Background: It has been proposed that the increasing incidence of thyroid cancer is due to increasing detection.
Methods: Using administrative data, we compare by year from 1993 to 2006, the rates of diagnostic imaging tests of the neck (computed axial tomography--CT, magnetic resonance imaging--MRI, and non-obstetrical ultrasound--US) to the incidence of thyroid cancer for the population of the Province of Ontario Canada.
Results: Women and men have different rates of tests, and those rates reflect the rates of new diagnoses of thyroid cancer.
Conclusions: The rising incidence of thyroid disease in women is associated with increasing numbers of diagnostic imaging tests.