Radiation dose in cardiac CT for preoperative diagnosis of children with congenital heart disease

One of the most common congenital conditions detected globally, congenital heart diseases, and CT techniques provide a high-quality and thorough presentation of heart anatomy, thoracic vasculature, and extracardiac structures, and hence, it is becoming a more popular non-invasive diagnostic imaging method for congenital heart disease. The drawbacks with CT imaging are the radiation exposure from repeated scans is also rising, especially in young patients. The present study is aimed to evaluate the radiation dose in gated and non-gated cardiac CT for preoperative diagnosis of pediatric patients with congenital heart diseases.

A total of 111 pediatric patients with mean age of 7.47 years were prospectively included in the study. The mean value of “Effective dose (E)” for gated CT at \(100\;{\text{kV}}_{{\text{p}}}\) $100{\text{kV}}_{\text{p}}$ was found to be \(4.71\;{\text{mSv}}\) $4.71\text{mSv}$ which is higher than mean “E” of \(3.95\;{\text{mSv}}\) $3.95\text{mSv}$ observed for gated CT at \(80\;{\text{kV}}_{{\text{p}}}\) $80{\text{kV}}_{\text{p}}$ . The average value of “E” for non-gated technique was observed less than that of gated technique at both \(100\;{\text{kV}}_{{\text{p}}}\) $100{\text{kV}}_{\text{p}}$ and \(80\;{\text{kV}}_{{\text{p}}}\) $80{\text{kV}}_{\text{p}}$ . The multiple regression analysis shows that “E” is significantly dependent on \({\text{DLP}}\left( {{\text{mGy}}\;{\text{cm}}} \right)\) $\text{DLP}\left(\text{mGy}\text{cm}\right)$ for both gated and non-gated techniques at 95% level of significance \(\left( {p < 0.05} \right)\) $\left(p<0.05\right)$ . The Student’s t-test verifies that the mean value of “E” for both the techniques at \(100\;{\text{kV}}_{{\text{p}}}\) $100{\text{kV}}_{\text{p}}$ and \(80\;{\text{kV}}_{{\text{p}}}\) $80{\text{kV}}_{\text{p}}$ are significantly different at 95% level of significance \(\left( {p < 0.05} \right)\) $\left(p<0.05\right)$ .

The effective dose received by pediatric patients is much higher when using ECG-gated acquisition with an average value of \(4.71\;{\text{mSv}}\) $4.71\text{mSv}$ and \(3.95\;{\text{mSv}}\) $3.95\text{mSv}$ at \(100\;{\text{kV}}_{{\text{p}}}\) $100{\text{kV}}_{\text{p}}$ , and at \(80\;{\text{kV}}_{{\text{p}}}\) $80{\text{kV}}_{\text{p}}$ respectively. Because low-voltage X-rays are more sensitive to high atomic number iodinated contrast media, the mean “E” for non-gated cardiac CT imaging at \(80\;{\text{kV}}_{{\text{p}}}\) $80{\text{kV}}_{\text{p}}$   is \(2.26\;{\text{mSv}}\) $2.26\text{mSv}$ , and results in significant reduction of effective dose.