Hi,
I want to use a MRI images dataset in order to detect heart failure with image processing techniques. In the beginning I should choose the kind of map I need. T1 map or T2 map, I should choose one of them.
But I don’t know what is the differences between them and which one is better for detecting heart failure.
Can anyone share some information about that?
T1 mapping allows you to quantify extracellular volume (ECV). Normal values for ECV are 25-28%, higher ECV values most usually represent interstitial myocardial fibrosis (as in hypertension, hypertrophic cardiomyopathy, severe aortic stenosis,...), values over 40% represent amyloidosis or infarction-related scar
T2 mapping measures specifically interstitial edema (thus, it is usually employed to detect the acute phase of myocardial infarction or acute myocarditis, as overtime edema will disappear)
One important point, though. Heart failure is defined CLINICALLY not by MRI techniques. MRI can help you to identify the cause of HF, but HF itself is diagnosed clinically (clinical history, physical examination, chest X ray,...)
T1 mapping allows you to quantify extracellular volume (ECV). Normal values for ECV are 25-28%, higher ECV values most usually represent interstitial myocardial fibrosis (as in hypertension, hypertrophic cardiomyopathy, severe aortic stenosis,...), values over 40% represent amyloidosis or infarction-related scar
T2 mapping measures specifically interstitial edema (thus, it is usually employed to detect the acute phase of myocardial infarction or acute myocarditis, as overtime edema will disappear)
One important point, though. Heart failure is defined CLINICALLY not by MRI techniques. MRI can help you to identify the cause of HF, but HF itself is diagnosed clinically (clinical history, physical examination, chest X ray,...)
Dear Amirali Mirsajadi , as Carlos G Santos-Gallego said, different echo times are useful for detecting different kinds of structures, being longer echoes generally better for structures with more water. If you want to identify a set of structures where part of them are better represented in T1 and another part better in T2 without having to run two sequences and to co-register them, there is always the possibility to run a multi-echo sequence. They are rarely used and maybe the operator of your MRI is not familiar with them, but most modern MRI scanners are able to run them and should possess a set of predefined acquisition protocols in for the most common.
Multi echo imaging sequences employ a series of echoes acquired as a train following after a single excitation pulse. Multiple symmetrical or asymmetrical echoes can be acquired, being T1/T2 sequences possible. Since slices at the same position produced by different echoes are separated only milliseconds in time, co-registration is normally not necessary.
In multi-echo spin echo imaging, each echo is formed by a 180° pulse, but also a FSE (TSE, RARE) or EPI sequence can be used. As a difference to a normal fast spin echo sequence, in multi echo imaging, separate images are produced from each echo of the train with different T2 weightings. The signal height reduces with transverse relaxation. This drop in signal can be used to calculate a pure T2 image.
In last years multi-echo sequences have been mostly being used for functional imaging purposes (https://cni.stanford.edu/wiki/MR_Protocols), but this is not the only application: 20-25 years ago, when we were working on several new image processing techniques for MRI data, multi-echo sequences were common acquisition protocols for anatomical images (https://surfer.nmr.mgh.harvard.edu/fswiki/FreeSurferWiki?action=AttachFile&do=get&target=FreeSurfer_Suggested_Morphometry_Protocols.pdf).
Aldo
T2 imaging will show you good morphology, if you need flow quantification, phase contrast is good, EPI with contrast if perfusion is objective.....
Protocol will vary according to your need i..e cause and what you want to see..
I hope this article will help you:
Article Magnetic resonance imaging in the evaluation of congestive c...
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