VISUALISING THE BOWEL Flashcards
what is fluoroscopy?
x-ray with contrast agent added e.g. barium or iodine
what is double contrast?
x-rays of the colon and rectum are taken using two forms of contrast to make the structures easier to see.
at what level does the coeliac trunk appear?
T12
at what level does the superior mesenteric artery appear?
L1
at what level does the inferior mesenteric artery appear?
L3
In CT, what is the unit for the radio density?
Hounsfield unit
what is a tomogram?
a two-dimensional image representing a slice or section through a three-dimensional object.
What is T2 imaging?
when fluid appears very bright and white
what are the types of MRI?
can be T1 or T2
can be fat saturated or non fat saturated
what is a fat saturated MRI?
an MRI technique used to suppress the signal from normal adipose tissue to reduce chemical shift artefact, improve visualization of uptake of contrast material and tissue characterization
what should you use MRI for?
soft tissue
what is a gastroscope?
a nasal/oral endoscope
what is a colonoscopy?
endoscopy from the anal canal
what laxative is given before a colonoscopy?
moviPrep
what would an inguinal hernia look like on MRI?
bowel seen in front of the transverses abdomens
what is a direct hernia?
the abnormal exit of tissue/organ directly through the wall of the inguinal canal
what is an indirect hernia?
the abnormal exit of tissue/organ directly through the inguinal canal via the top (usually a birth defect)
Outline an ERCP?
endoscope is passed down to the major duodenal papilla and then a cannula is passed up into the biliary tree and contrast agents can be injected here so the area can be visualised
why can MRCP be better than ERCP?
MRCP is non-invasive and can image the surrounding structures
how can you see splenomegaly on CT
enlarged spleen
left kidney lower than the right as its being pushed by the spleen (usually right is lower)
at what level re the kidneys?
T12-L3
why do you not see all the colon on one plane in a CT?
ascending and descending colon are retroperitoneal whilst horizontal colon is intraperitoneal
what are the 3 muscles of the abdominal wall?
from deep to superficial..
transversus abdominis
internal oblique
external oblique
how would ulcerative colitis present on barium enema?
lack of definitive haustrae (lead pipe colon)
what will radiographs of colorectal cancer show?
a barium enema will not make it all the way through the colon due to narrowing from tumours - this is called the apple core sign
what are the branches of the coeliac trunk?
left gastric artery, splenic artery and common hepatic artery
what does the left gastric artery give rise to?
oesophageal arteries before anastomosing with the r gastric artery
what are the branches of the splenic artery?
left gastroepiploic
short gastric
pancreatic
what does the common hepatic artery give rise to?
proper hepatic artery and gasproduodenal artery
what does the proper hepatic artery give rise to?
right gastric artery
right and left hepatic
cystic artery
what does the gasproduodenal artery give rise to?
right gastroepiploic
superior pancreaticoduodenal artery
what are the branches of the superior mesenteric artery?
jejunal arteries ill arteries ileocolic artery - anterior and posterior caecal artery right colic artery middle colic artery
what are the branches of the inferior mesenteric artery?
left colic atyery
sigmoid arteries
superior rectal arteries
where does an abdominal aortic aneurysm usually exist below?
below the level of the renal arteries (L1-l2)
what are the branches of the abdominal aorta?
infeiror phrenic arteries coeliac artery superior mesenteric artery middle suprarenal arteries renal arteries gonadal arteries inferior mesenteric artery median sacral artery lumbar artery
at what level are the gonadal arteries?
L2
