GI Imaging Flashcards
What are the methods of imaging of the GI tract?
Ultrasound
CT
Angiography
X-rays /radiographs
When are abdominal xrays requested?
What are the normal go to first line imaging methods instead of plain radiographs?
To see position of iatrogenic items/instruments
Confirm a Ureteric stone after a CT has been done (FOLLOW UP)
First line = ultrasound or CT
What follow up imaging method is done if a CT scan detects a Ureteric stone?
X-ray
What is the acronym used to remember how to analyse and abdominal x-ray?
ABDO-X
What does the acronym ABDO-X for interpreting abdominal x-rays stand for?
A = Air
B = bowel
D = Dense structures and calcification
O = organs and soft tissues
X = Xternal objects, lines and tubes
Where should air only be seen in the GI system?
Gut lumen
Gastric bubble
What is the gold standard imaging method of diagnosing pneumoperitonuem?
CT
What is Rigler Sign?
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
How do you identify small bowel on an abdominal x-ray?
Central
Plica circularis (run full thickness)
Contains air or fluid
How do you identify large bowel on x-ray?
Peripheral
H austral folds (dont run full thickness)
Contains air or faeces
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?
1 = small bowel (more central and Plica circularis
2 = large bowel (more peripheral and haustral lines)
What are the 2 main types of Volvulus that can obstruct the bowel?
Sigmoid Volvulus
Caecal Volvulus
How does a sigmoid Volvulus appear on an abdominal x-ray?
Coffee bean sign of large gas filled viscus from pelvis to epigastrium
Normally positioned caecum
How does a caecal Volvulus present on an abdominal x-ray?
No normal caecum
Normal sigmoid
Revers c shaped viscus right side
Go to the last slide and look at the x-rays on image 2:
What does image 1 show?
Caecal Volvulus
Go to the last slide and look at the x-rays on image 2:
What does image 2 show?
Sigmoid Volvulus
Coffee bean sign
What is Achalasia?
When you get impaired relaxation of the lower oesophageal sphincter
How can achalasia be seen with imaging?
Barium swallow given
Bird-break or rat-tail stricture of distal oesophagus seens
Food residue in the oesophagus
How does achalasia present?
Weight loss
Halitosis
Look at image 3:
What sign does this barium swallow show and what condition does it indicate?
Birds beak or rat-tail stricture of oesophagus
Achalasia
When is an endoscopic retrograde pancreatogram used?
Describe its route:
To see if theres any stones in the common bile duct
Oesophagus->stomach->dudoenum->ampulla of Vater->common bile duct
What are the advantages of ultrasound?
No radiation
Cheap
Portable
What is the disadvantage of ultrasound?
User dependant
Look at the last slide at image 4:
What type of imaging is this and what pathology is the imaging showing?
Dialation and left inguinal herniation of the bowel
What type of contrast is usually injected into the enteric system?
What type of contrast is usually swallowed?
Injected = iodine
Swallowed = barium
What imaging methods are used if a patient is known to have colon cancer?
What’s it assessing?
CT + contrast
Measure, invasion adn metastases
What imaging method is used to look for colon cancer?
CT colonogram
What imaging method is used for staging and follow up for rectal cancer?
MRI
What is visible on colonoscopy with Crohn’s disease?
Mouth to anus skip Edison’s
Transmural inflammation
Perianal fistulas, abcesses and fissures
What imaging method is done for diagnosing Crohn’s disease and follow up?
MRI
What imaging method is used to screen for Crohn’s disease?
Ultrasound
What is a potential complication of Ulcerative colitis?
Toxic megacolon
How can ulcerative colitis cause toxic megacolon?
The inflammation s so serve that nerve endings to the smooth muscles get paralysed
This leads to the smooth muscle staying dilated
What imaging method can be done to check for perofration in ulcerative colitis?
CT
How does a toxic megacolon appear on an abdominal. X-ray?
Colonic dilation
OEDMA
Pseudopolyps
What types of obstructions and vascular issues can an abdominal x-ray detect?
Calcification
Renal calculi
Vascular calcification
Calcification of pancreas following chronic inflammation
Why is barium contrast very useful?
Can highlight problems/anatomical variance with the stages of swallowing and a follow through which allows the contrast to pass tot he small intestine
What is the advantage and disadvantage of an abdominal CT scan?
High resolution image
High dose radiation
What are the advantages and disadvantages of abdominal MRI?
Adv:
-detailed + high contrast
-no radiation
Disadvantage:
Time consuming
What part of the abdomen is ultrasound often used to visualise?
Biliary tree for gallstones and dilated bile ducts
