Download Assess Ventricular Systolic and Diastolic Function

Assess Ventricular Systolic and
Diastolic Function
Robert J. Fleck, MD
May 18, 2012
Assess Ventricular Systolic Function
• Segmented K-space steady state free
precession (SSFP) is the standard
– Accurate
– Reproducible
– Published normal ranges for children
• Buechel, JCMR 2009, 11:19
• Robbers-Visser, JMRI 2009, 29:552-559
• Systematic differences between fast gradient
echo (FGE) and SSFP
Common Questions?
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How to choose the basal slice?
Do I include the LVOT?
What about the apex?
Include or exclude the papillary muscles?
How do I identify the atrium?
How do I know where the PV is located?
Should I include or exclude the moderator band?
How many slices do I need?
Why do we breathhold in expiration?
Why are there usually move LV contours than RV
contours?
How do I choose the basal slice?
This is the most important slice!
Is there thick myocardium?
Does it encompass > 50% of the
circumference when in diastole?
Does it get bigger during systole?
Then this is Atrium!
Do I include the LVOT?
• It is part of the LV, so it
is included
• Extend the epicardial
contour to the aortic
valve
• Often easier to see on
cine
• Epicardial contour
exclude fat
Why is this slice so important?
• End diastole has a
volume of ventricle
• End systole usually has
no volume of ventricle
• This is due to
shortening of the valve
plane during systole
Basal slice movement
4 chamber end diastole
4 chamber end systole
Why are there usually move LV
contours than RV contours?
• The tricuspid valve (TV)
is displaced apically
relative to the mitral
valve (MV)
•
shows TV location
•
shows MV location
How do I contour for the PV when I
can’t see it?
• Anatomically the PV
and AoV are closely
related
• SA stack the PV is
usually where the aorta
and pulmonary artery
cross
Contouring the RV
Start in the mid ventricle, it is easier and there are fewer decisions
We don’t worry about the trabeculations, but this needs to be consistent
between all readers of CMR
What about the basal slice of RV?
• Dialated RVs often
extend beyond the TV
plane
• This volume is not
present on systole
– It is significant
– Include it in your
contours
What about the basal slice of RV?
End Diastole
End Systole
What about the basal slice of RV?
First Basal Slice
Second Basal Slice
Other Questions
QUESTION?
• What about the apex?
• Include or exclude papillary
muscle?
• Moderator band
• How many slices do I need?
• Why image at end
expiration?
ANSWER
• This is a very small volume
do worry too much about
getting every last bit
• Your choice
• Exclude from the RV volume
only if large
• 10 to 14 slices should
suffice
• Postion of the heart is more
consistent
What is the most important advice?
• CONSISTENCY
–Within an Individual
–Within a group
• Avoid bias!!
• Start contouring in the midventricle
What to do with Tagged images?
Advantage of measuring myocardial
strain using tags
• Assess local myocardial deformation
• Quantitative analysis: Estimation of strain
• HARP : Harmonic phase MRI
– Fully automated and needs no interpolation
• Strain myocardial deformation
– If an element shorten, strain is negative
– If an element lengthens, strain is positive
Strain in Myocardium
% STRAIN % = {(Length ED – Length ES)/Length ED}* 100
• Radial
• Longitudinal
• Circumferential
Early Systole
Late Systole
Strain in Myocardium
% STRAIN % = {(Length ED – Length ES)/Length ED}* 100
• Radial
• Longitudinal
• Circumferential
Early Systole
Late Systole
Strain in Myocardium
% STRAIN % = {(Length ED – Length ES)/Length ED}* 100
• Radial
• Longitudinal
• Circumferential
Early Systole
Late Systole
Circumferential Strain (ECC%)
Tagged Image Data Analysis : HARP
5%
-25%
Normal
DMD
The maximum circumferential strain is low in DMD compared to
normal
Dysynchrony
A
A
B
BC
CA
A
control
B
DMD<10yrs
C
DMD>10yrs
A B BC C
Abnormal myocardial circumferential strain precedes global
functional decline in Duchenne Muscular Dystrophy
Why is tag derived strain better?
Strain each cardiac MRI of a patient decreased over time because it is a measure of
cardiac contractility
Choose the statement that best describes the
typical MR picture of restrictive cardiomyopathy in
children:
A. Increased left ventricular volume with decreased
ejection fraction and thickened pericardium
B. Increased left ventricular volume with normal
ejection fraction and normal pericardium
C. Normal left ventricular volume with decreased
ejection fraction and thickened pericardium
D. Normal left ventricular volume with normal
ejection fraction and normal pericardium
E. Normal left ventricular volume with decreased
ejection fraction and dilated left atrium
How do you assess diastolic
dysfunction?
RadioGraphics 2011; 31: 239-261
What is diastolic dysfunction?
• Heart failure in the presence of preserved EF
– Abnormal relaxation of myocardium
– 40-50% of all cases of heart failure
– High morbidity and mortality, especially in pediatrics
• Causes
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Age
Hypertension
Obesity and/or metabolic syndrome
Diabetes
Hypertrophic cardiomyopathy
How is it assessed by MR?
• We use the “easy way”
– Left atrium (LA) interacts with the LV to give a
“kick” of volume to stretch myocardium of the LV
– Diastolic dysfunction causes dilation of the
overworked LA
– Overtime the LA integrates the effects of increase
filling pressure of the LV
– Beware - Atrial fibrillation and mitral valve
stenosis or regurgitation can also cause dilation
4 chamber SSFP cine stack
Contour the atrium
Normal Values
Sarikouch, JMRI 33: 1028
We consider >50 ml/m2
abnormal
End Systole
Thank you!
?? Questions ??