Cardiac Flashcards
(275 cards)
prev of angina
2% population
Information is obtained about: - CT cardiac
Cardiac morphology and chamber size
Coronary anatomy and disease
when in cardiac cycle to do the scan
late diastole
optimal heart rate
<60s - ideal 55 - 60
Benefit of retrospective imaging
evaluate myocardial wall motion and EF
CT cardiac - contrast delivery parameters
During a single breath-hold, 25 ml of IV contrast is injected at a rate of between 4-6 ml/s.
dosing of metroprolol
5- 75mg but really up to 40mg
which is worse calcified or non calcified
Non-calcified plaque may be more unstable and prone to acute rupture leading
what kind of HU are plaques going to be
Soft 14
intermediate 91
Calcified 419
when is CT CA used?
if cant do the procedure due to anatomy - large aortic root
or pathology such as dissection
why is calcium scoring dubious
may have limited impact due to effects of remodelling
if no calcium then unlikely to have any plaque
if calcium - likely underestimates amount of plaque
Coronary calcium load has been found to progress over time, increasing by
15-25% per year
Agatston scoring system for calcium
3 mm slice thickness is a product of the area of calcification per coronary segment and a factor rated 1 through 4 dictated by the maximum calcium CT density within that segment
minimum density to be considered a plaque on the scoring system
130HU
What is a step artefact
Step artefact are forms of reconstruction artefact which may occur particularly as a consequence of cardiac arrhythmia. This results in visible ‘step’ increments on a single image which is reconstructed from several data sets.
CT CA artefacts
motion artefact
step artefact
partial voluming next to calcium
IV contrast timing or poor output in cardiomyopathy
what is ectopic origin of the artery - why is it important
exclude it in the young
second commonest cause of sudden death in young
.
.
Ao
Aorta
LA
left atrium
LCA
left coronary artery
Max intensity projection
MIP
PA
pulmonary artery
RVOT
right ventricle ouflow track