technetium isotope thyroid scan

Last reviewed 01/2018

Technetium isotope scans complement thyroid function tests by mapping the avidity with which different parts of the thyroid take up the isotope.

Common patterns are:

  • diffuse, homogenous uptake - indicates a normal gland or one where there is diffuse hyperactivity e.g. Grave's disease.
  • fragmented uptake - suggests a multinodular goitre.
  • "cold" nodule - an area of inactive tissue. May be a cyst or a non-functional tumour.
  • "hot" nodule - an area of hyperactive tissue. There is no uptake in suppressed adjacent tissue.