Technical principles of computed tomography in patients with congenital heart disease

Abstract

Cardiac magnetic resonance imaging and echocardiography are often the primary imaging techniques for many patients with congenital heart disease (CHD). However, with modern generations of CT systems and recent advances in temporal and spatial resolution, cardiac CT has been gaining an increasing reputation in the field of cardiac imaging and in the evaluation of patients with congenital heart disease. The CT imaging protocol depends on the suspected cardiac defect, the type of previous surgical repair, and the patient's age and level of cooperation. Various strategies are available for reducing radiation exposure, which is of utmost importance particularly in paediatric patients. A sequential segmental analysis is a commonly used approach to analysing congenital heart defects. Familiarity of the performing radiologist with dedicated CT protocols, the complex anatomy, morphology and terminology of CHD, as well as with the surgical procedures used to correct congenital abnormalities is a prerequisite for correct diagnosis.

Fig. 1

Non-ECG-synchronised CT in a 24-year-old man demonstrating a large atrial septal defect (arrow)

Fig. 2

Retrospective ECG-gated CT in a 14-year-old girl in a transverse (a) and short-axis reconstruction (b) performed for follow-up evaluation after surgical correction of a tetralogy of Fallot. The patch completely closes the ventricular septal defect (arrow). Note the overriding position of the aorta and the right ventricular hypertrophy

Fig. 3a–c

Prospective ECG-gated CT in a 20-year-old man. Transverse sections at the level of the pulmonary trunk (a), the origin of the coronary arteries (arrows in b) and the ventricles (c) demonstrate levo-transposition of the great arteries. The aorta (Ao) and the pulmonary trunk (PT) are transposed with the aorta anterior and to the left of the pulmonary artery. Note the superior cava vein draining into the left-sided atrium (arrow) and the pulmonary veins draining into the right-sided atrium (arrowheads)