Units of reconstructed images

Dear CASToR users,

Could you help us answer a question regarding the reconstructed image units in CASToR?

Basically, a student of mine reconstructed a Monte-Carlo simulation of a NEMA IQ phantom which should exhibit activities from 5.3kBq/ml in the background to around 21.2kBq/ml in the hot spheres. The reconstruction is performed using CASToR with a voxel size of 2x2x2mm3.

When visualizing the reconstructed images in amide we obtain values in the hot spheres in the order of magnitude of 4e-4, but we do not know which unit the images have and whether they are dependent on the voxel size. The 4e-4 should match the input of 21.2kBq/ml if we did not make a mistake using either GATE or CASToR.

Therefore, how can we convert the values of the reconstructed images into values of activity per ml (kBq/ml)?

While we are asking about units, what is the unit of the sensitivity map? The sensitivity map has values of about 1e5-1e6.

Thanks for your help and best regards,

Jan

P.S.: Seems like my student cannot post to the mailing list, so I tried on his behalf. If you need the exact command line arguments, I will ask my student and deliver them subsequently.

Dear CASToR users,

Could you help us answer a question regarding the reconstructed image units in CASToR?

Basically, a student of mine reconstructed a Monte-Carlo simulation of a NEMA IQ phantom which should exhibit activities from 5.3kBq/ml in the background to around 21.2kBq/ml in the hot spheres. The reconstruction is performed using CASToR with a voxel size of 2x2x2mm3.

When visualizing the reconstructed images in amide we obtain values in the hot spheres in the order of magnitude of 4e-4, but we do not know which unit the images have and whether they are dependent on the voxel size. The 4e-4 should match the input of 21.2kBq/ml if we did not make a mistake using either GATE or CASToR.

Therefore, how can we convert the values of the reconstructed images into values of activity per ml (kBq/ml)?

While we are asking about units, what is the unit of the sensitivity map? The sensitivity map has values of about 1e5-1e6.

Thanks for your help and best regards,

Jan

P.S.: Seems like my student cannot post to the mailing list, so I tried on his behalf. If you need the exact command line arguments, I will ask my student and deliver them subsequently.