Prenatal sonographic diagnosis of tetralogy of fallot

Utility of Pulmonary Angiography by 128-Slice Computed Tomographic Scanner in Diagnosis of Tetralogy of Fallot Cases

Tetralogy of Fallot (TOF) is a significant cause of cyanotic congenital heart disease (CHD) encountered in childhood with few cases manifesting in adulthood. It has four classical features (ventricular septal defect, overriding of aorta, hypertrophy of right ventricular hypertrophy, and right ventricular outflow tract obstruction), but the clinical presentation and course can be variable. Due to various anatomical variations and complex anatomy, presurgical planning and postoperative follow-up by pulmonary computed tomographic angiography (CTA) have a very important role. With continued technological advances and the availability of 128-slice computed tomographic (CT) scans, they now play an important role in TOF preoperative evaluation and workup, assisting by minimizing routine invasive digital subtraction catheter angiography. The fast scan of a 128-slice CTA with very sensitive detectors is a very useful modality for studying the complex anatomy and variations as well as its utilization for postoperative management. In this article, we report four cases of TOF where we used a 128-slice scan for performing pulmonary angiography (Optima 660, GE 128, 2180 Premier Row, Orlando, FL 32809, U.S.A.) for preoperative diagnosis and management of three cases and work up for revision surgery for an already operated case with a nonfunctional modified Blalock-Taussig shunt with additional lung parenchymal findings simultaneously. This study will explain the advantageous role of the 128-slice CT scanner over the lesser-slice CT scanners with the ability of pulmonary CTA to facilitate accurate diagnosis and postoperative management.

Cyanotic Congenital Heart Defects – literature review

Congenital heart defects are one of the most interesting and important chapters regarding abnormal fetal growth pathology. The objective of this article is to present a literature review for the main cyanotic congenital heart defects. The ones presented in the article are: tetralogy of Fallot, transposition of the great vessels, double outlet right ventricle, truncus arteriosus, total anomalous pulmonary venous circulation and additional information regarding very rare malformations such as pentalogy of Cantrell and Uhl anomaly. An early and precise identification of congenital heart defects is an important step in an accurate follow-up of a potential problematic pregnancy. Knowing the sonographic aspect, associated pathology and the current available treatment procedures are vital for the fetal outcome and for the physician to adapt the right management in every situation that might appear during the pregnancy and in the neonatal period.

Simultaneous real-time imaging of four-chamber and left ventricular outflow tract views using xPlane imaging capability of a matrix array probe

OBJECTIVES

To determine the feasibility and reliability of using xPlane imaging to examine simultaneously the four-chamber and left ventricular outflow tract (LVOT) views in real time, to assess rotation angles from the four-chamber view to the LVOT view, and to investigate factors affecting the angles.

METHODS

In 145 fetuses at 11-37 weeks' gestation, we visualized the four-chamber view in one of three cardiac positions: a subcostal view with the apex at the 3 or 9 o'clock position; an apical view with the apex at the 12 or 6 o'clock position; or a view with the fetal heart apex midway between these two positions. We then used the rotation function of xPlane imaging, using the four-chamber view as the reference plane, to visualize the LVOT view simultaneously in real time on the secondary image plane, on the right side of the split screen, by rotating a reference line from 0° with a rotation step of 5°. The rotation angle necessary for the first appearance of LVOT was recorded as the first rotation angle. The reference line was then rotated until the LVOT was just out of view, and this last rotation angle was recorded as the second rotation angle. The difference between these two angles was recorded as the angle span of the LVOT display. Reliability was assessed by intraclass correlation coefficient (ICC).

RESULTS

Of the 145 fetuses examined, 29 had cardiac defects. Using xPlane imaging, the LVOT was visualized successfully after 14 weeks in 95.1% of cases. The first and second rotation angles varied significantly with cardiac position (P < 0.001); when the fetal heart was examined using a subcostal approach with the apex at the 3 or 9 o'clock position, the first rotation angle was smaller than that at the apical view for normal hearts (20° vs. 50°, P < 0.001). There was also a significant difference for the second rotation angle and for the angle span, between fetuses with and without normal LVOT (P = 0.038 and 0.006, respectively). Regarding intra- and interobserver reliability for measurement of first and second rotation angles, the ICCs were high (range, 0.847-0.980).

CONCLUSION

Using xPlane imaging, it is feasible to examine simultaneously the four-chamber and LVOT views in real time, and measurement of the rotation angles between these two views is reproducible. The rotation angles depend on the position of the fetal heart, and the normality of the LVOT. Proposed algorithms for examination of the fetal heart with three-/four-dimensional ultrasonography may need to be adapted to optimize visualization of the standard planes.