A Taussig-Bing anomaly in a neonate

CT images acquired on a dual source CT, SOMATOM Force, showed a dextro-transposition of the great arteries (d–TGA), with the ascending aorta (AA) coming out of the right ventricle (RV), the pulmonary trunk (PT) arising primarily from the RV and partially overriding a high VSD, these all presenting a typical Taussig-Bing anomaly. A cardiomegaly with a right ventricular hypertrophy and an atrial septal defect (ASD) were also visualized. The origins and the courses of the coronary arteries were typical. Bilateral posterior hyperattenuation in the lungs were seen, suggesting pulmonary hypertension edema, and resulting in a limited volume of the inflated lungs. The bronchial tree appeared normal.

Fig. 2: An oblique MPR image (Fig. 2a) and a corresponding cVRT image (Fig. 2b) show a d–TGA with the AA coming out of the RV and the PT overriding a high VSD (asterisk), presenting a typical Taussig-Bing anomaly.

Fig. 4: cVRT images show a usual type of coronary arteries (arrows).

A Taussig-Bing anomaly is a rare congenital heart malformation, consisting of transposition of the aorta to the RV and malposition of the PT with subpulmonary VSD. [1] A thorough understanding of the malformed anatomical details of the heart is a pre-requisite for an appropriate planning of a successful surgical repair. CT imaging has been used in clinical practice for assessing cardiac anatomy, the great vessels and the coronary arteries. However, for neonates, it is still challenging due to motion artifacts caused by very high heart rate and voluntary movement. The radiation dose and the amount of contrast agent applied to a neonate also of great concern.

The dual source CT used for this examination, SOMATOM Force, provides a high speed scan mode, Turbo Flash, a prospectively ECG triggered spiral scanning at a speed of 737 mm/s. The acquisition of the entire thorax, of 90 mm in length, is completed in 0.12 s, in free breathing, with a high temporal resolution of 66 ms per image, obtaining optimal image quality despite a high and varying heart rate of 127 – 136 bpm. An integrated technical feature, CARE kV, automatically applies a low tube voltage setting of 70 kV, achieving an optimal enhancement and contrast-to-noise ratio with only 4 mL of contrast agent and 0.45 mGy of radiation dose. A cinematic volume rendered technique (cVRT) is applied to facilitate a lifelike visualization and demonstration of the complexity of the malformed cardiac anatomy in three dimensions. As shown in this case, the Turbo Flash mode with dual source CT provides great clinical benefits in cardiac CT imaging for neonates.