# Changing image display between 4.10.x and 4.8.x using the same Window level and lookup table ?

**URL:** https://discourse.slicer.org/t/changing-image-display-between-4-10-x-and-4-8-x-using-the-same-window-level-and-lookup-table/6842
**Category:** Support
**Created:** [May 18, 2019, 1:54pm UTC](https://discourse.slicer.org/t/changing-image-display-between-4-10-x-and-4-8-x-using-the-same-window-level-and-lookup-table/6842 "2019-05-18T13:54:11Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![runze](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/runze/32/10050_2.png) [@runze](https://discourse.slicer.org/u/runze)
#### Post date: [May 18, 2019, 1:54pm UTC](https://discourse.slicer.org/t/changing-image-display-between-4-10-x-and-4-8-x-using-the-same-window-level-and-lookup-table/6842/1 "2019-05-18T13:54:11Z")

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I used 4.8.1 and started to use 4.10.1 recently. I found that they showed the same image in different gray levels.

 ![10](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/1/6/16e37577276d4d369971597e7b2cdb2a0798f817.png)

I have the same window level and lookup table settings. The data was loaded through PETDICOMextension. It seems that the value of the pixels is the same.

Just wondering what is different between 4.8.1 and 4.10.1 in displaying the image?

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### Author: ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)
#### Post date: [May 18, 2019, 2:10pm UTC](https://discourse.slicer.org/t/changing-image-display-between-4-10-x-and-4-8-x-using-the-same-window-level-and-lookup-table/6842/2 "2019-05-18T14:10:43Z")

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I don’t see any difference between the two images above.

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### Author: ![runze](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/runze/32/10050_2.png) [@runze](https://discourse.slicer.org/u/runze)
#### Post date: [May 26, 2019, 1:27am UTC](https://discourse.slicer.org/t/changing-image-display-between-4-10-x-and-4-8-x-using-the-same-window-level-and-lookup-table/6842/3 "2019-05-26T01:27:21Z")

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For example, there are some black dots under the skin, maybe muscle. The bottom one (4.10.1) looks like less darker than the top one (4.8.1). Because the gray-scale represent the value of the pixels, it gives an impression that those pixels have different value, even though they are identical.

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### Author: ![pieper](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pieper/32/8_2.png) [@pieper](https://discourse.slicer.org/u/pieper)
#### Post date: [May 26, 2019, 5:55pm UTC](https://discourse.slicer.org/t/changing-image-display-between-4-10-x-and-4-8-x-using-the-same-window-level-and-lookup-table/6842/4 "2019-05-26T17:55:11Z")

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I agree with @lassoan that the effect is pretty subtle. @runze do you think these differences have clinical significance? Also do you have any way of knowing which one is more correct? (for example in comparison to a clinical system).