Cardiac Imaging Flashcards
Which cardiac imaging test is usually done on admission
CXR
What type of waves are used to bp create images of heart in echocardiography
Ultrasound
What type of echocardiogram is used to calculate velocity of blood flow and pressure gradients
Doppler
What can echocardiography be used to assess
Valves
Myocardial disease
Great vessels
Thrombus
Infection tumour
Shat directions does the heart contract in
Longitudinally
Radially
Circumferentially
3 windows heart can be viewed from in echocardiography
Parasternal - through LV
Apical - overall view of heart
Subcostal - fluid around heart
Are stenosis and regurgitation more common in the aortic and mitral valves, or pulmonary and tricuspid valves
Aortic and mitral
What can patient factors decrease effectiveness of echocardiography
Hugh BMI
COPD
Why can a better image be generated using transeosophageal echocardiography than regular echocardiography
Can use higher freq and lower wavelength
Where are images of the heart taken from in transesoohageal echocardiography
Probe passed down oesophagus
Advances of transesoohageal echocardiography over regular echocardiography
Don’t have to look through chest wall
Higher freq + lower wavelength
Better for viewing valves
Why is transesoohageal echocardiography often used post surgery
Scars and incisions get in way
What is TEE often used to assess
Endocarditis
Accurate valve assessment
Post operative
Pre ablation assessment of L atrial appendage
Oesophageal structure/diverticula/tumour
Varies
Recent eosophageal/gastric surgery
Which imaging is best for viewing plaques on coronary artery walls
CT coronary angiogram
What does CT FFR show
Ratio of flow from top to bottom of coronary artery
What conditions/medications are given before a CT coronary angiogram to improve image quality
Beta blockers
ECG gating
Breath hold
Why are beta blockers given before a CT coronary angiogram
Image clearer when heart moving slower
Why is ECG gating used in CT coronary angiography
To take image when heart is moving least - improves image quality
What are CT coronary angiograms often used
New onset chest pain
No previous CAD
assessing grafts in CABG patients
Disadvantages of CT coronary angiography
Radiation
Possible contrast allergy
Contrast can damage kidneys
What contrast do used in MRI
gadolinium
How does gadolinium provide contrast on MRI
Washed through healthy tissues but accumulates on scars and damage, changes magnetic properties of tissues where it accumulates
What can gadolinium cause in patients with poor renal function
Retroperitoneal fibrosis
What is the minimum eGFR for gadolinium to be used safely
50
Can an MRI be done on a patient with a pacemaker
No
What document must be given to a patient before being given an MRI
Pre check questionnaire
What conditions are MRI useful in diagnosis of
Discriminating MI and myocarditis
Cardiomyopathy
Storage disorders
Thrombus
Mass discrimination
How can MRI be used to differentiate myocarditis and MI
MI - gadolinium retention matches coronary territory
Myocarditis - patchy gadolinium retention
MPS
Myocardial perfusion scan
What does MPS assess
Tissue activity
How does MPS work
Radioactive 18FDG contrast injected into heart -> flow through muscle monitored -> tissue activity assessed
What contrast is used in MPS
18-FDG
What condition is MPS useful in diagnosis for
Myocardial ischaemia
What is used to put heart in pharmacological stress
Adenosine
Why may narrowing of coronary arteries be missed by MPS of all 3 main arteries are blocked
All areas of heart appear same as all have same perfusion and contrast reuptake
MPS disadvantages
Radiation
Stressing agents used
Time consuming
