Head and Neck ImagingColloid cyst, thyroid
cyst with gelatinous content within the
thyroid gland. Most
thyroid cysts originate from
cystic degeneration of adenomas. They appear as hypoechoic cysts on
ultrasound and low-density cysts on
CT; often they reveal high intensity on T1-weighted MR images, due to their high protein content.
RH