Study on diagnostic performance of fetal intelligent navigation echocardiography for congenital heart defect

Objective To evaluate the clinical value of fetal intelligent navigation echocardiography (5D Heart) in the display of key diagnostic elements in basic fetal echocardiographic views. Methods Using volume probe, 3D volume datasets of the 209 normal singleton fetuses in the second and third trimesters were acquired from a four-chamber view. After processing the datasets by using 5D Heart, 9 cardiac diagnostic planes were acquired and then the image qualities of key diagnosis elements of the heart and great vessels were graded by 3 doctors with different experiences of performing fetal echocardiography. Results Two hundred and sixty-two volume datasets were acquired from 209 normal fetuses, including 53 volume datasets collected when cardiac apex was in different directions, satisfactory datasets failed to be acquired in 27 fetuses because of the maternal obesity, the artifacts of fetal movement, or other influencing factors. Two hundred and thirty-one volume datasets of 182 fetuses could be used for 5D Heart analyzing and displaying, and the displaying rate of 9 standard diagnostic views was up to 88.2%. No significant difference was found when comparing the grading results of one observer in different periods of time, the grading results between two experienced doctors and the grading results among the experienced doctor and one relatively inexperienced doctor (P>0.05). Conclusions 5D Heart has high reliability and repeatability in obtaining fetal echocardiographic diagnosis views and displaying fetal elemental diagnostic information. Key words: Fetal echocardiography; Congenital heart disease; Fetal intelligent navigation echocardiography; Spatiotemporal image correlation

Objective To investigate the value of fetal intelligent navigation echocardiography (FINE, 5D Heart) in displaying the normal fetal heart structure during 20 to 38 weeks′ gestation. Methods Three-dimensional data of fetal heart during 20 to 38 weeks′ gestation were acquired using volume transducer prospectively. The STIC volume images were post-processed with 5D heart software by three physicians with different levels of echocardiographic examination and the quality of the section images were analyzed. The intra- and interobserver repeatability was analyzed for the qualification of section images. The correlation between the quality of image and gestational age, body mass index, the placenta position, fetal initial plane position were evaluated using univariate and multivariable logistic regression analysis. Results Two hundreds and five cases of pregnant women were included, and 9 cases were excluded.Volume data acquisition was completed in 180 pregnant women, and the image acquisition rate was 91.8%. The data were assessed twice by three observers and qualified 9 section images were gotten in 156-180 cases (degree of qualification 86.7%-100%). The screening images were satisfied in 152 cases (84.4%), dissatisfied with 28 cases (15.6%). The intra-observer agreement by three observers was absolute concord in four chamber view and abdomen/stomach view; excellent in three vessel trachea view(3VT), five chamber view, left ventricular outflow tract view and superior and inferior vena cava view; good in right ventricular outflow tract view, ductal arch view and aortic arch view. The inter-observer agreement by each of three observers was absolute concord in four chamber view and abdomen/stomach view; excellent in superior and inferior vena cava view; excellent to good in five chamber view, left ventricular outflow tract view, right ventricular outflow tract view; good in 3VT, ductal arch view and aortic arch view. In a univariate analysis, the quality of the image was associated with obesity (χ2=15.338, P=0.000), gestational age (χ2=23.356, P=0.000). Multivariable analysis showed that the obesity (OR=5.587, P=0.001) and gestational age (OR=8.843, P=0.000) were factors affecting the quality of the image. The average time spent in post-processing the images for first time by three observers was (2.77±1.39)min, and there was no significant difference among observers (P>0.05). Conclusions Fetal intelligent navigation echocardiography (FINE, 5D Heart) based on STIC volumes can successfully generate 9 standard fetal echocardiography views in 86.7%-100% of fetuses in the 2nd and 3rd trimesters. This method can simplify examination of the fetal heart and reduce operator dependency. Key words: Echocardiography; Fetal heart; Spatiotemporal image correlation; Fetal intelligent navigation echocardiography(FINE)

Objective To explore the applicability of fetal intelligent navigation echocardiography (FINE, 5D Heart) in displaying the normal fetal heart structure by a new sonographer and assess the value of this technique in fetal cardiac ultrasonography. Methods Eighty cases of normal fetal heart at the second trimester were scanned by an echocardiographic expert. STIC volume datasets with satisfactory from apical four-chamber and common 2D modality with 9 standard views of fetal echocardiogram were achieved for each case. The STIC volume images were post-processed with 5D heart software by two physicians with different levels of echocardiographic examination. The quality of the section images of 9 standard views from 2D 5D heart and were analyzed. The intraobserver and interobserver with common 2D modality repeatability were analyzed for the qualification of section images. The time spent in post-processing the images was record and analyzed. Results The qualified 9 section images with 2D were 75~80 cases (degree of qualification 93.8%~100.0%). The data were assessed twice by two observers and qualified 9 section images were got in 73~80 cases (degree of qualification 91.3%~100.0%). The intra-observer agreement by two observers was absolute concord in four chamber view and abdomen/stomach view (Kappa=1); excellent in three vessel trachea view (3VT, Kappa=0.851~0.882); good to excellent in five chamber view (Kappa=0.787~0.882); good in aortic arch view (Kappa=0.738~0.787), left ventricular outflow tract view (Kappa=0.709~0.787), right ventricular outflow tract view (Kappa=0.655~0.794), superior and inferior vena cava view (Kappa=0.647~0.649) and ductal arch view (Kappa=0.640~0.707). The inter-observer agreement by each two observers and 2D was absolute concord in four chamber view and abdomen/stomach view (Kappa=1); excellent in five chamber view (Kappa=0.851~0.902); good to excellent in ductal arch view (Kappa=0.749~0.820), aortic arch view (Kappa=0.707~0.882), right ventricular outflow tract view (Kappa=0.661~0.851) and 3VT (Kappa=0.655~0.851); good in left ventricular outflow tract view (Kappa=0.737~0.749), superior and inferior vena cava view (Kappa=0.655~0.794). The average time spent in post-processing the images for first time by three observers was (2.64±1.35) min, and there was no significant difference during the each observers (P>0.05). Conclusions 5D Heart represents a single method in obtaining 9 fetal diagnosis planes, which can be used easily by a sonographer lack of skills, and has high reliability and repeatability. It is helpful for improving the application of fetal heart screening. Key words: Echocardiography; Fetal; Spatiotemporal image correlation

Congenital heart disease (CHD) is the leading organ-specific birth defect, as well as the leading cause of infant morbidity and mortality from congenital malformations. Therefore, a comprehensive screening examination of the fetal heart should be performed in all women to maximize the detection of CHD. Four-dimensional sonography with spatiotemporal image correlation (STIC) technology displays a cine loop of a complete single cardiac cycle in motion. A novel method known as Fetal Intelligent Navigation Echocardiography (or FINE) was previously developed to interrogate STIC volume datasets using “intelligent navigation” technology. Such method allows the automatic display of nine standard fetal echocardiography views required to diagnose most cardiac defects. FINE considerably simplifies fetal cardiac examinations and reduces operator dependency. It has both high sensitivity and specificity for the detection of CHD. Indeed, FINE has been integrated into several commercially available ultrasound platforms. Recently, eight novel and advanced features have been developed for the FINE method and they will be described herein. Such features can be categorized based upon their broad goals. The first goal is to simplify FINE further, and consists of the following features: (1) Auto fetal positioning (or FINE align); (2) Skip points; (3) Predictive cursor; (4) Static mode volume; and (5) Breech sweep. The second goal is to allow quantitative measurements to be performed on the cardiac views generated by FINE: (6) Automatic cardiac axis; and (7) Cardiac biometry. Finally, the last goal is to improve the success of obtaining fetal echocardiography view(s); and consists of (8) Maestro planar navigation.

Objective To evaluate the value of fetal intelligent navigation echocardiography (5D Heart) and Virtual Intelligent Sonographer Assistance (VIS-Assistance®) in the display of key diagnostic elements in basic fetal echocardiographic views. Methods The heart volumes data of 209 normal fetuses were collected and then the offline analysis was conducted. Processing of the built-in VIS-Assistance® for each diagnosis plane was optimized. The display success rate and image quality difference of diagnosis images and diagnosis elements before and after the VIS-Assistance® processing as well as the repeatability between observers were analyzed and compared. Results Totally 262 fetal heart volume data were collected from 209 fetuses,and 231 volume data of 182 cases could be used for the analysis,with the acquiring success rate of 88.2%. For the display rate of 8 diagnosis sections of the 231 fetal heart volume data before and after VIS-Assistance® processing,abdominal transverse section at stomach level showed no significant difference,while the other diagnostic sections showed significant differences (all P<0.05),and the display rate after the processing was higher than that before the processing. For the image quality scores of diagnosis sections before and after VIS-Assistance® processing,abdominal transverse section at stomach level showed no significant differences,while other diagnostic sections showed significant differences (all P<0.01),and the image quality scores after the processing were higher than those before the processing. According to Bland-Altman analysis,95% credibility interval of the total scores of 8 sections measured by different observers before and after VIS-Assistance® were (-0.17/+ 0.18) and (-0.17/+ 0.18),respectively,6.06% (14/231) and 3.89% (9/231) of the points were outside the 95% credibility interval,and the rest had high consistency. Conclusions 5D Heart and VIS-Assistance® technology can significantly improve the display rate of diagnostic section and image quality of element structures,and has high reliability and repeatability in obtaining fetal cardiac diagnosis sections and displaying fetal elemental diagnostic information. Key words: Echocardiography; Heart difects,congenital; Fetus; Spatiotemporal image correlation

Objective To evaluate the value of fetal intelligent navigation echocardiography with color flow imaging (5D Heart Color) in the display of key diagnostic elements in basic fetal echocardiographic views. Methods The heart volumes datasets of 220 fetuses were collected and the offline analysis was conducted. Pearson correlations was used to compare the detection rate of blood flow element between 5D Heart Color software and color Doppler flow imaging(CDFI) in basic fetal echocardiographic views, and the detection rate of blood flow between normal fetuses (control group) and fetuses with cardiovascular abnormalities(case group). Bland-Altman analysis was used to prove consistency and reliability of the results. Results Totally 384 fetal heart volume datasets were collected from 220 fetuses, and 317 volume datasets of 200 cases could be used for the analysis, with the acquiring success rate of 82.6%. 5D Heart Color software and CDFI showed a close correlation in displaying key cardiovascular blood flow information in key fetal echocardiographic diagnosis sections (r=0.88, P<0.05); The detection rates of blood flow elements in control group and case group were 91.9% and 87.3%, respectively, with an average of 89.6% (r=0.9, P<0.05). Bland-Altman analysis showed close consistency between inter- and intra-observations in the detection rates of blood flow elements, and their 95% confidence intervals were (-0.1/+ 0.09) and (-0.09/+ 0.1), respectively, and the points outside the 95% confidence interval were 5.4%(17/231) and 5.7%(18/231), respectively. Conclusions 5D Heart Color software shows similar usefulness in the displaying key blood flow elements, comparing with CDFI, demonstrating higher reliability and repeatability in displaying fetal echocardiographic diagnosis views and diagnostic blood flow elements. Key words: Echocardiography; Congenital heart disease; Fetus; Fetal intelligent navigation echocardiography

Congenital heart defects (CHDs) are the most common congenital defect, occurring in approximately 1 in 100 live births and being a leading cause of perinatal morbidity and mortality. Of note, approximately 25% of these defects are classified as critical, requiring immediate postnatal care by pediatric cardiology and neonatal cardiac surgery teams. Consequently, early and accurate diagnosis of CHD is key to proper prenatal and postnatal monitoring in a tertiary care setting. In this scenario, fetal echocardiography is considered the gold standard imaging ultrasound method for the diagnosis of CHD. However, the availability of this examination in clinical practice remains limited due to the need for a qualified specialist in pediatric cardiology. Moreover, in light of the relatively low prevalence of CHD among at-risk populations (approximately 10%), ultrasound cardiac screening for potential cardiac anomalies during routine second-trimester obstetric ultrasound scans represents a pivotal aspect of diagnosing CHD. In order to maximize the accuracy of CHD diagnoses, the views of the ventricular outflow tract and the superior mediastinum were added to the four-chamber view of the fetal heart for routine ultrasound screening according to international guidelines. In this context, four-dimensional spatio-temporal image correlation software (STIC) was developed in the early 2000s. Some of the advantages of STIC in fetal cardiac evaluation include the enrichment of anatomical details of fetal cardiac images in the absence of the pregnant woman and the ability to send volumes for analysis by an expert in fetal cardiology by an internet link. Sequentially, new technologies have been developed, such as fetal intelligent navigation echocardiography (FINE), also known as "5D heart", in which the nine fetal cardiac views recommended during a fetal echocardiogram are automatically generated from the acquisition of a cardiac volume. Furthermore, artificial intelligence (AI) has recently emerged as a promising technological innovation, offering the potential to warn of possible cardiac anomalies and thus increase the ability of non-cardiology specialists to diagnose CHD. In the early 2010s, the advent of 3D reconstruction software combined with high-definition printers enabled the virtual and 3D physical reconstruction of the fetal heart. The 3D physical models may improve parental counseling of fetal CHD, maternal-fetal interaction in cases of blind pregnant women, and interactive discussions among multidisciplinary health teams. In addition, the 3D physical and virtual models can be an useful tool for teaching cardiovascular anatomy and to optimize surgical planning, enabling simulation rooms for surgical procedures. Therefore, in this review, the authors discuss advanced image technologies that may optimize prenatal diagnoses of CHDs.

Objective To explore the detection rate, types, accompanying abnormalities and prognosis of fetal congenital heart disease(CHD) in a single center in northwest China, in order to set up a foundation for further studying the epidemiological characteristics of fetal CHD and integrated management of fetal CHD in the prenatal and postnatal. Methods A total of 2 725 CHD in 45 015 fetus diagnosed by fetal echocardiography were enrolled. The fetal CHD detection rate and the composition ratio were calculated. Follow-up results between the simple CHD and complex CHD were analyzed. Results The detection rate of fetal CHD in our center was up to 6.1%. There were 1 589 cases of complex CHD, accounting for 58.3% in all the fetal CHD, of which the most common type was single ventricle, followed by tetralogy of Fallot, atrioventricular septal defect and double outlet right ventricle; Simple CHD 1 136 cases, accounting for 41.7% in all the fetal CHD, the most common type was ventricular septal defect. The number of abortion cases, intrauterine and postnatal natural deaths of fetal CHD accounted for 60.3% (1 357/2 251) of the total follow-up, of which complex CHD and chromosomal abnormalities accounting for the majority. 68 cases of CHD underwent surgical treatment after birth, of which complex CHD were predominant. 37 cases of simple CHD spontaneous closure and 27 cases of simple CHD genetic test results were abnormal. Conclusions The detection rate of CHD in this group is relatively high, which is related to the prenatal diagnosis consultation center. Fetal complex CHD is more common while the prognosis is worse than simple CHD. Prenatal and postnatal integrated management of fetal CHD has important clinical value in early treatment of complex CHD. Key words: Echocardiography; Congenital heart disease; Fetal; Integrated management

To evaluate the detection and accuracy of fetal echocardiography for congenital heart defects among high-risk populations. A prospective observational study of prenatal diagnosis of congenital heart disease was conducted in two tertiary obstetrics and gynecology hospitals between January 2003 and December 2004. Consecutive fetuses at risk of congenital heart disease underwent detailed fetal echocardiography during the study period. B-mode and colour/pulsed Doppler flow imaging were used in all cases. Follow-up was sought for all pregnancies. Indications for referral, maternal and gestational age at diagnosis, as well as prenatal and postnatal diagnosis were recorded prospectively. By comparing prenatal and postnatal diagnoses, sensitivity, specificity, and predictive values were estimated. A series of 2063 high-risk fetuses underwent detailed fetal echocardiography during the study period. The mean gestational age at examination was 26.5 weeks, ranging from 16 to 42 weeks. The most common indications for fetal echocardiography were advanced maternal age (31.7%), fetal arrhythmias (13.5%) and maternal infections (10.4%). Forty-three cases of fetal congenital heart disease were detected. The mean gestational age at prenatal diagnosis was 27.3 weeks ranging from 16 to 40 weeks. There were 3 false-negatives and 1 false-positive. The sensitivity, specificity, positive and negative predictive values were 92.1%, 99.9%, 97.2%, and 99.8%, respectively. Diagnostic accuracy was 86.1%. A cardiac defect suspected on routine prenatal sonography accounted for the highest proportion of abnormal cases (67.4%). As for pregnancy outcome, there were 24 (52.1%) terminations; 2.2% died in utero, 13% postnatally, and 28.3% survived. (1) Fetal congenital heart disease can be identified reliably by prenatal echocardiography. (2) Possible congenital heart disease or suspected heart defect noted on a screening obstetric sonogram is an important indication for fetal echocardiography. (3) A sequential segmental approach is critical for correct evaluation of the cardiac malformation. (4) The outcome of the patients with congenital heart disease is poor and a multidisciplinary approach is needed to the parental counseling and perinatal management planning.

To evaluate the detection rate of congenital heart defect (CHD) during the first trimester screening for chromosomal abnormalities, the role of ultrasound soft markers including increased nuchal translucency (NT), tricuspid regurgitation (TR) and abnormal ductus venosus (DV) flow in the screening for cardiac anomalies was also investigated. From January 2009 to January 2012, 4 673 fetuses were scanned at 11-14 weeks at Department of Fetal Medicine, the First Affiliated Hospital of Jinan University. The ultrasound findings and follow up outcomes were recorded, False-positive rate of different first-trimester ultrasound markers for the detection of CHD was calculated, sensitivity of the markers for all major CHD was calculated as well. There was a significant association between major CHD and first trimester ultrasound markers. (1) Overall findings:among the 4 673 fetuses, 31 fetuses were diagnosed CHD prenatally, 17, 12 and 2 of which were detected in the first, second and third trimester, respectively. In 22 of the 31 CHD cases, invasive procedure was performed, fetal karyotype was abnormal in 12 cases, including triosmy 21 (5 cases), trisomy 18 (2 cases), trisomy 13 (2 cases), Turner syndrome (2 cases) and pericentric inversion of chromosome 9 (1 cases). (2) NT measurement and prenatal detected CHD: in 4 673 cases, NT measurement between 95(th)-99(th) percentile were present in 206 (4.41%) , 5 cases were diagnosed CHD prenatally, in 4 of 5 cases were detected in first trimester; NT measurement <95(th) percentile were present in 4 430 (94.80%) , 16 cases were diagnosed CHD prenatally, in 5 of 16 cases were detected in first trimester; NT measurement>99(th) percentile (>3.5 mm) were present in 37 (0.79%, 37/4 673) , 10 cases were diagnosed CHD prenatally, in 8 of 10 cases were detected in first trimester. (3) TR and inverted a-wave at the DV and prenatal detected CHD: among 4 673 cases, TR or inverted a-wave at the DV were present in 51 (1.09%) , 98 (2.10%) respectively. TR was present in 8 of 31 CHD cases, inverted a-wave at the DV was present in 7 of 31 CHD cases. (4) Sensitivity of different first trimester ultrasound markers for detection of major CHD cases:in 31 CHD cases diagnosed prenatally, 23 cased were defined as major CHD. Sensitivity of at least one of the ultrasound markers, NT measurement between 95(th)-99(th) percentile, >99(th) percentile( >3.5 mm), TR or inverted a-wave at the DV for detection of major CHD cases was 74% (17/23), 22% (5/23), 39% (9/23), 35% (8/23), 30% (7/23) , respectively. (5) Specificity of different first trimester ultrasound markers for detection of CHD cases:specificity of NT measurement between 95(th)-99(th) percentile, >99(th) percentile (>3.5 mm), TR or inverted a-wave at the DV for detection of major CHD cases was 4.30% (201/4 673),0.58% (27/4 673),0.92% (43/4 673), 1.94% (91/4 673). Routine first trimester soft markers for chromosomal abnormalities screening combined with cardiac assessment can detect quite a number of major heart defects. Increased NT, TR and abnormal DV flow can be important indicators for echocardiography, which is favorable to early prenatal diagnosis of CHD.

ABSTRACTObjectiveTo evaluate the performance of color and bidirectional power Doppler ultrasound combined with Fetal Intelligent Navigation Echocardiography (FINE) in examining the fetal heart.MethodsA prospective cohort study was conducted of fetuses in the second and third trimesters with a normal heart or with congenital heart disease (CHD). One or more spatiotemporal image correlation (STIC) volume datasets, combined with color or bidirectional power Doppler (S‐flow) imaging, were acquired in the apical four‐chamber view. Each successfully obtained STIC volume was evaluated by STICLoop™ to determine its appropriateness before applying the FINE method. Visualization rates for standard fetal echocardiography views using diagnostic planes and/or Virtual Intelligent Sonographer Assistance (VIS‐Assistance®) were calculated for grayscale (removal of Doppler signal), color Doppler and S‐flow Doppler. In four cases with CHD (one case each of tetralogy of Fallot, hypoplastic left heart and coarctation of the aorta, interrupted inferior vena cava with azygos vein continuation and asplenia, and coarctation of the aorta with tricuspid regurgitation and hydrops), the diagnostic potential of this new technology was presented.ResultsA total of 169 STIC volume datasets of the normal fetal heart (color Doppler, n = 78; S‐flow Doppler, n = 91) were obtained from 37 patients. Only a single STIC volume of color Doppler and/or a single volume of S‐flow Doppler per patient were analyzed using FINE. Therefore, 60 STIC volumes (color Doppler, n = 27; S‐flow Doppler, n = 33) comprised the final study group. Median gestational age at sonographic examination was 23 (interquartile range, 21–27.5) weeks. Color Doppler FINE generated nine fetal echocardiography views (grayscale) using (1) diagnostic planes in 73–100% of cases, (2) VIS‐Assistance in 100% of cases, and (3) a combination of diagnostic planes and/or VIS‐Assistance in 100% of cases. The rate of generating successfully eight fetal echocardiography views with appropriate color and S‐flow Doppler information was 89–100% and 91–100% of cases, respectively, using a combination of diagnostic planes and/or VIS‐Assistance. However, the success rate for the ninth echocardiography view (i.e. superior and inferior venae cavae) was 33% and 30% for color and S‐flow Doppler, respectively. In all four cases of CHD, color Doppler FINE demonstrated evidence of abnormal fetal cardiac anatomy and/or hemodynamic flow.ConclusionsThe FINE method applied to STIC volumes of normal fetal hearts acquired with color or bidirectional power Doppler information can generate successfully eight to nine standard fetal echocardiography views (via grayscale, color Doppler or power Doppler) in the second and third trimesters. In cases of CHD, color Doppler FINE demonstrates successfully abnormal anatomy and/or Doppler flow characteristics. Published 2017. This article is a U.S. Government work and is in the public domain in the USA. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

ObjectiveFetal intelligent navigation echocardiography (FINE) is a novel method that automatically generates and displays 9 standard fetal echocardiographic views in normal hearts by applying intelligent navigation technology to spatiotemporal image correlation (STIC) volume data sets. The main objective was to determine the sensitivity and specificity of FINE in the prenatal detection of congenital heart disease (CHD).MethodsA case‐control study was conducted in 50 fetuses with a broad spectrum of CHD (cases) and 100 fetuses with normal hearts (controls) in the second and third trimesters. Using 4‐dimensional ultrasound with STIC technology, volume data sets were acquired. After all identifying information was removed, the data sets were randomly distributed to a different investigator for analysis using FINE. The sensitivity and specificity for the prenatal detection of CHD, as well as positive and negative likelihood ratios were determined.ResultsThe diagnostic performance of FINE for the prenatal detection of CHD was: sensitivity of 98% (49 of 50), specificity of 93% (93 of 100), positive likelihood ratio of 14, and negative likelihood ratio of 0.02. Among cases with confirmed CHD, the diagnosis with use of FINE completely matched the final diagnosis in 74% (37 of 50); minor discrepancies were seen in 12% (6 of 50), and major discrepancies were seen in 14% (7 of 50).ConclusionsThis is the first time the sensitivity and specificity of the FINE method in fetuses with normal hearts and CHD in the second and third trimesters has been reported. Because FINE identifies a broad spectrum of CHD with 98% sensitivity, this method could be used prenatally to screen for and diagnose CHD.

Congenital heart disease (CHD) is one of the most common organ-specific birth defects and a major cause of infant morbidity and mortality. Despite ultrasound screening guidelines, the detection rate of CHD is limited. Fetal intelligent navigation echocardiography (FINE) has been introduced to extract reference planes and cardiac axis from cardiac spatiotemporal image correlation (STIC) volume datasets. This study analyses the cardiac axis in fetuses affected by CHD/thoracic masses (n = 545) compared to healthy fetuses (n = 1543) generated by FINE. After marking seven anatomical structures, the FINE software generated semi-automatically nine echocardiography standard planes and calculated the cardiac axis. Our study reveals that depending on the type of CHD, the cardiac axis varies. In approximately 86% (471 of 542 volumes) of our pathological cases, an abnormal cardiac axis (normal median = 40-45°) was detectable. Significant differences between the fetal axis of the normal heart versus CHD were detected in HLHS, pulmonary atresia, TOF (p-value < 0.0001), RAA, situs ambiguus (p-value = 0.0001-0.001) and absent pulmonary valve syndrome, DORV, thoracic masses (p-value = 0.001-0.01). This analysis confirms that in fetuses with CHD, the cardiac axis can significantly deviate from the normal range. FINE appears to be a valuable tool to identify cardiac defects.

The purpose of this article is to describe the evaluation of a variety of congenital heart diseases (CHDs) using three-dimensional (3D) ultrasound with different software, such as Cristal Vue, Realistic Vue, LumiFlow, and Spatiotemporal Image Correlation (STIC), with HDlive and HDlive Flow Silhouette modes. These technologies provide realistic images of the fetal heart and cardiac vessels using a fixed virtual light source that allows the operator to freely select a better light source position to enhance the cardiovascular anatomical details. In addition, Fetal Intelligent Navigation Echocardiography (FINE) technology, also known as “5D Heart” or “5D”, is a technology that enables the automatic reconstruction of the nine standard fetal echocardiographic views and can alert non-specialists to suspected CHD. Through the use of artificial intelligence, an ultrasound machine is able to perform automatic anatomical and functional measurements. In addition, hese technologies enable the reconstruction of fetal cardiac structures in realistic images, improving the depth perception and resolution of anatomic cardiac details and blood vessels compared to those of standard two-dimensional (2D) ultrasound.

Objective To investigate the feasibility of three dimensional(3D) printing fetal heart from spatio-temporal image correlation (STIC) volume-rendered data. Methods Eight fetuses with normal heart and 3 fetuses with confirmed cardiac anomalies identified by two-dimensional echocardiography from February to May 2019 in Renmin Hospital of Wuhan University were prospectively enrolled in this study. All the fetuses underwent two-dimensional (2D) echocardiography and STIC technology examination. The 3D volume images of fetal heart were post-processed by Mimics software to create images of the fetal heart in standard tessellation language format(STL). The STL file was output to the 3D printer and the 3D printing models of fetal heart and great vessels were obtained. In the process, the numerical values of each index of fetal hearts were measured from 3D digital model, 3D printing models and routine echocardiography images, respectively. The accuracy of 3D modeling was assessed by comparing the measured values of the model with the measured values of the source data. Results In all the fetuses, STIC volume data of the fetal heart were successfully reprocessed and printed out, the anatomical structure and vascular course could be visually displayed. It showed no significant difference in all the heart size parameters between 3D digital model, 3D printing models and routine echocardiography images (all P>0.05). Moreover, the size parameters were concordant well between the two methods, all of the data points fell within the limits of agreement. Conclusions The 3D printing of fetal heart using STIC volume images as the data source is feasible. Key words: Three dimensional printing; Spatio-temporal image correlation; Congenital heart disease; Fetus