The Study Of Clinical Application By Dual-source CT In Heart

Part 1:The effect of different heart rate on image quality of Dual-source CT coronary angiography comparison with 64-detector row CTObjective:To compare the image quality and visibility of coronary arteries by dual-source CT and 64-detector row CT with different heart rate.Material and Methods:150 patients with suspected coronary artery disease underwent ECG-gating dual-source CT and 64-detector row CT coronary angiography,respectively.Data were retrospective reconstructed and reviewed by two observers.Image quality of mean heart rate and heart rate variability was evaluated by using a 4-point grading scale.Results:Over all image quality of low,moderate and high mean heart rate sub-group by DSCT were sufficient for diagnosis for 98.8%,98.6%and 97.5%of arterial segments,respectively.The mean score of three sub-group were 1.48±0.29, 1.54±0.25 and 1.60±0.33,respectively.The mean score of less than 5 beats per minute (bpm) sub- group by DSCT was 1.49±0.29.The mean score of more than 5 bpm sub-group by DSCT was 1.55±0.26.No significant correlation was found between mean heart rate and image quality in any segments or any patients.No significant correlation was found between heart rate variability and image quality in any segments.Over all image quality of low,moderate and high mean heart rate sub-group by 64-detector row CT were sufficient for diagnosis for 98.9%,97.0%and 90.5%of arterial segments,respectively.The mean score of three sub-group were 1.48±0.35,1.59±0.29 and 2.19±0.48,respectively.The mean score of less than 5 beats per minute(bpm) sub- group by DSCT was 1.49±0.33.The mean score of more than 5 bpm sub-group by DSCT was 2.11±0.50.No significant correlation was found between low and moderate mean heart rate sub group and image quality in any segments or any patients.Significant correlation was found between high mean heart rate and image quality in any segments.Significant correlation was found between heart rate variability and image quality in any segments.Conclusion:DSCT provides high diagnostic image quality withβ-blocker free compared to 64-detector row CT withβ-blocker medication. Part 2:Detection of myocardial perfusion abnormalities:standard dual-source coronary computed tomography angiography versus rest/Stress Technetium-99m single-photo emission computed tomographyObjective:To evaluate coronary dual source computed tomography angiography (corDSCTA) for detection of myocardial perfusion abnormalities compared with technetium-99m single-photo emission computed tomography(SPECT).Material and Methods:Fifty-five consecutive patients underwent both gated myocardial perfusion SPECT and corDSCTA.CorDSCTA was performed during a single arterial phase injection of contrast agent.Perfusion defects visualized by corDSCTA were correlated with findings of both rest and stress SPECT.Attenuation values of perfusion defects on DSCT were correlated with SPECT.The correlation of high grade stenotic(≥50%) coronary artery disease(CAD) with SPECT was evaluated. Results:24 patients showed abnormal findings on stress SPECT either due to ischemia or infarct.Compared to SPECT at rest,corDSCTA detected perfusion defects with a sensitivity and specificity of 100%and 78%,respectively.Compared to SPECT at stress,sensitivity and specificity values were 83.3%and 90.3%, respectively.Average attenuation values of perfusion defects on corDSCT which corresponded to chronic infarcts(-8.5±22.2HU) were significantly lower(p=0.002) compared to non-infarct related perfusion defects(43.1±17.5HU).With rest/stress SPECT serving as gold standard for the diagnosis of myocardial ischemia,corDSCTA diagnosed ischemic disease[based on the presence of high grade stenotic CAD(≥50%luminal narrowing)]with a sensitivity and specificity of 59%and 89%, respectively,in patients with no known history of myocardial infarction(n=44). Conclusion:CorDSCTA may serve as a diagnostic tool to detect perfusion abnormalities visualized by SPECT.There appears to be a limited correlation of coronary stenotic disease and SPECT findings. Part 3:Comparison study of measurement of left ventricular function by dual-source coronary computed tomographyObjective:To evaluate the accuracy of assessment of left ventricular function with dual source computed tomography compared with cardiac magnetic resonance imaging Material and Methods:21 patients with suspected coronary artery disease underwent dual-source CT and cardiac magnetic resonance imaging,respectively. ESV,EDV,SV and LVEF were determined for both modalities,and correlation coefficient were assessed.Results:In DSCT,ESV,EDV,SV and EF were 62.6±23.7ml,128.2±35.9m,60.7±19.4m,50.7±9.7%,respectively,compared with 67.6±20.4ml,124.5±32.3ml,55.1±19.6ml and 45.8±10.1%in MRI.EDV,ESV and EF were found significant correlations between DSCT and MR(P＜0.05).It was found non-significant correlation for SV(P＞0.05) EDV,SV in DSCT were overestimated at 5.5(-21～31.9)ml and 3.7(-37.8～45.2)ml,respectively,compared with MR.ESV in DSCT were underestimated at 5.1(-22.5～12.4) ml compared with MR.EF in DSCT was overestimated 4.6(-21～30.1)%compared with MR.Conclusion:DSCT offers the possibility to quantify the left ventricular function from coronary CT datasets with sufficient diagnostic accuracy compared with MRI.Part 4:Myocardial ischemia detection on the perfusion blood pool imaging by dual-energy computed tomography,initial experienceObjective:To evaluate the feasibility of myocardial ischemia detection by morphology and new application(Heart perfusion blood volume,Heart PBV) with a single dual-energy CT acquisition.Material and Methods:20 patients with low heart rate(＜70bpm) suspected coronary artery disease underwent dual-energy CT acquisition.10 patients also underwent gated myocardial perfusion SPECT,5 cases in CCA.The detection of myocardial ischemia by different modality(DECT,SPECT and corDSCTA were evaluated.Results:337 segments were showed by corDSCTA.18 segments showed significant stenosis(≥50%).Seventeen segments showed perfusion abnormalities on iodine map by DECT.DECT detected myocardial ischemia with 90.9%sensitivity,98.7%specificity,NPV 83.3%,PPV 99.4%,respectively,compared with SPECT in ten cases.Conclusion:DECT offers possibility and good correlation with SPECT in myocardial ischemia detection.And it was adding the value of the new modality in myocardial perfusion imaging assessment.