PET Image Window Level Range for Fusion with CT

[Bhuvan Bose]

I have 16-bit CT and 16-bit PET images that I intend to fuse. However, I noticed that the PET image has a Window Width of 78,876 and a Window Center of 39,438. Since these values exceed the maximum possible pixel value for unsigned 16-bit images (65,535), I would like to clarify:

Is it valid for the window level values to exceed 65,535 in this context?

If not, how should I convert or normalize these values to fit within the valid range of 16-bit data for proper image display and fusion?

Thanks

Bhuvan Bose

[Wim Corbijn]

Bhuvan,

The windowing is most likely outside the 65,535 due to a rescale slope or intercept value that changes the total range of values.

Windowing is to be applied after you took rescale slope and intercept into account.

Meaning that your window width is a correct vallue.

Even without rescaling the values are still correct, they might not be optimal but to my knowledge there is no requirement that you shall not go beyond the stored value range.

Regards

Wim