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3 - GI > deck_1672100 > Flashcards

Flashcards in deck_1672100 Deck (37)
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1
Q

Give five different types of imaging used to investigate the GI tract

A

• Plain x-rays • Contrast studies • Ultrasound • Cross-sectional imaging • Angiography

2
Q

Give two types of x-rays

A

• Abdominal x-ray • Erect cheat x-ray

3
Q

Give four types of contrast studies

A

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

4
Q

Give two types of cross sectional imaging

A

• Computed tomography • Magnetic resonance imaging

5
Q

What are the risks of imagine?

A

• Radiation ○ Carcinogenesis ○ Genetic ○ Developmental risk to foetus

6
Q

What is a contrast study used for?

A

• Defining hollow viscera

7
Q

Give a water soluble contrast

A

• Iodine used

8
Q

What is a barium enema used for?

A

• Study where contrast medium is inserted rectally

9
Q

What is ultrasound?

A

• Use of sound waves to generate an imahe • Frequency above audible range of human hearing Usually 2-18 MHz

10
Q

What are the advantages of ultrasound?

A

• Cheap compared to CT and MRI • Portable • Highly user dependent

11
Q

What can ultrasound be used for?

A

• To determine if patient has gall stones • See if common bile duct inflated • Liver, protal vein and appendix

12
Q

What is GI angiography?

A

• Injection of radio-opaque contrast agent intravenously and then using various methods to capture the image • Used for both bleeding and ischaemia to allow visualisation of the GI tract

13
Q

Give four key features of an abdominal x-ray

A

• Stomach • Small and large bowel • Soft tissues • Bones

14
Q

Give 6 soft tissues that can be visualised on an abdominal x-ray

A

• Liver • Spleen • Kidneys • Psoas major • Bladder • Lung bases

15
Q

When are the intestines visible?

A

When filled with gas

16
Q

When are the intestines not visible?

A

• When filled with fluid

17
Q

Give four common reasons for requesting an abdominal x-ray

A

• Acute abdominal pain • Small or large bowel obstruction • Acute exacerbation of IBDRenal colic

18
Q

What are the circular folds of the small bowel called?

A

• Valvulae conniventes • Appear as lines that appear to cross the whole of bowel lumen

19
Q

Where is the large bowel seen on an abdominal x-ray?

A

• Periphery • Possible to see haustra on the x-ray

20
Q

What does faeces look like on an x-ray?

A

Clouds in the lumen

21
Q

What is the rule of 3/6/9 in checking the small and large bowel for gas obstruction?

A

• Small bowel is said to be dilated when it is greater than 3cm • Large bowel when it is greater than 6cm • Caecum (when the ileocaecal valve is working) is said to be dilated when it is >9cm

22
Q

What does small bowel obstruction usually present with?

A

• Vomiting • Mild distension • Absolute constipation is a late feature

23
Q

Why may you vomit earlier in small bowel obstruction?

A

• Obstruction closer to mouth

24
Q

Give four causes of small bowel obstruction

A

• Adhesions • Hernias ○ Inguinal, femoral, incisional • TumoursInflammation

25
Q

What do people with large bowel obstruction present with?

A

• Abdominal pain and distension, with constipation as an early feature • Vomiting and faeculance is a late feature

26
Q

What is the abdominal pain like in large bowel obstruction?

A

• Colicky, but not as frequent as small bowel obstruction

27
Q

Give five causes of large bowel obstruction

A

• Colorectal cacrinoma • Diverticular stricture • Hernia • Volvulus • Pseudo-obstruction

28
Q

What is a volvulus?

A

• This is when a viscera twists around itself or the mesenteryMost common is a sigmoid/caecum volvulus

29
Q

What happens when a volvulus occurs?

A

• Twisting occurs and the enclosed loop of bile dilatesIncreases risk of perforating or cutting of its blood suppl

30
Q

Name 6 abnormalities which can be visualised on an x-ray

A

• Pancreatitis • Aneurysms • Nodes • Bones • Artifacts • Foreign body • Kidney stones

31
Q

What is an erect chest x-ray useful in diagnosing?

A

• A perforated bowel

32
Q

Give 6 causes of a perforated bowel

A

• Peptic ulcer • Diverticular disease • Tumor • Obstruction • Trauma • Iatrogenic

33
Q

Why does the chest x-ray need to be erect for a perforated bowel?

A

• The diaphragm will only be separated from other viscera by the air rising to the top

34
Q

What is normally found in the peritoneal cavity?

A

• Small amount of fluid

35
Q

What is an abdominal CT?

A

• High dose radiation • Good spatial resolution (Poor contrast compared to MRI)Use of IV or oral.rectal contrast

36
Q

What is MRI?

A

• No radiation • Good spatial and contrast resolutionTime consuming

37
Q

What is an MRI scan used to visualize the gall bladder and biliary tree?

A

• Magnetic resonance cholangio-pancreatogram