To Scan or Not to Scan In Congenital Hypothyroidism.

This article discusses whether scanning should be performed in congenital hypothyroidism or not. The goal of hypothyroid screening is early detection of low levels of thyroxine that are associated with a high frequency of mental retardation if the diagnosis is not made early, before clinical findings are obvious. In addition to detection, the system must provide for rapid reporting and bringing in of infants to start replacement therapy, as well as appropriate counseling and education of families to promote adherence to the treatment program, particularly since most children lack any signs or symptoms of hypothyroidism when seen. Any part of the evaluation that goes from optional to needed should enhance these goals. This is especially true of a procedure that might delay the start of treatment, no matter how briefly. Congenital hypothyroidism is a disease requiring lifetime therapy, but it does not necessarily follow that a diagnosis more specific than provided by the screening test and laboratory confirmation is needed. Although thyroid scanning remains the most accurate diagnostic modality to determine the anatomic cause of congenital hypothyroidism, there is no evidence to suggest that such knowledge leads to more effective treatment, better prognostication, or wiser counseling.