Reduction in SPECT bone imaging scan times through collimator design and accurate system modeling

The current conventional bone scan protocol involves a 15-minute whole-body planar scan followed by one or more tomographic acquisitions focused on a region of interest lasting 15 minutes or more per bed position. Through a detailed simulation study, we investigated methods for reducing the SPECT acquisition scan time while preserving lesion detection performance. We evaluated different collimator choices providing a range of sensitivity versus resolution trade-offs. We also evaluated the improvements obtained by improved system modeling (point spread function and attenuation correction) within the OSEM framework. Lesion detection performance was measured through LROC curves for a non-prewhitening matched filter (NPWMF) observer with location uncertainty. We also performed a subjective visual assessment of image quality. Our results demonstrate that acquisition times can be reduced by a factor of two over the current protocol by using an LEHR collimator pair in conjunction with attenuation correction and point spread function modeling.