<p>I have collected a EPI BOLD sequence data using Siemens skyra 3T. The voxel size is 3x3x3 mm^3. TR = 2s. I am seeing <a href="http://mri-q.com/gibbs-artifact.html" rel="nofollow noreferrer">Gibbs artifact</a> similar to the image:</p>

<p><a href="https://i.sstatic.net/qDdfF.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/qDdfF.jpg" alt="enter image description here"></a></p>

<p>People have suggested to smooth the data to get rid of it. But I will be doing MVPA (multi Variate Pattern Analysis). Since MVPA relies on spatial pattern, <a href="http://www.sciencedirect.com/science/article/pii/S1053811916001427" rel="nofollow noreferrer">smoothing</a> it is a bad idea. So can you please let me know if my results will be influenced by Gibbs artifact? 
Also, from whatever I read, Fourier reconstruction at lower spatial resolution could lead to this artifact. Can any MRI scanner hardware issue cause this artifact, like heating up of RF coil, etc.</p>

CC BY-SA 3.0
2017-04-24T06:48:56.120Z
Hi Aakash, welcome at CogSci. I made some minor edits to make your question more legible. Could you perhaps provide some extra clarification to your question. For example, why is smoothing the data troublesome for MVPA?
Robin Kramer-ten Have
CC BY-SA 3.0
2017-04-26T06:41:36.143Z
Hi Aakash, do you have a second account? I saw @AakashAgrawal make a suggested edit. If so, please stick to one account. It makes it easier for you to gain reputation and to organize other SE.networks
Robin Kramer-ten Have
CC BY-SA 3.0
2017-05-13T17:14:05.597Z
I'm unfamiliar with this field, but the link you give for smoothing says in the abstract "Moderate smoothing (up to 2.2 mm) improved the accuracies..."
mflo-ByeSE
<methodology><fmri><analysis>
What is the effect of Gibbs artifact on multi voxel pattern analysis?
Aakash
# What is the effect of Gibbs artifact on multi voxel pattern analysis?

(Asked by: username_0 on 2017-04-24)

I have collected a EPI BOLD sequence data using Siemens skyra 3T. The voxel size is 3x3x3 mm^3. TR = 2s. I am seeing [Gibbs artifact](http://mri-q.com/gibbs-artifact.html) similar to the image:

[![enter image description here](https://i.sstatic.net/qDdfF.jpg)](https://i.sstatic.net/qDdfF.jpg)

People have suggested to smooth the data to get rid of it. But I will be doing MVPA (multi Variate Pattern Analysis). Since MVPA relies on spatial pattern, [smoothing](http://www.sciencedirect.com/science/article/pii/S1053811916001427) it is a bad idea. So can you please let me know if my results will be influenced by Gibbs artifact?
Also, from whatever I read, Fourier reconstruction at lower spatial resolution could lead to this artifact. Can any MRI scanner hardware issue cause this artifact, like heating up of RF coil, etc.

**Tags:** methodology, fmri, analysis

> **Comments:**
> **username_1**: Hi username_0, welcome at CogSci. I made some minor edits to make your question more legible. Could you perhaps provide some extra clarification to your question. For example, why is smoothing the data troublesome for MVPA?  
> **username_1**: Hi username_0, do you have a second account? I saw @username_0Agrawal make a suggested edit. If so, please stick to one account. It makes it easier for you to gain reputation and to organize other SE.networks  
> **username_2**: I'm unfamiliar with this field, but the link you give for smoothing says in the abstract "Moderate smoothing (up to 2.2 mm) improved the accuracies..."  

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## 0 answers

