Imaging the Abdomen

Question 1

Main modality to examine abdomen

Answer 1

CT

Question 2

Benefits of using CT to image the abdomen

Answer 2

Excellent spatial resolution and soft tissue detail
Fast acquisition time
Can be reconstructed into 3D

Question 3

Attenuation

Answer 3

Term used to describe density on CT images

Measured in Hounsfield units (air and fat are negative, blood and bone are positive)

Question 4

Types of contrast

Answer 4

Oral
IV
Both
None

Question 5

What contrast to use if looking at
1. Solid organs
2. Urinary system
3. GI tract
and why?

Answer 5

1. IV contrast (demonstrates perfusion and better identification of focal abnormalities)
2. No contrast (better differentiation of calcification)
3. IV and oral contrast (GI tract is hollow, so better assessed with oral)

Question 6

Who cannot have contrast?

Answer 6

Patients with severe renal failure cannot receive IV contrast
Because it is excreted through the kidneys
May cause more damage (nephrotoxic)

Question 7

Bones of the abdomen

Answer 7

Lower ribs
Spine (upper thoracic, lumbar, sacrum)
Pelvis
Hips

Question 8

Muscles in the abdominal wall that you can see in axial CT

Answer 8

Rectus abdominis
Internal/external oblique and transversus abdominis
Psoas
Iliacus

Question 9

What modality is first line for examining the bladder?

Answer 9

Ultrasound

May be difficult to see on CT if its collapsed