COMPUTED TOMOGRAPHY CARDIAC IMAGING IN PEDIATRIC PATIENTS
WITH CONGENITAL HEART DEFECTS
Khasanova K.A.1,2, Kovalenko D.G.1, Purkina S.Ya.1, Ternovoy S.K.2,3
1 - Morozov Children's City Clinical Hospital.
2 – Sechenov University.
3 - A.L. Myasnikov Institute of Clinical Cardiology. Moscow, Russia.
С |
ardiac CT in children with congenital heart defects (CHD) is quiet challenging because of small volume of contrast agent (HF) used, a limited flow of its administration and a high heart rate, which contributes to its rapid leaching from areas of interest. Currently, there is no standardized technique for performing ECG-gated cardiac-CT in newborns and children of young age group.
Purpose. To improve the scanning protocol of ECG-gated cardiac-CT in children with congenital heart defects for simultaneous assessment of the of intra- and extracardiaс structures.
Materials and methods. A total of 79 children with CHD aged from 1 day to 3 years were enrolled. Ultravist-350 was used as a contrast agent, in a volume of 2 ml/kg. A bolus tracker technique was used to determine the delay time of the scan start. Depending on the planning area and the values of the threshold value (trigger), 6 groups of patients were formed: the area of interest on the right ventricle (RV) ranges of trigger values: a) 80-100 HU, b) 120-150 HU, c)180-200 HU; the area of interest on the left atrium (LA) with an assessment of ranges trigger values: a) 60 HU b) 80-100 HU c)120-150 HU. The quality of the images obtained was assessed on a scale of points (from 1 to 3 points), depending on the achievement of the target density (350 HU) in the areas of interest.
Results. When planning the trigger on the RV, the maximum number of points was in the group with a threshold value – 120-150 HU, the lowest points were in the group with a density threshold – 80-100 HU. When planning the bolus tracker on LA, the maximum number of points was obtained in the group with a density threshold value of 80-100 HU, the lowest in the group with a density threshold value of 60 HU. A comparative analysis of image quality when planning a "bolus tracker" on the RV (trigger – 120-150 HU) and LA (trigger – 80-100 HU) showed statistically significant differences: the scanning protocol with the location of the "bolus tracker" on the LA with a threshold density of 80-100 HU was significantly more effective in terms of the quality of the obtained images of the heart and major vessels in children with CHD (p=0.0031).
Discussion. The success of CT of the heart in children is determined by the correctly selected scanning parameters, the correct use of contrast agents and the choice of a technique for determining the delay in the start of tomography. When using a bolus tracker, the quality of the images obtained is affected by the planning area and the threshold value of the automatic bolus tracking program. The recommended planning areas and the optimal values of the threshold value of the "bolus tracker" for
obtaining diagnostic images of the heart in children differ according to the literature. In our study, it was demonstrated that the use of the heart CT protocol in children when planning a "bolus tracker" for the left atrium with a threshold value of 80-100 HU allows obtaining images of good and excellent quality with simultaneous visualization of intra- and extracardiac structures.
Conclusion. When performing a cardiac CT in children with CHD, it is necessary to perform bolus-tracking with planning of the area of interest on the left atrium with a threshold value of 90-100 HU bolus. If it is impossible to determine the location of the left atrium on native image series, planning the area of interest is permissible for the cavity of the right ventricle with a threshold bolus value of 120-150 HU. The duration of contrast agent administration in children should be equivalent to the duration of the scan, taking into account the time of transient delay.
Keywords: cardiac CT, children, CHD, scanning protocol, bolus tracking, congenital heart defects, contrast agent.
Corresponding author: Khasanova K.A., e-mail: Этот e-mail адрес защищен от спам-ботов, для его просмотра у Вас должен быть включен Javascript
For citation: Khasanova K.A., Kovalenko D.G., Purkina S.Ya., Ternovoy S.K. Computed tomography cardiac imaging in pediatric patients with congenital heart defects. REJR 2024; 14(4):80-92. DOI: 10.21569/2222-7415-2024-14-4-80-92.
Received: 24.10.24 Accepted: 20.11.24