Exponential Radon Projection

Hi Can any one help me implementing 'Exponential Radon'? the Radon function in Matlab is using the Linear Radon type for X-Ray.

but in SPECT tomography, the exponential type of radon is used.

I just want to compare if the exponential type can give better projections to be reconstructed.

Thank you

[Alan AF]

hello guys, there must be an answer? :)