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

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ruyi Zhang ◽  
Miao Wang ◽  
Yaqian Zhou ◽  
Shen Wang ◽  
Yiming Shen ◽  
...  
Keyword(s):  
Image Quality ◽  
Cadmium Zinc Telluride ◽  
Scatter Correction ◽  
Zinc Telluride ◽  
Acquisition Time ◽  
Energy Window ◽  
Image Correction ◽  
Recovery Coefficient ◽  
Czt Spect ◽  
Cadmium Zinc

Abstract 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.

scholarly journals Impacts of Acquisition and Reconstruction Parameters on the Absolute Technetium Quantification of the Cadmium-zinc-telluride Based SPECT/CT System: A Phantom Study

2021 ◽  
Author(s):  
Ruyi Zhang ◽  
Miao Wang ◽  
Yaqian Zhou ◽  
Shen Wang ◽  
Yiming Shen ◽  
...  
Keyword(s):  
Image Quality ◽  
Cadmium Zinc Telluride ◽  
Zinc Telluride ◽  
Acquisition Time ◽  
P Value ◽  
Energy Window ◽  
P Values ◽  
The Absolute ◽  
Ct System ◽  
Cadmium Zinc

Abstract BackgroundVarious acquisition and reconstruction parameters may affect the accuracy of the absolute SPECT quantification. However, many of the impacts of these parameters have not well been studied. This study aimed to evaluate the impacts of acquisition parameters (main energy window and acquisition time per frame) and reconstruction parameters (the number of iterations and subsets in iterative reconstruction, post-filter, and image correction methods) on the technetium quantification of the cadmium-zinc-telluride based SPECT/CT system. MethodsA phantom (PET NEMA/IEC image quality, USA) was filled with a 16:1 sphere-to-background activity concentration ratio of technetium and all spheres had 132400.81Bq/ml of radioactivity. Mean uptake values (calculated mean concentrations for spheres) were measured to evaluate the recovery coefficient (RC) changes under different acquisition and reconstruction parameters. 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.ResultsFor six spheres of the phantom, significant correlations were found between iterations and RCs (r=0.60~0.98 for 1~35 iterations, r=0.96~0.99 for 35~90 iterations, all P-values <0.05) as well as between the full width at half maximum (FWHM) of the Gauss filter and RCs (r=-0.90～-1.00, all P-values <0.05). 1~35 iterations had higher regression coefficients compared with those of 35~90 iterations (0.67~1.16 vs. 0.02~0.17). The AC (attenuation correction)+SC (scatter correction) +RR (resolution recovery correction) combination had more close to 100% RCs (42.42%~98.04%) with better image quality (31.52%~83.57%) than those of other correction combinations (all P-values <0.05). No significant statistical difference was found between the 15% energy window and the 20% energy window (P-value=0.061), nor between the 5 seconds/frame and 120 seconds/frame of acquisition time (P-value=0.943) in terms of RCs. ConclusionsThe CZT-SPECT/CT showed a good quantification accuracy of technetium. The favorable acquisition parameters may be 15% energy window and 40 seconds/frame of acquisition time. The favorable reconstruction parameters could be 35 iterations, 20 subsets, the AC+SC+RR correction combination, and FWHM 0.7mm of Gauss filter.

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

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.

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

2021 ◽  
Author(s):  
Yue Chen ◽  
Zekun Pang ◽  
Jiao Wang ◽  
Jianming Li
Keyword(s):  
Right Ventricular ◽  
Diastolic Function ◽  
Cadmium Zinc Telluride ◽  
Zinc Telluride ◽  
Left Ventricular ◽  
Ventricular Diastolic Function ◽  
Left And Right ◽  
Czt Spect ◽  
Cadmium Zinc ◽  
Better Than

Abstract 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.

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

Diagnostics ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2268
Author(s):  
Maria Normand Hansen ◽  
Christian Haarmark ◽  
Bent Kristensen ◽  
Bo Zerahn
Keyword(s):  
Count Rate ◽  
Cadmium Zinc Telluride ◽  
Standard Dose ◽  
Radionuclide Angiography ◽  
Zinc Telluride ◽  
Equilibrium Radionuclide Angiography ◽  
The Mean ◽  
Czt Spect ◽  
Cadmium Zinc

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.

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