Objective: To investigate the impact of reduced SPECT acquisition time on reconstructed image quality for diagnostic purposes. Method: Data from five patients referred for a routine bone SPECT/CT using the standard multi-bed SPECT/CT protocol were reviewed. The acquisition time was 900 s using gating technique; SPECT date was resampled into reduced data sets of 480 s, 450 s, 360 s and 180 s acquisition duration per bed position. Each acquisition time was reconstructed using a fixed number of subsets (8 subsets) and 4, 8, 12, and 16 iterations, followed by a post-reconstruction 3D Gaussian filter of 8 mm FWHM. Two Nuclear Medicine physicians analysed all images independently to score image quality, noise and diagnostic confidence based on a pre-defined 4-point scale. Results: Our result showed that the most frequently selected categories for 480 s and 450 s images were good image quality, average noise and fair confidence, particularly at lower iteration numbers 4 and 8. For the shortened acquisition time of 360 s and 180 s, statistical significance was observed in most reconstructed images compared with 900 s. Conclusion: The SPECT/CT can significantly shorten the acquisition time with maintained image quality, noise and diagnostic confidence. Therefore, acquiring data over 480 s and 450 s is feasible for WB-SPECT/CT bone scans to provide an optimal balance between acquisition time and image quality.

Background/Objectives: The purpose of this prospective study was to investigate the preferred reconstruction SPECT parameters for generating reprojected planar images in bone studies, and to evaluate, by visual reader assessment, the feasibility of using these reprojected images as a substitute for traditional planar whole-body (WB) bone scan images. This was a single-centre feasibility study; diagnostic accuracy was not assessed. Methods: Patients referred for planar bone scintigraphy (PBS) and WB-SPECT/CT were prospectively enrolled. Reprojected planar bone scintigraphy (R-PBS) data were generated using forward projection of the three-bed SPECT/CT data. Three nuclear medicine (NM) specialists, blinded to the imaging reconstruction, evaluated both sets of images in a randomised order. The preferred reconstruction parameters for R-PBS were determined by visual assessment using a 4-point ordinal visual scoring scale. A side-by-side comparison of PBS vs. R-PBS was conducted, including assessments of image quality, artefact generation, image preference, and any clinical significance that may affect report interpretation. The agreement between the physicians’ evaluations was measured using the Kappa coefficient test. Results: Of the four reconstruction parameter combinations, 6 iterations, 8 subsets, and a 5 mm Gaussian post-filter yielded the highest visual quality scores. PBS images scored higher on image quality, though this difference was not statistically significant (p > 0.05). The inter-rater agreement for image quality scores was moderate for both PBS and R-PBS images. The results indicate that among the 33 reader-level assessments derived from 11 patient pairs and reviewed by the 3 readers, PBS images were preferred 13 times (~40%), R-PBS 10 times (30%), and no preference was indicated for the remaining 10 (30%). Conclusions: In this small feasibility cohort, R-PBS images derived from fast WB-SPECT/CT data were of visual quality comparable to PBS and may have potential as an alternative to PBS. If confirmed in larger studies with formal diagnostic accuracy assessment, R-PBS could remove the need for a separate PBS acquisition and reduce overall patient imaging time.