Preliminary Diagnosis: Thyroid Adenoma
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 thyroid adenoma.
Advantages
-
Does not expose patients to ionizing radiation.
-
Highly portable and relatively inexpensive imaging modality.
Continue Reading -
Helps detail the vascularity and complexity of any suspected thyroid abnormalities.
-
Helps guide percutaneous biopsy and fine needle aspiration.
Disadvantages
-
Highly operator dependent.
III. What are the contraindications for the first-line imaging technique?
No specific contraindications to ultrasound exist.
IV. What alternative imaging techniques are available?
-
CT imaging with IV contrast.
-
MR of the thyroid bed.
-
Nuclear medicine thyroid scintigraphy utilizing Technetium 99m pertechtenate and I-123.
V. Describe the advantages and disadvantages of the alternative techniques for diagnosing thyroid adenoma.
CT imaging with IV contrast
Advantages
-
Offers better evaluation of the surrounding soft tissues and osseous structures than other imaging modalities.
-
Better evaluates for extension of local thyroid disease/neoplasm and distant metastasis.
Disadvantages
-
Less sensitive and specific in characterizing the complexity and vascularity of thyroid nodular lesions.
-
Less portable and relatively more expensive compared to sonographic imaging.
-
Exposes patients to ionizing radiation.
MR of the thyroid bed
Advantages
-
Does not expose patients to ionizing radiation.
-
Offers exquisite evaluation of the surrounding soft tissues.
-
Highly adept in detailing any evidence of distant cervical lymphadenopathy and metastasis.
Disadvantages
-
Less adept in detailing subtle thyroid mineralization, which is characteristic in certain thyroid abnormalities, i.e., medullary carcinoma.
-
Less adept in guiding percutaneous biopsy and therapy.
-
May be subject to motion and susceptibility weighted artifact, degrading image quality.
-
Expensive.
-
Time consuming.
Nuclear medicine thyroid scintigraphy utilizing Technetium 99m pertechtenate and I-123
Advantages
-
Moderate in sensitivity and moderate in detailing hot or cold thyroid nodules.
Disadvantages
-
Limited in detailing the surrounding soft tissues, vasculature, and osseous structures.
-
Exposes patients to ionizing radiation.
-
Limited in sensitivity and specificity in detecting and detailing small thyroid nodules.
-
Unable to adequately detail the vascularity of a thyroid lesion.
-
Expensive.
VI. What are the contraindications for the alternative imaging techniques?
CT imaging with IV contrast
-
May be contraindicated in pregnant patients.
-
IV contrast may be contraindicated in patients with renal failure or contrast allergy.
MR of the thyroid bed
-
Contraindicated in patients with non-MR compatible hardware.
Nuclear medicine thyroid scintigraphy utilizing Technetium 99m pertechtenate and I-123
-
May be contraindicated in pregnant and breast feeding patients.
Copyright © 2017, 2013 Decision Support in Medicine, LLC. All rights reserved.
No sponsor or advertiser has participated in, approved or paid for the content provided by Decision Support in Medicine LLC. The Licensed Content is the property of and copyrighted by DSM.