Satisfied quantitative value can be acquired by short-time bone SPECT/CT using a whole-body cadmium–zinc–telluride gamma camera

AbstractThe aim of this study was to evaluate the quantitative values of short-time scan (STS) of metastatic lesions compared with a standard scan (SS) when acquired by whole-body bone SPECT/CT with cadmium–zinc–telluride (CZT) detectors. We retrospectively reviewed 13 patients with bone metastases from prostate cancer, who underwent SPECT/CT performed on whole-body CZT gamma cameras. STSs were obtained using 75, 50, 25, 10, and 5% of the list-mode data for SS, respectively. Regions of interest (ROIs) were set on the increased uptake areas diagnosed as metastases. Intraclass correlation coefficients (ICCs) of standardized uptake values (SUVs) for the ROIs were calculated between the SS and each STS, and ICC ≥ 0.8 was set as a perfect correlation. Moreover, the repeatability coefficient (RC) was calculated, and RC ≤ 20% was defined as acceptable. A total of 152 metastatic lesions were included in the analysis. The ICCs between the SS vs. 75%-STS, 50%-STS, 25%-STS, 10%-STS, and 5%-STS were 0.999, 0.997, 0.994, 0.983, and 0.955, respectively. The RCs of the SS vs. 75%-STS, 50%-STS, 25%-STS, 10%-STS, and 5%-STS were 7.9, 12.4, 19.8, 30.8, and 41.3%, respectively. When evaluating the quality of CZT bone SPECT/CT acquired by a standard protocol, 25%-STS may provide adequate quantitative values.

Download Full-text

Impact of Reconstruction Parameters on Spatial Resolution and Its Comparison Between Cadmium-Zinc-Telluride SPECT/CT and Conventional SPECT/CT

10.21203/rs.3.rs-375105/v1 ◽

2021 ◽

Author(s):

Miao Wang ◽

Sheng Dong ◽

Ruyi Zhang ◽

Shen Wang ◽

Yiming Shen ◽

...

Keyword(s):

Spatial Resolution ◽

Cadmium Zinc Telluride ◽

Cutoff Frequency ◽

Zinc Telluride ◽

Whole Body ◽

Image Correction ◽

Butterworth Filter ◽

Czt Spect ◽

The Impact ◽

Cadmium Zinc

Abstract Background: To evaluate the impact of reconstruction parameters on spatial resolution of tomographic image in SPECT/CT, and to compare spatial resolution between a new polyvalent whole-body Cadmium-Zinc-Telluride camera (CZT-SPECT/CT) and a conventional dual-head Anger camera (conventional SPECT/CT). Spatial resolution was evaluated with four line sources filled with 99mTc in tomographic images reconstructed by varying reconstruction parameters. Ordered-subset expectation maximization (OSEM) algorithm was performed with varying iterations (1-20), the number of subsets was fixed at 10. Butterworth filter, Gauss filter and no-filter were selected respectively. Computed tomography-based attenuation correction (CTAC), scatter correction (SC), resolution recovery (RR) and no-correction (NC) were adopted for image correction respectively. Filtered back projection (FBP) with Butterworth filter and CTAC was also performed in image reconstruction. Spatial resolution was expressed by full width at half-maximum (FWHM) value.Results: The impact of reconstruction parameters on spatial resolution was identical in both cameras: FWHM values decreased with the increase of iterations and converged uniformly when the number of iterations was over 4. FWHM values decreased with the increase of cutoff frequency of Butterworth filter and increased with the increase of Gauss filter. SC and RR improved spatial resolution, whereas CTAC had negligible effect on spatial resolution reconstructed by OSEM. FWHM was generally lower with OSEM reconstruction than FBP reconstruction. On the whole, under the same reconstruction conditions, CZT-SPECT/CT had a lower FWHM value than conventional SPECT/CT.Conclusions: The spatial resolution was improved with the increase of iterations. Increasing the cutoff frequency of Butterworth filter and decreasing the Gauss filter enhanced spatial resolution. The spatial resolution was better reconstructed by OSEM associated with AC, SC and RR than FBP. CZT-SPECT/CT had better spatial resolution than conventional SPECT/CT.

Download Full-text