AQUIFER - RADIOLOGY LATEST
EXAM
What kinds of information can a echocardiogram provide? What are the
limitations? - ANSWERS-It can be used in the evaluation of:
-left ventricular size
-systolic and diastolic function
-global and regional wall motion
-function of the valves
-pericardial effusions
-estimate of LV ejection fraction
TTE (transthoracic echo) can be limited because it requires imaging
through an acoustic "window" between the ribs or inferior to the
sternum.
In obese patients, subcutaneous fat can degrade image quality. [not a
problem in TEE]
What is single-photon emission computed tomography (SPECT)? -
ANSWERS-Used to evaluate myocardial perfusion
END OF
PAGE
1
, AQUIFER - RADIOLOGY LATEST
EXAM
Most centers have adopted the use of 99m Tc sestamibi because it offers
advantageous spatial resolution and a lower radiation dose compared to
201-Tl
usually performed both at rest and with stress (either exercise or
chemical adenosine/regadenoson)
A perfusion defect is said to be "reversible" if it appears on the stress
images but not on the rest images
How are SPECT and CT angiography different? - ANSWERS-CT
angiography shows the PIPES but SPECT shows the literal
PERFUSION in the tissues themselves
What is CT calcium scoring? - ANSWERS-method of risk assessment
for coronary artery disease and is reserved for asymptomatic patients
quantity of calcium seen on CT correlates with risk for symptomatic
coronary artery disease and cardiovascular "events" such as myocardial
infarction.
END OF
PAGE
2
, AQUIFER - RADIOLOGY LATEST
EXAM
Not widely accepted nor paid for by insurance. Has also been used to
guide statin therapy decisions.
What scanning methods can be used to show myocardium viability? -
ANSWERS-1. MRI perfusion with 10 minute delayed imaging
2. Rest thallium scan (201-Tl isotope)
3. PET FDG scan
What is the gold standard imaging technique for myocardial viability? -
ANSWERS-Positron emission tomography (PET) is still considered to
be the gold standard imaging examination for myocardial viability,
...but MRI has high diagnostic accuracy and offers the substantial
advantage of high spatial resolution compared to PET and is likely to
replace PET imaging as the new "gold standard".
How does MRI with gadolinium contrast work to reveal diseased/scarred
myocardium? - ANSWERS-Gadolinium chelate contrast agent enters the
myocardium. If the myocardium is viable, the contrast agent washes out
after 2-4 minutes.
END OF
PAGE
3
, AQUIFER - RADIOLOGY LATEST
EXAM
Gadolinium is "trapped" in the extracellular tissues of scar and will wash
out much slower than normal myocardium.
So MRI images obtained 10 minutes after injection of gadolinium will
show normal myocardium to be black whereas scar (or other infiltrative
diseases such as amyloid) will retain gadolinium and appear white.
Below what percent of affected myocardium on delayed gadolinium
MRI myocardial viability scanning can the tissue likely be saved with
revascularization? - ANSWERS-If the thickness of delayed
enhancement (indicating infarct) is greater than 50% of the wall
thickness the myocardium is unlikely to recover function after
revascularization with angioplasty/stent or CABG.
What is the go-to imaging source for planning EVAR (endovascular
aortic repair) for AAA? - ANSWERS-CT angiography
Pre-procedure imaging is especially important when an EVAR is
planned because of the need to evaluate the size of the aorta, the
morphology of the neck of the AAA, and the relationship of the AAA to
branch vessels and their patency.
END OF
PAGE
4
EXAM
What kinds of information can a echocardiogram provide? What are the
limitations? - ANSWERS-It can be used in the evaluation of:
-left ventricular size
-systolic and diastolic function
-global and regional wall motion
-function of the valves
-pericardial effusions
-estimate of LV ejection fraction
TTE (transthoracic echo) can be limited because it requires imaging
through an acoustic "window" between the ribs or inferior to the
sternum.
In obese patients, subcutaneous fat can degrade image quality. [not a
problem in TEE]
What is single-photon emission computed tomography (SPECT)? -
ANSWERS-Used to evaluate myocardial perfusion
END OF
PAGE
1
, AQUIFER - RADIOLOGY LATEST
EXAM
Most centers have adopted the use of 99m Tc sestamibi because it offers
advantageous spatial resolution and a lower radiation dose compared to
201-Tl
usually performed both at rest and with stress (either exercise or
chemical adenosine/regadenoson)
A perfusion defect is said to be "reversible" if it appears on the stress
images but not on the rest images
How are SPECT and CT angiography different? - ANSWERS-CT
angiography shows the PIPES but SPECT shows the literal
PERFUSION in the tissues themselves
What is CT calcium scoring? - ANSWERS-method of risk assessment
for coronary artery disease and is reserved for asymptomatic patients
quantity of calcium seen on CT correlates with risk for symptomatic
coronary artery disease and cardiovascular "events" such as myocardial
infarction.
END OF
PAGE
2
, AQUIFER - RADIOLOGY LATEST
EXAM
Not widely accepted nor paid for by insurance. Has also been used to
guide statin therapy decisions.
What scanning methods can be used to show myocardium viability? -
ANSWERS-1. MRI perfusion with 10 minute delayed imaging
2. Rest thallium scan (201-Tl isotope)
3. PET FDG scan
What is the gold standard imaging technique for myocardial viability? -
ANSWERS-Positron emission tomography (PET) is still considered to
be the gold standard imaging examination for myocardial viability,
...but MRI has high diagnostic accuracy and offers the substantial
advantage of high spatial resolution compared to PET and is likely to
replace PET imaging as the new "gold standard".
How does MRI with gadolinium contrast work to reveal diseased/scarred
myocardium? - ANSWERS-Gadolinium chelate contrast agent enters the
myocardium. If the myocardium is viable, the contrast agent washes out
after 2-4 minutes.
END OF
PAGE
3
, AQUIFER - RADIOLOGY LATEST
EXAM
Gadolinium is "trapped" in the extracellular tissues of scar and will wash
out much slower than normal myocardium.
So MRI images obtained 10 minutes after injection of gadolinium will
show normal myocardium to be black whereas scar (or other infiltrative
diseases such as amyloid) will retain gadolinium and appear white.
Below what percent of affected myocardium on delayed gadolinium
MRI myocardial viability scanning can the tissue likely be saved with
revascularization? - ANSWERS-If the thickness of delayed
enhancement (indicating infarct) is greater than 50% of the wall
thickness the myocardium is unlikely to recover function after
revascularization with angioplasty/stent or CABG.
What is the go-to imaging source for planning EVAR (endovascular
aortic repair) for AAA? - ANSWERS-CT angiography
Pre-procedure imaging is especially important when an EVAR is
planned because of the need to evaluate the size of the aorta, the
morphology of the neck of the AAA, and the relationship of the AAA to
branch vessels and their patency.
END OF
PAGE
4
