Imaging of the Abdominal Viscera Flashcards
Abdominal radiography has a lower ———- and ———- than CT but still retains a useful role in diagnosis
Sensitivity and specificity
Abdominal radiography (AXR) features:
- patient supine
- exposure taken on expiration
- should include diaphragm, pubic symphysis, lateral flank lines
- sof tissue structures and bony detail should be well demonstrated
0 no overlying artefacts eg clothing, zips
Valid reasons for referral for abdominal radiography (AXR) (8):
- clinical suspicion of obstruction
- acute exacerbation of IBD
- palpable mass (specific circumstances)
- constipation (elderly)
- acute and chronic pancreatitis (specific circumstances)
- sharp/poisonous body eg battery
- blunt or stab injury
For abdominal pain only what imaging mode is appropriate?
- AXR not usually indicated
- US, erect CXR, CT KUB, CT abdomen
Inappropriate requests for abdominal radiography (AXR) (5):
- abdominal pain only
- Right or left iliac fossa pain
- Right upper quadrant pain
- Epigastric pain
- Altered bowel habits
Normal appearances of abdominal radiography (AXR)?
Large bowel and rectum = normal
Contains faeces and air giving a mottled appearance
Why refer to abdominal CT (5)?
- to assess tumour staging
- to determine disease eg cirrhosis
- to determine site and causes of obstruction
- to identify perforation - free air
- trauma
- for biopsy or other interventional procedure
What is shown?
- abdominal axial CT
- distended colon
Axial CT abdomen
What modality?
CT colonoscopy
CT colonoscopy (5):
- known as CTC or virtual colonoscopy
- can replace barium enemas for patients whom colonoscopy has failed
- assess for strictures/ Carcinoma of the colon
- minimally invasive low dose of radiations
- comparable accuracy to optical colonoscopy
CT colonoscopy can be viewed as a virtual colonoscopy by
Images obtained in all planes can be reconstructed to 3D
CT colonoscopy requirements:
- bowel must be empty; high dose laxative
- distended with gas via rectal tube
- IV contrast given to demonstrate tumours
Who can refer for MRI abdomen?
- not usually from primary care; outpatient/inpatient most common
- liver, gynaecological, prostate, MRI bowel most common
- patients must be able to lie still and be MRI safe
MRI of the bowl: generally called?
MR Enterography
MR enterography:
- commonly used to
- comparison to barium Studies
- assess for (4)
- commonly used to evaluate the extent of Crohn’s disease
- more sensitive and specific than barium studies
- assess for thickening of bowel wall, fistulae, abscesses, inflammatory changes
MR Enterography requires
- patients to starve for 4-6 hours
- drink 1.5L contrast to distend the bowel to evaluate the bowel wall
Which modality shown below?
Axial MRI abdomen
MR Enterography
Which modality shown below?
MR Enterography
MRCP stands for
Magnetic resonance cholangiopancreatography
MRCP (5):
- non invasive
- to assess biliary tree, pancreatic ducts; stones, strictures tumours
- replaces ERCP for some patients
- data obtained and reformatted to create 3D images
- breath hold technique used
Which imaging modality shown below?
What does the white arrows show?
MRCP
Abdominal ultrasound
- good first line test for solid viscera
- referral reasons should be specific and appropriate; jaundice, suspected gallbladder disease, mass
- all abdominal organs scanned in both transverse and longitudinal planes
What pathology? AXR
Small bowel obstruction
What pathology? AXR
Large bowel obstruction
Distended over gem
Perforation: what do the arrows show? What sign?
If abdominal perforation, exr may be appropriate & is seen by
A thin crescent of air under right hemidliaphragm, which is a normal finding in post operative period
What pathology shown below?
- Abdominal perforation
What pathology shown below?
Yellow-raunde=kidneystones
Red= larger = edge of liver over kidney = gallstones
Abdominal aortic aneurysm
- more than 5 1/2cm
- risk of rupture increases with size
- result in massive haemorrhage
- surgical repair
- sometimes an incidental finding
What imaging modality? What pathology?
Abdominal radiography (AXR)
Abdominal aortic aneurysm
What imaging modality? What pathology?
Abdominal axial CT
Abdominal aortic aneurysm
What imaging modality? What pathology?
Coronal volume CT with contrast
Abdominal aortic aneurysm