Endocrine Radiology

Question 1

What are the common indications for thyroid scans

Answer 1

1) differentiate between hyper functionality of the thyroid
2) assess modularity of the thyroid
3) assess for ectopic tissues

Question 2

What is used in thyroid scans?

Answer 2

123 Iodine scans

Question 3

What is the most common scan used to pick up incidental thyroid nodules?

Answer 3

Chest CT

Question 4

What is the #1 diagnostic testing for thyroid nodules

Answer 4

Fine needle aspiration biopsy (FNAB)

Question 5

What are the most common functional adenomas

Answer 5

Prolactinoma (lactotrophs)

Question 6

What genetic diseases are associated with pheochromocytoma

Answer 6

majority of cases are sporadic

MEN 2 = most common genetic disease
- always in the adrenal gland and always bilateral

Other genetic diseases:

• NF1
• Von Hippel Lindau disease
• Tuberous sclerosis
• sturge Weber disease

Question 7

Neuroendocrine tumor receptors

Answer 7

5 subsets of somatostatin receptor
(SSTR1-5)

octreotide has the strongest affinity for these receptors and therefore it is also used in conjunction with nuclear radiation to detect activity

Question 8

What is the msot common smite for Neuroendocrine tumors?

Answer 8

Small intestines

Then lungs and then pancreas rounds out top 3

Question 9

What are the subsets of pancreatic Neuroendocrine tumors

Answer 9

Nonfunctional (60%)

Functional (40%)

• insulinoma (40-60% and most common functional)
• gastrinoma (20-50%)
• glucagonoma (rare)
• somatostatinoma (rare)
• VIPoma (rare)

Question 10

Clinical features of each subset of functional pancreatic endocrine tumor

Answer 10

Insulinoma

• hypoglycemia and excessive catecholamine release
• can be anywhere in the pancreas
• evaluation = insulin, C-peptide levels

Gastrinoma

• PUD, gastric ulcers, GERD, diarrhea
• most common site = duodenum
• evaluation = fasting gastrin )not on PPI if the patient has one) levels, secretin stimulation test

Glucagonoma

• hyperglycemia, diabetes, venous thrombosis, depression
• most common site = pancreas tail
• evaluation = glucagon levels

Somatostatinoma

• diabetes, hypochloridemia, Cholelithiasis, diarrhea
• most common site is pancreatic head
• evaluation = somatostatin levels

VIPoma

• watery diarrhea, hypokalemia, achlorhydria
• most common site is pancreatic tail
• evaluation = VIP levels

Question 11

What are considered the appropriate indicated imaging for palpable thyroid nodules that are euthyroid (NO functional issues)

Answer 11

US thyroid

CT of neck with or without IV contrast

if there is physical functional issues = I-123 nuclear scans are now indicated