| PART ⅠClinical feasibility of low-dose stress dynamic myocardial CT perfusionPurpose To investigate the clinical feasibility of low-dose stress dynamic myocardial perfusion on the third generation dual-source CT during our daily application.Methods Consecutive symptomatic patients with suspended or known coronary artery disease(CAD)were prospectively recruited and scanned with an low-dose ATP-stress dynamic myocardial CTP protocol using third-generation DSCT.The image quality was assessed for CTP images with score from 1-4 basing on the AHA myocardium segmentation model.The effective radiation dose of CTP was recorded.Results 36 patients(21 men and 15 women;63.12±6.53 ys)finally underwent the CTP examination.All the tube voltage were automatically selected as 70kV,and the mean value of tube current was 482.73±102.45 mAs.The mean value of image quality of CTP was 1.14±0.35.The mean CTP effective radiation dose of CTP was 3.82±1.25 mSv.Conclusion The image quality of low-dose stress dynamic myocardial CT perfusion was good and this low-dose CTP scan protocol is feasible in our daily clinical application for CAD patients who need myocardial ischemia assessment.PART ⅡDiagnostic Performance and Optimal Analysis on Low-dose Stress Dynamic Myocardial CT Perfusion for Hemodynamically significant Coronary Artery DiseasePurpose The purpose of this study was to investigate the diagnostic value and optimal myocardial blood flow(MBF)analysis methods on low-dose dynamic myocardial CT perfusion(CTP)for functionally significant coronary artery disease(CAD).Methods Consecutive symptomatic patients were prospectively recruited and scanned with low-dose adenosine triphosphate-stress dynamic myocardial CTP protocol using third-generation dual-source CT.Qualitative assessment was based on visual analysis of the myocardial ischemia.For quantitative assessment,the evaluated MBF values include endocardial,epicardial and transmural layer of the myocardium.Segmental absolute MBF values were acquired for automatic analysis,and local absolute MBF values were obtained by manually drawn region of interest(ROI)for semi-automatic measurement.The relative MBF ratio was calculated by dividing the reference standard MBF value with the semi-automatic absolute MBF value manually obtained.Three different types of reference standard MBF value were identified based on 1)average segmental MBF value,2)75%percentile of the average segmental MBF value and 3)highest segmental MBF value.Accordingly,relative MBF Ration Ratio2 and Ratio3 were recorded.Myocardial ischemia diagnostic performance of different parameters were assessed using invasive coronary angiography&fractional flow reserve(ICA/FFR)as the reference standard.Areas under the receiver-operating characteristic curves(ROCs)were compared among qualitative and quantitative assessment results.Results Finally 52 patients(33 men and 19 women;62.21±6.77 ys)underwent the CTP examination.There were 116 vessels finally underwent ICA/FFR examination for analysis in our study.The mean radiation dose of all CTP scan was 3.86±1.27 mSv.According to the ICA/FFR results,47 vessels(40.50%)with 322 segments(36.4%)were qualitatively identified as causing ischemia in 32 patients(61.54%).For semi-automatic analysis,the absolute measured MBF value assessment showed that the endocardial layer was superior to all the other parameters(P<0.01)for predicting ischemia,the sensitivity,specificity,positive predictive value,negative predictive value and diagnostic accuracy were 82.76%,100.00%100.00%,90.29%and 93.38%,respectively.The area under the curve(AUC)was 0.947(95%CI:0.908-0.983).For relative MBF value assessment,the endo-cardial relative analysis method of Ratio3 showed the best performance,with AUC of 0.909,(95%CI:0.864-0.957).Conclusion The low-dose stress dynamic myocardial CT perfusion with third generation dual source CT has great performance for detecting the hemodynamically significant coronary artery disease.Quantitative assessment of semi-automatic endocardial layer MBF value and relative MBF Ratio3 that using the highest segmental MBF value for ratio calculation on stress dynamic myocardial CTP showed the optimal diagnostic accuracy for the detection of functionally significant CAD.PART ⅢClinical performance of one-stop low-dose stress dynamic myocardial perfusion on the third generation dual-source CTPurpose CT advances allow coronary arterial tree to be entirely covered during one CTP scan.The aim of this study was to investigate the performance of single-phase coronary CT angiography(SP-CTA)images extracted from stress dynamic myocardial CT perfusion(CTP)scans using third-generation dual-source CT(DSCT).Methods Consecutive symptomatic patients were prospectively recruited and scanned with an ATP-stress dynamic myocardial CTP and routine CCTA protocol using third-generation DSCT.All patients gave informed consent for this institutional review board-approved study.Images from the phase with the best enhancement of the coronary arteries of CTP scan were selected as the SP-CTA.Image quality(IQ)was assessed.Using invasive coronary angiography(ICA)as reference standard,the diagnostic performance for stenosis detection was compared for SP-CTA and routine CCTA.Results 56 patients successfully underwent the CTP and routine CCTA examination,among which 39 patients underwent ICA.The mean heart rate during CTP was much higher than that during CCTA(85.0±12.7 and 67.9±10.0 bpm,p<0.001).The qualitative IQ scores of SP-CTA were similar to that of routine CCTA(p>0.05).On a per-segment basis,the sensitivity,specificity,positive predictive value,negative predictive value,diagnostic accuracy and area under the receiver-operating-characteristic curve(AUC)results of SP-CCTA and routine CCTA for diagnosis of stenosis≥50% exhibit no significant difference(SP-CTA:85.0%,95.8%,81.9%,96.6%,93.8%and 0.891 vs routine CCTA:82.5%,97.2%,86.8%,96.1%,94.5%and 0.911;all P>0.05).The mean effective radiation dose of CTP and routine CCTA plus CTP were 3.92±1.72mSv and 5.98±2.01mSv(P<0.05),respectively.Conclusion With third-generation DSCT,the IQ and diagnostic value of SP-CTA was equivalent to routine CCTA.SP-CTA images from CTP is potentially feasible to replace a separate routine CCTA and this would allow for "one-stop" cardiac examination for high risk CAD patients who need myocardial ischemia assessment.PART ⅣClinical performance of innovative one-stop low-dose cardiac CT for coronary artery disease assessment:validation by Invasive Fractional Flow ReservePurpose To investigate the feasibility of low-dose stress dynamic myocardial perfusion on the third generation dual-source CT as innovative one-stop cardiac CT during our daily application.Methods Consecutive symptomatic patients with suspended or known coronary artery disease(CAD)were prospectively recruited and scanned with an low-dose ATP-stress dynamic myocardial CTP protocol using third-generation DSCT.Among the multi-phases of dynamic CTP images,the phase with the best enhancement of the coronary arteries was selected and extracted as single-phase coronary CT angiography(SP-CTA).The diagnostic value of CTP combined with SP-CTA as a one-stop cardiac CT imaging technology for myocardial ischemia was evaluated on per-patient basement and per-vessel basement.The invasive coronary angiography with Fractional Flow Reserve(ICA/FFR)were set as the diagnostic reference standard.The effective radiation dose of CTP was recorded.Results 65 patients successfully underwent the CTP examination.According to the ICA/FFR results,72 coronary arteries(40.4%)of 39 patients(60.0%)were diagnosed as causing ischemia.On per-vessel basement,the sensitivity,specificity,positive predictive value,negative predictive value and diagnostic accuracy of CTP and CTP+SP-CTA were 81.76%,82.28%,72.31%,86.57%,82.66% and 87.04%,91.30%,85.45%,92.31%,89.73%,respectively.The area under the receiver-operating-characteristic curve results of CTP+SP-CTA(AUC=0.959,95%CI:0.928-0.989)was much higher than CTP(AUC=0.894,95%CI:0.865-0.948)and SP-CTA(AUC=0.830,95%CI:0.754-0.906)(P<0.01)。The mean CTP effective radiation dose of CTP was 3.86±1.69 mSv.Conclusion The diagnostic value of low-dose stress dynamic myocardial CT perfusion combine with CTP-derived SP-CTA was great and it is potentially feasible as an innovative one-stop cardiac CT imaging in our daily clinical application for moderate-high CAD risk patients who need myocardial ischemia assessment. |
