Automated Sonography

Abstract

Objective. This study defines the spatial relationship of the diagnostic planes of the fetal heart to the 4-chamber view plane in the second trimester of pregnancy as a first step in the automation process. Methods. Three-dimensional static volumes of the fetal chest were acquired at the level of the 4-chamber view on 75 fetuses between 18 and 23 weeks' gestation. The spatial relationship of the diagnostic cardiac planes to the 4-chamber view plane were determined for each gestational week by using rotations along the x-, y-, and z-axes and a parallel slide (millimeters) when applicable. Results. The 5-chamber view (cardiac 1 plane) was best obtained by an initial parallel slide of the reference plane (plane A) toward the fetal head followed by a rotation along the y-axis. The right ventricular outflow tract (cardiac 2) and the abdominal circumference (cardiac 3) planes were best obtained by a parallel slide only: toward the fetal head in cardiac 2 and toward the fetal abdomen in cardiac 3. Conclusions. This study shows the spatial relationship of fetal cardiac diagnostic planes to the 4-chamber view plane in the second trimester of pregnancy in 3-dimensional volumes. Testing the clinical applicability of automated software based on these formulas is the next step. Key words: automated sonography; fetal echocardiography; 3-dimensional sonography; volume sonography.Received October 29, 2006, from the Departments of Obstetrics and Gynecology (A.A.) onography is an operator-dependent imaging modality, with the quality of the final image dependent in part on the manual skills of the operator performing the ultrasound examination. This inherent limitation of sonography has resulted in lack of consistency, standardization, and reproducibility of images, especially when compared with other imaging modalities, such as computed tomography and magnetic resonance imaging. In obstetric sonography, the limitation of the technology is compounded by a constantly moving target, the fetus, which adds technical difficulty to the examination. Mounting evidence suggests that the performance of obstetric sonography with regard to the detection of fetal abnormalities has been suboptimal. [1][2][3][4] A recent study addressing the value of ultrasound accreditation noted that more than 40% of practices seeking accreditation by the American Institute of Ultrasound in Medicine were operating below the minimum established professional standards for the performance of

Eleven fetal echocardiographic planes using 4-dimensional ultrasound with spatio-temporal image correlation (STIC): a logical approach to fetal heart volume analysis

“…Recently, a computer software that can automatically display cardiac outflow tracts after standardization of the fetal chest volume has been successfully validated[9,10]. We present a method to adjust virtual fetal position in STIC fetal heart volume datasets to a uniform fetal orientation (standardization of virtual fetal position) and a systematic approach to navigate in the standardized volumes to display the following 11 echocardiographic planes: (1) abdominal view; (2) four-chamber view; (3) five-chamber view; (4) three-vessel view; (5) three-vessel and trachea view; (6) transverse aortic arch; (7) long axis of the ductal arch; (8) long axis of the aortic arch; (9) long caval view; (10) left ventricular outflow tract (LVOT); and (11) short axis view of the great vessels.…”