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StanfordMIMI / DDM2

[ICLR2023] Official repository of DDM2: Self-Supervised Diffusion MRI Denoising with Generative Diffusion Models
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Experimenting on DCE-MRI simulated phantom with added noise #16

Open anudeepk17 opened 7 months ago

anudeepk17 commented 7 months ago

I was experimenting with a simulated 4D phantom of ellipse with 4th dimension being time. I generated a 3D ellipse with smaller ellipsed and changed signal intensity over time and concatenated it to make a 4D MRI. I added noise to it and ran the three stages. When the noise was high, the model performed fine. When I added less noise, the first stage was good. But the third stage and denoising gave empty image. I have added the results here. Can you guide me in debugging why this could be happening?

First stage:

image

But the third stage:

image

Whereas when I added high noise, the third stage looked like :

image

Thank you in advance for your time.

tiangexiang commented 6 months ago

Hi, thanks for your interest, and sorry for the late reply. There are two things that you can check quickly:

  1. Did you load Stage1 trained noise model into Stage3? See: https://github.com/StanfordMIMI/DDM2/issues/17
  2. Can you double-check the value scale of the noise? and make sure the added noise is all within the range of the data itself. (e.g. -1 to 1)