Judy A. Estroff

Robust Super-Resolution Volume Reconstruction From Slice Acquisitions: Application to Fetal Brain MRI

Fast magnetic resonance imaging slice acquisition techniques such as single shot fast spin echo are routinely used in the presence of uncontrollable motion. These techniques are widely used for fetal magnetic resonance imaging (MRI) and MRI of moving subjects and organs. Although high-quality slices are frequently acquired by these techniques, inter-slice motion leads to severe motion artifacts that are apparent in out-of-plane views. Slice sequential acquisitions do not enable 3-D volume representation. In this study, we have developed a novel technique based on a slice acquisition model, which enables the reconstruction of a volumetric image from multiple-scan slice acquisitions. The super-resolution volume reconstruction is formulated as an inverse problem of finding the underlying structure generating the acquired slices. We have developed a robust M-estimation solution which minimizes a robust error norm function between the model-generated slices and the acquired slices. The accuracy and robustness of this novel technique has been quantitatively assessed through simulations with digital brain phantom images as well as high-resolution newborn images. We also report here successful application of our new technique for the reconstruction of volumetric fetal brain MRI from clinically acquired data.

Bronchial Atresia Is Common to Extralobar Sequestration, Intralobar Sequestration, Congenital Cystic Adenomatoid Malformation, and Lobar Emphysema

Congenital cystic adenomatoid malformation (CCAM), intralobar sequestration (ILS), extralobar sequestration (ELS), and lobar emphysema (LE) are well-accepted entities; however, certain findings are common to all, particularly the parenchymal maldevelopment characterizing CCAM. Isolated reports have described bronchial atresia (BA) in some specimens in all 4 entities, but this finding has not been evaluated in a prospective manner. With the aid of a dissecting microscope, we prospectively examined 47 lung specimens resected during the past 4 years and submitted with the clinical impression of ELS (n = 11), ILS (n = 11), CCAM (n = 20), LE (n = 4), and airway-esophageal communication (n = 1). Most lesions were detected by prenatal ultrasound and were resected during infancy. The clinical impression and pathologic findings were compared. Pathologic examination revealed atresia of a lobar, segmental, or subsegmental bronchus in 100% of ELS, 82% of ILS, 70% of CCAM, and 50% of LE (those clinically recognized to have BA or minor CCAM) cases. Parenchymal maldevelopment that characterizes CCAM was present in 100% of CCAM cases (as expected by definition) as well as in 91% of ELS, 91% of ILS, and 50% of LE (those with BA) cases. Bronchial atresia is present in all ELS, most ILS and CCAM, and some LE cases, and its detection is greatly enhanced with the dissecting microscope. Bronchial atresia and CCAM nearly always coexist. It may be that both have the same etiopathogenesis with anatomic differences accounted for by aberrant genetic programs or other insults, perhaps modified by time of onset or duration.

First trimester bradycardia: a sign of impending fetal loss

Normal first trimester fetal heart rates rise from an average of 100 beats per minute (bpm) at 5 to 6 weeks to 140 bpm at 8 to 9 weeks. The heart rates of 65 consecutive first trimester fetuses between 5+ and 8+ weeks were measured to determine whether unusually slow first trimester fetal heartbeats are associated with a poor outcome. All five pregnancies in which heart rates were below 85 ended in spontaneous miscarriage. This study suggests that first trimester bradycardia may be associated with a poor prognosis for the pregnancy.

Fetal lung masses: prenatal course and outcome.

We describe 25 cases of echogenic or complex fetal lung masses seen sonographically and suspected of being cystic adenomatoid malformations or sequestrations of the lung. On the basis of prenatal sonographic appearance, 40% of fetuses were suspected of having type 1, 20% type 2, and 40% type 3 cystic adenomatoid malformations or sequestrations. Sixteen (64%) of the 25 fetuses with lung masses survived the perinatal period, and 80% of the nonaborted fetuses survived. Eleven infants (69% of liveborns) had no respiratory symptoms at birth. Nine of the survivors underwent surgical resections of their masses after birth, whereas the other seven children are being followed conservatively. The postnatal diagnoses revealed that four of the fetuses had sequestrations, one had a sequestration with elements consistent with cystic adenomatoid malformation, and two who were thought to have type 1 cystic adenomatoid malformation had an esophageal duplication cyst and a thoracic neuroblastoma, respectively. All the other infants who had a pathologic diagnosis or postnatal imaging had cystic adenomatoid malformations. Increasing mediastinal shift was associated with decreasing survival as 90% of fetuses with no mediastinal shift are alive, whereas 50% of the nonaborted fetuses with a severe mediastinal shift survived. Follow‐up scans in utero were available in 15 cases. The size of the mass became smaller in 53% during gestation. Seventy‐one percent of pregnancies had normal amniotic fluid volumes and 29% were complicated by polyhydramnios. Survival of nonaborted fetuses was 100% in pregnancies with normal amniotic fluid compared with 50% in those with polyhydramnios. Eight percent of the fetuses with chest masses had additional structural abnormalities and were karyotypically abnormal. In conclusion, many fetuses with lung masses show improvement of the sonographic findings in utero, and many infants may not be symptomatic at birth. Of the survivors in this series, only slightly greater than half underwent surgery.

How Accurately Does Current Fetal Imaging Identify Posterior Fossa Anomalies

OBJECTIVE The first objective of our study was to describe the prevalence and spectrum of posterior fossa anomalies over 5 years in a major fetal care center where the referral diagnosis (by fetal sonography) was investigated by fetal MRI and, if confirmed, by postnatal MRI if possible. The second objective was to assess the accuracy with which fetal MRI predicts postnatal MRI findings in this population. MATERIALS AND METHODS We retrospectively identified all cases of suspected fetal posterior fossa anomalies referred to our center from 2002 through 2006. We reviewed maternal, fetal, neonatal, and follow-up records of all cases and fetal and early postnatal imaging studies. RESULTS Of the 90 cases of suspected fetal posterior fossa anomalies (by fetal sonography) referred over the study period, 60 (67%) were confirmed by fetal MRI. Of 42 live-born infants, 39 (93%) underwent postnatal MRI. There was complete agreement in fetal and postnatal MRI diagnoses in 23 infants (59%). In 16 cases (41%), fetal and postnatal MRI diagnoses disagreed; postnatal MRI excluded fetal MRI diagnoses in six cases (15%) and revealed additional anomalies in 10 cases (26%). CONCLUSION Although a valuable adjunct to fetal sonography in cases of suspected posterior fossa anomaly, current fetal MRI, particularly in early gestation, has limitations in accurately predicting postnatal MRI abnormalities. Advancing the accuracy of MRI for the diagnosis of posterior fossa anomalies will require greater understanding of normal brain development and improved tissue resolution of fetal MRI. During the interim, our findings strongly support the need for postnatal MRI follow-up in cases with suspected posterior fossa anomalies by fetal MRI.

Neurological Complications of Hemolytic-Uremic Syndrome

Of 78 children identified with hemolytic-uremic syndrome at the Childrens Hospital, Boston, from 1976 to 1986, 16 patients (20.5%) had neurological manifestations during their hospitalization. The most common manifestations were significant alterations in consciousness (coma, stupor) in 12 patients, and either generalized or partial seizures in ten patients. Others included hemiplegia (4 patients), decerebrate posturing (3), cortical blindness (2), hallucinations (1), and dystonic posturing (1). Cranial computed tomographic scans were abnormal in eight of 11 patients scanned. The abnormalities included diffuse cerebral edema (4 patients), large vessel infarctions (3), diffuse multiple small infarcts (4), and multiple hemorrhages (1). Five patients died as a result of their central nervous system complications, and six had neurological sequelae at discharge. Five patients recovered and at discharge had no evidence of neurological dysfunction. (J Child Neurol 1989;4:108-113).

Neurodevelopmental outcome of fetuses referred for ventriculomegaly

To characterize the delivery and postnatal neurodevelopmental outcomes of fetuses referred for ventriculomegaly (VM).

Ultrasonographic Patterns of Reproductive Organs in Infants Fed Soy Formula: Comparisons to Infants Fed Breast Milk and Milk Formula

OBJECTIVE To determine if differences exist in hormone-sensitive organ size between infants who were fed soy formula (SF), milk formula (MF), or breast milk (BF). STUDY DESIGN Breast buds, uterus, ovaries, prostate, and testicular volumes were assessed by ultrasonography in 40 BF, 41 MF, and 39 SF infants at age 4 months. RESULTS There were no significant feeding group effects in anthropometric or body composition. Among girls, there were no feeding group differences in breast bud or uterine volume. MF infants had greater (P < .05) mean ovarian volume and greater (P < .01) numbers of ovarian cysts per ovary than did BF infants. Among boys, there were no feeding group differences in prostate or breast bud volumes. Mean testicular volume did not differ between SF and MF boys, but both formula-fed groups had lower volumes than BF infants. CONCLUSIONS Our data do not support major diet-related differences in reproductive organ size as measured by ultrasound in infants at age 4 months, although there is some evidence that ovarian development may be advanced in MF-fed infants and that testicular development may be slower in both MF and SF infants as compared with BF. There was no evidence that feeding SF exerts any estrogenic effects on reproductive organs studied.

Prenatal Diagnosis of the Megacystis-Megaureter Association

A total of 11 male neonates with hydronephrosis and a large bladder in utero had the megacystis-megaureter association. Prenatal ultrasound findings included bilateral hydroureteronephrosis; a large, smooth, thin-walled bladder, and normal volume of amniotic fluid. Postnatal studies demonstrated grades 4 to 5 bilateral reflux, a large bladder without obstruction and in 2 infants nonfunction of a kidney or renal moiety. Of 7 infants initially managed nonoperatively 5 have undergone surgery due to persistent reflux or breakthrough urinary infections. The prenatal diagnosis of the megacystis-megaureter association can be suspected with reasonable accuracy. Prompt postnatal continuous antibiotic prophylaxis and uroradiological confirmation allow for nonemergency management of this condition with excellent results.

Multi-Atlas Multi-Shape Segmentation of Fetal Brain MRI for Volumetric and Morphometric Analysis of Ventriculomegaly

The recent development of motion robust super-resolution fetal brain MRI holds out the potential for dramatic new advances in volumetric and morphometric analysis. Volumetric analysis based on volumetric and morphometric biomarkers of the developing fetal brain must include segmentation. Automatic segmentation of fetal brain MRI is challenging, however, due to the highly variable size and shape of the developing brain; possible structural abnormalities; and the relatively poor resolution of fetal MRI scans. To overcome these limitations, we present a novel, constrained, multi-atlas, multi-shape automatic segmentation method that specifically addresses the challenge of segmenting multiple structures with similar intensity values in subjects with strong anatomic variability. Accordingly, we have applied this method to shape segmentation of normal, dilated, or fused lateral ventricles for quantitative analysis of ventriculomegaly (VM), which is a pivotal finding in the earliest stages of fetal brain development, and warrants further investigation. Utilizing these innovative techniques, we introduce novel volumetric and morphometric biomarkers of VM comparing these values to those that are generated by standard methods of VM analysis, i.e., by measuring the ventricular atrial diameter (AD) on manually selected sections of 2D ultrasound or 2D MRI. To this end, we studied 25 normal and abnormal fetuses in the gestation age (GA) range of 19 to 39 weeks (mean=28.26, stdev=6.56). This heterogeneous dataset was essentially used to 1) validate our segmentation method for normal and abnormal ventricles; and 2) show that the proposed biomarkers may provide improved detection of VM as compared to the AD measurement.