ABSTRACT
Objective To discuss the value of volume helical shuttle(VHS) of high-definition CT(HDCT) in diagnosis and clinical path of tetralogy of Fallot(TOF).Methods 88 preschool children with TOF were examined with VHS of HDCT and echocardiography(ECHO).60 children were received surgery.Based on surgical data,the results of VHS of HDCT were compared with that of ECHO,assessing the display ability of basic deformity of TOF,the intra-cardiac lesion,extra-cardiac lesion and hemodynamics.The radiation dose(mSy) were calculated.Results The diagnostic accuracy of HDCT was 95.0％ and the ECHO was 90.0％ on the positional display.The results of HDCT were slightly smaller than ECHO on the measure of size of VSD,P ＜ 0.05,the difference was significant between the two methods.The display on right-to-left shunt of VSD using HDCT were all coincided with ECHO.One quarter of the cases showed the left-to-right shunt simultaneously.Whereas all the cases were showed slow bi-directional shunt by ECHO.There are 99 deformity in pulmonary artery stenosis,including right ventricular hypertrophy,outflow tract stenosis,pulmonary stenosis.The results of HDCT,ECHO and the operation showed no difference.All the McGoon ratio of HDCT were obviously higher than ECHO,P ＜0.01.Statistical difference was significant.The coincidence rates in aortic straddles by HDCT and ECHO both were 98.3％.Each has one case misdiagnosed.37 other intra-cardiac lesions,for example,foramen ovale and atrial septal defect.VAS has 25 misdiagnosed places and ECHO has 8.88 other extra-cardiac lesions,such as one side of pulmonary artery stenosis or atresia,collateral circulation between systemic and pulmonary circulation,coronary artery abnormal,patent ductus arteriosus(PDA) and so on.The diagnostic accuracy of HDCT was 98.8％ and the ECHO was 59.1％.Average effective dose with HDCT was(1.58 ± 0.43) mSv.Conclusion VHS of HDCT scan has obvious advantages in the diagnosis of TOF.Multiple data can reflect intra-cardiac lesion,extra-cardiac lesion accurately and intuitively.The radiation dose was in the acceptable range.Combining the HDCT VHS and the ECHO will become the clinical path of preoperative diagnosis,differential diagnosis and making the operation scheme in children with TOF.
ABSTRACT
Objective To assess the clinical value of volume helical shuttle (VHS) of highdefinition CT (HDCT) in the diagnosis of congenital heart disease (CHD).Methods Forty-three patients suffering from CHD were examined with VHS of HDCT and echocardiography (ECHO).Twenty-four patients (21 children,3 adults) received surgery.Based on surgical data,the diagnostic accuracy of CHD by VHS of HDCT was compared with that by ECHO with respect to the intra-cardiac lesion,extra-cardiac lesion and hemodynamics.The visibility of the origin and proximal course of coronary arteries was also evaluated on VHS.CT effective doses were calculated,using mSv =DLP × K. Results Thirty-six intra-cardiac deformities were found by operation,and the diagnostic accuracy of both VSH and ECHO were 100.0％ (36/36).VHS successfully detected 42 of 44 (95.4％) cardiac-vascular connection and large vascular deformities,whereas ECHO only detected 26 (59.1％ ).The right-to-left shunt and left-to-right shunt of septal defects revealed by VHS were 5 and 6 patients respectively,which all coincided with the results of ECHO.Fourteen bi-directional shunt of septal defects were detected by ECHO,and 13 of them were diagnosed as right-to-left shunt by HDCT except an illegibility in 1 patient.The origin and proximal course of coronary arteries were all visible on VHS.Effective dose for children was (3.38 ± 1.86) mSv,and for adults was ( 10.27 ± 2.59) mSv.Conclusions VHS of HDCT scan is advantageous in the diagnosis of CHD.It can depict the intra- and extra- cardiac structures as well as coronary arteries and provide hemodynamic information.