Comparison of two- and three-dimensional ultrasonography in the evaluation of fetal heart: image quality and time spent in the exam

Abstract

To compare fetal heart evaluation done through two-dimensional (2DUS) and three-dimensional ultrasonography (3DUS) as to optimal plane imaging, image quality, and time needed to perform the examination. Prospective study involving 12 normal pregnant women, with gestational ages ranging from 22 to 26 weeks, scanned with a VOLUSON 730 with a convex 4.0-7.0 MHz transducer, in both two- and three-dimensional modes. In each case, three basic view planes were obtained: four-chambers view, right, and left ventricular outflow tracts. Each view was subjectively evaluated by three different examiners as to image quality, and graded from 0 (minimum) to 4 (maximum) cross-marks (+). The sum of all grades obtained for each case was used to classify the quality of the exam as unsatisfactory (0 to 1+), poor (2 to 4+), regular (5 to 7+), and good (8 to 12+). The time taken to obtain the views was recorded for each case, starting with the acquisition of the first view on the 2D exam and with the identification and opening of the volume blocks on the three-dimensional software. The number of three-dimensional blocks with good, regular, poor, and unsatisfactory grades were, respectively, 6, 15, 9, and 10. The average in cross-marks of the cases graded good in each group without the worst result for each plane was 8. 2DUS was superior to 3DUS regarding the quality of the images obtained by the three pattern view planes and the average time to obtain high quality view planes was longer for 3DUS when compared to 2DUS. 2DUS offered better quality images and in less time than 3DUS. Three-dimensional ultrasound is an advancement in fetal heart evaluation; however two-dimensional ultrasound remains the best screening method in diagnosing cardiac malformations, due to the good quality of its images and the lesser time needed to perform the exam.