. However, for the thecal sac, which contains the spinal cord's cerebrospinal fluid, and lymph nodes, uptake is less clearly defined for iodinated agents, as their perfusion would depend on the presence of the blood-brain barrier and pathological conditions, respectively.