Comparison Of IQ-SPECT And Low Energy High Resolution Collimator SPECT In Clinical Application

Objective To investigate differences in cardiac function and perfusion parameters measured by IQ-SPECT and low energy high-resolution LEHR-SPECT,as well as effects of scattering correction(SC)and CT attenuation correction(AC)on myocardial perfusion imaging.Methods From May 2020 to September 2020,80patients performedSPECT myocardial perfusion imaging were retrospectively enrolled in Fuwai Hospital.According to the standardized left ventricular end-diastolic diameter of body surface measured by two-dimensional echocardiography,patients were divided into 2groups:Agroup(n=34)with significantly enlarged left ventricle and B group(n=46)with no significant enlargement of left ventricle.LEHR-SPECT and IQ-SPECT gated myocardial perfusion imaging were performed in all patients.Left ventricular end-diastolic volume(EDV),end-systolic volume(ESV),ejection fraction(EF),total resting score(SRS)and total perfusion defect(TPD)were measured.Parameters measured by two methods and differences before and after SC and AC were compared by usingpairedt test and Wilcoxon rank sum test.The correlation was analyzed by Pearson or Spearman correlation analysis,and the consistency was analyzed by Bland-Altman analysis.Results In A group,EDV,EF and SRS measured by IQ-SPECT were significantly lower than those assessed by LEHR-SPECT after SC and AC(EDV:(257±137)vs(276±154)ml,EF:(21±11)%vs(26±13)%,SRS:17(6,25)vs 18(8,28);t values:-2.63,-7.46,z=-2.14,all P<0.05);all parameters measured byLEHR-SPECT and IQ-SPECT hadwell correlation(r values:0.965,0.969,0.967,rsvalues:0.920,0.960,all P<0.001)and consistency.InBgroup,EDV and EF measured by IQ-SPECT were significantly lower than those assessed by LEHR-SPECT after SC and AC(EDV:(96 ±40)vs(107±39)ml,EF:(46±15)%vs(54±16)%;t values:-6.23,-10.71,both P=0.001);SRS and TPD measured by IQ-SPECT after SC and AC were significantly lower than NOSC and NOAC(SRS:2(1,4)vs 5(3,11),TPD:(3%(1%,5%)vs 7%(3%,12%);z values:-4.11,-4.16,both P<0.001);all parameters measured byLEHR-SPECT and IQ-SPECT had well correlation(r values:0.956,0.978,0.958,rsvalues:0.926,0.944,all P<0.001)and consistency.Conclusions There aregood correlation and consistency of left ventricular function and myocardial perfusion parameters acquired by IQ-SPECT and LEHR-SPECT.Moreover,IQ-SPECT hashigher sensitivity and resolution and is able to shortenacquisition time,resulting in great potential in clinical application.