ABSTRACT
Objective To evaluate the application of dual-source CT (DSCT) using low-dose technology in diagnosing complex congenital heart diseases. Methods The DSCT data of 31 cases with complex congenital heart diseas-es conifrmed by operation were retrospectively analysed and classiifed into four groups:group A(≤4 months old, n=12); group B (>4 months old~1 year old, n=3);group C (>1 year~6 years old, n=8) and group D (>6 years old, n=8). Results The diagnosis conformation rate of DSCT with surgery were 94.59%. The diagnostic conformation rate of intracardic anormalies using DSCT was 92.86%. And the diagnostic conformation of DSCT in patients with abnormal connection of atrium or ventri-cle to great vessels and the extrocardic anormalies was 95.65%. The average effective dose in each group were 1.16±0.06 mSv, 1.28±0.07 mSv, 1.96±0.54 mSv and 2.77±0.38 mSv, respectively. The ratio of the high quality images was 90.32%. Con-clusions The application of low dose technology in DSCT can clearly display the anomalies, and signiifcantly reduce the radiation dose without losing image quality as well.
ABSTRACT
Objective To investigate the development of the cervical cord in children by using diffusion tensor imaging.Methods Ninety healthy children were undergone with diffusion tensor imaging of the cervical cord by using single-shot spin-echo echo planar image sequence.The values of apparent diffusion coefficients (ADC), fractional anisotropy (FA), average length(Ltract) and volume of tracts(Vtract) were measured in the cervical regions.Results The measurements of each group were as follow:ADC value:0.9747 ±0.2777,0.8493 ±0.2236,0.8210 ±0.1432,0.9198 ± 0.1444,0.9048 ±0.1676;FA value:0.4117 ±0.0391,0.4712 ±0.0199,0.4944 ±0.0439,0.5608 ±0.0443,0.6169 ± 0.0551;Ltract:25.61 ±8.63,24.66 ±7.14,27.03 ±7.23,34.93 ±10.99,37.63 ±10.22;Vtract:3.07 ±1.49,3.00 ± 1.52,3.81 ±1.33,5.41 ±2.35,6.64 ±2.84.FA value, Ltract and Vtract showed significance in different age groups , while ADC value was found no difference ( P<0.001) .Post-Hoc test revealed that FA value was significantly different between age group I and Ⅱ.FA value, Ltractand Vtract presented significantly different between group ⅢandⅣ.FA value difference was also found between group Ⅳand V.FA value, Ltract and Vtract were all positively corelative with age (F=1.758, P=0.145 ) .Conclusion Development of the cervical cord shows periodicity with periodic features .Diffusion Tensor Imaging can be used as a tool to observe and evaluate development of the cervical cord in children .