| Part1Double low dose combined low velocity of flow injection in the application of the dual-source CT coronary angiography in normal body mass index patients Objective:Discuss the Feasibility of lower tube voltage and low dose of iodine-concentration contrast material,Low velocity of flow injection in Dual-source CT prospective ECGtrig-ger high pitch to scan for coronary artery imaging for normal body mass index patients.Methods:Select 120 cases patients of body mass index of 18.6 to 24.9 kg/m ~2,and heart rate<65 times/min,A group of 60 cases with 120 kV tube voltage,contrast media dosage0.9ml/kg,injection rate of 5.0ml/s,with prospective ECG-trigger scanning;group B of 60cases with 80kV tube voltage,contrast media dosage 0.7 ml/kg,injection rate of 3.5ml/s prospective ECG-trigger large pitch scan,Adopt iodine contrast media(Iohexol 350mg?/ml).Measured values of CT enhanced images and noise of two groups,calculate the signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR).The method of double blind to evaluate coronary artery using a 4-point scale,(1=non-diagnositic,4=excelent).ResultsGroup A average every measurement level enhanced CT value slightly higher than that of group B,there was no statistically significant difference(P>0.05).The image noise of group A is slightly higher than group B.SNR,CNR of group A was higher than group B,there were no statistically significant difference(P>0.05).Group B effective radiation dose is significantly lower in group A(Group B 0.39 mSv±0.02mSv,Group A 4.99mSv±1.36mSv,P<0.01).ConclusionIn patients of BMI 18.6 to 24.9 k g/m ~2,heart rate<65 times/min,Dual-source CT application prospective ECG-trigger and high pitch,low voltage,low dose contrast media,low flow rate injected scanning,in the cases,to ensure the quality of coronary arte-ry image,and radiation significantly reduced by 91.8%.PART2 THE VALUE OF SINOGRAM AFFIRMED ITERATIVE RECONSTRUCTION(SAFIRE)IN THE APPLICATION OF THE DUAL SOURCE CT THREE LOW SCHEME CORONARY COMPUTED TOMOGRAPHY ANGIOGRAPHY(CCTA)Objective: Discuss the sinogram affirmed iterative reconstruction(SAFIRE)in the application of the dual-source CT three low scheme(low tube voltage,low dose contrast agent,low flow rate injection)coronary computed tomography angiography(CCTA).Methods: Select 120 cases patients of body mass index(BMI)of 18.6 to 24.9 kg/m 2,heart rate< 65 bpm and use the contrast agent iohexol 350 mg I/ml.It was divided into two groups randomly according to random number method: 60 patients were in 120 k V group,using 120 k V tube voltages,contrast media dosage 0.9ml/kg,and injection rate of 5.0 ml/s to carry out prospective ECG-trigger scanning.The image reconstruction was based on filtered back projection(FBP).60 patients were in 80 k V group,using 80 k V tube voltage,contrast media dosage 0.7 ml/kg,injection rate of 3.5 ml/s to carry out prospective ECG-trigger high-pitch scan.The image reconstruction was based on iterative reconstruction technique.Measure the values of CT enhanced images and noise of two groups of arterial lumen and left ventricular bottom muscle,calculate the signal-to-noise ratio(SNR)and contrast to noise ratio(CNR).The method of double blind was used to evaluate coronary artery in 4-point scale(1=non-diagnostic).Record the average volume CT dose index(CTDIvol)and the dose length product(DLP)for each patient and calculate the effective radiation dose.Results: The difference in the CT value,image noise,SNR,CNR between the two groups was not significant(P>0.05).The effective radiation dose(4.99 ± 1.36)m Sv in 80 k V group was significantly lower than that in 120 k V group(0.39 ± 0.02)m Sv and had statistically significant difference(P<0.01).Conclusions: In the patients of body mass index(BMI)18.6 to 24.9 kg/m2,HR< 65 bpm,the application of dual-source CT prospective ECG-trigger high pitch three-low scheme combined with the iterative reconstruction algorithm coronary angiography,can guarantee the quality of the image. |
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