Thyroiditis

Preliminary Diagnosis: Thyroiditis

I. What imaging technique is first-line for this diagnosis?

Ultrasound of the thyroid gland.

II. Describe the advantages and disadvantages of this technique for diagnosing thyroiditis.

Advantages

• Highly portable imaging modality.

• Does not expose patients to ionizing radiation.

• Offers exquisite detail of the vascularity of the thyroid bed.

• May guide percutaneous biopsy or other treatment.

Disadvantages

• Limited in evaluating the surrounding soft tissue and osseous structures.

III. What are the contraindications for the first-line imaging technique?

No specific contraindications to ultrasound exist.

IV. What alternative imaging techniques are available?

• Nuclear medicine imaging of the thyroid gland.

• MR imaging with IV contrast.

• CT imaging with IV contrast.

V. Describe the advantages and disadvantages of the alternative techniques for diagnosing thyroiditis.

Nuclear medicine imaging of the thyroid gland

Advantages

• Highly sensitive and specific in detailing a hot and/or cold nodule and may additionally help characterize Iodine uptake to detail hypo- versus hyper-thyroidism.

• Offers the ability to focus on functional imaging qualities and is highly limited in detailing the anatomical evaluation of the thyroid bed and surrounding soft tissue, vasculature, and osseous structures.

Disadvantages

• Does not guide percutaneous intervention.

• May be subject to both false positives and negatives.

MR imaging with IV contrast

Advantages

• Highly sensitive and specific in detailing the surrounding soft tissue.

• Does not expose patients to ionizing radiation.

• May help detect subtle edema within the thyroid bed.

Disadvantages

• Expensive.

• Time consuming.

• Limited in evaluating the osseous and air density structures.

• Subject to motion and susceptibility weighted artifact, degrading image quality.

CT imaging with IV contrast

Advantages

• Offers detailed evaluation of the surrounding soft tissues, vascular structures, and osseous structures.

• May help guide percutaneous intervention, i.e., biopsy.

• Better characterizes the primary process and details any secondary complications.

Disadvantages

• Exposes patients to ionizing radiation.

• Less adept in detailing functioning qualities of the thyroid gland.

VI. What are the contraindications for the alternative imaging techniques?

Nuclear medicine imaging of the thyroid gland

• Contraindicated in pregnant patients and those breastfeeding.

MR imaging with IV contrast

• May be contraindicated in those with non-MR compatible hardware.

CT imaging with IV contrast

• May be contraindicated in pregnant patients.

• May be contraindicated in patients with renal failure or contrast allergy.