imaging the abdomen

Question 1

what are the imaging modalities for the abdomen?

Answer 1

• X-ray (plain film)/ fluoroscopy
• US
• CT
• MRI

Question 2

name some imaging lingo? 3

Answer 2

• Plain imaging vs cross sectional
• Axial/ coronal/ sagittal planes
• Spatial vs contrast resolution

Question 3

name different types of MRI? 3

Answer 3

• T1 and T2 are the most common image sequences
• T1- fluid is black
• T2- fluid is white

Question 4

what is a contrast? 3

Answer 4

• Used to increase contrast resolution
• Give intravenously or enteral before a skan
• Is either more or less sense than surrounding tissues (XR/CT) or paramagnetic (MRI

Question 5

X-ray:
pros? 4
cons? 2

Answer 5

• cheap and quick
• easy for patient
• high spatial resolution (good for bone)
• low radiation dose
• poor contrast resolution (poor for soft tissue)
• planar imaging (superimposes structures)

Question 6

CT:

pros? 3
cons? 2

Answer 6

• quick, widely available
• cross sectional images
• high contrast resolution
• radiation dose
• IC contrast risks

Question 7

US:

pros? 3
cons? 1

Answer 7

• check, quick, no radiation
• cross sectional images
• US guided interventions
• saved images are only a snapshot of the examination (report operator dependent)

Question 8

MRI:

pros? 3
cons? 4

Answer 8

• contrast resolution
• specific applications
• no radiation
• limited availability
• patient experience
• expense
• magnet/contrast risks

Question 9

what things are important to consider in abdominal imaging? 3

Answer 9

• solid vs hollow viscera
  -intra-peritoneal vs retro-peritoneal
  systemic vs portal circulation

Question 10

name 3 solid viscera?

Answer 10

• liver
• spleen
• pancreas

Question 11

how are the hepatic segments divided?

Answer 11

horizontal by the portal vein

vertically by hepatic veins

Question 12

what are he hollow viscera? 3

Answer 12

• stomach
  small bowel
• large bowel

Question 13

what scans do we use for hollow viscera? 3

Answer 13

X-ray first
- CT or MRI
Fluoroscopy (screening)

Question 14

stomach X-ray:
position? 2
contents?
mucosal/wall pattern?
size?

Answer 14

• upper left quadrant
• funds directly under left hemidiaphragm
• obliquely oriented
• fluid and air
• rural folds
• variable

Question 15

small bowel X-ray:
position?
contents?
mucosal/wall pattern? 2
size?

Answer 15

• central abdomen
• fluid and air
• encircling valuable conniventes- more widely spaced in the ileum
• wall pattern can be effaced if distended
• <3 cm diameter

Question 16

large bowel X-ray:
position?
contents?
mucosal/wall pattern?2
size?2

Answer 16

• peripheral- the large bowel frames the small bowel
• faeces (liquid/ hard)
• haustral folds interspaced with Plicae semilunaris
• wall pattern can be effaced if distended
• <6 cm
• <9 cm for the caecum

Question 17

name 3 different contrasts?

Answer 17

Single contrast= barium follow through

Double contrast= barium meal

Double contrast barium enema: difficult for frail patients

Question 18

what happens in CT colonography?

Answer 18

• Put air into the large bowel and CT scan