GI Imaging

Question 1

What are the methods of imaging of the GI tract?

Answer 1

Ultrasound
CT
Angiography
X-rays /radiographs

Question 2

When are abdominal xrays requested?

What are the normal go to first line imaging methods instead of plain radiographs?

Answer 2

To see position of iatrogenic items/instruments
Confirm a Ureteric stone after a CT has been done (FOLLOW UP)

First line = ultrasound or CT

Question 3

What follow up imaging method is done if a CT scan detects a Ureteric stone?

Answer 3

X-ray

Question 4

What is the acronym used to remember how to analyse and abdominal x-ray?

Answer 4

ABDO-X

Question 5

What does the acronym ABDO-X for interpreting abdominal x-rays stand for?

Answer 5

A = Air
B = bowel
D = Dense structures and calcification
O = organs and soft tissues
X = Xternal objects, lines and tubes

Question 6

Where should air only be seen in the GI system?

Answer 6

Gut lumen
Gastric bubble

Question 7

What is the gold standard imaging method of diagnosing pneumoperitonuem?

Answer 7

CT

Question 8

What is Rigler Sign?

Answer 8

Indicates massive pneumoperitoneum

Where the bowel wall looks crispy and clearly defined due to gas being present on both sides

Only seen in massive pneumoperitoneum

Question 9

How do you identify small bowel on an abdominal x-ray?

Answer 9

Central
Plica circularis (run full thickness)
Contains air or fluid

Question 10

How do you identify large bowel on x-ray?

Answer 10

Peripheral
H austral folds (dont run full thickness)
Contains air or faeces

Question 11

Go to the last slide and look at image labelled 1:

Which image shows the large bowel and which x-ray shows the small bowel and why?

Answer 11

1 = small bowel (more central and Plica circularis

2 = large bowel (more peripheral and haustral lines)

Question 12

What are the 2 main types of Volvulus that can obstruct the bowel?

Answer 12

Sigmoid Volvulus
Caecal Volvulus

Question 13

How does a sigmoid Volvulus appear on an abdominal x-ray?

Answer 13

Coffee bean sign of large gas filled viscus from pelvis to epigastrium
Normally positioned caecum

Question 14

How does a caecal Volvulus present on an abdominal x-ray?

Answer 14

No normal caecum
Normal sigmoid
Revers c shaped viscus right side

Question 15

Go to the last slide and look at the x-rays on image 2:

What does image 1 show?

Answer 15

Caecal Volvulus

Question 16

Go to the last slide and look at the x-rays on image 2:

What does image 2 show?

Answer 16

Sigmoid Volvulus

Coffee bean sign

Question 17

What is Achalasia?

Answer 17

When you get impaired relaxation of the lower oesophageal sphincter

Question 18

How can achalasia be seen with imaging?

Answer 18

Barium swallow given

Bird-break or rat-tail stricture of distal oesophagus seens

Food residue in the oesophagus

Question 19

How does achalasia present?

Answer 19

Weight loss
Halitosis

Question 20

Look at image 3:

What sign does this barium swallow show and what condition does it indicate?

Answer 20

Birds beak or rat-tail stricture of oesophagus

Achalasia

Question 21

When is an endoscopic retrograde pancreatogram used?

Describe its route:

Answer 21

To see if theres any stones in the common bile duct

Oesophagus->stomach->dudoenum->ampulla of Vater->common bile duct

Question 22

What are the advantages of ultrasound?

Answer 22

No radiation
Cheap
Portable

Question 23

What is the disadvantage of ultrasound?

Answer 23

User dependant

Question 24

Look at the last slide at image 4:
What type of imaging is this and what pathology is the imaging showing?

Answer 24

Dialation and left inguinal herniation of the bowel

Question 25

What type of contrast is usually injected into the enteric system? What type of contrast is usually swallowed?

Answer 25

Injected = iodine Swallowed = barium

Question 26

What imaging methods are used if a patient is known to have colon cancer? What’s it assessing?

Answer 26

CT + contrast Measure, invasion adn metastases

Question 27

What imaging method is used to look for colon cancer?

Answer 27

CT colonogram

Question 28

What imaging method is used for staging and follow up for rectal cancer?

Answer 28

MRI

Question 29

What is visible on colonoscopy with Crohn’s disease?

Answer 29

Mouth to anus skip Edison’s Transmural inflammation Perianal fistulas, abcesses and fissures

Question 30

What imaging method is done for diagnosing Crohn’s disease and follow up?

Answer 30

MRI

Question 31

What imaging method is used to screen for Crohn’s disease?

Answer 31

Ultrasound

Question 32

What is a potential complication of Ulcerative colitis?

Answer 32

Toxic megacolon

Question 33

How can ulcerative colitis cause toxic megacolon?

Answer 33

The inflammation s so serve that nerve endings to the smooth muscles get paralysed This leads to the smooth muscle staying dilated

Question 34

What imaging method can be done to check for perofration in ulcerative colitis?

Answer 34

CT

Question 35

How does a toxic megacolon appear on an abdominal. X-ray?

Answer 35

Colonic dilation OEDMA Pseudopolyps

Question 36

What types of obstructions and vascular issues can an abdominal x-ray detect?

Answer 36

Calcification Renal calculi Vascular calcification Calcification of pancreas following chronic inflammation

Question 37

Why is barium contrast very useful?

Answer 37

Can highlight problems/anatomical variance with the stages of swallowing and a follow through which allows the contrast to pass tot he small intestine

Question 38

What is the advantage and disadvantage of an abdominal CT scan?

Answer 38

High resolution image High dose radiation

Question 39

What are the advantages and disadvantages of abdominal MRI?

Answer 39

Adv: -detailed + high contrast -no radiation Disadvantage: Time consuming

Question 40

What part of the abdomen is ultrasound often used to visualise?

Answer 40

Biliary tree for gallstones and dilated bile ducts