Fetal magnetic resonance imaging in isolated diaphragmatic hernia: volume of herniated liver and neonatal outcome

OBJECTIVE

We sought to use magnetic resonance (MR) imaging (MRI) to estimate percentage of fetal thorax occupied by lung, liver, and other abdominal organs in pregnancies with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

This was a retrospective study of pregnancies with isolated CDH referred for MRI between August 2000 and June 2006. Four regions of interest were measured in the axial plane by an investigator blinded to neonatal outcome, and volumes were then calculated. The percentages of thorax occupied by lung, liver, and all herniated organs were then compared with neonatal outcomes.

RESULTS

Fifteen CDH fetuses underwent MRI at a median gestational age of 29 weeks. Liver herniation was found in 93%. When the liver occupied > 20% of the fetal thorax, neonatal deaths were significantly increased. Percentages of lung and other herniated organs were not associated with outcome.

CONCLUSION

In our MR series of isolated CDH, neonatal deaths were significantly increased when > 20% of the fetal thorax was occupied by liver.

Design of a light stimulator for fetal and neonatal magnetoencephalography

The design, safety analysis and performance of a fetal visual stimulation system suitable for fetal and neonatal magnetoencephalography studies are presented. The issue of fetal, neonatal and maternal safety is considered and the maximum permissible exposure is computed for the maternal skin and the adult eye. The risk for neonatal eye exposure is examined. It is demonstrated that the fetus, neonate and mother are not at risk.

Reagent strip testing for antenatal screening and first meaningful of asymptomatic bacteriuria in pregnant women

OBJECTIVE

To evaluate the diagnostic performance of reagent strip test as a screening test for asymptomatic bacteriuria (ABU) in pregnant women.

MATERIAL AND METHOD

Three hundred and sixty asymptomatic pregnant women who attended their first antenatal appointment at Rajavithi Hospital from August 1st to October 31st, 2005 were enrolled Those with symptoms of urinary tract infection within one month, those who had been prescribed antibiotics during the previous 7 days, and those with medical or obstetric complications, vaginal bleeding and a history of urinary tract diseases were excluded Urine specimens were collected by clean-catched midstream urine technique for urine dipstick and culture.

RESULTS

The prevalence of ABU was 10.0% The urine dipstick nitrite leukocyte esterase and combined test had a sensitivity of 16.7%, 75.0% and 16.7%, specificity of 99.1%, 67.9% and 99.4%, positive predictive value of 66.7%, 20.6% and 75.0%, negative predictive value of 91.5, 96.1% and 91.5%, accuracy of 90.8%, 68.6% and 91.1%, respectively.

CONCLUSION

Reagent strip testing indicated a fair sensitivity for routine antenatal screening for asymptomatic bacteriuria in pregnant women

Misuse of prenatal diagnostic technology for sex-selected abortions and its consequences in India

During 1800, the British Government found that there were no daughters in a village in the Eastern Uttar Pradesh region of India. According to the 2001 Census, there were less than 93 women for every 100 men in the Indian population. The prevailing concept that the birth of a female child can signal the beginning of financial ruin and extreme hardship for a poor Indian family is understandable. What is surprising is that even high-income families do not want a female child. The Government of India in its 10th Plan recognized the rights of the female child to equal opportunity, to be free from hunger, illiteracy, ignorance and exploitation. In the National Policy for the Empowerment of Women 2001, a policy framework was laid down for the elimination of discrimination against, and violation of, the rights of the female child. However, the situation continues to worsen, and studies have revealed that sex-selected abortions are practised among all communities despite enactment of laws prohibiting prenatal sex determination. In this paper, we examine the functioning and consequences of the misuse of this technology.

Biochip for separating fetal cells from maternal circulation

Isolation of fetal cells from maternal circulation is the subject of intense research to eliminate the need for currently used invasive prenatal diagnosis procedures. Fetal cells can be isolated using magnetic-activated cell sorting or fluorescence-activated cell sorting, however no technique to specifically isolate and use fetal cells for genetic diagnosis has reached routine clinical practice. This paper demonstrates the use of a micromachined device to separate fetal cells from maternal circulation based on differences in size and deformation characteristics. Nucleated fetal red blood cells range in diameter from 9 to 12 microm can deform and pass through a channel as small as 2.5 microm wide and 5 microm deep. Although the white blood cells range in diameter from 10 to 20 microm, they cannot deform and are retained by the 2.5 microm wide and 5 microm deep channels under our experimental conditions. Fetal cells were isolated from cord blood and DNA analysis confirmed their fetal origin with ruled out maternal contamination.

Thoracoamniotic Shunting with Double-Basket Catheters for Fetal Chylothorax in the Second Trimester

The progress of a fetal severe pleural effusion at mid-trimester is extremely poor. We encountered a fetus that developed a severe left pleural effusion at 21 weeks of gestation. The pleural effusion was removed by thoracocentesis at 22 weeks. Cytology revealed abundant lymphocytes, suggesting chylothorax. However, a reaccumulation of pleural effusion with hydrops was subsequently noted, and a thoracoamniotic shunt with double-basket catheters was installed at 23 weeks. The pleural effusion decreased after 24 weeks and completely disappeared at 26 weeks. At 40 weeks of gestation, a female infant was born by vaginal delivery, with no evidence of pleural effusion. We would like to stress that thoracoamniotic shunt with double-basket catheters in the second trimester is effective for pleural effusion with hydrops.

IRM fœtale : indications, limites et dangers

Although prenatal sonography remains the primary imaging method for screening fetal anomalies, fetal MRI with ultrafast imaging technique is a complementary imaging method as soon as the second trimester. It allows better tissue contrast images than does US, a large field of view of the foetus and is not limited by large maternal body habitus and oligohydramnios, without any risk for the foetus. In the future, the development of new techniques (diffusion-weighted imaging, proton MR spectroscopy) and faster sequences will make it possible to widen the indications i.e. cardiac, functional renal and cerebral imaging.

A fast and easy nitroblue tetrazolium method for carrier screening and prenatal detection of chronic granulomatous disease

BACKGROUND

Analysis of the functional activity of neutrophils is of great importance in the differential diagnosis of patients with recurrent bacterial infections. It has long been established that stimulated polymorphonuclear leukocytes reduce nitroblue tetrazolium. Application of a simple and reliable nitroblue tetrazolium method that clearly differentiates the chronic granulomatous disease patients and heterozygote carriers in some groups suspected to have chronic granulomatous disease was investigated.

METHODS

This study consisted of 197 samples taken from 100 children (2 - 24-month-old) and 81 neonates (aged < 2 months) referred to our center either due to a suspected bacterial infection or suspected immunodeficiency. The sample also included 16 cord blood samples. Fifty healthy adult individuals were enrolled in this study and were diagnosed as normal control. Neutrophil reduction of nitroblue tetrazolium can be stimulated in vitro by protein kinase agonists such as phorbol myristate acetate, resulting in release of superoxide anion.

RESULTS

Phorbol myristate acetate is an exceptionally powerful stimulant and when used in conjunction with glass adherence, caused nearly all normal neutrophils to become transformed and reduced nitroblue tetrazolium to formazan deposits. Of 197 blood samples, 9 were diagnosed as having unrelated chronic granulomatous disease and 7 were carriers of X-linked or autosomal recessive chronic granulomatous disease. The carriers had a range of 15 - 75% stimulated neutrophils.

CONCLUSION

We have established a phorbol myristate acetate-stimulated nitroblue tetrazolium test for detection of chronic granulomatous disease patients, which clearly differentiates the chronic granulomatous disease patients from heterozygote carriers. The results in cord fetal blood indicate that this test may be used for antenatal diagnosis of affected boys, carrier females, and autosomal recessive variants of chronic granulomatous disease. The technique is simple, fast, inexpensive, and requires only a few microliters of blood.

Dynamic motion analysis of fetuses with central nervous system disorders by cine magnetic resonance imaging using fast imaging employing steady-state acquisition and parallel imaging: a preliminary result

OBJECT

The authors present a novel cine magnetic resonance (MR) imaging, two-dimensional (2D) fast imaging employing steady-state acquisition (FIESTA) technique with parallel imaging. It achieves temporal resolution at less than half a second as well as high spatial resolution cine imaging free of motion artifacts for evaluating the dynamic motion of fetuses in utero. The information obtained is used to predict postnatal outcome.

METHODS

Twenty-five fetuses with anomalies were studied. Ultrasonography demonstrated severe abnormalities in five of the fetuses; the other 20 fetuses constituted a control group. The cine fetal MR imaging demonstrated fetal head, neck, trunk, extremity, and finger as well as swallowing motions. Imaging findings were evaluated and compared in fetuses with major central nervous system (CNS) anomalies in five cases and minor CNS, non-CNS, or no anomalies in 20 cases. Normal motility was observed in the latter group. For fetuses in the former group, those with abnormal motility failed to survive after delivery, whereas those with normal motility survived with functioning preserved. The power deposition of radiofrequency, presented as specific absorption rate (SAR), was calculated. The SAR of FIESTA was approximately 13 times lower than that of conventional MR imaging of fetuses obtained using single-shot fast spin echo sequences.

CONCLUSIONS

The following conclusions are drawn: 1) Fetal motion is no longer a limitation for prenatal imaging after the implementation of parallel imaging with 2D FIESTA, 2) Cine MR imaging illustrates fetal motion in utero with high clinical reliability, 3) For cases involving major CNS anomalies, cine MR imaging provides information on extremity motility in fetuses and serves as a prognostic indicator of postnatal outcome, and 4) The cine MR used to observe fetal activity is technically 2D and conceptually three-dimensional. It provides four-dimensional information for making proper and timely obstetrical and/or postnatal management decisions.

MRI of the olfactory bulbs and sulci in human fetuses

BACKGROUND

There is limited knowledge of the MRI pattern of the development of fetal olfactory bulbs and sulci.

OBJECTIVE

To describe the MRI appearance of olfactory bulbs and sulci in normal in vivo fetuses according to gestational age.

MATERIALS AND METHODS

Olfactory bulbs and sulci were retrospectively assessed on brain MRI examinations of 88 normal fetuses between 24 and 39 weeks gestational age. Two reference centres were involved in the study and both used routine protocols that included axial and coronal T2- and T1-weighted sequences at 1.5 T. The results were compared both with the commonly used neuropathological data in the literature and with personal neuropathological data. Pearson's chi-squared test or Fisher's exact test were performed. One case of olfactory agenesis associated with CHARGE syndrome was identified.

RESULTS

T2-weighted coronal sequences were the most sensitive for detecting olfactory bulbs and sulci. Olfactory sulci were significantly better detected from 30 weeks onwards (90.9-100%; P<0.001). MRI showed a posteroanterior development of these sulci. Olfactory bulbs were better detected from 30 to 34 weeks (80-90.9%; P<0.002). Comparison with neuropathological data confirmed the posteroanterior development of the sulci and showed an important delay in detection of the olfactory structures (bulbs and sulci). No difference was observed between the two centres involved.

CONCLUSIONS

To date, fetal MRI can depict olfactory sulci from 30 weeks gestational age onwards and olfactory bulbs from 30 to 34 weeks gestational age. This preliminary reference standard is useful to assess the normality of the olfactory system and to diagnose olfactory agenesis.

Rapid genetic analysis of oculocutaneous albinism (OCA1) using denaturing high performance liquid chromatography (DHPLC) system

OBJECTIVES

To present the prenatal genetic diagnoses and counseling for two cases of oculocutaneous albinism (OCA) type I family by detection of mutations in the OCA1 gene by denaturing high performance liquid chromatography (DHPLC) system and a review of the literature.

METHODS

All DNA samples were extracted from peripheral whole blood and amniocentesis-derived cells. Mutation analysis was performed for all five coding exons of the TYR gene, which were amplified by PCR. DHPLC was used for heteroduplex detection and sequence analysis was performed to demonstrate the mutation loci.

RESULTS

Case 1: After sampling of blood from the family members and performing amniocentesis of the fetus, it was demonstrated that the affected boy and the female fetus were shown to be compound heterozygotes for mutations in the TYR gene. In addition, it was shown that the parents were carriers of the two mutations. However, the couple chose to keep the baby. Case 2: Mutation analysis of the DNA of the siblings revealed two heterozygous mutations in the TYR gene. Her husband is free of the disease. According to the principles of autosomal recessive inheritance, the incidence of affected offspring is very low.

CONCLUSIONS

Herein we introduce a novel application for molecular diagnostic of DHPLC coupled with direct sequencing, which can provide an effective and exact diagnosis in patients with albinism. Clinicians should be cognizant of the risk of OCA inheritance by the offspring through careful identification of genetic mutations and the inheritance mode, both important to ensure comprehensive genetic counseling.

Four-dimensional ultrasonographic guidance for invasive obstetric procedures

OBJECTIVE

This pilot study evaluated the use of 4-dimensional (4D) real-time ultrasonographic needle guidance for amniocentesis, chorionic villus sampling (CVS), cordocentesis, and intrauterine transfusions.

METHODS

Ninety-nine consecutive procedures were performed with 4D (real-time) multiplanar ultrasonographic imaging. Amniocentesis was done freehand in 3 orthogonal planes of view. Chorionic villus sampling, cordocentesis, and intrauterine transfusions were accomplished with a needle guide and 2 projected orthogonal planes.

RESULTS

Needle tip visualization in the A, B, and C orthogonal planes during amniocentesis was noted in 93%, 63%, and 69% of cases, respectively. When a needle guide was used during CVS and cordocentesis, the needle tip was always seen in the 2 projected orthogonal planes, and no lateralization occurred. Four intrauterine transfusions were done with the 4D technique. The only procedural complication in any patient was bradycardia from vessel spasm during an intrauterine transfusion, requiring a cesarean delivery. There were no statistical differences (P > .05) between the numbers of needle insertions required in the 4D group compared with a historical control group in which 2-dimensional ultrasonographic needle guidance was used.

CONCLUSIONS

In this feasibility study, a real-time 4D needle guidance technique was successfully used to perform amniocentesis, CVS, cordocentesis, and intrauterine transfusion. This appeared to contribute to the accuracy of needle placement by eliminating the lateralization phenomenon when a fixed needle guide attachment was used (for CVS and cordocentesis). Needle tip visualization was seen in each orthogonal plane in most freehand 4D amniocentesis cases. Future developments in 4D ultrasonographic technology may refine the utility of this technique for invasive obstetric procedures.

Automatic Computerized Diagnosis of Fetal Sinusoidal Heart Rate

OBJECTIVES

Computerized automatic detection of pathologic fetal sinusoidal heart rate (FSHR) and its differentiation from physiologic FSHR is the purpose of this study. The results will be applied in the objective evaluation of fetal heart rate (FHR) with artificial neural network computer.

METHODS

FHR tracings of pathologic FSHR of 9 cases of fetal-neonatal anemia, death, or severe asphyxia, those of 7 physiologic FSHR followed by normal outcome, and those of 5 normal FHR are processed with fast Fourier transform (FFT) analysis after digitization, and their power spectrums are obtained. The peak power spectrum frequency (PPSF), peak power spectrum density (PPSD), the area under the power spectrum of 0.03125-0.1 Hz (La), the area under the whole power spectrum (Ta), and the ratio of La/Ta (%) of pathologic FSHR are compared to those of physiologic FSHR and normal FHR.

RESULTS

The La/Ta ratio and PPSD are significantly larger in the pathologic FSHR than those of physiologic FSHR and normal FHR. The true positive rate is 100%, false negative and false positive rates are 0%, respectively, when the pathologic FSHR is diagnosed by such combined criteria as 39% or more of La/Ta ratio and 300 or more of PPSD.

CONCLUSION

Pathologic FSHR is clearly separated from physiologic FSHR and normal FHR by the La/Ta ratio and PPSD obtained by FFT frequency analysis of FHR. Consequently, it is capable to automatically diagnose pathologic FSHR, and to apply it to neural network computer evaluation of FHR.

Preliminary Investigations into a New Method of Functional Assessment of the Fetal Heart Using a Novel Application of ‘Real-Time’ Cardiac Magnetic Resonance Imaging

OBJECTIVES

Because of quantitative echocardiographic limitations of fetal ventricular volumes as well as poor windows, we sought to determine if real-time magnetic resonance imaging (MRI) could be used.

METHODS

Real-time, functional, true fast imaging with steady-state precession, cardiac MRI was performed on 2 fetuses (one with hypoplastic left heart syndrome and one with ductal constriction). Fetal echocardiography was performed and cardiac index by Doppler was used to validate volume measures by MRI.

RESULTS

This technique was able to visualize the beating heart and assess ventricular volumes. Cardiac index and assessment of right ventricular hypertrophy and dilation by echocardiography were consistent with the ventricular volumes and right ventricular hypertrophy obtained by cardiac MRI.

CONCLUSION

Real-time, functional fetal cardiac MRI is possible and can be used to quantitatively assess ventricular volumes and cardiac index in utero.

[Pulsoximetric sensor for diagnosis of intrauterine foetus state during parturition]

Detrimental changes in the degree of blood hemoglobin saturation with oxygen are important evidence of hypoxic states and can be regarded as objective indication to surgical delivery. A new method of fetal pulsoximetry was developed. This method is based on the use of a non-disposable atraumatic pulsoximetric sensor of reflectory type for diagnosis of intrauterine foetus state during parturition. The clinical trial of the system was carried out in 44 women in childbirth and revealed clear differentiation between hypoxic states.

[A test system of prenatal screen for Down's syndrome]

This paper presents a test system of prenatal screen for Dow's syndrome, based on the quantitative test technology of gold immunochromotographic assay (GICA). The prenatal screen for Down's syndrome and the risk rate of Down's syndrome are given by calculating with the screen software. The test system features easy operation, fastness and individual tests.

Prenatal diagnosis of a long QT syndrome by fetal magnetocardiography in an unshielded bedside environment

OBJECTIVE

The potentially life threatening long QT syndrome should be diagnosed during pregnancy to improve perinatal care.

METHODS

A patient with a family history for a hereditary long QT syndrome presented at 30 weeks of her first pregnancy with fetal bradycardia and a narrow oscillation bandwidth on cardiotocography without structural abnormalities of the fetal heart. Fetal magnetocardiography was performed with a prototype biomagnetometer/gradiometer device in a magnetically unshielded environment. The cardiac time intervals were determined in the averaged PQRST complex.

RESULTS

The QT time and the frequency-corrected QTc showed a marked prolongation to 380 ms and 0.52 s, respectively. The findings were confirmed in the postnatal electrocardiogram after spontaneous term delivery in a perinatal center. The causative mutation on chromosome 11 had been passed on to the newborn from his mother.

CONCLUSION

Bedside fetal magnetocardiography revealed the exact diagnosis of the long QT syndrome in a period of the gestation when the fetus was electrically isolated by the vernix caseosa that hinders electrocardiography. To patients at risk of fetal cardiac abnormalities, magnetocardiography can be offered as a non-invasive diagnostic bedside procedure. The diagnosis should trigger closer surveillance and delivery in a perinatal center.

Role of fetal ultrasound and magnetic resonance imaging in the prenatal diagnosis of migration disorders

OBJECTIVES

To evaluate the contribution and limitations of fetal ultrasonography (US) and magnetic resonance imaging (MRI) for the diagnosis and management of migration disorders.

METHODS

Over a 5-year period, 14 fetuses with pathological migration disorders, without an infectious context, were taken care of in our centre. All underwent US; nine underwent MRI as well. Sonographic and MRI data were compared with neuropathological data.

RESULTS

The diagnosis of gyral disorders was obtained by US in 1/14 cases; other cerebral abnormalities were found suggesting neuronal disorder in the remainder. Cerebral MRI suggested gyral abnormality in eight of the nine cases.

CONCLUSIONS

US performance is increasing. MRI appears to be a promising method for the diagnosis of fetal migration disorders, giving better results than US. It may be recommended in cases of abnormal cerebral US findings or familial clinical history. However, interpretation of MRI can be tricky and the resulting diagnosis occurs late within the pregnancy.

Characterization of Fetal Arrhythmias by Means of Fetal Magnetocardiography in Three Cases of Difficult Ultrasonographic Imaging

Characterization of ultrasound detected fetal arrhythmias is generally performed by means of M-mode and pulsed Doppler echocardiography (fECHO), sonographic techniques that allow only indirect and approximate reconstruction of the true electrophysiological events that occur in the fetal heart. Several studies demonstrated the ability of fetal magnetocardiography (fMCG) to identify fetal arrhythmias. We report on three women, studied after the 32nd gestational week, who were referred for fMCG because of unsatisfying fetal cardiac visualization with fECHO due to maternal obesity, fetus in constant dorsal position hiding the fetal heart, intrauterine growth retardation, and oligohydramnios. Minor pericardial effusion was present in the third patient and digoxin therapy was given. FMCG were recorded with a 77-channel MCG system working in a shielded room. Independent Component Analysis (FastICA algorithm) was used to reconstruct fetal signals. The good quality of the retrieved fetal signals allowed real-time detection of arrhythmias and their classification as supraventricular extrasystoles (SVE), with/without aberrant ventricular conduction and/or atrioventricular block. The time course of the fetal cardiac rhythm was reconstructed for the entire recording duration; hence, fetal heart rate variability could be studied in time and frequency. Since isolated extrasystoles may progress to more hazardous supraventricular tachycardias, the noninvasive antenatal characterization of, even transient, fetal arrhythmias and their monitoring during pregnancy can be of great clinical impact.