Congenital Heart Disease and Radiology

1. Congenital Heart Disease and Radiology Ankit L. Pansara Chicago Medical School

2. What is the role of the radiologist in assessing suspected CHD? • The INITIAL role of the radiologist is to evaluate the chest radiograph and to provide an ordered, logical differential diagnosis. *It is usually not possible to give a precise diagnosis in these cases (using plain film). • MR may be used to assess cardiac chamber size and position, wall thickness, the presence of intracardiac shunts, and the position of the coronary arteries.

3. What are the most common acyanotic CHDs? • The first consideration in diagnosing CHD should be whether the infant is clincally cyanotic. • Acyanosis implies a left-to-right shunt, and the most common causes include ASD, VSD, PDA, and endocardial cushion defects. • These typically cause enlargement of specific chambers.

4. CXR evaluation of cardiac chamber size • RA: right heart border on frontal view • RV: anterior heart border on lateral view • LA: posterior-superior heart border on lateral view • LV: left inferior heart border on frontal view

5. VSD Diagnosis on CXR • Isolated small VSD: normal heart size and vascularity • Moderate defects with normal PA pressures but high flow: increased vascular markings and varying degrees of cardiomegaly • Large defects with significant L-to-R shunting: increased pulmonary vascular markings, cardiomegaly, prominent PA segments, splaying of the R and L bronchi, and LA enlargement • Large defects with pulmonary vascular dx: RVH with upturned apex and prominent proximal PA segments in the absence of increased vascular markings in the periphery. Heart size often appears to be normal.

6. VSD results in enlarged RV, PA, and LA

7. VSD

8. ASD Diagnosis on CXR • Mild to moderate cardiomegaly with a large RA, RV, and PA segment • Pulmonary vascular markings are increased • Enlargement of the RV is often only manifested on a lateral view. • Many patients will have a normal CXR

9. ASD results in enlarged RA and RV(this has been closed with a transvenous “cardioseal” device

10. PDA Diagnosis on CXR • The findings vary in proportion to the degree of the L-to-R shunting • With a larger shunt, there is cardiomegaly with enlargement of the LV, LA, and prominent pulmonary vasculature

11. PDA results in enlargement of PA, LA, and LV

12. How does assessment of pulmonary blood flow aid in the diagnosis of cyanotic CHD? • Cyanosis implies either admixture of oxygenated and deoxygenated blood, which would appear as increased blood flow to the heart, or that blood is shunted away from the lungs, which would appear as decreased blood flow. * Assessment of blood flow includes looking for shunt vessels at the periphery of the lung fields of behind the liver shadow.

13. Eisenmenger Complex • Defintion – the combination of VSD with pulmonary HTN and consequent R-to-L shunt through the defect, with or without an associated overriding aorta • CXR • RV enlargement on lateral projection • Enlarged central pulmonary arteries • Normal to decreased pulmonary vascular markings peripherally

14. Eisenmenger Complex

15. Which CHDs appear with cyanosis and increased pulmonary blood flow? • These include total anomalous pulmonary venous return, truncus arteriosus, transposition of the great vessels, tricuspid atresia, and single ventricle. Hypoplastic left heart syndrome may appear with CHF and cyanosis.

16. Major Causes of CHF in newborn • Constitutional problems such as anemia, hypoglycemia, sepsis • Primary pump problems such as hypoplastic left heart • Outflow obstructions such as aortic stenosis or coarctation of the aorta • Inflow problems such as cor triatriatum or mitral valve stenosis • Extracardiac shunts such as vein of Galen malformation or a hemangioendothelioma Cor triatriatum – a heart with 3 atrial chambers, the LA being subdivided by a transverse septum with a single small opening which seperates the openings of the pulmonary veins from the mitral valve

17. Coarctation of the Aorta

18. Pulmonary Atresia and Stenosis

19. Aberrant R Subclavian

20. TOF Diagnosis on CXR • Cyanotic TOF: boot-shaped heart caused by an enlarged RV with absence of a radiographic main PA segment • Decreased pulmonary vascular markings (PVM) • Acyanotic TOF and TOF/pulmonary atresia with major aorta pulmonary collateral arteries (MAPCA), normal to increased PVMs • Absent PV, mildly enlarged cardiac silhouette, dilated PAs, hyperinflated lungs

21. TOFImage #1 shows typical cardiac shape and decreased pulmonary vascularity. Image #2 made after BT shunt surgery shows clips on subclavian artery. Image #3 shows edema in right lung due to overperfusion following shunt surgery.

22. Glycogen Storage Dis (Pompe)Due to deficiency of acid alpha glucosidase, it is a fatal disease of many organs including the heart. Newborns infants may be well but soon develop muscle atonia, cannot feed and their hearts become enormous. Glycogen accumulates in all organs.

23. Kartagener’s Syndrome

24. Marfan SyndromeDilatation of the aortic root may require grafting. The pectus excavatum is probably asymptomatic. The incidental neural crest tumor is probably asymptomatic as well.

25. Ebstein AnomalyCongenital downward displacement of the tricuspid valve into the right ventricle

26. References Alpert MD, Joseph S., Editor. The AHA Clinical Cardiac Consult. Lippincott William & Wilkins. 2001 Pretorius MD, E. Scott and Solomon MD MBA, Jeffrey A. Radiology Secrets. 2nd Ed. Elsevier Inc. 2006. Stedman’s Medical Dictionary. 27th Ed. Lippincott Williams & Wilkins. 2005.