Imaging

Question 0

<3 cm adrenal mass
Known primary cancer elsewhere 
Homogeneous
HU between -10 and 10 on plain CT
Diagnosis?

Answer 0

Adenoma

Question 1

What’s the classic difference between retroperitoneal fibrosis masses and malignant masses

Answer 1

Retroperitoneal fibrosis pulls ureters medially.

Retroperitoneal fibrosis does not grow behind the aorta

Question 2

10 on plain CT

Next step?

Answer 2

Give IV contrast to calculate washout

Question 3

<3 cm adrenal mass
Known primary cancer elsewhere
Heterogeneous on plain CT
Next step?

Answer 3

Consider MRI, PET or Bx (last resort)

Question 4

<-10 HU
(Regardless of heterogeneity or not)
Diagnosis?

Answer 4

Myelolipoma

Question 5

Adrenal CT with IV contrast
Washout >60%
Diagnosis?

Answer 5

Adenoma

Rare hyper vascular mets

Question 6

Adrenal CT

Washout formula

Answer 6

IE-DE/IE-UE 
IE: immediate enhanced
DE: delayed enhanced
UE: unenhanced 
All In HU

Question 7

Adrenal CT with IV contrast
Washout <60%
Diagnosis?

Answer 7

Indeterminate

Use MRI, PET, bx (last resort)

Question 8

10 HU
Known primary cancer elsewhere
CT washout <60%
MRI shows loss of signal on out of phase or opposed phase chemical shift images. 
Diagnosis?

Answer 8

Lipid rich adenoma

MRI CANNOT ASSESS FOR WASHOUT

Gadolinium relationship to signal intensity is NON LINEAR

Question 9

50% fat

Diagnosis?

Answer 9

Myelolipoma

Question 10

Adrenal mass >5 cm
No previous hx of cancer
Most likely dx

Answer 10

Adrenocortical carcinoma

Question 11

<3 cm adrenal mass on MRI
Bright on t1
Bright on t2
Dark on fat suppression 
Diagnosis?

Answer 11

Myelolipoma