Session 10

Question 1

Types of GI imaging

Answer 1

AXR
Barium swallow
Ultrasound
CT
MRI
Angiography

Question 2

Interpretation of Abdo X ray

Answer 2

A = air
B = bowel (dilation/thickening)
D = dense structures or calcification (bones/kidney stones)
O = organs and soft tissues
X = external objects, line and tubes

Question 3

What is Rigler sign

Answer 3

Double wall sign, free air in peritoneal cavity

Thick white lines on X ray

Question 4

Differentiating small and large bowel obstruction

Answer 4

Question 5

Difficulty with differentiating between LB and SB dilation

Answer 5

Most cases of LB dilation also have SB dilation, ileo-caecal valve allows reflux back

Question 6

What is this

Answer 6

Sigmoid volvulus

Caused by psychotropic meds/constipation

Bowel stretches, more mobile, coffee bean sign

Caecum normal position so not caecal volvulus

Question 7

What is this

Answer 7

Caecal volvulus

Congenital

Rudimentary mesentery

Caecum not in normal position

Question 8

What does fluoroscopy do

Answer 8

Live X ray to produce video

Question 9

What is this

Answer 9

Thumb sign

Epiglottitis

Question 10

What does a barium swallow investigate

Answer 10

Upper GI tract

Question 11

What does this show

Answer 11

Oesophageal carcinoma

Apple core sign, due to strictures

Question 12

What is this

Answer 12

Thickened bumps

Nut cracker oesophagus

marked muscular spasm

Question 13

What is this

Answer 13

Achalasia

LOS narrows at bottom

Dennervation, sustained muscular spasm, weight los

Question 14

What is ERCP

Answer 14

Endoscopic retrograde cholangial pancreatogram

Question 15

How does ERCP work

Answer 15

Ampulla of vater = wire to common bowel duct

Inject contract

Question 16

What does this show and how can it be treated

Answer 16

Defect- stone blocking contrast in common bile duct

Basket used to drag stones out, or nick Ampulla to allow stones out, plastic stent

Rectify jaundice

Question 17

Ultrasound uses

Answer 17

Soft tissues
Abdominal viscera
Blood vessels

Can see reduced peristalsis of bowel = Crohns/inflammation

Doppler: colours, motion depicted though sound waves

Question 18

CT uses

Answer 18

Acute abdo pain/symptoms

Rotating X ray beam

Looking for cancer

Question 19

Good way to look for disease of ureters/urinary bladder

Answer 19

CT scan

Question 20

Types of contrast in CT

Answer 20

Iodine contrast makes it brighter

oral, enema, injected into bladder, artery

Question 21

MRI use

Answer 21

Soft tissues of abdomen

Question 22

What does this show

Answer 22

gall stones and bile

Question 23

Angiography usage to locate bleeding

Answer 23

Feed wires into arterial system
Usually femoral

Inject contrast, leaks out at point of bleeding

Can induce thrombosis at correct area

Question 24

Label

Answer 24

Question 25

Types of X rays available

Answer 25

Abdominal X ray Erect chest x ray

Question 26

Types of contrast studies available

Answer 26

Barium swallow Barium enema Barium meal/follow through Water soluble contrast studies

Question 27

Why request an AXR

Answer 27

Acute abdo pain Small or large bowel obstruction- CT for SB, abdo x ray for LB Acute exacerbation of IBD= see toxic mega colon with perforation Renal colic = CT, abdo x ray to check stone has passed

Question 28

Features of small bowel on x ray

Answer 28

Central position Often dont see Valvular conniventes: cross entire wall, thin

Question 29

Features of large bowel on X ray

Answer 29

Peripheral position hasutra Transverse colon hang down to pelvis Sigmoid can loop and be Long

Question 30

Features of small bowel obstruction

Answer 30

CT first line Identify level and cause of obstruction Determine whether bowel is strangulated Central position of gas filled and distended loops of bowel, white lines pass full width

Question 31

Features of large bowel obstruction

Answer 31

CT first line Abdo X ray can see colonic distension, small bowel dilation (dependent on duration of obstruction or incompetence of ileocecal valve)

Question 32

What not to use in small bowel obstruction

Answer 32

Plain abdominal radiographs unless CT unavailable

Question 33

Large bowel has the ability to extend up to

Answer 33

6cm

Question 34

Sigmoid volvulus cause

Answer 34

Twist at base of sigmoid mesentery which is in a fixed position (asterisk) in left iliac fossa

Question 35

Cause of toxic megacolon

Answer 35

Acute deterioration with UC or colitis Colonic dilation Oedema Pseudopolyps Colon dilated with extensive mucosal islands indicating bowel wall inflammation

Question 36

Perforation investigations

Answer 36

Erect CXR Peptic ulcer, diverticular, tumour, obstruction, trauma, iatrogenic

Question 37

Pneumpperitoneum investigations

Answer 37

Erect CXR Show free abdo gas,

Question 38

What has largely replaced barium swallow

Answer 38

Upper GI endoscopy for peptic ulcer disease and evaluation of haematemesis

Question 39

How does ultrasound generate image

Answer 39

Frequency above audible range of human hearing 20KHz Usually 2-18 MHz

Question 40

Features of USS

Answer 40

Cheap compared to CT and MRI Portable - fast Highly user dependent

Question 41

CT scan features at T12

Answer 41

Aortic hiatus of diaphragm

Question 42

CT scan features at L1

Answer 42

Transpyloric plane Fundus of gallbladder Pylorus of stomach neck of pancreas SMA Hilum of kidneys

Question 43

CT scan features at L3

Answer 43

Umbilicus IMA

Question 44

CT scan features at L4

Answer 44

Iliac crest Bifurcation of abdominal arota

Question 45

What level is this from

Answer 45

T12

Question 46

What level is this

Answer 46

L1

Question 47

What level is this

Answer 47

L3

Question 48

MRI and CT comparison

Answer 48

Question 49

Features of GI Angiography

Answer 49

A way of visualising the vasculature associated with the intestines CT angiography has replaced conventional angiography for mesenteric vasculature