I saw and answered your support ticket on the same issue. If you have further questions, please post them there.
For others who might be interested, here is the main part of the reply:
As long as you provide a valid image through the byte array, you should not have a problem with displaying the issue, except for the cases where your site operates on a WebFarm or WebGarden environment (these are unsupported by RadBinaryImage).
If you are not sure how to check the image, you could see if it is correctly displayed when streamed through a custom http handler, as the one shown in this thread:
All the best,
the Telerik team
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