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TOOLS
» K-Space Tool

What happens in k-space? This tool allows you to choose changes to be made to a k-space data set. The result of these changes is seen and discussed.

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K-Space Tool: Low Pass Filter

The low pass filter cuts out all the high spatial frequency data from the periphery of k-space (it allows low spatial frequencies to pass). This results in a lack of detail on the image, although the coarse contrast of the image remains.

im_lpf (12K) k_lpf (4K)

Further reading on this topic:
Books: MRI From Picture to Proton p52-53, 119
Online: e-MRI

Choose from the list below alter k-space.

Alter k-space...

Introduction.
Apply a low pass filter—see only the contrast of the image.
Apply a high pass filter—see only the detail of the image.
Introduce random motion artefacts—cf coughing, swallowing, moving.
Introduce periodic motion artefacts—cf breathing, pulsatile flow.
Add random noise.
Add more random noise.
Create a large RF spike near centre of k-space.
Create a small RF spike near centre of k-space.
Create a large RF spike at the periphery of k-space.
Create a small RF spike at the periphery of k-space.
Reduce the scan percentage—miss out the top and bottom of k-space.
Acquire just over half of k-space—partial Fourier with three extra lines.
Remove every other k-space line—similar to how SENSE (sensitivity encoding) achieves accelerated data acquisition.

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revise, v. To go over (a subject already learnt) in preparation for an examination. (OED) [Latin re-, + visare, to visit again, look at again]

(This page: http://www.revisemri.com/tools/kspace/k_lpf)

TOOLS» K-Space Tool

K-Space Tool: Low Pass Filter

TOOLS
» K-Space Tool