Thyroid Function of Pediatric Subjects Following Isovue® Administration

Inclusion Criteria: * Is male or female from 0 to 3 years of age; * Is scheduled to undergo a radiologic examination that requires intravascular administration of ISOVUE as part of his/her standard of care; * Has normal baseline thyroid function tests (TSH, total T3, total T4, and fT4) performed at a local laboratory with blood sample obtained within one week prior to ISOVUE administration; * Written informed consent is obtained from the subject's parent(s) or legally acceptable representative(s) (according to local regulations) who are willing to comply with the protocol requirements. Exclusion Criteria: * Has any known allergy to one or more of the ingredients of ISOVUE; * Has been diagnosed with congenital hypothyroidism; * Has undergone radiation treatments to the head or neck; * Is currently on thyroid replacement therapy; * Is on therapy with dopamine or any treatment which may affect the thyroid function testing results; * Has been exposed to any topical iodinated product within 30 days prior to enrollment in the present study; * Has been exposed to an iodinated contrast agent within 1 year prior to enrollment in the present study, including any administration of iodinated contrast agents during placement of a central line; * Has any medical condition or other circumstances which would significantly decrease the chances of obtaining reliable data, achieving study objectives, or completing the study and/or post-dose follow-up examinations.