Assessment of fetal pulmonic stenosis by ultrasonography

This study was designed to determine (1) the value of Doppler echocardiography in depicting the presence of a fetal pulmonary stenosis, (2) its reliability in the assessment of the severity of the lesion, and (3) the usefulness of additional markers from the left side of the heart as criteria of severity. Fourteen pregnant ewes were included in this study (gestational age, 90 to 120 days). Banding of the fetal main pulmonary artery created mild (n = 3), moderate (n = 3), and severe (n = 5) stenosis. Three lambs were sham operated. Intrauterine fetal Doppler echocardiographic data obtained 15 days after surgery were compared with preoperative values. Peak velocities recorded through the band increased linearly from baseline in the groups with mild and moderate stenosis but did not show any further increase in the group with severe stenosis. Compared with the sham-operated group, right ventricular output in the group with stenosis was either similar or reduced significantly. The increase in right ventricular free wall thickness was significantly greater in the groups with stenosis compared with that of the sham-operated group; the correlation with the degree of severity was r = 0.65 and p < 0.05. A A stronger positive correlation was found between the severity of stenosis and aortic valve diameters: r = 0.82 and p < 0.01. The strongest correlation was found for right ventricular/left ventricular outputs (r = 0.92; p < 0.001). Thus Doppler peak velocities through the obstruction can help detect pulmonic stenosis but are not reliable for the assessment of its severity during fetal life. Other ultrasound measurements such as the size of the aortic anulus and especially the ratio of right ventricular/left ventricular output could be used as sensitive markers of the severity of stenosis.     

Ultrasound evaluation of the width of the fetal nose

The aim of the study was to construct a normal range for the width of the fetal nose during gestation. The study group included 229 healthy pregnant women with normal singleton pregnancies at 15-42 weeks of gestation. The ultrasound measurements were taken at the level of the lower border of the ala nasi, using the modified coronal view. Routine biometric measurements were obtained from the participants, including biparietal diameter, head and abdominal circumferences, cerebellum and femur lengths. Our results were used to construct objective measurements of the fetal nasal width across all gestational ages. We conclude that the nasal width can be easily measured from 15 weeks of gestation using the modified coronal view. A linear growth relationship was found between nasal width and gestational age, biparietal diameter, head and abdominal circumferences, and transcerebellar and femoral lengths. We feel that such measurements may prove useful in the diagnosis of cases at high risk for fetal facial abnormalities.     

Predicting birth weight by fetal upper-arm volume with use of three-dimensional ultrasonography

Previously, we demonstrated elevated cortisol production/release in response to the administration of the serotonin precursor, L-5-hydroxytryptophan (L-5-HTP) in untreated patients with obstructive sleep apnea (OSA). We hypothesized that if this elevated cortisol response to L-5-HTP was related to OSA, this finding would not be present in OSA patients treated with nasal continuous positive airway pressure (nCPAP). Eleven OSA patients treated for at least 1 month with nCPAP were studied. On two different days, we measured blood cortisol level every 15 min for 4 h following the ingestion of L-5-HTP, 0.4 mg/kg, or placebo, both given with carbidopa, a peripheral tryptophan decarboxylase inhibitor, used to prevent peripheral L-5-HTP metabolism before brain absorption. For a given subject, the cortisol response was calculated as the difference between the area under the curve of the L-5-HTP and placebo responses. In the nCPAP-treated OSA patients, this net cortisol response, 577 +/- 240 min.micrograms/dL, was less than the value found in the previously studied untreated OSA group, 1,198 +/- 227 min.micrograms/dL (p < 0.05) and not different from the previously studied nonapneic control group, 469 +/- 154 min.micrograms/dL. From these results, we speculate that nCPAP treatment reverses the elevated cortisol response to serotonergic stimulation seen in untreated OSA patients.     

Doppler ultrasonography of canine maternal and fetal arteries during normal gestation

Two-dimensional ultrasonography was used in combination with colour-flow imaging and pulsed wave Doppler ultrasonography to study the maternal circulation and the development of fetal vascularization in six Beagles during normal gestation. For the first time, the development of the circulation was demonstrated in the bitch and her fetuses intra vitam. The bloodstream was examined in small uteroplacental arteries, the umbilical artery, the fetal aorta and the common carotid artery. The duration of the study was from week 3 after insemination until birth. Relatively large vessels were detected by cross-sectional ultrasonography, and small vessels were detected by colour-flow imaging. In pulsed wave Doppler ultrasonography, the blood flow was measured and described using the parameters of systolic peak velocity, diastolic peak velocity, end-diastolic velocity, pulsatility index, resistance index, A:B ratio (systolic peak velocity:end-diastolic velocity) and S:D parameter (systolic peak velocity:diastolic peak velocity). The development of the measured parameters is typical and similar to that in humans. The systolic peak velocity of the canine maternal uteroplacental arteries shows important differences in comparison with humans. The pulsatility index, resistance index and A:B ratio decrease in nearly all vessels. Only the fetal common carotid artery has constant pulsatility and resistance indices during gestation. For the first time, the quality and quantity of the normal blood flow have been monitored during the whole of gestation. A normal circulation is fundamental for supplying the fetus adequately with oxygen and nutrients and thus for physiological development. These ultrasonographic results are the basis for further clinical studies.     

Three-dimensional ultrasonography of the fetal distal lower extremity: normal and abnormal

The objective of this study was to compare two-dimensional and three-dimensional ultrasonographic evaluation of fetal distal lower extremities. Data from two-dimensional and three-dimensional ultrasonographic examinations from 40 distal lower extremities in 33 fetuses from a predominantly high-risk patient population were compared. Three-dimensional ultrasonography routinely provided three orthogonal planes (coronal, sagittal, and axial) for distal lower extremity evaluation. Specific features of distal lower extremity evaluation were not different using two-dimensional and three-dimensional ultrasonography. Rotation of the rendered volume provided assistance in assessing all but one of 40 distal lower extremities. Time from image acquisition to assessment for two views (coronal and sagittal) was longer with three-dimensional ultrasonography (8.2 min) than with two-dimensional ultrasonography (3.2 min). Confidence in the diagnosis of abnormal distal lower extremities was slightly improved using three-dimensional ultrasonography compared to two-dimensional ultrasonography. Pregnancy management was assisted in three of the four cases with isolated limb anomalies. In conclusion, three-dimensional ultrasonography improves the ability to evaluate the fetal distal lower extremity because of the multiplanar nature of volume assessment and the ability to rotate volume data sets. In addition, it provides assistance in counseling families, particularly for cases involving isolated limb anomalies.     

Telemedicine and fetal ultrasonography: assessment of technical performance and clinical feasibility

OBJECTIVE: Our aim was to determine the performance and clinical feasibility of telesonography for the interpretation of fetal anatomic scans sent from a remote location compared with those obtained at a tertiary care prenatal ultrasonography center. STUDY DESIGN: Routine ultrasonographic studies from 35 patients were remotely interpreted. Evaluation included a blinded comparison of the sonographer's assessment of 38 fetal structures with that of the physician at the tertiary care center. Technical evaluation included system reliability and the number of digital telephone lines required for adequate real-time visualization. RESULTS: The mean gestational age at the time of the ultrasonography was 25.84 +/- 6.8 weeks (range 14 to 38). There was complete consistency of interpretation for 25 of 38 (66%) fetal structures. Thirteen structures had discrepancies in visualization, reflecting a difference in the adequacy of visualization, not the normalcy or identity of the structures. Three digital (integrated switching digital network, ISDN) telephone lines were required for real-time visualization. CONCLUSION: Our preliminary experience supports telesonography as a clinically useful tool for remote interpretation of fetal ultrasonographic examinations. Further studies are warranted for the continued evaluation of this emerging technology.     

Measurement of fetal cells in the maternal circulation

There is evidence that the quantitation of fetal-maternal hemorrhage may be useful in reducing some of the RhoGAM failures in preventing Rh sensitization. The Betke-Kleihauer technique is a well-established method that has been used to estimate the amount of transplacental hemorrhage. Recently, a kit (Fetaldex) has become available for use in the detection and quantitation of fetal-maternal hemorrhage. Using control blood smears, we compared the results of the Fetaldex kit with those results obtained by the Betke-Kleihauer technique. The data indicate that the Fetaldex method is as accurate as the Betke-Kleihauer technique in detecting and measuring fetal red cells in the maternal circulation.     

Echographic markers of fetal chromosomopathies. Diagnostic possibilities with transvaginal ultrasonography and our experience

OBJECTIVE: Aim of this study was to evaluate, during early pregnancy, the correlation of some anomalies and malformations with fetal chromosomopathies. EXPERIMENTAL DESIGN: Morphostructural and biometric anomalies in chromosomopathic fetuses were evaluated. PATIENTS: 1331 pregnancies at high risk for genetic disease and malformations referred to our center for prenatal diagnosis. METHOD: Scans were performed using endovaginal convex probes (5.0 to 7.0 MHz). SURVEYS: Urinary, cardiac and cerebral malformations as well as alterations of bone growth were evaluated. RESULTS: With respect to the other malformations, cystic hygroma is more frequently associated with an abnormal fetal karyotype. CONCLUSIONS: The majority of morphostructural abnormalities diagnosed during first trimester by transvaginal sonography cannot, in according to personal experience, be used as markers of chromosomopathies.     

Prenatal diagnosis of an extensive fetal lymphangioma using ultrasonography, magnetic resonance imaging and cytology

An unusual case of fetal lymphangioma diagnosed before delivery is reported in a second trimester pregnant woman. The lymphangioma was suspected at 28 weeks on the basis of the ultrasound appearances and progression of the lesions with advancing gestation. MRI was used to evaluate the extent and the tissue characteristics of the lesions. Cytology of the fluid aspirated from the cystic lesions showed abundant lymphocytes and macrophages, confirming the diagnosis of a lymphangioma. The parents opted for a pregnancy termination because of the rapid growth of the lesions and the poor prognosis. It is suggested that the combination of these tests could enable the early diagnosis of these tumours at a stage when the lesion is relatively limited and accessible to therapy in utero.     

Phasic flow events at the aortic isthmus-ductus arteriosus junction and branch pulmonary artery evaluated by multimodal ultrasonography in fetal lambs

OBJECTIVES: We assessed the phasic flow and interaction between the pulmonary trunk and aortic isthmus flow at their junction in the lamb fetus in late gestation and also assessed the interaction of the left pulmonary artery branch. STUDY DESIGN: With echocardiographic and Doppler ultrasonographic and saline-contrast techniques, we studied 7 fetal lambs with arterial and venous catheters in place to assess direction, velocity, and timing of flow at the aortic isthmus, ductus arteriosus, and proximal left pulmonary artery. RESULTS: At the isthmus-ductus junction, ductus systolic flow occurred later (0.048 +/- 0.006 second, mean +/- SD) and accelerated more slowly than isthmus flow but with higher velocities (peak 70.7 +/- 7.1 vs 63.1 +/- 6.3 cm/s, velocity time integral 5.7 +/- 1.2 vs 4.5 +/- 1.3 cm, respectively; P <.001). There was a small degree of late systolic flow reversal and admixture from both sources. Signals from the left pulmonary arterial branch showed a sharp, brief systolic forward flow with a peak velocity of 48.8 +/- 9.1 cm/s, followed by late systolic and diastolic flow reversal with a peak velocity of 23.5 +/- 8.7 cm/s. CONCLUSION: The differences in the flow timing may be the result of different timing of ventricular contraction, resistances in the vascular beds, and ductus constriction, both anatomic and physiologic.     

Measurement of fetal tissue protein synthetic rate in the lamb in utero

The fractional synthesis rate of the mixed proteins in the organs of fetal lambs at 123 to 130 days' gestation were calculated from measurements of the rate of uptake of L14Clysine by the protein in the steady state in utero. The fractional synthesis rates were 82, 121 and 99 per cent per day for the brain, liver and cardiac muscle respectively; the average values of 40 per cent for skeletal muscle was significantly smaller than for the other tissues. The fetal fractional protein synthetic rates measured were similar to those of the newborn lamb, but faster than in the adult sheep by a factor of 10. Similar differences in synthesis rates have been observed between the young and adult rat and the possible reasons for the change in fractional rate during growth are discussed.     

Identification of a parathyroid adenoma by operative ultrasonography

During surgery, real-time ultrasound scanning accurately localized a parathyroid adenoma posterior to be the superior pole of the right thyroid lobe. This was made feasible because of the ultrasound features of parathyroid tissue and current developments in ultrasound instrumentation.     

Glaucomatous cupping of the optic disk by ultrasonography

B-scan ultrasonography was used to evaluate advance glaucomatous cupping of the optic disk (0.7 cup/disk ratio or greater) in one normal subject and six patients with glaucoma. The normal eye emitted a continuous echo from the posterior pole, which conformed to its mild degree of concavity. The glaucomatous eyes emitted echos from the posterior pole, demonstrating the more extreme concavity of the optic cup. Ultrasonographic evaluation of an acrylic plate containing holes of known diameter demonstrated the limits of resolution and artifacts that resulted from this examination.     

Effects of target width and crosshair width on tracking performance.

In improving the ability of radar operators to follow something appearing on radar screens, what is the best relative size of crosshair compared to that of the target? The use of the Optical Comparator provided close control over variables under investigation and allowed recording of time and error scores. "An analysis of variance performed on the recovery time scores indicates that the target width and crosshair width main effects and their interaction are not statistically significant factors… . There is a tendency for decreased recovery time as target width increases, and an indication of an optimum crosshair width within the range of –1??" and –1??"." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Delivery of nasal powders of beta-cyclodextrin by insufflation

PURPOSE: Delivery of nasal powders of granulated beta-cyclodextrin by insufflation was studied in order to find the relationship between powder properties and delivery behavior. METHODS: Three nasal powder formulations, prepared by granulating beta-cyclodextrin with different binders, were delivered from a powder insufflation device, in which the dose to be emitted was loaded in a gelatin capsule. The delivery sequence of powder was recorded and characterized using an image analysis program. RESULTS: Particle size was the main parameter affecting nasal powder delivery, both as to the amount of dose sprayed and the aspect of cloud produced. Between 50-150 mu m of particle size a substantial change in delivery behavior of powders was observed. Powder of around 100 mu m in size showed useful insufflation characteristics for nasal delivery. Bioavailability of nasal formulations of progesterone/beta-cyclodextrin powders was discussed in term of delivery behavior. CONCLUSIONS: The formulation approaches for improving nasal delivery of powders require the use of size optimized carriers. Insufflation of powders over 50 mu m can favour the particle deposition by impaction, whereas for powders below 50 mu m, deposition by sedimentation is moved. beta-cyclodextrin is a suitable carrier for achieving high systemic availability following nasal administration of powder formulations.