Imaging of Large + Small Bowel Flashcards
What are the 4 parts of the duodenum?
- Duodenal bulb
- Sup duodenal flexure to inferior flexure
- Inferior duodenal flexure
- Midline to Ligament of Treitz
What does thumb-printing on abdominal XR indicate?
Bowel gas
Bowel wall oedema
Colitis?
When causes extraluminal gas?
- Pneumatosis
- Pneumoperitoneum (Riglers sign)
What are normal bowel gas patterns?
Small bowel
- central
- gas/fluid
- valvulae conniventes
- jej < 3.5cm
- ileum < 3cm
- distal ileum < 2.5cm
Large bowel
- peripheral location
- faeces
- hasutra
- distended with gas if > 5cm
- > 6cm toxic megacolon
- 9 cm = impending perf
What are the causes of SBO on AXR?
- Adhesions
- Hernia
- Intussuspection
- IBD
- Tumour
What are the causes of LBO on AXR?
- Colorectal cancer
- Volvulus
- IBD = toxic megacolon
- Diverticular disease
What are the signs on perforation on XR?
- Rigler Sign - both sides of bowel wall visible, triangle of gas
- Falciform Sign - falciform ligament outlined with free abd gas
- Football Sign - abs looks like football
What are the limitations of Ba enema?
- CI’s = acute colitis/ diverticulitis, recent colonic surgery, colostomy/ ileostomy
- Mobility (need to turn several times)
- Anal tone
- Inadequate bowel prep
- Overlapping bowel loops
- Poor views of ano-rectal junction
What are barium enemas useful for?
Assessing colonic mucosa in detail
What are CT’s useful for?
Assess both sides of bowel wall - extra + intra luminal detail
What CT’s are specific for bowel?
CT Enterogram
- small bowel crowns
- small bowel tumour
CT Colonography
- colonic polyp
- colonic tumour
What should you consider when deciding if pt is fit to prep for CTC?
- Mobility + ability to follow instructions
- Impaired renal function
- Congestive HF
- Dehydration
- Obstruction
- Active IBD
- Electrolyte disturbance
- Allergies
What is optical colonoscopy good for?
Allows direct visualisation of pathology
Biopsies can be taken
