Study On Clinical Application Of Three-and Four-dimensional Ultrasonography In The Prenatal Diagnosis

Part One Systematic analysis of the normal fetal facial anatomy in utero with three-dimensional sonographyObjectives The aim of this study was to explore the clinical value of three-dimensional ultrasonography(3DUS) in systematic and precise analysis of fetal facial features.Material and methods: From Feb.2006 to May.2006, 134 healthy pregnant women, the mean menstrual age ranged from fifteen to forty weeks, received prenatal fetal facial anatomic estimation by two-and three-dimensional ultrasonography. Their fetuses were normal in postnatal outcomings. The imaging system we used were GE VOLUSONE 730 Expert, which provides conventional two-dimensional ultrasound images and can also generate high-quality three-dimensional images in the surface and transparent mode. All volume data were analyzed in version 6.0 of the 4DView Software (GE Medical Systems Kretztechnik GmbH & Co OHG). The visualization rate of each representative sagittal, axial and coronal section planes of fetal face and the examination time were calculated using two- and three-dimensional ultrasonography separately.Results By off-line analysis of three-dimensional volume databases, the fetal facial feature could be reviewed in sagittal, axial and coronal section planes. The representative structure, such as nasal, lip, alveolus, maxillae processus palatinus, palatal horizontal plate, all could be revealed in 3DUS. The rate of visualization of coronal section planes of fetal face was statistically improved in 3DUS including the alveolus view (88.06 % vs. 55.97%,P<0.05), the palate view (69.40% vs. 43.28%,P<0.05), and the post-palate view(50.74% vs. 39.55%, P<0.05).The examination time was shortened. In rendering image of 3DUS,the profile and configuration of fetal face could gain comprehensive estimation. The visualization rate of fetal faces was 84.31% in fetuses with menstrual age of 24-28w and 83.59% in fetuses with menstrual age of 28-32w, which were statistically different from the visualization rate in fetuses with menstrual age of 16-20w and 36-40w (P<0.05). The visualization rates was 87.04% in fetuses with position of left/right occipito-anterior and 87.50% in fetuses with position of occipito-posterior, which were statistically different from fetuses with position of occipito-anterior and breech(P<0.05). Conclusions By analysis of rendering image and the three simultaneous reference planes, 3DUS allows easier, more rapid screening and more precise evaluation of the different facial features of fetuses. Part two Prenatal evaluation of fetal facial abnormalities with three-dimensional ultrasonographyObjectives The aim of this study was to explore the clinical value and additional information provided by three-dimensional ultrasonography in evaluation of fetal facial abnormalities .Material and methods: From May.2006 to Feb.2008, 539 pregnant women with high risk factors, the mean menstrual age ranged from fifteen to forty weeks, received prenatal fetal anatomic estimation by two-and three-dimensional ultrasonography. The imaging system we used was GE VOLUSONE 730 Expert, which provides conventional two-dimensional ultrasound images and can also generate high-quality three-dimensional images in the surface ,transparent and planer mode. After the diagnosis with conventional 2DUS by series sagittal, axial and coronal scanning of fetal face, examiner preformed 3D/4DUS to acquire volume datasets of the fetal face with acquisition time ranged from 3s to 6s per volume and scan angle ranged from 40°to 70°. All volume data were analyzed in version 6.0 of the 4DView Software (GE Medical Systems Kretztechnik GmbH & Co OHG). An independent examiner blinded to the indication of 2DUS explored 3D/4DUS volume databases and gained diagnostic impression. Findings of 3D/4DUS and 2DUS were compared respectively to those of subsequent autopsy examinations. All images were stored for further estimation by two sonographists to codetermine whether 3D/4D volume provided advantageous, equal or disadvantageous diagnosis information when compared with 2DUS.Results Among 373 fetuses with postnatal outcomings, 47 fetuses were confirmed with 69 facial abnormalities, including 20 cases of cleft lip,18 cases of cleft palate,6 cases of hypertelorism,8 cases of hypotelorism,2 cases of ear hypogenesis, 8 cases of lower-set ear,2 cases of proboscis,3 cases of nasal bone absence, 2 case of micrognathia. The sensitivity of detecting anomalies by 3D/4DUS was significantly different to 2DUS(88.41% vs. 73.91% ,P<0.05). However, the sensitivity of detecting cleftlip was similar between 3D/4DUS and 2DUS(85.0% vs. 95.0%, P>0.05). Compared with 2DUS, the 3D/4D volumes provided additional diagnosis information in 26 abnormalities (37.68%), equivalent diagnosis information in 39 abnormalities (56.52%) and disadvantageous diagnosis information in 4 abnormalities (5.79%).Conclusions Three-dimensional ultrasonography volume provides a novel means of visualizing the feature of fetal face. Our observations suggested that three-dimensional ultrasonography was a powerful adjunctive tool to 2DUS, in providing more comprehensible and vivid impression of fetal facial abnormalities .It may enhance the diagnostic potential sensitivity in prenatal diagnosis of fetal facial abnormalities.Part Three Evaluation of fetal extremities abnormalities in utero using four-dimensional ultrasonographyObjectives The aim of this study was to describe normal and abnormal fetal extremities by four-dimensional ultrasonography and to explore its clinical diagnosis value in prenatal evaluation of fetal extremities anomalies.Material and methods From May.2006 to Feb.2008, 539 high risk pregnancies with the mean menstrual age ranged from sixteen to forty weeks, received prenatal fetal anatomic estimation by 2DUS and 3DUS. The volume datasets of fetal extremities were acquired with the'4D real-time'option with acquisition time less than 20s per volume cine and scan angle ranging from 30 to 60°. All volume data were analyzed in version 6.0 of the 4DView Software (GE Medical Systems Kretztechnik GmbH & Co OHG). Volume data were reviewed in'plane'and'render'option. Findings of 3D/4DUS and 2DUS were compared respectively to subsequent autopsy examinations.Results The ability to visualize fetal hand was better with 4DUS than with 2DUS in fetuses with gestational ages of 20-24w (89.66% vs. 74.71%,P<0.05) and 24-28w (88.52% vs. 73.77% ,P<0.05). Among 373 fetuses with postnatal outcomings, 56 extremities anomalies of 45 fetuses were confirmed, including club foot, clenched hand, polydactyly, overlapping finger, absent antebrachium, osteogenesis inperfecta, absent middle phalanx of 5th finger, absent fibula ,et al. The sensitivity(78.57% vs. 55.35% ,P<0.05) and positive prospective value (84.61% vs. 65.95%, P<0.05) of detecting extremities anomalies by 4DUS was significantly different to 2DUS,Conclusions The enhanced display of external profile and internal structural of fetal extremities by 4DUS increased the confidence and veracity of the abnormality. The novel technology offers the potential to provide greater information in prenatal evaluation for both normal and abnormal extremities. Part four Three-dimensional Tomographic Ultrasound Imaging for evaluation of normal and abnormal fetal internal structure.Objectives The purpose of this study was to investigate the use and potential of Tomographic Ultrasound Imaging(TUI) in describing the fetal internal structure (mainly involving fetal central nervous system and abdomen) and to assess the clinical value and the feasibility in diagnosis of fetal internal anomalies.Material and methods From May.2006 to Feb.2008, 539 high risk pregnancies with the mean menstrual age ranged from sixteen to forty weeks, received prenatal fetal anatomic estimation by two-and three-dimensional ultrasonography. After the diagnosis with conventional 2DUS by series sagittal, axial and coronal scanning, examiner preformed'3D static'to acquire representative volume datasets of the fetal head , thorax and abdomen. All volume data were analyzed with TUI mode in version 6.0 of the 4DView Software (GE Medical Systems Kretztechnik GmbH & Co OHG) by an independent examiner blinded to the indication of 2DUS. Findings of TUI and 2DUS were compared respectively to subsequent autopsy examinations.Result By TUI display of three-dimensional volume databases, the fetal internal structure could be reviewed in sagittal, axial and coronal section planes. The rate of visualization of fetal head was better by TUI mode than 2DUS in the first coronal view (87.36% vs78.45% ,P<0.05) , the mid-sagittal plane(78.16% vs. 35.34% ,P<0.01) and the parasagittal plane (70.11% vs. 34.20%, P<0.01). Other representative views of fetal head and abdomen were gained similar visualization rate in 2DUS and TUI . A total of 58 anomalies, excluding facial ,extremities and heart anomalies, were confirmed postnatally. The sensitivity of detecting internal structure anomalies showed no significant difference between TUI and 2DUS (98.3% vs93.5%, P>0.05). Conclusions Three-dimensional TUI display can deliver informative images of the region of interest regardless of fetal position. It may be particularly helpful for evaluation of fetal normal and abnormal internal structure.Part five Prenatal assessment of the fetal heart using Tomographic Ultrasound Imaging display of four-dimensional volume datasets acquired with spatiotemporal image correlation (STIC).Objective The objective of this study was to investigate the feasibility of examining the fetal heart with Tomographic Ultrasound Imaging (TUI) using four-dimensional(4D) volume datasets acquired with spatiotemporal image correlation (STIC).Material and methods 253 pregnant women underwent two-dimensional and four-dimensional fetal echocardiography. After the diagnosis with conventional 2DUS fetal echocardiography, volume datasets were acquired with spatiotemporal image correlation in B-mode and Color Doppler Image. Volume acquisition time was between 7.5 and 12.5 seconds and, whenever possible, the procedure was performed in the absence of fetal movements or breathing. In version 6.0 of the 4DView Software (GE Medical Systems Kretztechnik GmbH & Co OHG), volume datasets were reviewed offline using TUI, a new display modality that automatically slices 3D/4D volume datasets, providing simultaneous visualization of up to eight parallel planes in a single screen. Visualization rates for standard transverse planes used to examine the fetal heart were calculated and compared between TUI and 2DUS. Diagnoses by TUI were compared to postnatal diagnoses.Results (1) The Four-chamber view, five-chamber view, pulmonary artery view and three-vessel view were visualized in 91.45%, 87.53%, 83.36% and 86.72% respectively, of the volume datasets acquired with B-mode. The visualization rates of the pulmonary artery view and the three-vessel view were improved(P<0.05). (2) These views were visualized in 93.45% ,89.72%,85.25% and 89.72 % respectively of the volume datasets acquired with Color Doppler Image. The visualization rates of the pulmonary artery view were improved(P<0.05). (3) The sensitivity of TUI to diagnose congenital heart disease was similar to 2DUS (86.95% VS 91.31%, P>0.05) Conclusions Standard transverse planes commonly used to examine the fetal heart can be automatically displayed with TUI in the majority of fetuses undergoing 4DUS with STIC. It may be particularly helpful for evaluation of fetal congenital heart disease.