Normal radiographic heart volume in the neonate. 3. Comparison with the cardiothoracic ratio.

The diagnostic power of the heart volume and the cardiothoracic ratio in congenital heart disease in neonates has been compared. A consecutive series of 130 children with suspicion of heart disease examined radiologically at between 48 h and 15 days of age were followed for 14 +/- 10 months. Of these, 16 (12%) were diagnosed as having congenital heart disease. The number of false positive and negative diagnoses was less for heart volume than for cardiothoracic ratio using +2 SD as limit for pathology. Accuracy, sensitivity and specificity was 84, 75, and 85% respectively for heart volume and 73, 57, and 75% for cardiothoracic ratio. Cases that were false positive with both methods were significantly more often examined between 48 and 72 hours of age indicating that the explanation might be a somewhat late closure of the ductus arteriosus.