Optimising Imaging Protocols for Whole-Body SPECT/CT

Abstract

Aim: This thesis investigates the application of whole-body single photon emission computed tomography/computed tomography (WB-SPECT/CT) imaging in clinical practice. Method: The first study was a systematic review and meta-analysis of 11 studies to examine the diagnostic performance of WB-SPECT/CT in detecting bone metastasis and its added value compared to planar bone scintigraphy (PBS). The second study optimised the acquisition and reconstruction parameters to preserve image quality while reducing acquisition time by utilising a phantom and clinical example. In the third study, 5 patients recruited to evaluate the clinical image quality, noise, and diagnostic confidence for various acquisition durations and iterative reconstructions. In the fourth study, 11 participants referred for bone scintigraphy using PBS and SPECT/CT to investigate the feasibility of reprojected fast WB SPECT/CT images in clinical practice. Results: The first study showed that WB-SPECT/CT performed better than PBS. The second study revealed that as the number of iterations increased, there was a corresponding improvement in overall contrast recovery, but it also increased noise levels. Additionally, the two smallest spheres (13 and 10 mm) were invisible at 3 s/view as they did not conform to the Rose criterion of Contrast to noise ratio> 5. The final study showed that the data acquired for 480 s and 450 s corresponded to ratings of good image quality, average noise and fair confidence, with no statistically significant difference between the two acquisition times. Conclusion: Rapid scanning approaching 450 seconds per bed position is feasible for WB bone SPECT/CT to provide an optimal balance between acquisition time and image quality. Furthermore, R-PBS derived from fast WB bone SPECT/CT data may be a viable alternative to PBS. Moreover, a reduced acquisition time for SPECT/CT imaging increases the potential of WB-SPECT to be adopted in a broader range of clinical applications.