Imaging of Acute Abdominal Pain

Question 1

primary imaging in acute abdo pain?

Answer 1

X ray
CT
US

Question 2

secondary imaging in acute abdo pain?

Answer 2

MRI

fluoroscopy (contrast studies etc - not as common)

Question 3

what can an X ray exclude?

Answer 3

bowel perforation/obstruction

Question 4

benefits of US in acute abdo pain?

Answer 4

clear visualisation of solid organs, free fluid, aorta and pelvis
can correlate where you US with where the patient says they are sore

Question 5

best imaging in acute abdo pain?

Answer 5

CT

Question 6

risks of CT?

Answer 6

slightly increases chance of cancer
renal impairment (from contrast)

Question 7

MRI is second line test for what?

Answer 7

hepatobiliary
small bowel
pelvis

Question 8

features of appendicitis?

Answer 8

periumbilical pain which then localises to RIF
nausea
vomiting

Question 9

imaging in appendicitis?

Answer 9

CT and US (Not X ray)

- ideally use US first, then CT if inconclusive

Question 10

appendicitis on US?

Answer 10

fluid and oedematous tissue around appendix

Question 11

appendicitis on CT?

Answer 11

large, distended, inflamed appendix

can sometimes see an obstruction (impacted faeces etc)

Question 12

possible complications of diverticulitis?

Answer 12

abscess
obstruction
perforation
fistulae

Question 13

diverticulitis on CT?

Answer 13

thickened, inflamed colon
can see abscess as gas and fluid contained within a pocket
can see fistula as fine line of contrast between organs (few hours after taking oral contrast) and can sometimes have gas in the organ

Question 14

imaging in diverticulitis?

Answer 14

X ray (look for perforation or obstruction)
then usually have CT

Question 15

diagnosis of cholecystitis?

Answer 15

one local sign of inflammation (RUQ pain etc)
one sign of inflammation (raised WCC, CRP, fever etc)
confirmatory imaging

Question 16

imaging in cholecystitis?

Answer 16

US (very good for gallstones)
- shows wall thickening and local fluid (normal bile in gallbladder should be dark and not really visible on US)
can do CT but can give false -ve (thickened walls and fluid around gallbladder)
MRI if biliary tree is dilated (MRCP shows stones in bile duct etc)

Question 17

emphysematous cholecystitis?

Answer 17

diabetics
air in gallbladder wall
usually needs surgery

Question 18

management of cholecystitis?

Answer 18

can try medical/conservative (antibiotics)
interventional radiology (percutaneous drainage, ERCP)
surgery (often needed)

Question 19

common causes of small bowel obstruction?

Answer 19

adhesions
cancer
herniae
gallstone ileus

Question 20

symptoms of small bowel obstruction?

Answer 20

vomiting
pain
distension

Question 21

signs of small bowel obstruction?

Answer 21

increased bowel sounds
tenderness
palpable loops

Question 22

imaging in small bowel obstruction?

Answer 22

shows site, cause, severity and complications (e.g perforation, ischaemia etc)

Question 23

conservative management in small bowel obstruction?

Answer 23

drip and suck

gut rest is enough in some causes (Adhesions etc)

Question 24

imaging used in small bowel obstruction?

Answer 24

1st = X ray
- generally shows distended loops of bowel filled with gas (can be missed if filled with fluid)
CT = more specific
- shows gas or fluid filled loops of distended small bowel
- can show most causes but cant see adhesions

Question 25

gallstone ileus on CT?

Answer 25

round, bright white, laminated stone in right iliac fossa

Question 26

causes of large bowel obstruction?

Answer 26

colorectal cancer volvulus diverticulus

Question 27

presentation of large bowel obstruction?

Answer 27

often less dramatic than small bowel (less vomiting etc)

Question 28

imaging in large bowel obstruction?

Answer 28

X ray can show grossly dilated large bowel but generally cant show the cause CT better for showing cause

Question 29

common causes of perforation?

Answer 29

perforated ulcer diverticular disease less commonly due to cancer or ischaemia

Question 30

imaging in perforation?

Answer 30

X ray - can show some larger volumes free gas but may miss small gas pockets and doesnt show site or origin - wriglers sign CT - more sensitive and specific - shows free gas and fluid - often shows clues to site of origin (distribution of gas, localised inflammatory change or the actual defect in organ wall)

Question 31

normal blood flow to bowel?

Answer 31

20% of CO

Question 32

definition of ischaemia in bowel?

Answer 32

if blood flow drops to <10% of CO

Question 33

causes of bowel ischaemia?

Answer 33

arterial occlusion venous occlusion non-occlusive hypoperfusion

Question 34

features of bowel ischaemia?

Answer 34

``` severe abdo pain vomiting diarrhoea distension borderline amylase raised WCC acidotic on ABGs ```

Question 35

imaging in bowel ischaemia?

Answer 35

biphasic CT = first line (arterial then venous phase)

Question 36

features of bowel ischaemia on imaging?

Answer 36

low density/non enhancing vessel indicates thrombus can get free fluid perforated bowel submucosal haemorrhage gas in gut wall gas in vessels (mesenteric or portal vein)

Question 37

definitive treatment for aortic aneurysm?

Answer 37

EVAR