Re: RAI Uptake Scan - COLD vs. HOT nodule
I know only that cold nodules don't take up much iodine - they don't produce much thyroid hormone. Hot nodules take up lots of iodine, and are areas where hormone is produced.
Cold nodules can become cancerous, and it is therefore suggested to keep an eye on them, either by Fine Needle Aspiration, and/or removal. Almost all cancers are from cold nodules, but not all cold nodules are cancerous.
Hot nodules are not usually a cause for concern.
Hope that helps.