Imaging of the GI Tract Flashcards
imaging methods
conventional xray ultrasound CT MRI nuclear medicine and hybrid imaging
comventional xray
this is used as the first imagineer investigation in the acute abdomen and you’re looking for:
- gas
- soft tissue
- calcification
- foreign object
how is a conventional xray performed
supine or erect
supine
gas seen as blobs of dark and Lucent areas
erect
air(dark)/fluid(bright) levels seen
what is the normal gas distribution within the body
stomach Lt upper portion
small intestine - 2/3 gas filled loops which are no larger than 2.5cm centrally
large intestine is mostly in the detail portion i.e sigmoid colon and rectum. peripherally and lower pelvis max diameter should be 5.5 cm however caecum and the beginning of the colon can be up to 8cm
small intestine obstruction
- distended more than 2.5cm
- multiple central fluid levels
- less gas or no gas in the large intestine
large intestine obstruction
- distended gas filled loop or air fluid levels at the periphery
- caecum over 9cm and the rest is over 5/6
- look for hausfrau to differentiate
- less or no gas beyond the level of obstruction
where would gas in the wrong place be
outside the intestine and the stomach
- due to intestinal perforation
- introduced from the outside by injury, operation
where would you look for gas in the wrong place
below diaphragm in ERECT film
surrounding the intestine
gas collection (different shape)
gas outlining the ligaments and muscles
sigmoid volvulus
coffee bean
what kind of calcification should you look for
gall, renal uretic bladder stones
calcification in the vessel wall
calcification in organs
fluro
- contrast (barium or thin water soluble contrast ) swallow
- meal
- follow through
- ## enema
nuclear medicine
Tc pertechnatate scan (meckles scan) to identify the meckles diverticulum which can cause bleeding, obstruction particularly in children
