Suppression of fat signal is used in MRI images when the fat signal causes artefacts or otherwise obscures a tissue of interest.
There are a number of fat suppression methods. Which one you choose depends on the pros and cons of each technique. These change with field strength, field-of-view size, whether regional or global fat suppression is required, whether an increase in scan time is acceptable, etc. Additionally, the absolute quality of fat suppression may not motivate the choice of technique; contrast between tissues of interest may be more important. Overall SNR in an image may also be a deciding factor.
Here is a brief summary of fat suppression techniques.
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Moving from 1.5T to 3T?
The value of higher field strength for clinical imaging has been indicated in some clinical applications. Research studies are likely to confirm clinical utility of 3.0T vs. 1.5T—studies showing not just signal-to-noise ratio, contrast-to-noise ratio, or even diagnostic sensitivity and specificity—but effects on patient management, and ultimately, effects on patient outcome.
What are the MR physics issues which are relevant when comparing field strengths?
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Here is a basic summary of what DTI is all about, and what some of those DTI parametric maps represent.
A one-page cheat sheet is at the end.
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Not all clinical MR images are created equal.*
After the using the Fourier transform to transform our measured k-space data into image space, the image data is of complex type. This image data is then manipulated for different clinical utility. For example, a magnitude image is used to maximise the signal-to-noise ratio (SNR). Phase images are used to measure flow. Let’s look at how our MR signal is recorded and how these image types are calculated.
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Here’s a top tip for any student of MRI physics: never say a sentence about “frequencies” without specifying what type of frequencies you mean. So “frequency relates to position” is not allowed.
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