A quantitative SPECT regime

A quantitative SPECT (single photon emission computed tomography) regime based on simultaneous acquisition of emission and transmission data has been developed and validated. Transmission data are acquired using a scanning collimated line source and incorporated into a modified convolution-subtraction scatter correction method which produces transmission-dependent scatter fractions. This method tailors scatter fraction to attenuation path length, falling to zero outside the body. Following scatter correction, emission data are reconstructed using filtered backprojection, and attenuation correction is performed in a two-step procedure using reconstructed narrow-beam attenuation data from the line source measurements. The quantitative accuracy of this regime has been assessed in heart and lung phantom distributions, as well as in a human-lung perfusion scan with ^99mTc-macroaggregates. The use of simultaneously acquired transmission data for scatter and attenuation correction yields accurate results and promises great potential for practical quantitative SPECT