[Show abstract][Hide abstract] ABSTRACT: Aortic isthmus (AoI) velocity waveforms are considered powerful indicators of hemodynamic deterioration in intrauterine growth-restricted (IUGR) fetuses. However, technical difficulties in sampling AoI velocity waveforms from the longitudinal aortic arch (LAA) have limited its clinical application thus far. In this study, we tested the possibility of recording AoI velocity waveforms from the 3-vessel (3V) view of the fetal mediastinum and comparing the agreement of these measurements with recordings from the LAA.
Doppler measurements of the pulsatility index (PI) from the AoI were performed in 70 fetuses (20 IUGR and 50 normally grown) between 20 and 34 weeks' gestation. All measurements were sampled in both the LAA and 3V views by the same investigator. Reliability was evaluated with intraclass correlation coefficients (ICCs), and Bland-Altman plots were generated. The time required to complete the measurements was compared.
A high degree of reliability was observed between PI values obtained from LAA and 3V views in both IUGR and normally grown fetuses (all fetuses: ICC, 0.976; 95% confidence interval [CI], 0.961-0.985; normally grown: ICC, 0.839; 95% CI, 0.731-0.906; IUGR: ICC, 0.954; 95% CI, 0.886-0.982). However, recordings from the 3V view were significantly less time-consuming than those from the LLA view (mean +/- SD, 30.4 +/- 14.2 versus 52.8 +/- 29.4 seconds; P < .0001) and showed higher intraobserver reproducibility.
In IUGR and normally grown fetuses, AoI waveforms can be reliably obtained from the 3V view with higher reproducibility and a shorter recording time.
Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine 11/2008; 27(11):1617-22. · 1.40 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To evaluate the incidence of abnormalities in velocity waveforms from ductus venosus (DV) and aortic isthmus (AoI) in fetuses with intrauterine growth restriction (IUGR) and their reciprocal temporal relationship.
DV and AoI velocity waveforms were recorded in 31 IUGR fetuses characterized either by absent end diastolic (20) or reverse flow (11) in umbilical artery. Abnormal velocity waveforms in DV and AoI were defined in presence of reverse diastolic flows.
Abnormal DV velocity waveforms were present in 10 fetuses and were always associated with abnormalities. Abnormal AoI flows were also present in 10 fetuses of the remaining 21 fetuses with normal DV velocity waveforms (47.6%). Longitudinal monitoring of fetuses with normal DV flows showed a significantly shorter time interval in the onset of reverse flow in DV when abnormalities in AoI were present (4 vs 14 days p=0.001) irrespectively of gestational age or other potential confounding variables.
Our data suggest that AoI velocity waveforms become abnormal at an earlier stage of fetal compromise than DV.
[Show abstract][Hide abstract] ABSTRACT: A low combined cardiac output (CCO) to the placenta (placenta/CCO fraction) has been reported in growth-restricted (IUGR) fetuses, but the temporal sequence of these modifications in relation to other changes in the fetal circulation is unknown. The aim of this study was to evaluate the placenta/CCO fraction in relation to other hemodynamic changes in fetuses at risk of developing IUGR.
We studied 340 singleton nulliparous pregnancies characterized at 20-24 weeks by abnormal uterine artery pulsatility index (PI) values (> 95(th) centile). At this gestational age we measured fetal biometry and Doppler waveforms from the umbilical artery (UA), middle cerebral artery (MCA), ductus venosus (DV), umbilical vein (UV) and outflow tracts of both ventricles. The diameters of the semilunar valves and UV were measured and CCO (left cardiac + right cardiac outputs) and UV blood flow were calculated. The placenta/CCO fraction was calculated as UV flow as a percentage of CCO.
There were 283 pregnancies with birth weight >or= 10(th) centile and normal UA-PI throughout gestation (Group A), 34 with birth weight < 10(th) centile and normal UA-PI throughout gestation (Group B) and 23 with birth weight < 10(th) centile and abnormal UA-PI developing later in gestation (Group C). At 20-24 weeks there were no differences among the three groups in fetal biometric parameters, PI values from the UA, MCA and DV, and CCO. UV flow and placenta/CCO fraction were significantly lower in Group C compared with Group A (UV flow delta value = - 1.439, P < 0.0001; placenta/CCO fraction delta value = - 1.74, P < 0.0001) but not in Group B.
Our data suggest that, in fetuses developing IUGR secondary to placental compromise, UV flow and placental/CCO fraction are already reduced by 20-24 weeks, and that this reduction occurs earlier than do modifications in fetal size and arterial and venous PI values.
Ultrasound in Obstetrics and Gynecology 09/2008; 32(2):155-9. · 3.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to test the possibility of diagnosing ventricular septal defects (VSDs) by using tomographic ultrasound imaging (TUI) on 4-dimensional volumes of the fetal chest obtained with spatiotemporal image correlation and the color Doppler function.
We retrospectively evaluated the 4-dimensional spatiotemporal image correlation volumes of 8 fetuses with VSDs (single in 7 and double in 1) between 20 and 33 weeks' gestation. The data were analyzed to determine whether VSDs were correctly identified in at least 1 of 7 automatically generated TUI displays.
All of the included VSDs were correctly identified with the use of an interslice distance in the TUI function ranging from 0.8 to 2 mm without the need to further manipulate the volume.
This automatic approach shows good retrieval of diagnostic cardiac planes in fetuses with VSDs, which may improve the diagnostic accuracy for this disease.
Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine 08/2008; 27(7):1071-5. · 1.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to assess, in second-trimester fetuses with transposition of the great arteries (TGA), the performance of software (sonographically based volume computer-aided analysis) that automatically retrieves diagnostic cardiac planes from a 4-dimensional volume of the fetal chest obtained with spatiotemporal image correlation.
We retrospectively evaluated the 4-dimensional spatiotemporal image correlation volumes of 12 fetuses with TGA (complete TGA, 10 cases; correct TGA, 2 cases). The data were analyzed to determine whether the target diagnostic planes, that is, cardiac plane 1 (left ventricle outflow tract) and cardiac plane 2 (right ventricle outflow tract), were correctly identified in at least 1 of the 7 automatically generated tomographic sonographic image displays and whether they allowed diagnosis of TGA.
In 9 of 10 fetuses with complete TGA, target diagnostic cardiac plane 1 showed a branching arterial vessel (pulmonary artery) arising from the left ventricle, whereas in 7 of 10 fetuses, the aorta arising from the right ventricle was shown. In both cases with correct TGA, the pulmonary artery starting from the morphologic left ventricle was shown, whereas in 1 of 2, the connection of the aorta with the morphologic right ventricle was found. In all of the fetuses with TGA, a ventricular arterial connection anomaly was shown in either cardiac plane 1 or 2.
This automatic approach shows good retrieval of diagnostic cardiac planes in fetuses with TGA, which may improve diagnostic efficacy for this disease.
Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine 06/2008; 27(5):771-6; quiz 777. · 1.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To compare the efficacy of uterine artery Doppler velocimetry and three-dimensional ultrasound placental volume calculation alone or in combination in predicting at 11-14 weeks of gestation those pregnancies who will develop pre-eclampsia.
This was a prospective study of 348 nulliparous women scheduled for a routine prenatal ultrasound examination at 11-14 weeks. Color and pulsed wave Doppler was used to obtain uterine artery flow velocity waveforms transabdominally and the mean pulsatility index (PI) of the uterine arteries was calculated. The placental volume was measured by three-dimensional ultrasound using the virtual organ computer-aided analysis. Outcome variables considered were pre-eclampsia and pre-eclampsia requiring delivery <32 weeks.
Pre-eclampsia developed in 4.1% of the patients studied and in 1.7% a delivery before 32 weeks was required. Placental volume resulted significantly lower in pregnancies who will develop pre-eclampsia (t=4.636, p<0.003) and this was particularly evident in those pregnancies delivering <32 weeks (t=9.704, p<0.0002). No relationship was found between placental volume and mean uterine artery PI (r=-0.08, p=0.327). Uterine artery PI and placental volume showed similar sensitivities in predicting pre-eclampsia (50% vs. 56%) and pre-eclampsia with delivery <32 weeks (66.7% vs. 66.7%). The combination of uterine artery PI and placental volume gave better results when compared to the single use of one of these parameters (pre-eclampsia sensitivity 68.7%, pre-eclampsia requiring delivery <32 weeks 83.3%).
The combination of abnormal uterine artery Doppler and low placental volume at 11-14 weeks achieves better results than does either test alone in the prediction of pre-eclampsia.
European Journal of Obstetrics & Gynecology and Reproductive Biology 06/2008; 138(2):147-51. · 1.63 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To prospectively analyze the accuracy and rapidity of four-dimensional (4D) ultrasonography with spatiotemporal image correlation (STIC) in the assessment of four-chamber view and outflow tracts in unselected fetuses and in fetuses with congenital heart defects (CHD) at 19-23 weeks of gestation.
112 consecutive pregnancies undergoing routine second-trimester ultrasonographic scan and 10 pregnancies with fetuses with CHD affecting the great arteries formed the study group. From the four-chamber view, volumes of the fetal heart were acquired by the STIC technique and stored for a later offline analysis that was performed by two examiners blinded to the characteristics of the fetuses. Offline analysis was performed using a simplified multiplanar approach based on 3 different steps and one rotation finalized to visualize the four-chamber view and the left and right outflow tracts.
Adequate recognition of four-chamber view and outflow tracts was obtained in more than 80% of the volumes. There were no false-positives and only one observer had a false-negative (interrupted aortic arch classified as normal). The mean time required to interpret 4D volumes was 3.7 min.
The standard fetal cardiac anatomy survey can be performed in the second-trimester fetus by 4D STIC in both normal and abnormal hearts. This approach may reduce the operator's dependency in diagnosis of CHD.
Fetal Diagnosis and Therapy 01/2008; 24(2):126-31. · 2.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To assess the agreement of stroke volume (SV) measured with two-dimensional (2D) ultrasonography with Doppler capability (vs) four-dimensional (4D) with spatiotemporal image correlation (STIC) in normal and growth restricted fetuses.
2D Doppler and 4D STIC were used to measure SV of 40 normal fetuses at 20 to 22 and 28 to 32 weeks, and 16 growth-restricted fetuses at 26 to 34 weeks of gestation. Intraclass correlation was used to evaluate the agreement between left and right SV obtained by the two techniques, and proportionate Bland-Altman plots constructed. The time necessary to obtain SV was analyzed.
The intraclass correlation coefficient between 2D Doppler and 4D STIC measurements for the left ventricle were 0.977 and 0.980 for the right ventricle. The proportionate limits of agreement between the two methods were 18.7 to 23.9% for the left ventricle and - 20.9 to 21.7% for the right ventricle. The time necessary to measure SV was significantly shorter with 4D STIC (3.1 (vs) 7.9 min p < 0.0001) than with 2D Doppler.
There is a good agreement between SV measured either by 2D Doppler or by 4D STIC. The 4D STIC represents a simple and rapid technique to estimate fetal SV and promises to become the method of choice.
[Show abstract][Hide abstract] ABSTRACT: To establish the potential role of three-dimensional (3D) power Doppler evaluation of the placental circulation in aneuploidy screening at 11 to 13 + 6 weeks of gestation.
3D power Doppler ultrasound examination of the placenta was performed in 25 pregnancies with fetuses with abnormal karyotype and in 100 control pregnancies at 11 to 13 + 6 weeks of gestation. Using the same pre-established settings for all cases, the vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were calculated for the whole placenta.
In the chromosomally normal group all the vascular indices increased significantly with advancing gestation between 11 and 13 + 6 weeks (VI: r = 0.482, P < 0.001; FI: r = 0.295, P = 0.0029; VFI, r = 0.484, P < 0.001). In the chromosomally abnormal group, the flow indices were not significantly different from normal in cases with trisomy 21 (13 cases), but they were significantly reduced compared with normal in cases with trisomies 13 and 18 (VI: t = 8.321, P < 0.0001: FI: t = 12.934, P < 0.0001; VFI: t = 7.608, P < 0.0001).
3D power Doppler evaluation of the placental circulation is not useful in screening for trisomy 21, and unlikely to further increase the already high detection rate for trisomies 13 and 18. However, we provide normal ranges of placental vascular indices between 11 + 0 and 13 + 6 weeks of gestation, which may be useful in future research on placental vascularity in certain at-risk pregnancies.
Ultrasound in Obstetrics and Gynecology 09/2007; 30(3):259-62. · 3.14 Impact Factor