Thyroid Imaging

Question 1

How are radiographs used on thyroids?

Answer 1

May suggest a thyroid lesion by noting mass effect on SOFT TISSUES or on tracheal air column.

• NOT USEFUL TO DETECT THYROID DISEASE

Question 2

Best modality to detect and characterized thyroid nodule

Answer 2

Ultrasound

Question 3

Best modality to detect lymph node metastasis in postop pt of thyroid cancer

Answer 3

Ultrasound

- real time guidance for FNA

Question 4

How is CT useful in thyroid diseases?

Answer 4

Useful to define extension to lymph node and distant metastasis

Good anatomic evaluation of thyroid bed
- thyroid is hyperdense and hypervascular

Question 5

How is MRI useful in thyroid diseases?

Answer 5

Useful for infiltrating disease particularly in post-therapy neck where anatomy is distorted
- extent of disease

Detection of deep nodal disease

Cant differentiate solid vs cystic nodule (US can)

Question 6

Which iodine scan is used to evaluate the fxn of the thyroid gland and thyroid nodule in pts with abnormal thyroid fxn?

Answer 6

I123 scan

Question 7

Which iodine scan is useful for diagnostic and therapeutic role (ie: cancer)

Answer 7

I131 scan

- can dx diffuse thyroid Ca lung mets

Question 8

With the I123 thyroid scan, what does a Hot large thyroid gland indicate?
Cold nodule?

Answer 8

Hot: Graves disease

Cold:
solid - cancer
- biopsy is next step
cyst - benign

Question 9

Imaging test of choice to evaluate a thyroid lesion size, location, and simple cyst vs not simple cyst

Answer 9

Ultrasound

Question 10

What is the imaging test of choice to evaluate a pt with Hyperthyroidism

Answer 10

Radioactive iodine scan

thyroid gland takes up iodine

Question 11

Are radiographs useful in detecting thyroid disease?

Answer 11

• NOT USEFUL TO DETECT THYROID DISEASE