| Part ?:Feasibility Study of Wide Detector Low Dose CT in Infant with Congenital Heart DiseaseObjectiveTo investigate the diagnostic ability,image quality and radiation dosage of the wide detector low dose CT scanner in infant with congenital heart disease.Materials and MethodsTotally 100 consecutive children with congenital heart disease were enrolled in the study,all of them were younger than 3 years old.According to different scanning schemes,they were divided into two groups.In the low-dose CT group,50 patients,31 males and 19 females,aged 12 days to 32 months,were scanned by wide detector low dose CT.In the control group,50 cases,26 males and 24 females,aged 19 days to 27 months,were scanned by multi-slice CT with volume spiral shuttle technique.The detection rate of cardiovascular malformations was calculated and compared with the results of operation.CT value and image noise of ascending aorta,main pulmonary artery,left ventricle,diaphragm horizontal descending aorta and chest wall muscle tissue were measured,and signal-to-noise ratio?SNR?and contrast-to-noise ratio?CNR?were calculated.The objective image quality of intracardiac structure,extracardiac structure and coronary artery was evaluated by double blind method.The volume CT dose index(CTDIvol)and dose-length product?DLP?were recorded and the effective dose?ED?was calculated.The diagnostic detection rate,image quality and radiation dose were compared between the two groups.Results142 and 131 cardiovascular malformations were found in low-dose CT group and control group with wide-body detector.The diagnostic detection rates of the two groups were 95.07%and 94.66%,respectively.There was no significant difference??2=0.877,P=1.000?.The image quality scores of intracardiac structure,extracardiac structure and coronary artery in low dose group were 3.71±0.82,4.69±0.51 and3.28±0.90,respectively.The image quality scores of intracardiac structure,extracardiac structure and coronary artery in control group were 3.52±0.65,4.60±0.61 and 2.30±0.82,respectively.There was no significant difference in subjective image quality scores of intracardiac structure and extracardiac structure between the two groups?P>0.05?.There was significant difference of coronary artery image quality scores between the two groups?P=0.000?,and which in the low dose group was significantly higher than in the control group.Objective evaluation of image quality is as followed.There were no significant difference?P>0.05?of CT value of ascending aorta?565.15±184.55 vs.526.00±184.10?,image noise?28.07±9.64 vs.24.95±5.89?,SNR?21.43±7.96 vs.21.82±8.32?and CNR?19.06±7.72 vs.19.58±8.22?in low dose group and control group.There were no significant difference?P>0.05?of CT value of main pulmonary artery(575.95±259.78 vs.537.06±198.40,image noise?25.62±10.87 vs.26.66±8.25?,SNR?23.66±8.66 vs.22.25±11.42?and CNR?20.94±8.19 vs.20.03±11.02?.There were no significant difference?P>0.05?of CT value of left ventricular?554.96±213.85 vs.520.57±173.34?,image noise?30.14±12.34 vs.26.71±8.18?,SNR?19.92±7.99 vs.21.13±9.40?and CNR?17.58±7.44 vs.18.92±8.86?.There were no significant difference?P>0.05?of CT value of descending aorta at diaphragm level?539.40±175.28 vs.524.90±189.52?,image noise?25.96±10.99 vs.23.29±8.54?,SNR?23.83±11.50 vs.26.47±15.98?and CNR?20.96±10.30 vs.23.74±15.11?.Compared with the control group,CTDIvol?t=-14.856,P=0.000?,DLP?t=-12.595,P=0.000?and effective dose ED?t=-11.642,P=0.000?were significantly different in the low-dose CT group with wide body detector.The wide detector low dose CT scan with decreased the radiation dose by 76%compared with multi-slice CT volume spiral shuttle scan.ConclusionsWide detector low dose CT with ECG-gated triggered on cardiac end-systolic phase for congenital heart disease in infants can obtain satisfactory image quality and ideal diagnostic efficiency,especially for the diagnosis of combined coronary artery anomalies with unique advantages,and can significantly reduce the effective radiation dose.Part ?: Application of Wide Detector Low Dose CT in the Diagnosis of Complex Congenital Heart Disease in ChildrenObjective To evaluate the clinical value of wide detector low dose CT in the diagnosis of complex congenital heart disease by comparing the results with those of transthoracic echocardiography?TTE?and surgery.Materials and Methods108 children with congenital heart disease were enrolled in the study.There were60 males and 48 females with an average age of 31.4±35.1 months?median 19.5months,ranging from 12 days to 15 years?,average weight of 11.8±7.9 kg?median9.7 kg,ranging from 2.5 to 56 kg?,average height of 84.6±23.6 cm?median 80.0 cm,ranging from 47.0 to 156.0 cm?,average heart rate of 115.9 ± 21.3 beats/min?median 115.5 beats/min,ranging from 59 to 171 beats/min?.The sensitivity,specificity,correct index,positive predictive value,negative predictive value,accuracy and detection rate of the two methods for the diagnosis of complex congenital heart disease were evaluated and compared.CTDIvol and DLP of each child were recorded and effective radiation dose E was calculated.The effective radiation doses of different age groups were compared.Results1.A total of 291 abnormal cardiac structures were found in 108 children with complex congenital heart disease.There were 251 correct diagnoses and 41 incorrect diagnoses by wide detector low dose CT.There were 273 correct TTE diagnoses and19 incorrect TTE diagnoses.The sensitivity,specificity,correct index,positive predictive value,negative predictive value,accuracy and detection rate of low dose CT with wide body detector were 86.25%,99.95%,0.862,99.60%,98.12%,98.27%and 86.25% respectively,and which of TTE were 93.81%,99.95%,0.938,99.64%,99.14%,99.20% and 93.81%,respectively.The accuracy rate of the two methods was significantly different?P=0.000?,and the accuracy rate of TTE was significantly higher than that of low dose CT with wide body detector.The detection rate of TTE was significantly higher than that of low dose CT with wide body detector?P=0.000?.2.Surgical results revealed 58 abnormal cardiac and great vascular connections.All 58 malformations were correctly diagnosed by low-dose CT with wide-body detector,and one was incorrectly diagnosed.There were 55 correct diagnoses and 9incorrect diagnoses in TTE.The sensitivity,specificity,correct index,positive predictive value,negative predictive value,accuracy and detection rate of low-dose CT with wide body detector were 100.0%,99.79%,0.998,98.31%,100.0%,99.81%and 100.0% respectively,and which of TTE were 94.83%,98.76%,0.936,90.16%,99.37%,98.33% and 94.83%,respectively.There were no significant difference in diagnostic accuracy and detection rate between low-dose CT with wide-body detector and TTE for abnormal cardiac and great vascular connections?P=0.625?.3.Surgical results revealed 175 abnormal extracardiac structures.Low-dose CT with wide-body detector was correct in 174 malformations and incorrect in 2malformations.There were 139 correct TTE diagnoses and 53 incorrect TTE diagnoses.The sensitivity,specificity,correct index,positive predictive value,negative predictive value,accuracy and detection rate of low dose CT with wide body detector were 99.43%,99.95%,0.994,99.43%,99.95%,99.90% and 99.43%,respectively,and which of TTE were 79.43%,99.09%,0.785,89.10%,98.10%,97.42% and 79.43%,respectively.The accuracy rates of the two methods were significantly different?P=0.000?,and the accuracy rate of CT with wide body detector was significantly higher than that of TTE.The detection rates of the two methods were significantly different?P=0.000?,and the detection rate of CT with wide body detector was significantly higher than that of TTE.4.The sensitivity,specificity,correct index,positive predictive value,negative predictive value,accuracy and detection rate for all cardiac malformations of low-dose CT with wide body detector were 92.18%,99.93%,0.921,99.38%,99.09%,99.11% and 92.18% respectively,and which of TTE was 89.12%,99.46%,0.886,95.11%,98.73%,98.37% and 89.12%,respectively.There were no significant difference in the accuracy and detection rate between the two methods in the diagnosis of all cardiac structural abnormalities?P=0.114?.5.The overall average CTDIvol,DLP and ED of 108 children were 1.39±0.38 m Gy,20.62±6.79 m Gy·cm and 0.57±0.15 m Sv,respectively.There were significant differences within the three age groups?All P values =0.000?.CTDIvol and DLP had significant differences among the three age groups?P<0.05?,and increased significantly with age?Table 2-11,2-12?.The EDs of three grpups were 0.64±0.17 m Sv,0.53±0.12 m Sv and 0.49±0.08 m Sv,respectively.There was no significant difference between the groups of > 1,?5 years old and > 5 years old?P=0.273?,but there was significant difference between the groups of ?1 years old and > 1,?5years old,?1 years old and > 5 years old?P=0.001,0.000?.The general trend was that the ED decreased with the increase of age,the lower the age,the higher the ED,the dose of children under 1 year old was significantly higher than that of children over 1 year old.Conclusion There is no significant difference between wide detector low dose CT and TTE in the overall diagnostic efficiency of congenital heart disease in children;TTE has more relative advantages in the diagnosis of intracardiac structural abnormalities,while low-dose CT with wide-body detector has more advantages in the diagnosis of extracardiac structural abnormalities.The combination of the two may complement each other and improve the diagnostic efficiency.In this group of children,the ED is relatively high in the age group less than 1 year old.Part ?: Quantitative evaluation of cyanotic complex congenital heart disease in children by low-dose CT with wide-body detectorObjective To compare the measurement of large vessel diameter,ventricular septal defect size and Mc Goon ratio in wide detector low dose CT with TTE in cyanotic complex congenital heart disease,and to evaluate the clinical value of wide detector low dose CT.Materials and Methods48 children with cyanosis congenital heart disease were enrolled in this study.There were 23 males and 25 females,with an average age of 28.2 ± 33.9 months?median 17.50 months,range 12 days to 15 years?,average weight of 11.1 ± 6.4kg?median 10.0 kg,range 2.8-41 kg?,average height of 82.2 ±20.7 cm?median78.0 cm,range 47.0-156.0 cm?,average heart rate 116.3 ± 20.5 beats/min?median115.0 beats/min,range 80-171 beats/min?.To compare the difference of measurement value of main pulmonary artery,left pulmonary artery,right pulmonary artery,descending aorta,ventricular septal defect and Mc Goon ratio between wide detector low dose CT and TTE.The age,weight and heart rate of 41 children under three years old were further studied.The standard age of each group was less than 12 months and more than 12 months,the heart rate was less than 120 beats per minute and more than120 beats per minute,and the body weight was less than 10 kg and more than 10 kg.The effects of age,heart rate and weight on the diameter of large vessels,ventricular septal defect and Mc Goon ratio were analyzed.Results1.The diameters of main pulmonary artery,left pulmonary artery,right pulmonary artery and descending aorta measured by low-dose CT with wide body detector were 9.6 ± 3.8 mm,8.7 ± 3.4 mm,7.8 ± 3.1 mm and 9.2 ± 2.3 mm,respectively.The measured values of the main pulmonary artery,left pulmonary artery,right pulmonary artery and descending aorta by TTE were 8.3±3.2 mm,6.2±2.7 mm,6.2 ± 2.4 mm and 7.7 ± 1.8 mm,respectively.There were significant differences in the measured values of main pulmonary artery,left pulmonary artery,right pulmonary artery and descending aorta between the two methods?t = 4.324,P =0.000;t = 7.663,P = 0.000;t = 4.290,P = 0.000;t = 8.026,P = 0.000?.The diameter of aorta and pulmonary artery measured by wide detector low dose CT was significantly higher than that measured by TTE.The Mc Goon ratio of wide detector low dose CT was significantly higher than that of TTE?1.8 ± 0.5 vs.1.6 ± 0.4,t=2.721,P=0.009?,and the Mc Goon ratio of wide detector low dose CT was significantly higher than that of TTE.The size of VSD was also significantly different between wide detector low dose CT and TTE?11.5 ±3.5mm vs.13.0±3.5mm,Z=-3.519,P=0.000?.The size of VSD measured by l wide detector low dose CT was significantly smaller than that measured by TTE.2.The measurement values of aortic pulmonary artery diameter and ventricular septal defect size were related to age.There was no significant difference between the two methods in children under 1 year old.The results of Mc Goon ratio were related to body weight.The bigger the body weight,the better the consistency of Mc Goon ratio between the two methods.Which of low-dose CT measurements of wide-body detectors were significantly higher than that of TTE.The Mc Goon ratio and the size of VSD were related to heart rate.The faster the heart rate,the better the consistency of the two methods.Conclusion The measured values of pulmonary artery and Mc Goon ratio obtained by l wide detector low dose CT are higher than those obtained by TTE,while VSD measured by wide detector low dose CT is lower than that obtained by TTE.Age,weight and heart rate have certain influence on the difference between the two methods.It should be given when using wide detector low dose CT and TTE to quantitatively evaluate cyanosis congenital heart disease in children.Be careful.Part ?: Value of wide detector low dose CT in Evaluation of Coronary Artery Anomaly in Complex Congenital Heart DiseaseObjective To evaluate the interpretability,image quality and radiation dose of wide detector low dose CT in different segments of coronary artery in children with congenital heart disease?CHD?,and to evaluate its value in diagnosis of coronary artery anomaly of CHD.Materials and Methods134 children with congenital heart disease who underwent low-dose CT examination with wide body detector were enrolled in the study.Among them,73 were males and 61 females,with an average age of 30.27±36.67 months?median17.00 months,range 12 days to 15 years?,average weight of 11.40±7.72 kg?median9.15 kg,range 2.48-53 kg?,average height of 83.73±24.25 cm?median 76.50 cm,range 47.00-163.00 cm?,average heart rate of 115.87±21.30 beats / min?median115.00 beats / min,range 59-171 beats / min?.To analyze the incidence of coronary artery anomalies in wide detector low dose CT images.The coronary artery was divided into 11 segments,and the interpretability and image quality scores of each segment were compared.All cases were divided into four groups according to their ages: group 1: age ?1 year old,60 cases;group 2: 1 year < age ?5 years old,48cases;group 3,5 years < age ? 10 years old,19 cases;age > 10 years old,7 cases.Coronary artery score,objective image quality and radiation dose were compared among different age groups.Results1.A total of 16 cases of coronary artery anomalies were found in 134 patients,with an incidence of 11.9%,including 2 cases of left single coronary artery,3 cases of right single coronary artery,1 case of anterior descending branch originating from right coronary artery,1 case of circumflex branch originating from right coronary artery,3 cases of right coronary artery originating from left sinus of autonomic artery,1 case of high opening of right coronary artery,1 case of anterior descending branch-right ventricular fistula and 1 case of right coronary artery-right ventricular fistula.There were 1 case of circumflex branch-right atrial fistula,1 case of left coronary artery originating from pulmonary artery,1 case of coronary artery stenosis and occlusion.2.The scores of 1180 segments are more than 2 in 134 patients,with a total interpretability rate of 80.8%?1180/1460?.The order of interpretability from high to low is LO,LM,LAD1,RO,LAD2,RCA1,LCX1,RCA3,LAD3,RCA2 and LCX2.The highest interpretability rate was LO,98.5%;in addition,LM,LAD1,RO and LAD2 were ranked above 90.0%;LCX2?41.8%?and RCA2?62.1%?were ranked as the lowest.The interpretability from the proximal segment to the distal segment decreased by 96.9%?253/261?,88.5%?470/531?,76.3%?203/266?and 63.5%?254/400?,respectively.3.The scores of 11 segments of coronary artery from high to low were LO,LM,RO,LAD1,RCA1,LAD2,RCA3,LCX1,LAD3,RCA2 and LCX2.There were significant differences in the scores of each segment among different groups??2 =359.105,P=0.000?.The further results showed that there was no significant difference in LO,LM and RO scores?P > 0.05?.LAD1 score was significantly lower than LO?P = 0.027?and LM?P = 0.029?,but there was no significant difference with RO?P >0.05?.There were no significant difference between LAD2 and LCX1,RCA1 and RCA3?P > 0.05?.There was no significant difference between LAD3 and LCX1,LAD3 and RCA2?P > 0.05?.There was no significant difference between LCX1 and LAD2,LAD3 and RCA3?P>0.05?.There were no significant difference between RCA1,LAD2 and RCA3?P>0.05?.There were no significant difference between RCA2 and LAD3?P > 0.05?.There were no significant difference between RCA3 and LAD2,LCX1 and RCA1?P>0.05?.LCX2 was significantly different from all the other 10 segments?P=0.000?.There were significant differences among the remaining segments?P<0.05?.4.The results of comparing the scores of LO,LM,LCX1 and RCA2 in different age groups showed significant differences??2= 12.648,14.390,10.650,10.134;P =0.005,0.002,0.014,0.017?.There was no significant difference in RO,LAD1,LAD2,LAD3,LCX2,RCA1 and RCA3 scores among age groups?P > 0.05?.5.The CT value,image noise,SNR and CNR of low-dose CT images of wide-body detectors in different age groups are shown no significant difference?F=0.800,0.475,0.600,0.753;P=0.496,0.700,0.616,0.523?,and the image quality is independent of age.6.CTDIvol and DLP increased significantly with age.There were significant differences in effective radiation dose between four groups?F=5.160,P=0.002?.There were significant differences in radiation dose between group 1 and group 2,group 1 and group 3,P values were 0.002 and 0.001,respectively.There were no significant differences in other groups?P > 0.05?.The younger the age is,the greater the radiation dose is.The radiation dose of infants under one year old is the largest.The radiation dose of children over 10 years old is increased.The lowest radiation dose is in the age group of 5-10 years old.Conclusion Wide detector low dose CT has unique advantages in the diagnosis of coronary artery anomalies in children with congenital heart disease,which can be completed simultaneously with the assessment of cardiac and great vascular structure.There was no significant difference in the objective index of image quality among different age groups.The interpretability rate of 11 segments of coronary artery was 80.8%.The interpretability and score of coronary artery were higher in the main opening and proximal segments,and decreased with the decrease of diameter.The scores of left coronary artery orifice?LO?,left main artery?LM?,proximal circumflex branch?LCX1?and middle right coronary artery?RCA2?were significantly different among age groups,and increased with age.The ED of infants under 1 year old was the highest?0.63 +0.17 m Sv?. |
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