Thyroid Radiology Flashcards Preview

• US
• CT
• MRI
• PET scan
• Fxnal imaging

• US: best for detecting and characterizing nodules
• Can use doppler to tell if node is vascularized
• Normal appearance → homogeneous
• Nodule is discrete area within gland that is distinct from normal/surrounding thyroid parenchyma

• Solid → discrete well-defined nodule
• Cystic → discrete well-defined fluid filled
• Complex → discrete nodule with both fluid and solid comp
• Cancer → punctate very small heterogeneous clarifications

• useful to define extension to lymph nodes and distant metastases
• Normal → hyperdense and hypervascular, homogeneous

• Useful for observing tissue invasion from metatasis
• Useful for infiltrative disease, especially in post surgery where anatomy is distorted
• Detection of deep nodal disease
  • Can’t differentiate b/w solid vs cystic nodule
• T2: Thyroid is slightly hyperintense

• PET scan: thyroid cancer staging - look for metastatic disease
  • Detects hypermetabolic adenopathy
• Functional imaging: Iodine scan → evaluate the function of the gland
  • Use radiotracer for diagnostic/therapeutic purposes

Normal thyroid US

• hyperdense
• hypervascular

Normal CT

Solid nodule

Cystic nodule

Complex nodule

Thyroid cancer

Hashimoto's disease

• hot nodule
• malignancy unlikely

• Cold nodule = possibly malignant
• US + FNAB to determine malignancy