Heart and Great Vessels: Congenital Heart Disease
CHD has an incidence of approximately 8 per 1000 live births; the 10 most common entities account for 80% of all cases ( Table 1.74 ).
Historically, the conventional chest radiograph has played a significant role in the work-up of children with CHD. There have been numerous descriptions that were so-called diagnostic for CHD; one could think of the “egg on string” sign in case of transposition of the great vessels. However, as the presentation of CHD on the chest radiograph depends on a multitude of factors, these signs are not diagnostic (for completeness, we will present them in the tables of this chapter).
A study in 128 children with suspected CHD showed that conventional chest radiograph has a sensitivity of 26%–59% for structural heart disease and an equally poor positive predictive value of 46%–52%. It is important to note that there is no evidence that conventional radiographs can serve as a screening test for CHD.
Currently, the most widely adopted diagnostic strategy is primary imaging with cardiac US. Based on the US findings, either CT, if anatomy needs to be depicted, or MRI, if functional imaging or depiction of intracardiac anatomy is needed, will be performed. Diagnostic angiography is now rarely performed and only in those cases where CT and/or MRI are not diagnostic or if pressure measurements are necessary.
It is also important to note that cardiac imaging is a “team sport” in which a close collaboration between the cardiologists and radiologists is essential.
Transposition of great vessels
Tetralogy of Fallot
Hypoplastic left heart syndrome
CHD with left-to-right shunt
Ventricular septal defect
Patent ductus arteriosus
Atrial septal defect
Arterioventricular septal defect
Cardiac Positional Anomalies
On chest radiographs, the position of the heart can be defined as dextrocardia, mesocardia, and levocardia. However, as the position of the heart is defined by the position of the atria, where the right atrium lies on the right side and the left atrium on the left side, plain radiographs cannot rule out positional anomalies in all cases. For this, cardiac US is the diagnostic modality of choice.
The tracheobronchial tree morphology is, in general, in keeping with the position of the atria and thus can serve as a guide in deciding the cardiac situs on chest radiographs.