Optimal number of views in 360° SPECT imaging

This study examined SPECT-reconstructed image quality as a function of the number of views, and determined the minimum number of views necessary to remove aliasing artifacts in 360° SPECT. Methods: Computer simulation was performed using a two-dimensional Shepp-Logan head phantom and a high- resolution parallel-beam collimator with and without photon attenuation. Results: In 360° SPECT, aliasing artifacts were reduced by changing the number of views from an even number 16 to its neighboring odd numbers 15 or 17, from 32 to 31 or 33 and from 64 to 63 or 65. Image quality of 15 or 17 views, 31 or 33 views and 63 or 65 views was similar to that of 32, 64 and 128 views, respectively. Conclusion: Replacing an even number of views by its neighboring odd numbers in 360° SPECT significantly decreased aliasing artifacts. Thirty-one or 33 views are sufficient to remove most of the aliasing artifacts in 360° SPECT with a matrix of 64 x 64 pixels. This method can be applied to fast 360° SPECT since fewer views are used.