Medical Imaging

Question 1

Where does the thyroid begin in development?

Answer 1

Junction of the trachea and the larynx

Question 2

What happens to thyroid as we age?

Answer 2

Nodularization

Question 3

What are the two reasons to image the thyroid?

Answer 3

Function

Morphology

Question 4

What are the functional diseases that warrant imaging? (4)

Answer 4

• Grave’s
• Toxic adenoma
• Toxic multinodular goiter
• Thyroiditis

Question 5

What is the role of imaging in hypothyroidism?

Answer 5

None–treated with hormone replacement

Question 6

What is struma ovarii?

Answer 6

Stem cells of the ovaries develop to produce thyroid tissue

Question 7

What is the best test for evaluating the hyperthyroid testing?

Answer 7

Nuclear iodine uptake and scan

Question 8

What is the role of US, MR, and CT in evaluating functional hyperthyroidism?

Answer 8

Not helpful

Question 9

What is the normal and radioactive form of iodide?

Answer 9

127 is normal

123 is radioactive

Question 10

What are the rays that are given off by I 123? Why are these useful?

Answer 10

Gamma

same spectrum as xrays

Question 11

What is the use of markers in thyroid uptake scans?

Answer 11

Measurement standard

Question 12

What are uptake scans?

Answer 12

Baseline and after I 1 23 administration measurements at 6 and 24 hours to measure

Question 13

What is the normal range of uptake scans for the thyroid?

Answer 13

10-25%

Question 14

How do you diagnose Grave’s disease on a thyroid uptake scan?

Answer 14

Way more uptake than usual, but uniform (like, 75% uptake)

Question 15

What are the uptake scans like with thyroid adenomas?

Answer 15

High uptake in one area, while the rest are downregulated

Relatively normal uptake levels though

Question 16

What are the uptake scans like with multiple thyroid adenomas?

Answer 16

Uptakes mildly elevated, and irregular uptake spots

Question 17

What are the uptake scans like with thyroiditis?

Answer 17

Virtually no uptake–caused by the release of thyroid hormone, rather than an increased uptake/production

Question 18

What is the role of imaging with morphological thyroid disease? (3)

Answer 18

• Something palpated
• Screening for familial ds
• Incidental finding

Question 19

Human fingers cannot reliably palpate nodules less than what cm in size?

Answer 19

1 cm

Question 20

Prominent thyroid without focal nodule = ?

Answer 20

Diffuse goiter

Question 21

True or false: in general, there is no need to image a prominent thyroid without a focal nodule

Answer 21

True

Question 22

What are the three major etiologies of distinct thyroid nodules?

Answer 22

• Cysts
• Benign adenomas
• Malignancy

Question 23

What imaging modality is most useful for evaluating thyroid nodules without systemic ssx?

Answer 23

Ultrasound

Question 24

Black structure with fussy interior findings on US = ?

Answer 24

Malignancy

Question 25

How effective is ultrasound in evaluating for malignant vs benign growth?

Answer 25

Poor

Question 26

True or false: “Hot” nodules are almost alway benign

Answer 26

True

Question 27

True or false: “Cold” nodules are almost alway benign

Answer 27

False- indeterminate

Question 28

What are the ultrasound characteristics of malignant thyroid nodules? (3)

Answer 28

• Microcalcifications
• Greater than 2.5 cm
• Fast increase in size