Preliminary Evaluation Of Image Quality And Clinical Application Of Domestic NET632 SPECT Myocardial Perfusion Imaging

Part Ⅰ: Image quality and semi-quantitative parameter evaluation of NET632 SPECT myocardial perfusion imagingObjective Taking the image quality and semi-quantitative parameters obtained by Symbia T16SPECT myocardial perfusion imaging（MPI）as the"reference standard",the image quality and semi-quantitative parameters obtained by NET632 SPECT MPI were evaluated for the consistency and difference with the former,to clarify the feasibility of NET632 SPECT applied to clinical MPI examination.Methods In this study,image quality and semi-quantitative parameters were compared and evaluated.Among them,the evaluation of image quality adopts two methods:qualitative observation and image scoring.All patients underwent resting or stress-gated MPI on the same day on the two models respectively,and all images were reconstructed and post-processed with Corridor 4DM software to obtain the left ventricular resting perfusion total score（SRS）and the total stress perfusion score（SSS）two blood perfusion parameters and three functional parameters of left ventricular end-diastolic volume（EDV）,end-systolic volume（ESV）and left ventricular ejection fraction（LVEF）.Results 1.The reconstructed spatial resolution of NET632 SPECT is about 6.0 mm,and that of Symbia T16 SPECT is about 8.4 mm;the sensitivity of NET632 SPECT is 92 s^-1/（k Bq/cm²）,which is about four times that of Symbia T16 SPECT.The image resolution,contrast of cold area and the ability to distinguish cold area of myocardial perfusion physical model obtained by MPI on NET632 SPECT are slightly better than Symbia T16 SPECT.The image resolution obtained by MPI on NET632 SPECT,and the clarity of left ventricular structure and myocardial contour were slightly better than that of Symbia T16 SPECT.2.Thirty-seven patients（mean age,59.43±9.97 years）underwent rest-gated MPI on NET632 SPECT and Symbia T16 SPECT,respectively.Among them,there were fifteen males（40.54%）and twenty-two females（59.46%）.The resting-gated MPI image quality scores obtained by patients on the two models had good consistency as a whole,and the difference was statistically significant（P value<0.05）.Twenty-seven patients（mean age,57.41±9.46 years）underwent stress-gated MPI on the two models,respectively.Among them,there were nine males（33.33%）and eighteen females（66.67%）.The stressing-gated MPI image quality scores obtained by patients on the two models had good consistency as a whole,and the difference was statistically significant（P value<0.05）.3.The intraclass correlation coefficient（ICC）values of the semi-quantitative parameters SRS,EDV,ESV and LVEF measured by resting-gated MPI in thirty-seven patients were 0.868,0.586,0.791 and 0.641,respectively,and the difference was statistically significant（all P values<0.001）.The differences of SRS,EDV,ESV and LVEF measured on the two models were generally within the 95%confidence interval,and the two had good consistency.The ICC values of the semi-quantitative parameters SSS,EDV,ESV and LVEF measured by stressing-gated MPI in twenty-seven patients were 0.822,0.783,0.931 and 0.719,respectively,and the differences were statistically significant（all P<0.001）.The differences of SSS,EDV,ESV and LVEF measured on the two models were generally within the 95%confidence interval,and the two had good consistency.Conclusion Qualitative observation of the physical model of myocardial perfusion and the image quality obtained by MPI on NET632 SPECT is slightly better than that of Symbia T16SPECT.The resting and stressing-gated MPI image quality scores obtained on the two models were generally consistent.The semi-quantitative parameters measured on the two models had good repeatability and consistency.NET632 SPECT can be used for MPI examination in clinic and is suitable for related medical research.Part Ⅱ: Evaluation of NET632 SPECT myocardial perfusion imaging in the diagnosis of coronary heart diseaseObjective To explore the consistency or difference in the diagnostic performance of NET632 SPECT and Symbia T16 SPECT 99 m Tc-MIBI gated MPI in patients with confirmed or suspected coronary heart disease（CAD）.Methods Two-day rest-stress-gated MPI was used.Resting and stress-gated MPI examinations were performed on eleven clinically collected patients with confirmed or suspected CAD.All patients underwent coronary CT（CTA）or coronary angiography（CAG）within two months before or after MPI examination.Each patient was randomly and sequentially collected on two models during the same imaging project.The images collected on the two models were reconstructed and post-processed using Corridor 4DM software.The left ventricle was divided into seventeen myocardial segments,and the CTA or CAG results were used as the "reference standard" to compare the images obtained after resting and stress tests to determine the myocardial lesions corresponding to abnormal blood vessels.The sensitivity,specificity and accuracy of MPI in the diagnosis of cardiomyopathy in CAD patients on the two models were calculated,and the difference and consistency in the detection of cardiomyopathy between the two models were evaluated.Results 1.All eleven patients underwent resting and stress MPI examinations on the two models and were included in the analysis.Diagnosed by CTA or CAG,seven cases were positive and four cases were negative.Of the thirty-three major coronary arteries in eleven patients,fourteen were abnormal,and nineteen were not significantly abnormal.2.Diagnosed by NET632 SPECT MPI,ten cases were positive and one case was negative.Of the thirty-three major coronary arteries in eleven patients,twenty-one were abnormal,and twelve had no obvious abnormality.Taking the results of CTA or CAG in diagnosing 33 vessels as the "reference standard",NET632 SPECT MPI in diagnosing myocardial lesions corresponding to 33 vessels has a sensitivity of 92.86%,a specificity of 57.89%,an accuracy of 72.73%,a positive predictive value was 61.90%,and the negative predictive value was91.67%.3.Diagnosed by Symbia T16 SPECT MPI,nine cases were positive and two cases were negative.Of the thirty-three major coronary arteries in eleven patients,seventeen were abnormal,and sixteen had no obvious abnormality.Taking the results of CTA or CAG in diagnosing 33 vessels as the "reference standard",Symbia T16 SPECT MPI in diagnosing myocardial lesions corresponding to 33 vessels had a sensitivity of 71.43%,a specificity of63.16%,an accuracy of 66.67%,a positive prediction value was 58.82%,and the negative predictive value was 75.00%.4.The sensitivity,accuracy,positive predictive value and negative predictive value of NET632 SPECT MPI for detecting myocardial lesions in CAD patients were higher than those of Symbia T16 SPECT,but the specificity was lower than the latter.However,after testing and calculation,the two models had good consistency in the detection of myocardial lesions in CAD patients（Kappa value=0.511）,and the difference was statistically significant（P<0.05）.Conclusion The diagnostic efficacy of NET632 SPECT and Symbia T16 SPECT MPI in patients with confirmed or suspected CAD had good consistency.NET632 SPECT MPI can more accurately detect the cardiomyopathy in patients with confirmed or suspected CAD,and can be used in clinical MPI examination and related medical research to provide help for the early diagnosis and prognosis of CAD patients.