AXR interpretation

Question 1

What are the indications for an AXR?

Answer 1

• ibd exac
• palp mass
• foreign body
• blunt or stab abdo injury
• constipation*
• acute or chronic pancreatitis*

*only in certain circumstances

be aware an abdo x ray is 35x the radiation that of CXR so not always worth the radiation!

Question 2

what may you see on an axr relating to multiple myeloma?

Answer 2

• multiple myeloma lytic lesions are seem in vertebrae, ribs, skull, shoulder and pelvis
• bence jones proteins are in 40-60% of patients
• most have elevated serum protein - 80-90% in the globulin fraction, esp IgG
• multiple myeloma is the most common primary malignant neoplasm of the skeletal system - its a malignancy of plasma cells
• avg age 60-60 with M<f></f>

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Question 3

What are the stages of reading a AXR?

Answer 3

PE BBC A

1. indications/pt detailes
2. Projection
3. Exposure
4. BBC for AXR: Bowel
5. Bones
6. Calcification
7. and artefact

Question 4

What do you look for regarding projection in an AXR?

Answer 4

• projection

AP supine is norm

Lateral decubitus in paeds patient

[When medical professionals use this term to describe the position of a patient, they first state the part of the body on which the patient is resting followed by the word decubitus. For example, the right lateral decubitus position (RLDP) would mean that the patient is lying on his or her right side]

Question 5

Wht should the exposure be in an AXR?

Answer 5

exposure should be

• hemidiaphragm to pubic symphysis

Question 6

What is the first “B” you look at in AXR?

Answer 6

• bowel (+ other organs)
• small or large?
  
  • cant differentiate normally
• Diameter?
• content - ?air, ?faceces (mottled)
• bowel wall ?oedema ?riglers sign (air on both sides of bowel wall - pneumoperitoneum)

Dilation rules of bowel:

• small bowel >3cm = dilation
  
  • is ~central/in middle of abdo
  • valvulae conniventes - go all the way across small bowel
• large bowel >6cm
  
  • is ~peripheral abdo
  • has haustra - DONT go all the way across
  • [toxic megacolon]
• Caecum > 9cm
  
  • these show deficiency in wall

other organs (not common to see them): liver, gallbladder & contents, kidney, psoas muscle

Question 7

What is the second “B” you look at on an AXR?

Answer 7

• bones
• e.g.
  
  • ribs, pelvis, spine, sacrum, vertebrae fractures
  • degenerative changes
  • scoliosis
  • tumours inc metastatic deposition

Question 8

What should you look at for C in a axr?

Answer 8

Calcification

• gallbladder,
• AAA,
• pancreatic vasculature calcification

Question 9

What are causes of bowel spasms causes?

Answer 9

• electrolyte imbalances can cause bowel spasms
  
  • Ca2+
  • Na+
  • K+
  • Mg2+

NB: hypokalcaemia cannot be corrected without correcting hypomagnesia

Question 10

What are the large bowel obstruction causes?

Answer 10

• Crohns or UC
  
  • strictures!
  • can be sub or mucosa

1. Colorectal cancer
2. diverticular and its strictures
3. volvulus

Question 11

What is sigmoid volvulus?

Answer 11

can happen aftter CRC and diverticular disease

its commonest in caecum or in sigmoid colon

sigmoid volvulus has increased ischaemia and perforation risk

in elderly chronic constipation

surgery

need decompression- flatus tube; use drip and suck NG tube; give IV fluids - want to avoid dehydration

So volvulus and strictures = likely causes of large bowel obstruction –> high pitched tinkling bowel sounds

Question 12

What are the causes of small bowel obstruction?

Answer 12

• if small bowel obstruction
• make nil by mouth
• can px as N+V before absolute constipation
• cause: adhesions, hernias and malignancy
  
  • check for scars from px surgery