The evaluation of slant hole collimator in myocardial perfusion SPECT: a simulation study

Introduction: We have investigated cardiac SPECT with slant hole collimator in which the holes are slanted towards the target organ, to provide greater sensitivity over the parallel hole collimator. In addition, parallel hole collimator was used to obtain a comparison in FWHM, sensitivity, Compton and photoelectric area values in the simulations. Materials and Methods: A NaI: Tl crystal with a parallel and slant hole collimators were employed in the simulations. The collimator holes were slanted at a specific angle range of 0-30 degree. The NCAT phantom and a filtered-back projection algorithm was used for data generation and image reconstruction. The projection data acquired from the LAO position to provide lower attenuation to the heart. We also evaluated conventional MPS utilizing LEHR parallel hole collimator for the sake of comparison. Results: The evaluation of the reconstructed data showed that the FWHM for PH-SPECT ranged from 9.9 to 10.4 mm, while that for SH-SPECT ranged from 17 to 19 mm. The sensitivity values showed that conventional SPECT with 18.9 Cps/MBq, while that SH-SPECT provided higher sensitivity (18.93 to 25.21 Cps/MBq) compared with PH-SPECT. Furthermore, the Compton and photoelectric area in energy spectrum were 5.62 and 8.62%, 5.7 and 21.67% respectively for PH and SH SPECT. Conclusion: SH-SPECT is able to acquire higher sensitivity gain over the PH-SPECT.