Effect of B-mode optimization techniques on fetal bowel echogenicity using computerized image analysis.

OBJECTIVES: The purpose of this study was to provide and compare measurable parameters for normal fetal bowel echogenicity under predefined B-mode scanning presets. METHODS: Forty healthy fetuses underwent 14- to 17-week ultrasound scans, and 40 underwent 21- to 25-week scans. Sagittal, coronal, and axial fetal abdominal images were tested using predefined B-mode presets. The presets differed from fundamental imaging by isolated activation of harmonic imaging, compound resolution imaging, speckle reduction imaging, focus and frequency composite imaging, and coded excitation imaging features. A transabdominal probe was used in all fetuses, and transvaginal images were added for the 14- to 17-week scans. The images were studied with custom-developed software, which provided a grayscale analysis of the pixels in the region of interest within the image. The mean brightness of the pixels from the fetal bowel area was calculated. RESULTS: The 14- to 17-week transabdominal scans showed significantly higher mean brightness on harmonic imaging compared to fundamental imaging (P < .01). Activation of coded excitation and compound resolution imaging in these scans resulted in a significant decrease in the mean brightness compared to fundamental imaging. Mean bowel brightness values on the 21- to 25-week transabdominal scans did not differ significantly with the use of the different imaging presets compared to fundamental imaging. CONCLUSIONS: Transabdominal harmonic imaging in the early second trimester may significantly increase the mean brightness of the fetal bowel tissue. Contrarily, compound resolution imaging and coded excitation imaging produce the opposite effect on bowel echogenicity.

Variations of the origin of renal arteries in the fetus identified on power Doppler and 3D sonography.

PURPOSE: To investigate anatomic variations of renal arteries (RAs) using 2-dimensional (2D)/3D power Doppler sonography (PDUS) in normal fetuses and in fetuses with renal anomalies. METHODS: The origin, direction, and distribution of RAs were studied in 120 fetuses without renal malformations using 2D/3D PDUS. Studies were performed between 14 and 17 weeks of gestation age on 64 male and 56 female fetuses. PDUS of the RAs was also performed in 12 fetuses with renal anomalies. RESULTS: In 117/120 fetuses, a single RA was found to originate from each side of the abdominal aorta. The origin of the right RA from the abdominal aorta was superior to, at the same level as, and inferior to that of the left RA in 47% (55/117), 25.5% (30/117), and 27.5% (32/117) of the cases, respectively. An accessory right RA was found in 3 cases. Bifurcation of the right RA was found in 2 cases. There were no variations of the origin of renal vessels in 69% of the cases (83/120), whereas the remaining 31% (37/120) had 1 or several variation patterns. Variations in renal vessels were found in 8 of the 12 fetuses with renal malformations: accessory artery in 3 cases, origin of the right RA from the iliac artery in horseshoe kidney and in 2 cases with pelvic kidney, and bifurcation in 2 of the fetuses with double collecting system. CONCLUSIONS: Variations in origin and distribution of fetal RAs are frequently observed in normal pregnancies. The majority of renal malformations are associated with such vascular variations.

[Ultrasound in the evaluation of intrauterine infection during pregnancy].

Ultrasound has an important role in the detection and follow- up of intrauterine infection. Viral infections are a major cause of fetal morbidity and mortality. Transplacental transmission of the virus, even in sub-clinical maternal infection, may result in a severe congenital syndrome. Prenatal detection of viral infection is based on fetal sonographic findings and PCR to identify the specific infectious agent. Most affected fetuses appear sonographically normal, but serial scanning may reveal evolving findings. Common sonographic abnormalities, although non-specific, may be indicative of fetal viral infections. These include growth restriction, ascites, hydrops, ventriculomegaly, intracranial calcifications, hydrocephaly, microcephaly, cardiac anomalies, hepatosplenomegaly, echogenic bowel, placentomegaly and abnormal amniotic fluid volume. Some of the pathognomonic sonographic findings enable diagnosis of a specific congenital syndrome (e.g., ventriculomegaly and intracranial and hepatic calcifications in cytomegalovirus or in toxoplasma; eye and cardiac anomalies in congenital Rubella syndrome; limb contractures and cerebral anomalies in Varicella Zoster virus). When abnormalities are detected on ultrasound, a thorough fetal evaluation is recommended because of multiorgan involvement.

Evaluation of fetal cerebrovascular circulation and brain development: the role of ultrasound and Doppler.

The human fetal brain is protected from pressure changes by autoregulation of the cerebral circulation. However, antenatal intrauterine cerebrovascular events are found to play an important role in the pathogenesis of perinatal brain damage. Changes in placental vascular resistance, cardiac contractibility, vessel compliance, and blood viscosity alter the normal dynamics of fetal cerebral circulation. The introduction of various sonographic techniques and the collection of data from the arterial and venous cerebral circulation provide a powerful tool for the evaluation of physiological and pathological hemodynamic events. Anatomic and physiological considerations of cerebral vasculature in healthy and disease states are relevant in studying brain development and variations in fetal brain blood perfusion. The major role of ultrasound and Doppler modalities in the evaluation of fetal cerebrovascular circulation is enabled by implementation of these considerations. Changes in flow characteristics in fetal cerebral vasculature can be used for clinical decision making in situations of fetal compromise, such as growth restriction and anemia.

Fetal eyeball volume: relationship to gestational age and biparietal diameter.

OBJECTIVE: To measure and determine normal values of the fetal eyeball volume between 14 and 40 weeks of gestation. METHODS: The volume of the fetal eyeball was measured with three-dimensional ultrasound between 14 and 40 weeks of gestation using the VOCAL software.Only singleton pregnancies without fetal growth restriction, diabetes mellitus, hypertension or major fetal malformation were included. RESULTS: Over all, 203 women were studied. In 125 both eyeballs were measured while in 78 only one eyeball was measured. The volume of the eyeball correlated strongly with gestational age (right: R = 0.946, P < 0.001, n = 171. left: R = 0.945, P < 0.001, n = 156), and with the biparietal diameter (BPD) (right: R = 0.949, P < 0.001, n = 171. left: R = 0.953, P < 0.001, n = 156). Using regression analysis the best correlation between eyeball volume and the BPD were: square of right eyeball = -0.180 + 0.187 BPD, square of left eyeball = -0.182 + 0.187 BPD. CONCLUSIONS: The volume of the eyeball has strong positive correlations with gestational age and BPD. Our data may be helpful in fetuses suspected of having eye anomalies.

Expectant management of pregnancy-related high-velocity uterine arteriovenous shunt diagnosed after abortion.

OBJECTIVE: To assess sonographic and clinical outcome in women with pregnancy-related uterine arteriovenous malformations (AVMs) diagnosed after abortion. METHOD: Twelve patients diagnosed as having AVMs after abortion were followed-up until resolution of the lesions. RESULTS: The 9 asymptomatic patients were managed expectantly for 4 to 10 weeks without further complications. None of the 12 required aggressive interventions such as transcatheter arterial embolization, and 6 had uncomplicated pregnancies after resolution of the lesions. CONCLUSION: Expectant management is an option in many women with pregnancy-related uterine AVMs.

Three-dimensional sonographic volumetry of the gestational sac and the amniotic sac in the first trimester.

OBJECTIVE: The purpose of this study was to measure the volumes of the gestational sac and amniotic sac in normal pregnancies during the first trimester with 3-dimensional sonography to prepare nomograms. METHODS: One hundred fifty-one patients between 6 and 12 weeks' gestation were studied. Nine aborted and were excluded, leaving 142 patients for evaluation. Inclusion criteria were a singleton viable pregnancy shown by transvaginal sonography and continuation of the pregnancy beyond 24 weeks. Women with known thrombophilia or fetal malformations were excluded. In all patients, gestational sac and amniotic sac volumes were measured by 3-dimensional transvaginal sonography with virtual organ computer-aided analysis software. RESULTS: The mean gestational sac volume was 20.35 mL (range, 0.7-113 mL) and correlated closely with the gestational age (GA) (r2 = 0.769; P << .001) and crown-rump length (CRL) (r2 = 0.823; P << .001). The mean amniotic sac volume was 3.69 mL (range, 0.01-92.1 mL) and also had a strong correlation with the GA (r2 = 0.869; P << .001) and CRL (r2 = 0.919; P << .001). CONCLUSIONS: Gestational sac and amniotic sac volumes show excellent correlation with the GA and CRL and hence may be used for determining the GA. Larger studies are needed to determine the importance of these volumes in predicting normal pregnancy outcomes and whether these volumes can be used in the management of pregnancies at risk for abortion.

Fetal weight estimation for prediction of fetal macrosomia: does additional clinical and demographic data using pattern recognition algorithm improve detection?

OBJECTIVE: The aim of this study was to test whether pattern recognition classifiers with multiple clinical and sonographic variables could improve ultrasound prediction of fetal macrosomia over prediction which relies on the commonly used formulas for the sonographic estimation of fetal weight. METHODS: THE SVM ALGORITHM WAS USED FOR BINARY CLASSIFICATION BETWEEN TWO CATEGORIES OF WEIGHT ESTIMATION: >4000gr and <4000gr. Clinical and sononographic input variables of 100 pregnancies suspected of having LGA fetuses were tested. RESULTS: Thirteen out of 38 features were selected as contributing variables that distinguish birth weights of below 4000gr and of 4000gr and above. Considering 4000gr. as a cutoff weight the pattern recognition algorithm predicted macrosomia with a sensitivity of 81%, specificity of 73%, positive predictive value of 81% and negative predictive value of 73%. The comparative figures according to the combined criteria based on two commonly used formulas generated from regression analysis were 88.1%, 34%, 65.8%, 66.7%. CONCLUSIONS: The SVM algorithm provides a comparable prediction of LGA fetuses as other commonly used formulas generated from regression analysis. The better specificity and better positive predictive value suggest potential value for this method and further accumulation of data may improve the reliability of this approach.

Sonographic findings in fetal viral infections: a systematic review.

UNLABELLED: Viral infections are a major cause of fetal morbidity and mortality. Transplacental transmission of the virus, even in subclinical maternal infection, may result in a severe congenital syndrome. Prenatal detection of viral infection is based on fetal sonographic findings and polymerase chain reaction to identify the specific infectious agent. Most affected fetuses appear sonographically normal, but serial scanning may reveal evolving findings. Common sonographic abnormalities, although nonspecific, may be indicative of fetal viral infections. These include growth restriction, ascites, hydrops, ventriculomegaly, intracranial calcifications, hydrocephaly, microcephaly, cardiac anomalies, hepatosplenomegaly, echogenic bowel, placentomegaly, and abnormal amniotic fluid volume. Some of the pathognomonic sonographic findings enable diagnosis of a specific congenital syndrome (eg, ventriculomegaly and intracranial and hepatic calcifications in cytomegalovirus, eye and cardiac anomalies in congenital rubella syndrome, limb contractures and cerebral anomalies in varicella zoster virus). When abnormalities are detected on ultrasound, a thorough fetal evaluation is recommended because of multiorgan involvement. TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians. LEARNING OBJECTIVES: After completion of this article, the reader should be able to recall that both clinical and subclinical maternal viral infections can cross the placenta, explain that there are specific sonographic findings along with laboratory findings to detect infectious agents, and state that when sonographic abnormalities are detected fetal viral infections need to be considered.

Instability of Doppler cerebral blood flow in monochorionic twins.

OBJECTIVE: The purpose of this study was to evaluate Doppler flow velocity changes in cerebral vessels of monochorionic twins with twin-twin transfusion syndrome (TTTS). METHODS: Repeated Doppler umbilical and cerebral blood flow studies were performed in 7 twin pairs with TTTS. Eight monochorionic twin pairs and 11 dichorionic twin pairs served as control groups. The following Doppler parameters were assessed: umbilical artery pulsatility index (PI), middle cerebral artery (MCA) PI, cerebroplacental ratio, delta PI between the umbilical artery and MCA, and peak systolic velocity (PSV) in the MCA. RESULTS: Significant variations in PSV in the MCA and cerebral indices were found in the study group of monochorionic twins with TTTS. Periods of high PSV with low PI in the MCA were followed by lower PSV in the same fetus. Repeated measurements in the comparison groups were stable without significant variations. The delta cerebroplacental ratio was significantly higher in the study group (0.38 versus 0.09 and 0.19 in the comparison groups; P < .02). CONCLUSIONS: Significant changes in Doppler flow velocity and indices suggest instability of cerebral blood flow with episodes of "hyperperfusion" in monochorionic twins with TTTS. Further studies are needed to elucidate the relationship of these transient changes to neurologic sequelae in the neonate.

Decidualization of ovarian endometriosis during pregnancy mimicking malignancy.

OBJECTIVE: The purpose of this series is to present deciduosis (the formation of extrauterine decidua) as one of the differential diagnoses of a malignant tumor during pregnancy. METHODS: Two cases are described in which pregnant patients had a pelvic tumor. The lesions, which were diagnosed in the early second trimester, consisted of complex masses with an extensive blood supply and had a sonographic appearance of a malignant tumor. The high suspicion for malignancy necessitated surgical intervention. RESULTS: During surgery, the lesions were observed to be of an ovarian origin with papillary excrescences covering their exterior. The lesions were excised and sent for histologic examination. The results showed a markedly decidualized endometriotic cyst in both cases. CONCLUSIONS: This phenomenon is a diagnostic challenge and should be considered in the differential diagnosis of a malignant mass during pregnancy.

Variables associated with successful vaginal birth after one cesarean section: a proposed vaginal birth after cesarean section score.

The objective of this study was to define the variables associated with vaginal birth after cesarean section (VBAC) and to develop a scoring system for the prediction of successful VBAC. We searched our computerized database for parturients with a history of one low-transverse cesarean section (CS) who were delivered during the year 2000. Variables were categorized according to the time period in which they were obtained: (1) first prenatal visit, (2) at the onset of labor, and (3) during labor. Univariate and multiple stepwise logistic regression models were fitted to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Of the 475 parturients with a history of one previous CS, 136 underwent elective CS and 339 underwent a trial of VBAC, of whom 82% were successful. Of the variables that can be obtained at the onset of labor, five were significantly associated with successful VBAC: abnormal presentation as the indication for the primary CS (OR, 7.4; 95% CI 2.8 to 19.2), a previous VBAC (OR, 7.2; 95% CI, 2.1 to 24.8), cervical dilation (OR, 2.5; 95% CI, 1.3 to 4.9), gestational age < or = 41 weeks (OR, 2.8; 95% CI, 1.1 to 7.1), and lower gestational age at the primary CS (OR, 1.2; 95% CI, 1.02 to 1.4). In the proposed VBAC score, each of the four most significant variables was assigned a score ranging between 0 and 3 based on the probability for VBAC. A score < or = 2 was associated with a success rate of 42%, a score between 3 and 6 was associated with a rate of 81%, and a score between 7 and 10 was associated with a 98% successful VBAC rate (p < 0001). The proposed VBAC score may help obstetricians when counseling their patients regarding the individual likelihood of a successful VBAC.