| ObjectiveFirst-pass CT myocardial perfusion(CTP)was performed in patients with suspected coronary artery disease(CAD)at rest.Coronary artery stenosis and myocardial perfusion was evaluated.To evaluate the left ventricular myocardial perfusion characteristics during systolic and diastolic periods in normal and abnormal coronary arteries.Materials and Methods1.Clinical data:more than 300 patients with suspected coronary heart disease in Linyi people's Hospital were prospectively collected from December 2017 to January 2018.All patients were examined by CCTA,and the degree of coronary artery stenosis was evaluated.coronary angiography(CAG)was performed on patients with stenosis?50%at any position of the lumen.Screening through group criteria and exclusion criteria,a total of 86 patients were included.2.CCTA+CTP:to obtain first myocardial perfusion image,coronary artery imaging was performed with SIEMENS Definition Flash CT scanner.1)positioning image scanning2)prospective ECG gating technique was used for low dose cardiac scan to obtain calcification score and further clarify the scanning range3)retrospective ECG gating technique was used for coronary artery imaging4)reconstruction of first-pass myocardial perfusion image using GEaw4.6workstation3.Coronary angiography(CAG):using Philips digital x-ray angiography XPER FD10to perform coronary angiography.4.Image analysis:CCTA images and CAG images were analyzed by 2 senior doctors(over 10 years of working experience).CT myocardial perfusion was divided into systolic(sys)group and diastolic(Dias)group according to cardiac cycle.CT myocardial perfusion was divided into sys negative group(0-49%stenosis),sys positive group(?50%stenosis),Dias negative group(stenosis 0-49%)and Dias positive group(stenosis?50%)according to the degree of coronary artery stenosis and cardiac cycle shown by CAG.5.Statistical analysis:using spss 20.0 statistical software,the measurement data were compared with paired sample t-test,count data were compared with?2 test.Using CAG as gold standard,the sensitivity,specificity,positive predictive value and negative predictive value of CCTA in diagnosing coronary artery stenosis were calculated.Using paired t test,the differences between sys group and Dias group CTP were analyzed.Normal distribution was used to analyze the distribution characteristics of CT values of each myocardial segment in sys negative group and Dias negative group.P<0.05 indicates that the difference is statistically significant.Results1.86 patients with suspected CAD who underwent ccta were selected.The mean age was(59.59±10.71)years old,BMI(24.80±3.22)kg/m~2,heart rate(70±8.59)bpm.among them,53(61.6%)were male,50(58.1%)were hypertension,30(34.9%)were dyslipidemia,19(22.1%),27(31.4%)were smokers,27(31.4%)were alcoholics and 2(2.4%)were family history.2.The sensitivity,specificity,positive predictive value and negative predictive value of CCTA for coronary stenosis diagnosis were 73.5%,92.3%,69.6%and 93.6%respectively.3.After screening,the mean CT value of left ventricular myocardium in Sys group was lower than that in Dias group(t=-3.478,P=0.001).4.Sys negetive group of 17 myocardial segments with CT values of 95%reference range,1 segment?54.68HU,2 segment?64.10HU,3 segment?55.24HU,4 segment?33.60 HU,5 segment?58.52HU,6 segment?67.02 HU,7 segment?61.20 HU,8segment?59.14 HU,9 segment?54.17 HU,10 segment?44.33HU,11 segment?59.22HU,12 segment?59.39HU,13 segment?57.00HU,14 segment?61.29 HU,15segment?40.62HU,16 segment?62.32HU,17 segment?36.74HU.And the CT value of segment 4,10,15 and 17 were significantly lower than that of other segment.5.Dias negetive group of 17 myocardial segments with CT values of 95%reference range,1 segment?54.20HU,2 segment?53.08HU,3 segment?63.76HU,4 segment?15.80 HU,5 segment?66.18HU,6 segment?69.76HU,7 segment?56.39HU,8 segment?63.00 HU,9 segment?61.59HU,10 segment?40.11HU,11 segment?62.74HU,12segment?60.46HU,13 segment?57.20HU,14 segment?56.85HU,15 segment?43.88HU,16 segment?62.33HU,17 segment?31.30HU.And the CT value of segment4,7,9 and 10 were significantly lower than that of other segment.6.The 95%reference value range of CT value of 17 segments of myocardium in Sys negetive group was not significantly different from Dias negetive group(t=0.351,P=0.730).7.Comparing sys group with Dias group,the average CT value of left ventricular wall in sys group was lower than that in Dias group(t=-8.686,P=0.000);There was no statistical difference between the sections 7,13 and 17(P>0.05)and showed statistical difference between the sections 2,3,5,6,9,11,14 and 16(P<0.05).8.Comparing sys group with Dias group in Dias positive group,the average CT value of left ventricular wall myocardium in sys group was lower than that in Dias group(t=10.986,P=0.000);There was no significant difference between the sections 2,3,5,9,11and 14(P>0.05),and showed significant difference between the sections 1,6,7,10,13,15and 16(P<0.05).Conclusions1.In resting state,when the coronary artery stenosis is more than 50%,the myocardial perfusion in the systolic and diastolic phase can be reduced.2.In resting sCTMPI,for patients with coronary artery stenosis<50%had different myocardial perfusion during systolic and diastolic phase.3.In resting sCTMPI,for patients with coronary artery stenosis more than 50%,the lower left ventricular wall and the apex were affected by BH artifacts,and the corresponding CT values were often lower in systolic and diastolic phase than in other myocardial segments. |
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