Units of reconstructed images

Dear Tmerlin,

I have two questions about calibration.

Firstly, is calibration inversely proportional to time and voxel spacing?So it would be better if I could compute the calibration factor per second, then I could get the corresponding calibration factor by dividing with the scanning time.

Secondly, should I make a mask to fit the cylinder? Cuz, there are noises in full image(and I found add min angle and small FOV causes the highlight at the edge of FOV, as shown in the following figure, raw image 280x280x280, m means min angle, f mean 200x200x280). And should I do all correction before computing calibration?(normalization and attenuation are necessary)


Best,
Hannah