Iodine is a basic atomic element bearing No. 53 in the Periodic Table of Elements. Its high atomic density makes it an excellent product to absorb x-rays and also allows better visualisation of organs that one wishes to investigate.
Allergy problems with iodine are relatively frequent and of varying intensity. This point will always be checked prior to any possible injection. Note that in many situations, it is possible not to use such an injection or to use other methods of testing that do not require the same product
The other potential problem is that of kidney function that can affect some patients, especially diabetics. It is thus sometimes necessary to check kidney function before (and sometimes after) an iodine injection. The dosage of blood creatinine is the test of choice to make.
Generally, the injection of iodine will be used in the investigation of tumour or inflammatory lesions because the breakage of the vascular barrier resulting from these pathologies causes a release of the product in the soft tissues which border it, thus allowing its detection.
The vascular regions or barriers that are broken appear denser than those which are integrated and in which the dye remains in the vessels instead of breaking into the soft tissue of the surrounding areas.