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Biomedical subjects

R Achiron

Publications and source records attributed to R Achiron.

At least 55 records · Page 3Linked to original sources
PubMed2000

Sonographic and clinical characteristics of struma ovarii.

Our objective was to evaluate the preoperative clinical, laboratory, and sonographic characteristics of struma ovarii in comparison to ovarian dermoid cysts. A retrospective review of gynecologic patients operated on for mature cystic teratoma over a 10 year period identified 12 cases of struma ovarii. These cases, combined with 4 additional cases from an earlier report, were the subject of this study. Results were compared to 32 cases of ovarian dermoid cysts. Ovarian struma ovarii occurred in 12 (4.8%) of 251 cases of ovarian dermoid cysts. Most patients were premenopausal, and the mean lesion diameter was 57.3 mm (range, 30-95 mm). Struma ovarii occurred more frequently (68.8%) in the right adnexa and was seen with a normal CA-125 level. Blood flow, assessed by Doppler ultrasonography, was located in the center of the lesion in all cases of struma ovarii. Rare cases were seen with elevated tumor markers and low resistance blood flow. With regard to dermoid cysts, blood flow had a higher resistive index. In addition, no blood flow could be detected from the center of the echoic lesion in dermoid cysts (P < 0.0001). In summary, it is difficult to distinguish between struma ovarii and dermoid cysts on the basis of their sonographic appearance. Nevertheless, Doppler flow may aid in the preoperative diagnosis of struma ovarii. Blood flow signals, detected from the center of the echoic lesion, and low resistance to flow may be more common in struma ovarii.

Adult↗
PubMed2000

Contribution of color Doppler flow to the ultrasonographic diagnosis of tubal abnormalities.

Our objective was to characterize tubal abnormalities with color Doppler ultrasonography. We evaluated 25 women with adnexal masses suggestive of tubal masses using gray scale sonography. Color Doppler flow was added to further characterize the adnexal lesion. Of 18 women diagnosed as having hydrosalpinx, in 6 cases the diagnosis was tuboovarian abscess and in 1 case the diagnosis was tubal torsion. In the periphery of the hydrosalpinx, color Doppler flow revealed a mean resistive index of 0.752 +/- 0.04. In the periphery of the tuboovarian abscess, an abundant flow with reduced resistance to flow (mean resistive index = 0.448 +/- 0.04) was seen. The difference was statistically significant (P < 0.0001). In the case of adnexal torsion, no blood flow was detected in the lesion. All cases but one were confirmed in either laparoscopy or laparotomy or during colpotomy and drainage of the abscess. For adnexal masses suggestive of tubal lesions, color Doppler flow can further characterize the masses by detecting a significantly richer and low resistant blood flow in cases of tuboovarian abscess in comparison to hydrosalpinx.

Adult↗
PubMed1999

Pulmonary agenesis, microphthalmia, and diaphragmatic defect (PMD): new syndrome or association?

We present the prenatal diagnosis of a 22-week-gestation fetus with unilateral pulmonary agenesis, diaphragmatic hernia, microphthalmia, pulmonary vessel agenesis, and intrauterine growth retardation. The "association" of pulmonary agenesis, diaphragmatic defect, and microphthalmia was described previously in two patients but the resemblance was not noted by the authors. While each case differs slightly in some of the associated anomalies, it is evident that the mainstay of diagnosis is similar to the case presented here and that this represents a new syndrome or association.

Abnormalities, Multiple↗
PubMed1999

Prenatal diagnosis of distal arthrogryposis type 1.

A 23-year-old woman, gravida 1 parity 0, was referred for routine ultrasound examination at 23 weeks gestation. Fetal anatomy was normal. However, both hands demonstrated clasped thumbs without extension. Repeated ultrasound examination verified the bilateral hands posture. The position of the hands did not change following sound stimulation. The child was diagnosed as distal arthrogryposis type 1. Prenatal counselling by the pediatric orthopedic surgeon, geneticist and gynecologist, was provided, to inform the parents on the probable outcome of the fetus and the hands. The parents were advised to continue with the pregnancy. A 1,975-g healthy boy was delivered by spontaneous vaginal delivery. Neonatal examination confirmed the prenatal diagnosis of arthrogryposis type 1. Following reconstructive surgery the child functions well with both his hands.

Adult↗
PubMed1999

Selective termination for structural, chromosomal, and mendelian anomalies: international experience.

OBJECTIVE: Our purpose was to evaluate the outcomes of selective termination for fetal anomalies at 8 centers with the largest known experiences worldwide. STUDY DESIGN: Outcomes in 402 cases of selective termination in pregnancies with dizygotic twins from 8 centers in 4 countries were analyzed by year, gestational age at procedure, and indication. Reductions of fetuses were as follows: 2 to 1, n = 345; 3 to 2, 39; >/=4 to 2 or 3, n = 18. Potassium chloride was used in all procedures. RESULTS: Selective termination resulted in delivery of a viable infant or infants in >90% of cases. Loss up to 24 weeks occurred in 7.1% of cases in which the final result was a singleton fetus and in 13.0% of cases in which the final result was twins. Loss was 6.6% as a result of structural abnormalities, 7.0% for chromosomal abnormalities, and 10% for mendelian abnormalities (difference not statistically significant). Loss rates for procedures were as follows: 9-12 weeks, 5.4%; 13-18 weeks, 8.7%; 19-24 weeks, 6.8%; and >/=25 weeks, 9.1% (difference not statistically significant). Mean gestational age at delivery was 35.7 weeks. No differences were seen in outcomes by maternal age. The rate of very early premature deliveries has fallen in recent years. There were no known cases of disseminated intravascular coagulation or serious maternal complications. CONCLUSION: (1) Selective termination, in the most experienced hands, can be technically performed in all 3 trimesters with good outcomes in >90% of cases. (2) The previously observed increase in second- versus first-trimester losses has diminished. (3) Third-trimester procedures, where legal, can be performed with a good outcome for the surviving fetus.

Chromosome Aberrations↗
PubMed1999

Pregnancy and multiple sclerosis: a 2-year experience.

OBJECTIVE: To present our experience with management of parturients with multiple sclerosis and to examine the role of intravenous immunoglobulin (IVIg) in the prevention of postpartum exacerbations of the disease. METHODS: Fifteen patients with multiple sclerosis with a relapsing-remitting course were followed during pregnancy and 6 months postpartum. To prevent postpartum exacerbations, 14 of the patients had received IVIg after delivery. RESULTS: None of the patients who received postpartum IVIg relapsed during the 6 months after delivery. None of the observed obstetric complications nor the operative deliveries could be related to the coexistence of multiple sclerosis. CONCLUSION: Postpartum IVIg treatment is beneficial in preventing acute childbirth-associated exacerbations in patients with relapsing-remitting multiple sclerosis. Furthermore, this disease does not seem to increase obstetric complications.

Adult↗
PubMed1999

The development of the fetal sternum: a cross-sectional sonographic study.

OBJECTIVE: To assess the relationship between gestational age and sonographic appearance of the various sternal components and establish growth during human gestation. DESIGN: A prospective cross-sectional study. METHODS: The study was performed on 252 consecutive normal singleton pregnancies from 19 weeks of gestation until term, using transabdominal high-resolution ultrasound techniques. The sternal length, as well as the number of ossification centers at each gestational age, were recorded. RESULTS: The first occasion at which a fetal human sternum could be visualized with two to three ossification centers was at 19 weeks' gestational age. The fifth ossification center was first visualized at 29 weeks' gestation. The mean +/- SE of sternal length varied from 15 +/- 0.98 mm (95% confidence interval (CI) 12.79-17.21) at 19-20 weeks, to 36.50 +/- 0.29 mm (95% CI 35.58-37.42) at 37-38 weeks' gestation. Sternal length as a function of gestational age was expressed by the regression equation: sternal length (mm) = -11.06 + 1.39 x gestational age (weeks). The correlation coefficient, r = 0.924 for sternal length, was found to be highly statistically significant (p < 0.0001). CONCLUSIONS: The presented data offer normative measurements of the fetal sternum which may be helpful in the prenatal diagnosis of congenital syndromes that include, among other manifestations, abnormalities of sternal development.

Confidence Intervals↗
PubMed1999

Simultaneous multigate spectral Doppler imaging of the umbilical artery and placental vessels: novel ultrasound technology.

OBJECTIVE: To establish gestational age-specific nomograms of pulsatility indices in the umbilical artery and chorionic and intraplacental vessels, using novel ultrasound technology. STUDY DESIGN: A prospective, cross-sectional study of 160 healthy singleton pregnancies between 18 and 33 weeks of gestation. MEASUREMENTS: Using simultaneous multigate spectral Doppler imaging specialized hardware and software, we measured the flow velocity waveforms of the umbilical artery, chorionic and intraplacental vessels. Computerized automatic mapping calculated the pulsatility indices in regions of interest. RESULTS: Data were adequately obtained for 160 fetuses. The pulsatility index values in the three sites measured decreased with advancing gestational age; the correlation coefficients r = -0.74, r = -0.67 and r = -0.68 for the umbilical artery, chorionic and intraplacental vessels, respectively, were found to be highly statistically significant (p < 0.0001). CONCLUSION: Simultaneous multigate spectral Doppler imaging provides simultaneous measurements of the velocity waveforms in the umbilical artery, chorionic and intraplacental vessels, and is a feasible and reproducible method of obtaining these data. The normal data presented may facilitate early detection of flow disturbances in the fetoplacental circulation.

Adult↗
PubMed1999

Placental blood flow measured by simultaneous multigate spectral Doppler imaging in pregnancies complicated by placental vascular abnormalities.

OBJECTIVE: To evaluate the role of placental blood flow measurements by simultaneous multigate spectral Doppler imaging in pregnancies complicated by intrauterine growth restriction (IUGR), and for early detection of placental vascular abnormalities in high- and low-risk pregnancies. METHODS: To assess the sensitivity and specificity of abnormal placental blood flow in detecting IUGR, we followed 22 women whose pregnancies were complicated by IUGR at 28-34 weeks' gestation, and compared the findings with those obtained in 22 matched controls. We defined placental blood flow impedance as abnormal when 10% of placental pulsatility index (PI) measurements were greater than, or equal to, the mean umbilical artery PI (placental PI/umbilical PI > or = 1). To determine the predictive value of abnormal placental blood flow measurement for identifying developing uteroplacental insufficiency, we examined an unselected group of 100 low- and high-risk patients at 20-22 weeks' gestation. We correlated the Doppler findings with the development of pre-eclampsia, IUGR, placental abruption, oligohydramnios and the presence of persistent late decelerations during labor. RESULTS: Placental blood flow determination was more sensitive than umbilical artery blood flow in detecting abnormal umbilical-placental flow impedances as manifested by the presence of IUGR. Of the 100 mixed high- and low-risk patients examined at 20-22 weeks, 32 had abnormal placental blood flow. Of these, 19 (59.4%) subsequently developed pathologies associated with placental vascular disease. Of the 68 patients with normal placental blood flow, only six (8.8%) developed such pathologies. The sensitivity was 76% (19/25), with positive predictive value 59.4% (19/32); the specificity was 82.7% (62/75), with negative predictive value 91.2% (62/68). CONCLUSIONS: Abnormal intraplacental blood flow at 28-34 weeks' gestation is strongly associated with IUGR. In addition, it has moderate positive and negative predictive values for identifying subsequent development of uteroplacental vascular abnormalities.

Adult↗
PubMed1999

Development of the fetal uterus between 19 and 38 weeks of gestation: in-utero ultrasonographic measurements.

In-utero assessment of the internal female genitalia is important for determination of fetal gender in fetuses with suspected genital tract anomalies. We therefore measured fetal uterine transverse width and circumference from 19 weeks of gestation until term, using transvaginal and transabdominal high-resolution ultrasound techniques in order to establish nomograms. A prospective, cross-sectional study on 180 normal singleton pregnancies was performed. Data were obtained for 140 normal fetuses. The mean +/- SD uterine width and circumference were 12.9 +/- 4.1 mm (95% confidence interval 12.1-13.7), and 40.2 +/- 12.5 mm (95% confidence interval 37.9-42.5) respectively. Uterine size as a function of gestational age was expressed by the regression equations: uterine width (mm) = 12.9 + 0.7 x gestational age (weeks), and uterine circumference (mm) = 40.2 + 2.1 x gestational age. The correlation coefficients, r = 0.885 and r = 0.888, for uterine width and circumference, by gestational age respectively, were highly statistically significant (P < 0.001). A nomogram of uterine width and circumference per gestational week, and the 95% prediction limits were defined. The present data offer baseline measurements of the fetal uterus that may allow intrauterine assessment of the female genital tract and associated fetal gender.

Cross-Sectional Studies↗
PubMed1999

The relationships between endometrial thickness, and blood flow and pregnancy rates in in-vitro fertilization.

To establish whether endometrial blood flow and thickness can predict the success rate of in-vitro fertilization, 156 cycles were evaluated. The parameters were: endometrial colour and power Doppler pulsatility index (PI), resistance index (RI), systolic/diastolic ratio (S/D) and endometrial thickness. Each patient was studied: on the day of ovum retrievalpickup, and on the day of embryo transfer. Non-endometrial parameters studied were: age, oestrestrogen and progesterone concentrations, number of oocytes, and number of embryos. Pregnancy was achieved in 31 cycles. On the day of ovum retrieval, patients who conceived had PI, RI, and S/D values of 0.997, 0.563, and 2.403, respectively. Patients who did not conceive had values of 0.994, 0.584, and 2.477 respectively. The power Doppler technique provided similar results. On the day of embryo transfer, pregnant patients had PI, RI and S/D values of 1.096, 0.590 and, 2.597 respectively, while in the non-pregnant patients the values were 1.104, 0.603 and, 2.723 respectively. Power Doppler showed similar numbers. The differences between pregnant and non-pregnant patients were not statistically significant in any of the parameters. Endometrial thickness and blood flow does not seem to correlate with pregnancy rate in IVF.

Cell Division↗
PubMed1999

Assessment of fetal cardiovascular function: ultrasound study of the fetal circulatory compartments.

Recent advances in high-resolution ultrasonography combined with color-coded Doppler analysis have enabled a new insight to be gained into fetal physiology and allowed the investigation of small, previously inaccessible fetal vessels under normal and abnormal conditions. In addition, the findings in some cases contradict the accepted fetal pathophysiology derived from animal studies. The aim of the present study is to describe new reports assessing the major compartments of the fetal cardiovascular system (heart, lung, splanchnic and fetal venous circulations) and to discuss the developments in these fields.

Cardiovascular Physiological Phenomena↗
PubMed1999

[Sonographic demonstration of a levonorgestrel-releasing IUD (Mirena)].

Mirena, a new intra-uterine device (IUD) introduced in Israel during the past year, releases 20 mcg/day of levonorgestrel for 5 years. It has the advantages of reduced pregnancy rates and diminished menstrual blood loss, together with a low risk of pelvic inflammatory disease compared with current IUD's. It has a typical sonographic appearance, differing from that of regular IUD's, which was demonstrated in all 15 women examined in this study. Its sonographic appearance includes both proximal and distal ends of the vertical arm of the device, which extend into the internal cervical os and fundal region, respectively. Acoustic shadowing between both ends defines the location of the device, which should help avoid consultations due to "lost IUD's."

Contraceptive Agents, Female↗
PubMed1998

Fetal enterolithiasis and anhydramnios; due to in utero hepatorenal syndrome?

Enterolithiasis is a rare, prenatal ultrasonographic finding. Previously reported cases were invariably associated with major fetal malformations. We describe a case of fetal enterolithiasis and anhydramnios in an anatomically normal fetus who, at autopsy, showed end-stage fetal liver disease. Fetal hepatorenal syndrome is the most probable cause of this in utero sonographic combination.

Adult↗
PubMed1998

The development of the foetal thyroid: in utero ultrasonographic measurements.

OBJECTIVE: The early recognition of potentially treatable thyroid disease in the foetus frequently depends on the detection of abnormal growth of the foetal thyroid gland. We have therefore established nomograms for foetal thyroid transverse width and circumference from 14 weeks of gestation until term, using transvaginal and transabdominal high-resolution ultrasound techniques. DESIGN: A prospective, cross-sectional study of 193 normal singleton pregnancies was performed. MEASUREMENTS: Thyroid size was measured by transvaginal ultrasonography between 14 and 17 weeks, and by abdominal ultrasound from 18 to 37 weeks of gestation. RESULTS: Data was accurately obtained for 193 foetuses. The mean +/- SD thyroid width and circumference were 11.7 +/- 4.1 mm (95% confidence interval 11.1-12.3) and 39.5 +/- 14.1 mm (95% confidence interval 37.4-41.6), respectively. Thyroid size as a function of gestational age was expressed by the regression equations: thyroid width (mm) = -3.94 + 0.68 x gestational age (weeks), and thyroid circumference (mm) = -1.38 + 0.23 x gestational age (weeks). The correlation coefficients, r = 0.91 and r = 0.93, for thyroid width and circumference, respectively, were found to be highly statistically significant (p < 0.0001). The normal mean of thyroid width and circumference for each week of gestational age and the 95% prediction limits were defined. CONCLUSIONS: The present data offer normative measurements of the foetal thyroid that may facilitate the prenatal diagnosis of foetal goitre and make early administration of in utero treatment possible.

Cross-Sectional Studies↗
PubMed1998

In utero ultrasonographic measurements of fetal aortic and pulmonary artery diameters during the first half of gestation.

The study was conducted to construct a normal range for the diameters of the aortic root and pulmonary artery during the first half of gestation. With the use of transvaginal and transabdominal high-resolution ultrasound techniques, a prospective, cross-sectional study was performed on 139 normal singleton pregnancies at between 14 and 26 weeks. Great vessel diameters were measured by transvaginal ultrasonography until 17 weeks, and by transabdominal ultrasound between 18 and 26 weeks' gestation. The results showed that the aortic diameter (AD) as a function of gestational age (GA) was expressed by the regression equation AD = -16.0331 + 2.2563 x GA, and the pulmonary artery diameter (PD) by PD = -14.7637 + 2.4026 x GA; AD and PD are expressed in millimeters and GA in weeks. The correlation r2 = 0.94 was found to be highly statistically significant (p < 0.0001) for both great vessels. The normal mean of aortic and pulmonary artery diameter per week and the 95% prediction limits were also defined. During the study period we evaluated two cases with arterial diameters outside the 95% confidence limits; one had aortic coarctation and the other tetralogy of Fallot. The normative data established by us may be helpful in the prenatal diagnosis of congenital heart defects that include, among their manifestations, discordant diameters of the great vessels.

Aorta↗