imaging the abdominal viscera

Question 1

what are the 4 types imaging?

Answer 1

• x ray/fluoroscopy
• ultrasound (US)
• computed tomography (CT)
• magnetic resonance imaging (MRI)

Question 2

what are the 3 planes of imaging?

Answer 2

• axial
• coronal
• sagittal

Question 3

what are the 2 main types of image sequencing in MRI?

Answer 3

T1 and T2

Question 4

what is the difference between T1 and T2 image sequencing of MRI?

Answer 4

• T1 = fluid is black

- T2 = fluid is white

Question 5

what does contrast do?

Answer 5

increases contrast resolution

Question 6

how is contrast given?

Answer 6

intravenously or enterally

Question 7

what are the pros of x-ray?

Answer 7

• cheap
• quick
• easy for patient
• high spacial resolution (good for bone)
• low radiation dose

Question 8

what are the cons of x-ray?

Answer 8

• poor contrast resolution (poor for soft tissue)

- planar imaging (superimposes structures)

Question 9

what are the pros of CT?

Answer 9

• quick
• widely available
• cross sectional images
• high contrast resolution (good for soft tissue)

Question 10

what are the cons of CT?

Answer 10

• radiation dose

- IV contrast risks

Question 11

what are the pros of ultrasound?

Answer 11

• cheap
• quick
• no radiation
• cross sectional images
• US guided interventions

Question 12

what are the cons of ultrasound?

Answer 12

• saved images are only a snapshot of examination (report operator dependent)

Question 13

what are the pros of MRI?

Answer 13

• contrast resolution
• specific applications
• no radiation

Question 14

what are the cons of MRI?

Answer 14

• limited availability
• patient experience (duration, claustrophobia)
• expense
• magnet/contrast risks

Question 15

how is the liver divided into hepatic segments?

Answer 15

• portal vein horizontally

- hepatic vein vertically

Question 16

how do you image the abdomen?

Answer 16

• bowel (hollow viscera): stomach, small bowel, large bowel
• x-ray: a goof first test for bowel
• CT and MRI increasingly useful

Question 17

where do you position the imaging device for the stomach?

Answer 17

• left upper quadrant
• funds directly under left hemidiaphragm
• obliquely orientated

Question 18

where do you position the imaging device for the small bowel?

Answer 18

central abdomen

Question 19

where do you position the imaging device for the large bowel?

Answer 19

peripheral: the large bowel frames the small bowel

Question 20

what is contained in the stomach?

Answer 20

fluid and air

Question 21

what is contained in the small bowel?

Answer 21

fluid and air

Question 22

what is contained in the large bowel?

Answer 22

faeces (liquid/hard)

Question 23

what is the mucosal/wall pattern for the stomach?

Answer 23

rugal folds

Question 24

what is the mucosal/wall pattern for the small bowel?

Answer 24

• encircling valvulae conniventes: more widely spaced in ileum
• wall pattern can be effaced if distended

Question 25

what is the mucosal/wall pattern for the large bowel?

Answer 25

• haustral folds interspaced with Plicae

- wall pattern can be effaced if distended

Question 26

what is the size of the stomach?

Answer 26

variable

Question 27

what is the size of the small bowel?

Answer 27

<3cm diameter

Question 28

what is the size of the large bowel?

Answer 28

<6cm

<9cm for the caecum