CMR post-processing

1. CMR post-processing for beginners
DR.SHAIMAA NABIL, MSC CARDIOLOGY, FEBC

2. The aim of the Task Force is to recommend requirements and standards
for image interpretation and post-processing enabling qualitative and
quantitative evaluation of CMR images. Furthermore, pitfalls of CMR
image analysis are discussed where appropriate. It is an update of the
original recommendations published 2013

3. Ventricular Chambers Assessment
Visual analysis Quantitative analysis

4. 1- Visual analysis: (Systematic Approach)
1- Review all cines in cine mode and check for artifacts, especially in
patients with irregular heart rates.
2- Assessment of heart anatomy and hemodynamic interactions
between both ventricles. (ex: shunts, ventricular dilation or
hypertrophy , constrictive physiology).
3- Assessment of Extra-cardiac Structures.

5. 4- Assessment of LV function from a global and segmental perspective (Long
and short axis cine images)
Segmental wall motion is based on segmental wall thickening during systole
Wall motion is categorized as:
 Normokinetic (1)
 Hypokinetic (2)
 Akinetic (3)
 Dyskinetic (4)
Train Your Eyes

6. Normokinetic Hypokinetic Akinetic

7. Dyskinetic

8. 5- In presence of segmental wall motion abnormalities, use of standard LV
segmentation nomenclature corresponding to the supplying coronary artery
territories is recommended

9. 2- Quantitative analysis
• General recommendations:
In patients with severe arrhythmias, the end-systolic volumes tend to be
overestimated and ejection fraction underestimated.
In case of significant artifacts this should be denoted in the report
Contours of endocardial and epicardial borders at end-diastole and end-systole

10. Left Ventricle
The LV end-diastolic image should be chosen as the image with the largest LV blood
volume
 The LV end-systolic image should be chosen as the image with the smallest LV blood
volume
 Deviations may occur and extra care should be taken in the setting of LV dyssynchrony or
paradoxical septal motion.
 Papillary muscles and trabecular tissue are myocardial tissue and thus ideally should be
included with the myocardium as part of LV mass, they are often included in the blood pool
volume in clinical practice, which is acceptable
How to do Ventricular Contouring

11. The LV outflow tract is included as part of the LV blood volume. When aortic valve cusps
are identified on the basal slice(s) the contour is drawn to include the outflow tract to the
level of the aortic valve cusps
 Most Basal parts: the basal slice may be defined by at least 50% of the blood volume
surrounded by myocardium

12. a and b illustrate the approach with inclusion of the papillary muscles as part of the LV
volume

13. c and d show the approach with exclusion of the papillary muscles from the LV volume
Only Hypertrophied
myocardial diseases we
use the exclusion papillary
muscle from LV volume

14.  Linear Dimensions: Cavity diameter and LV wall thickness can be obtained similar to
echocardiography using two CMR approaches
 Basal short-axis slice: immediately basal to the tips of the papillary muscles.
 3-chamber view: in the LV minor axis plane at the mitral chordae level basal to the tips
of the papillary muscles
For maximal LV wall thickness, the measurement should be made perpendicular to the
LV wall to ensure accurate measurements
The 3-chamber view
is most comparable to
data obtained with
echocardiography

15. Right Ventricle
 Assessment of global and regional RV function (septal wall, free wall)
 An axial stack of cines covering the RV provides the best identification of the tricuspid
valve plane. A short-axis stack of cines is best for delineating the inferior wall.
The RV end-diastolic image should be chosen as the image with the largest RV blood
volume
RV end-systolic image should be chosen as the image with the smallest RV blood volume
The pulmonary valve may be visualized, and contours are included just up to, but not
superior to this level
RV trabeculae and papillary muscles are typically included in RV volumes

16. (a) and systole (b) in a stack of transaxial slices covering the whole RV

17. Here, the yellow contours indicate the RV in diastole (c) and systole (d)

18. Flow image interpretation and post-processing
CMR flow imaging provides information about blood flow velocities (Venc) and volumes
 Valves cines can give valuable information on flow in relation to adjacent structures,
notably on the directions, valve regurgitation, stenoses or shunts. Such information can
be important in assessing the credibility of measurements of flow
Check for the appropriate velocity encoding

19. Flow Measurement
 Review phase and magnitude images side by side : Trace the borders of the vessel of
interest on each phase and magnitude image so that only the cavity of the vessel is
included , make sure the noise outside the vessel is not included

21. Derived parameters include:
•Net volume [ml| = (Forward volume - Backward volume )
•Regurgitant fraction [%] = (Backward flow/ Forward Flow) x 100.
•Cardiac output (liters/min = (net flow [ml] x heart rate [beats/minute])/1000)
Quantitative aortic regurgitant volume may be inaccurate in the presence of a large,
dilated aorta. An alternative is to subtract net pulmonary artery flow or the sum of caval
return (SVC and IVC) from the forward flow across the aortic valve in the absence of
significant aortic to pulmonary collateral flow
Aortic Regurgitant Volume= Forward Ao Flow - (SVC +IVC) OR (Net Pulm. Flow)

22. Regurgitant volumes of the atrioventricular valves (Mitral and Tricuspid) may be obtained
by either of 2 methods
1- Direct measurement of diastolic flow across the valve and subtraction of systolic forward
flow across the associated semilunar valve
2- Indirect measurement of ventricular stroke volume and subtraction of forward flow
across the associated semilunar valve
(MR= LVSV- Forward Ao. Flow)

23. Frequently asked Questions
1- Include or Exclude the papillary muscles?
Both methods are right, So all cases include the papillary muscles with the blood volume
except the Hypertrophied diseases exclude them to be with myocardial mass.
2- Exclude the mitral valve?
No as we noticed in this updated statement
Diastole Systole

24. 3- Include LVOT or not?
The LV outflow tract is included as part of the LV blood volume till reaching to the aortic
cusps.
4- Basal parts is so difficult to be identified how can we do that?
At least 50% of the blood volume surrounded by myocardium is part of LV.
5- How can I recognize the wall motion abnormalities types?
Remember (Segmental wall thickening during Systole If you could not see this
thickening it is abnormal motion) and Train you eyes a lot to get the eye memory
Frequently asked Questions

25. 6- Include or exclude the RV Trabeculations with blood volume?
RV Trabeculations typically included in RV blood volume.
7- Flow measurements can I use Amplitude image rather than Magnitude Image with
the Phase image?
Yes, But better to use the default one to see the anatomy and sharp Cusps outline of the
aorta which decreasing the pitfalls and mistakes
Frequently asked Questions

26. Thank You