ABSTRACT
Objective@#To investigate the impact on myocardial blood flow (MBF) quantitation with multi-pinhole cadmium zinc telluride (CZT)-SPECT with or without partial physical corrections.@*Methods@#A total of 30 patients (18 males, 12 females; age: (63±9) years) with suspected or known coronary heart diseases who underwent dynamic SPECT from July 2018 to January 2019 in Fuwai Hospital were enrolled. Images were reconstructed using different corrections: no correction (NC), partial corrections ((noise reduction (NR), NR+ scatter correction (SC), NR+ SC+ resolution recovery (RR)), NR+ SC+ RR+ attenuation correction (AC; total corrections, TC). Kinetic modeling integrated one-tissue two-compartment model while using index of fitting quality (R2) and fraction blood volume (FBV) to assess the quality of modeling. Rest MBF (RMBF), stress MBF (SMBF) and myocardial flow reserve (MFR) quantified from no correction (NC) or partial corrections were compared with those of TC. Wilcoxon signed rank test and linear regression analysis were used to analyze the data.@*Results@#Compared to TC, NC showed the lowest R2 (rest: 0.69, stress: 0.78; z values: 4.78 and 4.78, both P<0.01) and highest FBV (rest: 0.37, stress: 0.40; z values: -3.40 and -3.30, both P<0.01). The improvement of R2 and FBV was consistent with increased corrective terms. Compared with TC, NC overestimated SMBF and MFR (z values: 1.27 and -3.50, both P<0.01), all partial corrections overestimated RMBF and SBMF (z values: from -4.55 to 1.27, all P<0.01). NR and NR+ SC underestimated MFR (both P<0.05). Linear regression analysis showed that the regressive coefficients of RMBF between NC, NR, NR+ SC, NR+ SC+ RR and TC were 0.908-1.210, and Bland-Altman plots of RMBF demonstrated positive or negative biases (-0.07, 0.21, 0.26, 0.15 ml·min-1·g-1). The regression coefficients of SMBF were 1.129-1.308, and Bland-Altman plots demonstrated positive biases (0.60, 0.25, 0.28, 0.24 ml·min-1·g-1). The regression coefficients of MFR were 0.907-1.318, and Bland-Altman plots demonstrated positive or negative biases (0.70, -0.11, -0.05, 0.01).@*Conclusion@#Full physical corrections can improve the index of fitting quality in the kinetic modeling and reduce left ventricle spillover, which help to warrant the accuracy of SPECT myocardial blood flow quantitation with multi-pinhole CZR-SPECT.
ABSTRACT
Objective To investigate the impact on myocardial blood flow (MBF) quantitation with multi-pinhole cadmium zinc telluride (CZT)-SPECT with or without partial physical corrections. Methods A total of 30 patients (18 males, 12 females; age: (63±9) years) with suspected or known coronary heart diseases who underwent dynamic SPECT from July 2018 to January 2019 in Fuwai Hospital were enrolled. Images were reconstructed using different corrections: no correction (NC), partial corrections ((noise re-duction ( NR) , NR+scatter correction ( SC) , NR+SC+resolution recovery ( RR) ) , NR+SC+RR+attenua-tion correction ( AC;total corrections, TC) . Kinetic modeling integrated one-tissue two-compartment model while using index of fitting quality ( R2 ) and fraction blood volume ( FBV) to assess the quality of modeling. Rest MBF ( RMBF) , stress MBF ( SMBF) and myocardial flow reserve ( MFR) quantified from no correc-tion ( NC) or partial corrections were compared with those of TC. Wilcoxon signed rank test and linear re-gression analysis were used to analyze the data. Results Compared to TC, NC showed the lowest R2( rest:0.69, stress:0.78;z values:4.78 and 4.78, both P<0.01) and highest FBV ( rest:0.37, stress:0.40;z values: -3.40 and -3.30, both P<0.01). The improvement of R2 and FBV was consistent with increased corrective terms. Compared with TC, NC overestimated SMBF and MFR ( z values:1.27 and-3.50, both P<0.01), all partial corrections overestimated RMBF and SBMF (z values:from -4.55 to 1.27, all P<0.01). NR and NR+SC underestimated MFR (both P<0.05). Linear regression analysis showed that the regressive coefficients of RMBF between NC, NR, NR+SC, NR+SC+RR and TC were 0.908-1.210, and Bland-Altman plots of RMBF demonstrated positive or negative biases (-0.07, 0.21, 0.26, 0.15 ml·min-1·g-1). The regression coefficients of SMBF were 1. 129-1. 308, and Bland-Altman plots demonstrated positive biases (0. 60, 0.25, 0.28, 0.24 ml·min-1·g-1). The regression coefficients of MFR were 0.907-1.318, and Bland-Altman plots demonstrated positive or negative biases (0.70,-0.11,-0.05, 0.01). Conclusion Full physical corrections can improve the index of fitting quality in the kinetic modeling and reduce left ventricle spillover, which help to warrant the accuracy of SPECT myocardial blood flow quantitation with multi-pin-hole CZR-SPECT.
ABSTRACT
The dedicated cardiac cadmium-zinc-telluride (CZT) SPECT device has been commercially applied to the clinics in recent years. Compared to the traditional SPECT, cardiac CZT SPECT has better image quality, higher spatial and energy resolution with shorter acquisition duration and lower radiation exposure. With these advantages, the clinical application of cardiac CZT SPECT is of great potential. This review summarizes the technological advances, clinical progress and current shortages of cardiac CZT SPECT.
ABSTRACT
Objective To evaluate the effect of anticoagulant therapy by pulmonary ventilation/perfusion (V/Q) imaging in chronic thromboembolic pulmonary hypertension (CTEPH) patients.Methods Thirtysix CTEPH patients (16 males,20 females,average age:(53.8±13.8) years) diagnosed by pulmonary angiography from January 2013 to December 2015 were included in this retrospective study.All patients received anticoagulant therapy for more than 6 months.They underwent pulmonary V/Q imaging before and 6 months after anticoagulant therapy.The numbers of pulmonary segments with perfusion defect,percentage of perfusion defect score (PPDs) and pulmonary arterial systolic pressure (PASP) before and after anticoagulant therapy were measured by echocardiography.Pair t test was used for data analysis.Results Before anticoagulant therapy,there were 319 pulmonary segments with perfusion defect in 36 CTEPH patients,8.9± 3.4 on average,and reduced to 8.4+3.6 after anticoagulant therapy (t =3.101,P＜0.01).The PPDs before and after anticoagulant therapy were (43.3±19.7)％ and (40.8±+20.5)％ (t=2.364,P＜0.05).In the subgroup of 9 patients with improved pulmonary perfusion,the PASP significantly decreased from (68.7±27.3)to (56.1 +±34.8) mmHg (1 mm Hg =0.133 kPa;t =2.465,P＜ 0.05) after anticoagulant therapy.In contrast,in the subgroup of 27 patients with no improved pulmonary perfusion,the PASP before and after anticoagulant therapy were (71.3±26.9) and (76.7±35.0) mmHg respectively (t=-1.511,P＞0.05).Conclusion Pulmonary V/Q imaging is a reliable method for evaluating the changes of pulmonary perfusion before and after anticoagulant therapy,and it is valuable for assessing the effect of anticoagulant therapy in CTEPH patients.