Formation and Characterization of CuPt-A type Ordered Structure in Cadmium Zinc Telluride Single Crystals

Cadmium Zinc Telluride (CdZnTe) single crystals have been widely ultilized in various photoelectron devices such as radiation detectors and solar cells. Different types of ordered phases have also been investigated...

An Algorithm for Individual Dosage in Cadmium–Zinc–Telluride SPECT-Gated Radionuclide Angiography

The aim of the present study was to test an individualised dose without compromising the ease of analysing data when performing equilibrium radionuclide angiography (ERNA) using cadmium–zinc–telluride (CZT) SPECT. From March 2018 to January 2019, 1650 patients referred for ERNA received either an individualised dose of 99mTc-labeled human serum albumin (HSA) according to their age, sex, height, and weight (n = 1567), or a standard dose of 550 MBq (n = 83). The target count rate (CRT) was reduced every two months from 2.7 to 1.0 kcps. A final test with a CRT of 1.7 kcps was run for three months to test whether an agreement within 2% points for the determination of LVEF, on the basis of only two analyses, was obtainable in at least 95% of acquisitions. All the included ERNAs were performed on a dedicated cardiac CZT SPECT camera. When using the algorithm for an individualised dose, we found that agreement between the measured and predicted count rate was 80%. With a CRT of 1.7 kcps, the need for more than two analyses to obtain sufficient agreement for LVEF was 4.9%. Furthermore, this resulted in a mean dose reduction from 550 to 258 MBq. Patients’ weight, height, sex, and age can, therefore, be used for individualising a tracer dose while reducing the mean dose.

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

The 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.

Impacts of acquisition and reconstruction parameters on the absolute technetium quantification of the cadmium–zinc–telluride-based SPECT/CT system: a phantom study

Background The digital cadmium–zinc–telluride (CZT)-based SPECT system has many advantages, including better spatial and energy resolution. However, the impacts of different acquisition and reconstruction parameters on CZT SPECT quantification might still need to be validated. This study aimed to evaluate the impacts of acquisition parameters (the main energy window and acquisition time per frame) and reconstruction parameters (the number of iterations, subsets in iterative reconstruction, post-filter, and image correction methods) on the technetium quantification of CZT SPECT/CT. Methods A phantom (PET NEMA/IEC image quality, USA) was filled with four target-to-background (T/B) ratios (32:1, 16:1, 8:1, and 4:1) of technetium. Mean uptake values (the calculated mean concentrations for spheres) were measured to evaluate the recovery coefficient (RC) changes under different acquisition and reconstruction parameters. The corresponding standard deviations of mean uptake values were also measured to evaluate the quantification error. Image quality was evaluated using the National Electrical Manufacturers Association (NEMA) NU 2–2012 standard. Results For all T/B ratios, significant correlations were found between iterations and RCs (r = 0.62–0.96 for 1–35 iterations, r = 0.94–0.99 for 35–90 iterations) as well as between the full width at half maximum (FWHM) of the Gaussian filter and RCs (r = − 0.86 to − 1.00, all P values < 0.05). The regression coefficients of 1–35 iterations were higher than those of 35–90 iterations (0.51–1.60 vs. 0.02–0.19). RCs calculated with AC (attenuation correction) + SC (scatter correction) + RR (resolution recovery correction) combination were more accurate (53.82–106.70%) than those calculated with other combinations (all P values < 0.05). No significant statistical differences (all P values > 0.05) were found between the 15% and 20% energy windows except for the 32:1 T/B ratio (P value = 0.023) or between the 10 s/frame and 120 s/frame acquisition times except for the 4:1 T/B ratio (P value = 0.015) in terms of RCs. Conclusions CZT-SPECT/CT of technetium resulted in good quantification accuracy. The favourable acquisition parameters might be a 15% energy window and 40 s/frame of acquisition time. The favourable reconstruction parameters might be 35 iterations, 20 subsets, the AC + SC + RR correction combination, and no filter.

Evaluation of Biventricular Function by Cadmium-zinc-telluride SPECT Gated Tomographic Radionuclide Angiography: Comparison to Conventional SPECT

To compare and analyze the consistency and repeatability of left ventricular (LV) and right ventricular (RV) functions obtained by radionuclide multi-gated acquisition (MUGA) with cadmium-zinc-telluride SPECT (CZT-SPECT) and conventional SPECT(C-SPECT) with sodium iodide (NaI) crystal detectors. Seventy-seven patients who underwent C-SPECT planar MUGA and CZT-SPECT tomographic MUGA on the same day were respectively enrolled and reviewed. Comparing the correlation and difference of LVEF, RVEF, PER, and PFR between the two cameras, The repeatability of the left and right ventricular function parameters obtained by the two cameras was also compared. There was a good correlation (R = 0.831, P < 0.001) of LVEF obtained by the two cameras, the comparison of RVEF (r=0.619, P＜0.001), LVPER (r=0.672, P＜0.001) and LVPFR (r=0.700, P＜0.001) showed a modest correlation and the comparison of RVPER (r=0.463, P＜0.001), LVPFR (r=0.253, P＜0.05) showed a poor correlation. In terms of repeatability, the intraclass correlation coefficient (ICC) of RVPFR(P) was good (0.698, P＜0.001), while the ICC in other groups was excellent (0.823 ~ 0.989, P ＜0.001). The repeatability of LVEF and RVEF measured by CZT-SPECT was better than C-SPECT. The repeatability of LVEF and PER measured by two cameras was better than their respective RVER and PFR. The repeatability of PER and PFR of LV was better than RV for both cameras. CZT-SPECT tomographic MUGA had a good correlation with C-SPECT cardiac planar MUGA in evaluating left and right ventricular systolic function and left ventricular diastolic function, and the repeatability above was even better. The determination of right ventricular diastolic function still needed further study. MUGA with CZT-SPECT will play an important and unique role in the clinical application of accurate evaluation of biventricular function in the future.