Prenatal Visualization of the Pulmonary and Aortic Valves and Leaflets Is Feasible Using 4-Dimensional Sonography.

OBJECTIVES: The purpose of this study was to determine whether the morphologic characteristics and area of the semilunar valves in healthy fetuses and fetuses with cardiac defects can be visualized by using spatiotemporal image correlation (STIC). METHODS: Spatiotemporal image correlation volumes from 74 healthy fetuses were recorded in 5 examinations between the 15th and 36th weeks of pregnancy. Second, we recorded STIC volumes from 64 fetuses with various cardiac defects. The quality of the volumes was rated. The areas of the aortic and pulmonary valves were measured in systole by rendering the valves on 4-dimensional sonography. The number of leaflets was examined. Longitudinal data analysis using linear mixed models was performed. RESULTS: Two hundred ninety-three volumes from normal hearts were examined. In 82.5%, the quality of the normal volumes was sufficient. Visualization of the valve opening was feasible in 96.1% of the normal hearts and 97.4% of the abnormal hearts. The success rate of visualization of the pulmonary and aortic valve leaflets was dependent on the gestational age, with the highest percentage (72.1% in normal hearts) at 19 to 24 weeks. Longitudinal regression analysis showed a positive relationship of the aortic and pulmonary valve areas with gestational age (P < .0001) and fetal biometric measurements (P < .0001). Fifty-eight abnormal volumes were examined. Cardiac defects with abnormal valve areas due to aortic and pulmonary stenosis could be clearly visualized by using STIC. CONCLUSIONS: Examination of the morphologic characteristics of the semilunar valves using STIC is feasible, which is difficult when using 2-dimensional sonography. With increasing implementation of 4-dimensional sonography, the understanding of rendered images might be useful for anyone practicing fetal echocardiography.

Bartter syndrome type III and congenital anomalies of the kidney and urinary tract: an antenatal presentation.

Bartter syndrome encompasses a variety of inheritable renal tubular transport disorders characterized by hypokalemia and hypochloremic metabolic alkalosis. Bartter syndrome Type III is caused by genetic alterations in the chloride channel kidney B (CLCNKB) gene and often presents in the first 2 years of life, known as classic Bartter syndrome. However, in rare cases Bartter syndrome Type III has an antenatal presentation with polyhydramnios, premature delivery and severe dehydration in the first weeks of life. Associations between congenital anomalies of the kidney and urinary tract and Bartter syndrome are extremely rare. This case report presents a girl with Bartter syndrome Type III due to a homozygous CLCNKB mutation and bilateral congenital anomalies of the kidney and urinary tract. In addition, we describe the antenatal presentation as well as its perinatal management.

Spatiotemporal image correlation artifacts in an in vitro model.

An experimental in vitro setting with a latex miniature balloon was designed to test the accuracy of volumetric measurements by spatiotemporal image correlation. Two-dimensional images clearly showed the round balloon as a thin echogenic ring in a translucent area. Four-dimensional reconstructed images, however, showed a severely distorted balloon. The artifacts disappeared when the surroundings of the balloons were made echogenic, mimicking the in vivo setting. We hypothesize that the artifacts were the result of gating errors. These experiments can be relevant for analysis of spatiotemporal image correlation volumes in daily practice.

Feasibility of automated 3-dimensional fetal cardiac screening in routine ultrasound practice.

OBJECTIVE: The purpose of this study was to prospectively assess the clinical feasibility of an automated 3-dimensional (3D) software tool for extended basic cardiac screening in routine ultrasound practice. METHODS: During the 2-month study period, all gravidas fitting our inclusion criteria were consecutively included. Cardiac 3D volumes were acquired within the time slot allocated for the usual 2-dimensional fetal examination. All volumes were assessed on their quality, based on display of the 4-chamber view, and on the ability to sufficiently display diagnostic cardiac planes (left ventricular outflow tract [LVOT], right ventricle outflow tract [RVOT], and stomach location) with Sonography-Based Volume Computer-Aided Diagnosis software (SonoVCAD; GE Healthcare, Milwaukee, WI). RESULTS: Volume acquisition was successful in 107 of 126 cases (85%). For each sonographer, more than 70% of the acquired cardiac volumes were of high or sufficient quality. Separately analyzed, diagnostic planes of the LVOT, RVOT, and stomach location were visible in 62.1%, 81.6%, and 92.2%, respectively. An extended basic fetal cardiac examination based on retrieval of all diagnostic cardiac planes from a single volume using SonoVCAD could be performed in 46.6% of the cases. CONCLUSIONS: This study shows that cardiac volume acquisition can be incorporated in a routine ultrasound screening program without much difficulty. However, currently, SonoVCAD software still lacks the consistency to be clinically feasible for cardiac screening purposes. Further advances in ultrasound technology and familiarization with 3D ultrasound might improve its performance.