Improving the image quality of short-time bone SPECT using CZT detectors with SwiftScan

Objective: This study aimed to evaluate the quality and associated quantitative values of bone single-photon emission computed tomography (SPECT) with and without SwiftScan using a semiconductor camera equipped with a cadmium-zinc-telluride (CZT) detector. Methods: Ten patients with bone metastases from prostate cancer who underwent list-mode SPECT/computed tomography using a whole-body semiconductor camera were included in this study. A total dose of 740 MBq was administered. Standard SPECT images were taken approximately 3 h later, and images were constructed with and without SwiftScan. Results: A total of 130 metastatic lesions in 10 patients were analyzed. The dose injected was 732.8 (662.3-878.1) MBq, and the time to start the test after injection was 200.5 (165།220) min. The intraclass correlation coefficient (ICC) was 0.952 at 5% for the standard time without SwiftScan and 0.990 with SwiftScan. The percentage of maximum standardized uptake value (SUVmax) changes of > 10% without SwiftScan was 0.7% at 100% of the images in the list mode data, 4.6% at 75%, 16.9% at 50%, 28.5% at 25%, 56.2% at 10%, and 68.4% at 5%. In contrast, with SwiftScan, SUVmax changes of > 10% were associated with 0.75% at 75%, 3.85% at 50%, 20.8% at 25%, 30.8% at 10%, and 40.8% at 5%. The contrast-to-noise ratios (CNR) were 95.3 at 75%, 88.3 at 50%, 69.2 at 25%, 45.7 at 10%, and 31.6 at 5% without SwiftScan, and were 96.9, 91.7, 78.0, 71.6, and 62.0, respectively, with SwiftScan. Conclusion: SwiftScan can produce reliable images even with ultrashort acquisition times, and improves image quality and associated quantitative values. The method reported herein can be used to reduce SPECT inspection time.