Uncorrected pink tetralogy of Fallot in an adult patient: incidental CT findings.

Tetralogy of Fallot (TOF), one of the most common congenital heart diseases, has four major components: right ventricular hypertrophy, overriding aorta, membranous ventricular septal defect, and right ventricular outflow tract obstruction. If not already present at birth, cyanosis develops in the first year of life. Survival of the patient depends on the degree of pulmonary obstruction and the pulmonary blood supply. Patients rarely survive after the fourth decade of life. Limitation of blood to the lungs combined with ventricular septal defect results in supply of oxygen-poor blood to the body, causing cyanosis (blue coloration) in the patient. If the pulmonary stenosis is mild and ventricular septal defect is in balance, however, the noncyanotic patient is referred as having "pink tetralogy of Fallot."