Clinical Correlation - Tuckman 2 Flashcards
CT 4 colors
black - air
dark grey - fat
light grey - muscles, vessels without contrast (soft tissue)
white - bone
what modality is CT?
x-rays - interact w/ electrons - the more electron dense something is, the more x-rays are blocked -> more white
first CT scans
only heads
10 slices at a time, 1cm thick
took 1 hour
CT scans now
45 seconds
head to toe
can go as thin as 1mm thick (usually do 5mm)
what are the windows you can assign to CT depending on what densities you want to see?
- bone window
- lung window
- soft tissue window
CT used for…
chest, abdomen and pelvis - less sensitive to motion
- appendicitis
- kidney stones
the more fat you have in a tissue, how does color change?
gets darker
what shape would a tumor show be?
sphere unless there is something inhibiting it, so no matter what way you cut it, it will show up as a circle
where can you get granulomas?
spleen, lungs, liver - calcifications mostly from fungus (used to be from TB)
which crus of diaphragm tends to start higher?
right crus
how to differentiate splenic artery and vein
artery - tortuous
vein - straighter
shapes of adrenal glands
long, Y-ish shaped things - if has a round thing = tumor
right more V shaped, left more Y shaped
which is usually higher: tail or head of pancreas?
tail
what is special about SMA that makes it easy to see?
always has fat around it
what is more sensitive to gallstones than CT?
ultrasound
whiter areas around edge of aorta (or vessels) signifies what?
atherosclerosis
what does a narrowed renal artery lead to?
HTN - kidney controls bp (if less blood gets to kidney, it thinks you need higher bp, so increases it)
how can you differentiate ileum from jejunum and colon?
ileum more gassy, not as big as colon and has no haustra
what are surgeons expected to do for appendices?
never miss an abnormal one.. take out about 15% of normal ones due to oversuspicion
normal appearance of appendix
has a little gas, thin walls
reindeer sign
IVC + three hepatic veins
