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Background: Accurate diagnosis of hepatic vein (HV) stenosis by real-time and color Doppler US (CD-US) after segmental liver transplantation in children can decrease morbidity because it allows unnecessary biopsy, obstruction or thrombosis and loss of the graft to be avoided.Objective: To evaluate CD-US parameters to predict HV stenosis after segmental liver transplantation in children.Materials and Methods: Retrospective review of 79 CD-US examinations measuring velocity at the HV anastomosis (HV1) and the main trunk 1-2 cm proximal to the HV/IVC anastomosis (HV2), the HV1/HV2 ratio and the spectral waveform of HV2. The study group comprised patients with stenosis confirmed by angiography. The control group comprised patients with a good clinical outcome.Results: HV stenosis was seen in 12 CD-US examinations. The mean HV1/HV2 ratio was higher in the study group (6.0 versus 4.0). An HV1/HV2 ratio of >4.1 was predictive of HV stenosis (sensitivity 83%, specificity 76%).Conclusion: An HV1/HV2 ratio of >4.1 is a highly predictive CD-US parameter for the detection of hemodynamically significant HV stenosis on angiography. [ABSTRACT FROM AUTHOR]

Background: Accurate diagnosis of portal vein (PV) stenosis by real-time and color Doppler US (CD-US) after segmental liver transplantation in children can decrease morbidity by avoiding unnecessary biopsy, PV hypertension, thrombosis and loss of the graft.Objective: To evaluate CD-US parameters for the prediction of PV stenosis after segmental liver transplantation in children.Materials and Methods: We retrospectively reviewed 61 CD-US examinations measuring the diameter at the PV anastomosis, velocities at the anastomosis (PV1) and in the segment proximal to the anastomosis (PV2), and the PV1/PV2 velocity ratio. The study group comprised patients with stenosis confirmed by angiography and the control group comprised patients with a good clinical outcome.Results: PV stenosis was seen in 12 CD-US examinations. The mean PV diameter was smaller in the study group (2.6 mm versus 5.7 mm) and a PV diameter of <3.5 mm was highly predictive of stenosis (sensitivity 100%, specificity 91.8%).Conclusion: A PV diameter of <3.5 mm is a highly predictive CD-US parameter for the detection of hemodynamically significant stenosis on angiography. [ABSTRACT FROM AUTHOR]

OBJECTIVE: We evaluated the use of fetal magnetic resonance imaging in predicting outcomes after ultrasonographic diagnosis of left-sided congenital diaphragmatic hernia.Study Design: Forty-one pregnant women carrying fetuses with congenital diaphragmatic hernia underwent 43 magnetic resonance imaging scans. Lung volumes were calculated by summing the areas on 6-mm axial sections. The presence or absence of liver herniation was noted. A liver/diaphragm ratio was obtained by using the distances from the superior aspect of the liver and the diaphragmatic remnant to the apex of the chest. RESULTS: Mean gestational age was 26 weeks and overall survival was 59%. Neither right, left, nor total lung volume measurements were predictive of survival. Liver herniation into the left side of the chest was predictive of outcome at P <.05. The liver/diaphragm ratio was predictive of outcome at P =.03. CONCLUSION: Fetal magnetic resonance imaging permits calculation of lung volumes, but these volumes are not predictive of outcome. However, both the presence of liver herniation and the volume of liver within the chest, as reflected by the liver/diaphragm ratio, help predict outcome in left-sided congenital diaphragmatic hernia. [ABSTRACT FROM AUTHOR]

Lignin-containing cellulose nanofibrils (LCNFs) are mainly produced commercially from treated wood pulp, which can decrease some of the carbon-negative benefits of utilizing biomass feedstock. In this work, LCNFs are prepared from non-wood feedstocks, including agricultural residues such as hemp, wheat straw, and flax. These feedstocks allowed for the preparation of LCNFs with a variety of properties, including tailored hydrophobicity. The feedstocks and their subsequent LCNFs are extensively characterized to determine the roles that feedstocks play on the morphology and properties of their resultant LCNFs. The LCNFs were then incorporated into paper handsheets to study their usefulness in papermaking applications, which indicated good potential for the use of wheat straw LCNFs as a surface additive to improve the oil resistance coating.

With sustainability at the forefront of material research, recyclable polymers, such as vitrimers, have garnered increasing attention since their introduction in 2011. In addition to a traditional glass-transition temperature ( T g ), vitrimers have a second topology freezing temperature ( T v ) above which dynamic covalent bonds allow for rapid stress relaxation, self-healing, and shape reprogramming. Herein, we demonstrate the self-healing, shape memory, and shape reconfigurability properties as a function of experimental conditions, aiming toward recyclability and increased useful lifetime of the material. Of interest, we report the influence of processing conditions, which makes the material vulnerable to degradation. We report a decreased crosslink density with increased thermal cycling and compressive stress. Furthermore, we demonstrate that shape reconfigurability and self-healing are enhanced with increasing compressive stress and catalyst concentration, while their performance as a shape memory material remains unchanged. Though increasing the catalyst concentration, temperature, and compressive stress clearly enhances the recovery performance of vitrimers, we must emphasize its trade-off when considering the material degradation reported here. While vitrimers hold great promise as structural materials, it is vital to understand how experimental parameters impact their properties, stability, and reprocessability before vitrimers reach their true potential., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

Terrestrial organisms that use traveling waves to locomote must leverage heterogeneities to overcome drag on the elongate body. While previous studies illuminated how habitat generalist snakes self-deform to use rigid obstacles in the surroundings, control strategies for multi-component terrain are largely unknown. We compared the sand-specialist Chionactis occipitalis to a habitat generalist, Pantherophis guttatus, navigating a model terrestrial terrain-rigid post arrays on a low-friction substrate. We found the waveshapes used by the generalist were more variable than the specialist. Principal component analysis revealed that while the specialized sand-swimming waveform was always present on C. occipitalis, the generalist did not have a similarly pervasive low-dimensional waveshape. We expected the generalist to thus outperform the specialist in the arrays, but body slip of both species was comparable on level ground and in all trials the snakes successfully traversed the arena. When we further challenged the snakes to ascend an inclined lattice, the sand-specialist had difficulty maintaining contact with the obstacles and was unable to progress up the steepest inclines in the largest lattice spacings. Our results suggest that species adapted to different habitats use different control modalities-the specialist is primarily controlling its kinematics to achieve a target shape while, consistent with previous research, the generalist is using force control and self-deforms in response to terrain contacts. While both strategies allowed progress on the uninclined low-friction terrain with posts, the more variable waveshapes of the generalist may be necessary when faced with more challenging locomotor tasks like climbing inclines., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.)

While terrestrial locomotors often contend with permanently deformable substrates like sand, soil, and mud, principles of motion on such materials are lacking. We study the desert-specialist shovel-nosed snake traversing a model sand and find body inertia is negligible despite rapid transit and speed dependent granular reaction forces. New surface resistive force theory (RFT) calculation reveals how wave shape in these snakes minimizes material memory effects and optimizes escape performance given physiological power limitations. RFT explains the morphology and waveform-dependent performance of a diversity of non-sand-specialist snakes but overestimates the capability of those snakes which suffer high lateral slipping of the body. Robophysical experiments recapitulate aspects of these failure-prone snakes and elucidate how re-encountering previously deformed material hinders performance. This study reveals how memory effects stymied the locomotion of a diversity of snakes in our previous studies (Marvi et al., 2014) and indicates avenues to improve all-terrain robots., Competing Interests: PS, HA, JR, SA, CH, AH, KD, JM, KK, DG No competing interests declared, (© 2020, Schiebel et al.)

Limbless animals like snakes inhabit most terrestrial environments, generating thrust to overcome drag on the elongate body via contacts with heterogeneities. The complex body postures of some snakes and the unknown physics of most terrestrial materials frustrates understanding of strategies for effective locomotion. As a result, little is known about how limbless animals contend with unplanned obstacle contacts. We studied a desert snake, Chionactis occipitalis , which uses a stereotyped head-to-tail traveling wave to move quickly on homogeneous sand. In laboratory experiments, we challenged snakes to move across a uniform substrate and through a regular array of force-sensitive posts. The snakes were reoriented by the array in a manner reminiscent of the matter-wave diffraction of subatomic particles. Force patterns indicated the animals did not change their self-deformation pattern to avoid or grab the posts. A model using open-loop control incorporating previously described snake muscle activation patterns and body-buckling dynamics reproduced the observed patterns, suggesting a similar control strategy may be used by the animals. Our results reveal how passive dynamics can benefit limbless locomotors by allowing robust transit in heterogeneous environments with minimal sensing., Competing Interests: The authors declare no conflict of interest., (Copyright © 2019 the Author(s). Published by PNAS.)

The ability to change shape and control curvature in 3D structures starting from planar sheets can aid in assembly and add functionality to an object. Herein, we convert planar sheets of shape memory polymers (SMPs) into 3D objects with controllable curvature by dictating where the sheets shrink. Ink patterned on the surface of the sheet absorbs infrared (IR) light, resulting in localized heating, and the material shrinks locally wherever the temperature exceeds the activation temperature, T a . We introduce two different mechanisms for controlling curvature within SMP sheets. The 'direct' mechanism uses localized shrinkage to induce curvature only in regions patterned with ink. The 'indirect' mechanism uses localized shrinkage in regions patterned with ink to induce curvature in neighboring regions without ink through a balance of internal stresses. Finite element analysis predicts the final shape of the polymer sheets with excellent qualitative agreement with experimental studies. Results from this study show that curvature can be controlled by the distribution and darkness of the ink pattern on the polymer sheet. Additionally, we utilize the direct and indirect curvature mechanisms to demonstrate the formation and actuation of gripper devices, which represent the potential utility of this approach.

Objective: Our objective was to develop and validate a prognostic score for predicting mortality at the time of extracorporeal membrane oxygenation initiation for children with respiratory failure. Preextracorporeal membrane oxygenation mortality prediction is important for determining center-specific risk-adjusted outcomes and counseling families., Design: Multivariable logistic regression of a large international cohort of pediatric extracorporeal membrane oxygenation patients., Setting: Multi-institutional data., Patients: Prognostic score development: A total of 4,352 children more than 7 days to less than 18 years old, with an initial extracorporeal membrane oxygenation run for respiratory failure reported to the Extracorporeal Life Support Organization's data registry during 2001-2013 were used for derivation (70%) and validation (30%). Bidirectional stepwise logistic regression was used to identify factors associated with mortality. Retained variables were assigned a score based on the odds of mortality with higher scores indicating greater mortality. External validation was accomplished using 2,007 patients from the Pediatric Health Information System dataset., Interventions: None., Measurements and Main Results: The Pediatric Pulmonary Rescue with Extracorporeal Membrane Oxygenation Prediction score included mode of extracorporeal membrane oxygenation; preextracorporeal membrane oxygenation mechanical ventilation more than 14 days; preextracorporeal membrane oxygenation severity of hypoxia; primary pulmonary diagnostic categories including, asthma, aspiration, respiratory syncytial virus, sepsis-induced respiratory failure, pertussis, and "other"; and preextracorporeal membrane oxygenation comorbid conditions of cardiac arrest, cancer, renal and liver dysfunction. The area under the receiver operating characteristic curve for internal and external validation datasets were 0.69 (95% CI, 0.67-0.71) and 0.66 (95% CI, 0.63-0.69)., Conclusions: Pediatric Pulmonary Rescue with Extracorporeal Membrane Oxygenation Prediction is a validated tool for predicting in-hospital mortality among children with respiratory failure receiving extracorporeal membrane oxygenation support.

This communication reports the blood concentrations of alcohol and drugs from 376 cases of alleged driving under the influence of drugs analysed at the Forensic Science Service Chorley and London laboratories between February 2010 and March 2011. The samples were analysed for alcohol, amphetamine, benzodiazepines, cocaine, MDMA, opiates, γ-hydroxybutyrate (GHB), ketamine, methadone and methylmethcathinone (the 4-isomer of which is known as mephedrone). The results were interpreted with respect to the number and type of drugs of abuse detected and the concentrations measured. Alcohol was quantified in 113 cases (30%), and of these a level in excess of the prescribed UK limit for driving of 80 mg% was present in 90 cases. In 80 cases, only the concentration of alcohol was measured, the concentrations of both drugs and alcohol were measured in 33 cases. In the remaining 263 cases, only the concentrations of relevant drugs of abuse were measured. The most common drug of abuse quantified was cocaine which was detected in 92 cases, either as the active drug or as its major metabolite benzoylecgonine, followed by diazepam which was quantified in 76 cases. Concentrations of some new drugs, and drugs rarely reported in driving under the influence cases are also presented., (Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.)

Objective: The purpose of this study was to determine whether prenatal MRI provides additional information about fetal sacrococcygeal teratoma compared with prenatal sonography., Materials and Methods: Twenty-two pregnant women with fetal sacrococcygeal teratoma underwent prenatal MRI (mean gestational age, 23 weeks). The size, location, mass characteristics, and compressive effects of the tumors were determined and correlated with sonography and postnatal findings., Results: Based on the MRI findings, the following American Academy of Pediatrics, Surgical Section classifications were assigned: type I in six patients, type II in 12, and type III in four. No type IV tumors were found. The sacrococcygeal teratoma appeared entirely cystic in five fetuses, microcystic in one, mixed cystic and solid in 12, and solid in four. The diagnosis of sacrococcygeal teratoma was accurate in all cases assessed at our center using both MRI and sonography. Two additional patients initially referred with the diagnosis of sacrococcygeal teratoma had a different diagnosis at reevaluation at our institution (healthy, n = 1; myelomeningocele, n = 1). MRI was superior to sonography for detecting displacement of the colon (n = 11), urinary tract dilatation (n = 9), hip dislocation (n = 4), intraspinal extension (n = 2), and vaginal dilation (n = 1). In fetuses with sacrococcygeal teratoma types II and III, MRI better showed the cephalic extent of the tumor compared with sonography. MRI findings were confirmed at surgery or autopsy in all patients. Three fetuses with high output cardiac physiology underwent open fetal resection of the tumor at 21-, 24-, and 26-weeks' gestational age with two surviving., Conclusion: Our results show that ultrafast fetal MRI is a useful adjunct to the prenatal evaluation of fetal sacrococcygeal teratoma. Compared with sonography, MRI more accurately characterized the intrapelvic and abdominal extent of the tumors and provided more information on compression of adjacent organs. The additional anatomic resolution provided by MRI resulted in more accurate prenatal counseling and improved preoperative planning for surgical resection.

Background: The use of the ex utero intrapartum treatment (EXIT) procedure has salvaged many fetuses with giant neck masses. Despite an adequate airway, a subset of these patients die from an inability to achieve adequate gas exchange., Methods: We reviewed our experience with the EXIT procedure from 1996 to 2004. The EXIT was used to deliver 23 fetuses with giant neck masses., Results: Three fetuses with giant cervical teratomas died of severe pulmonary hypoplasia. On postmortem, these patients had severe airway distortion by the mass. The carina was retracted superiorly to the first or second rib resulting in compression of the lungs in the apices of the chest and pulmonary hypoplasia. Hypoplasia was reflected in the lung weights of 24 vs 38 g and 17 vs 34 g for age-matched normal lung., Conclusions: Unsuspected obstructive fetal neck masses can be fatal because of an inability to secure an airway. Prenatal ultrasonography can identify fetuses at risk, allowing the fetus to be salvaged using the EXIT procedure. Despite obtaining airway control, a subset of these patients will die because of pulmonary hypoplasia. When counseling patients with large cervical masses it is important to discuss potential pulmonary hypoplasia in these patients.

The ability to identify and confidently diagnose a wide range of congenital fetal thoracic lesions has increased tremendously in the past 2 decades with the emergence of high-resolution sonography and ultrafast MRI sequences. Imaging studies constitute a vital component in the diagnosis of these lesions, whether in the fetal, neonatal or childhood periods. In addition to providing a road map for potential intervention, imaging techniques have provided important information about normal development, natural history, and prognosis. In the prenatal stage, these features aid in family counseling, pregnancy management, and the identification of a subgroup of patients who may benefit from fetal intervention. In the neonatal and childhood periods, imaging studies facilitate timely diagnosis and institution of appropriate therapeutic strategies.

Improvements in magnetic resonance imaging (MRI) technology continue to provide faster scan times and higher resolution increasing the applications for fetal imaging. MRI is an adjunct to good prenatal ultrasound scan (US). It provides significant additional information that improves diagnostic accuracy in evaluation of the fetal brain, spine, neck, chest, abdomen, and urinary tract. MRI provides important anatomic information that helps in planning delivery and surgical procedures.

Extrarenal collections of urine have long been associated with obstructive uropathy and may preserve renal function by acting as a "popoff" valve. Although urinary extravasation manifested as urinary ascites carries a favorable prognosis, perinephric urinomas occurring prenatally are associated with poor renal function in most cases. We report the case of a baby girl with a urinoma diagnosed by fetal magnetic resonance imaging and discuss the significance of this radiologic finding.

Presently, MRI is an adjunct to prenatal sonography. It provides information that can aid in the diagnosis of fetal anomalies, affect prenatal counseling and management of the pregnancy, and guide prenatal intervention and delivery planning. With further advances in technology, particularly shorter scan times and better image resolution, the applications for fetal imaging are likely to increase.

Purpose: To overcome the difficulty of poor signal-to-noise ratio of magnetic resonance imaging (MRI) in evaluating heavy iron overload by using a single voxel magnetic resonance spectroscopy (MRS) technique., Materials and Methods: A single voxel STEAM pulse sequence with a minimum TE of 1.5 msec and a sampling volume of 36.6 cm(3) was developed and applied to 1/T2 measurement of the liver in 14 patients with thalassemia whose liver iron concentration was determined through biopsy., Results: The iron level ranged from 0.23 to 37.15 mg Fe/g dry tissue with a median value of 18.06. In all cases, strong MR signals were obtained. 1/T2 was strongly correlated with the liver iron concentration (r = 0.95, P < 0.00005)., Conclusion: The single voxel MRS measurement of T2 in liver iron overload overcomes the difficulty of lack of detectable signals in conventional MRI when the iron level is high. There is an excellent correlation between the iron level and 1/T2., (Copyright 2002 Wiley-Liss, Inc.)

MR imaging plays a valuable role in the evaluation of foot and ankle in infants and children. In young children with nonossified bones, MR imaging offers the advantage of effectively demonstrating the cartilaginous anlage in addition to soft tissue and bone marrow. The MR imaging examination is tailored to the clinical question, the child's age, foot size, and ability to cooperate. This article reviews the MR imaging of a number of familiar and uncommon disorders of the pediatric foot and ankle.

Developmental and acquired abnormalities of the hips are common in childhood. Radiographs, MR imaging, CT, and nuclear medicine play an important role in the diagnosis and management of these disorders. Knowledge of the surgical and clinical treatments of these disorders is important to interpret accurately the radiology studies and impact treatment of the children.

Ultrafast magnetic resonance imaging (MRI) sequences have changed the use of MRI to evaluate fetal abnormalities. Currently, the best application is the evaluation of suspected brain abnormalities found on ultrasound. MRI differentiates the various types of fetal ventriculomegaly. Superior posterior fossa visualization allows differentiation of Dandy-Walker malformation from a large cisterna magna. Anomalies of the corpus callosum can be seen. MRI also is valuable in the evaluation of fetal giant neck masses for planning delivery of the baby and surgery for life-threatening airway obstruction. In the chest, MRI differentiates masses such as diaphragmatic hernia, cystic adenomatoid malformation, and sequestration, and it aids in planning fetal surgery because MRI directly visualizes the position of the lung, liver, and bowel.

Fetal thoracic abnormalities are increasingly being detected using prenatal ultrasound. Prenatal magnetic resonance imaging is an important adjunct in evaluation of fetal chest lesions. It can help differentiate different masses and is most helpful in evaluation of large or atypical masses. It also is very important in planning in utero interventional procedures, delivery, and immediate postnatal surgery.

Objective: The purpose of our study was to determine if a standard imaging protocol using ultrafast MR sequences could adequately reveal normal posterior fossa anatomy in fetuses and, if so, to document a template on MR imaging for normal posterior fossa development., Materials and Methods: A retrospective review found 66 MR imaging studies of 63 fetuses, 16-39 weeks' gestation age (mean, 25 weeks' gestation), who were referred between June 1996 and May 1999 for evaluation of non-central nervous system anomalies revealed on prenatal sonography. All fetuses had normal brains and spines on prenatal sonography. The standard MR imaging protocol included axial, sagittal, and coronal half-Fourier acquisition single-shot turbo spin echo (HASTE); sagittal and coronal two-dimensional fast low-angle shot (FLASH); and axial turbo T1-weighted FLASH images through the fetal brain. Structures that we analyzed were the fourth ventricle, the cisterna magna, the vermis, the cerebellar hemispheres, and the brainstem. Using the HASTE sequences, we documented gestational age-specific signal intensity changes in the cerebellar hemispheres and the brainstem., Results: The posterior fossa anatomy was sufficiently well defined to exclude abnormalities of the fourth ventricle and cerebellar vermis in all cases. Because of high T2-weighting, good contrast enhancement, and good signal-to-noise ratios, HASTE images provided the best anatomic definition of the posterior fossa., Conclusion: Normal posterior fossa anatomy can be adequately shown on ultrafast MR images, which can be helpful when prenatal sonography is equivocal.

Ultrafast MRI sequences have changed the use of MRI for evaluating fetal abnormalities. Currently, the best application is the demonstration of normal fetal brain development and the further definition of suspected brain abnormalities found on ultrasound. MRI differentiates well the various types of fetal ventriculomegaly. Superior posterior fossa visualization allows differentiation of Dandy Walker malformation from a large cisterna magna. Anomalies of the corpus callosum and some disorders of neuronal migration can be seen. MRI is also valuable in the evaluation of fetal giant neck masses for planning delivery of the baby and surgery for life threatening airway obstruction. In the chest, MRI differentiates masses such as diaphragmatic hernia, cystic adenomatoid malformation and sequestration, and aids in planning fetal surgery because MRI directly visualizes the position of the lung, liver and bowel. MRI defines abnormalities of the urinary tract by demonstrating dysplastic pathology in the renal cortex and dilation of the collecting systems. Oligohydramnios does not effect MRI., (Copyright 2000 Harcourt Publishers Ltd.)

The authors recently managed a case of combined pure esophageal, duodenal, biliary, and pancreatic ductal atresia in a fetus and newborn with Trisomy 21. The authors present a case report and review of the literature, emphasizing the prenatal radiographic features of the combined lesions and the high incidence of associated anomalies including Down's syndrome. Prenatal suspicion of these anomalies warrants karyotype analysis as well as careful pre- and postnatal screening for other anomalies.

Background: Congenital lobar emphysema (CLE) is a rare anomaly of lung development that usually presents in the neonatal period with respiratory distress and pulmonary lobar hyperinflation. The routine use of prenatal ultrasonography has resulted in the early identification and serial evaluation of congenital lung lesions. CLE can be distinguished from other congenital lung lesions on ultrasonography by the differences in echogenicity and reflectivity., Methods: Two cases of CLE diagnosed at midgestation by ultrasonography and ultrafast fetal magnetic resonance imaging (MRI), along with serial sonographic documentation of their prenatal course were reviewed., Results: The CLE lesions decreased in size over the course of the pregnancy, similar to that seen with other congenital lung lesions such as cystic adenomatoid malformation and bronchopulmonary sequestration. However, these neonates with CLE showed marked air-trapping and respiratory distress requiring lobectomy in the early neonatal period., Conclusions: These cases provide insight into the prenatal course of CLE and underscore the need for continued postnatal evaluation of fetuses even those in whom the lesions appear to have resolved in utero. These patients should have ready access to postnatal surgical intervention.

The development of ultrafast magnetic resonance imaging scanners and sequences provides a new tool for the diagnosis of fetal anomalies. Magnetic resonance imaging is a valuable adjunct to prenatal ultrasound especially for the evaluation of suspected fetal brain anomalies, chest masses, abdominal masses, and renal diseases.

Purpose: To evaluate prenatal magnetic resonance (MR) imaging for diagnosis of fetal chest masses and to determine if MR imaging provides information in addition to that of ultrasonography (US)., Materials and Methods: Eighteen pregnant women were referred for MR imaging of possible fetal chest tumors seen at US (16 congenital cystic adenomatoid malformation [CCAM], two bronchopulmonary sequestration [BPS]). The presence, position, size, and characteristics of masses were determined and correlated with postnatal results., Results: The MR imaging diagnoses were three cases of congenital diaphragmatic hernia, nine of CCAM, two of BPS, and one each of foregut cyst, lung atresia, tracheal atresia, and bronchial stenosis. MR imaging results were in agreement with US results in nine fetuses and in disagreement in nine. MR imaging diagnoses were confirmed at surgery or autopsy in 17 fetuses. MR imaging results led to an error in diagnosis in one fetus with BPS., Conclusion: Fetal chest masses had characteristic MR imaging appearances. MR imaging was accurate for distinguishing congenital diaphragmatic hernia from CCAM and was useful for less common diagnoses and determination of the origin of very large chest tumors. Prenatal diagnosis was changed in some patients owing to MR results and affected treatment and counseling of parents. MR imaging is a valuable adjunct to US for prenatal diagnosis of fetal chest masses.

The objective of this paper is to evaluate the efficacy of various magnetic resonance imaging (MRI) sequences and the general usefulness of prenatal MRI in determining the position of the fetal liver and visualizing lung tissue in fetuses who have congenital diaphragmatic hernia (CDH). This was a retrospective review of prenatal MRI of fetuses with a confirmed diagnosis by surgery or autopsy of CDH. MRI was performed in a 1.5-Tesla magnet using fast gradient echo, half-Fourier single-shot turbo spin-echo (HASTE) and echo planar images. The presence of a chest mass, position of the stomach and liver and visualization of the lungs by MRI was noted in all fetuses. This was compared to ultrasound studies performed the same day and correlated with postnatal or autopsy studies. The fetuses were 18-36 weeks gestational age (mean 24.5 weeks). MRI diagnosed left CDH (33), right CDH (4), and bilateral CDH (1) and agreed with the postnatal diagnosis in all patients. Ultrasound (US) diagnosed left CDH (33), right CDH (2), and congenital cystic adenomatoid malformation (3). MRI changed the diagnosis in four patients. The fetal liver was easily demonstrated with MRI in all fetuses and was herniated into the chest in 25 of the 38. US diagnosed liver up in 21. Correlation with postnatal studies found MRI correctly diagnosed liver position in 37 out of 38 cases. US correctly diagnosed liver position in 32 out of 38. Both lungs could be visualized in all fetuses with MRI. MRI accurately and easily diagnoses CDH and can differentiate it from other chest masses. MRI was superior to US in demonstrating the position of the fetal liver above or below the diaphragm. MRI reliably visualized fetal lung tissue. These findings are important for counseling parents, selecting fetal surgical candidates, and estimating prognosis.

MR imaging can be extremely helpful in evaluating congenital and acquired deformities of the foot and ankle. Knowledge of the normal developmental anatomy of the foot and ankle is important to accurately identify abnormalities versus normal variants. The foot and ankle may be abnormal because of trauma, infection, tumor, or systemic disease. MR imaging can help in the differential diagnosis of abnormalities as well as in treatment planning and follow-up.

Airway compromise at birth can be anticipated with giant neck masses, so that as much anatomic information as possible is necessary prior to delivery to establish a diagnosis and assess the airway. With this study, we evaluated the usefulness of prenatal magnetic resonance imaging (MRI) for evaluation of giant fetal neck masses prior to operating on placental support, the Ex Utero Intrapartum Treatment (EXIT) procedure, performed to secure the neonatal airway. Three pregnant women with an ultrasound (US) diagnosis of fetal giant neck mass were referred for prenatal MRI. As this was our initial experience performing prenatal MRI, a variety of imaging sequences were used including spin-echo, fast gradient-echo, half-fourier single shot turbo spin-echo (Haste), and echo-planar imaging (EPI). All sequences performed were able to demonstrate the fetal airway relative to the mass. In addition, the images were able to give a more global definition of the mass because of the larger field of view than could be obtained with MRI compared to US. The Haste sequence provided the best definition of a mass because of decreased motion artifacts. The prenatal diagnosis on MRI was teratoma in two and lymphangioma in one and was confirmed at birth. MRI provided essential information about the diagnosis and the anatomy of the giant neck masses and adjacent airway in three fetuses prior to selection for the EXIT surgical procedure.

Although significant anomalies of the fetal thorax are uncommon, with improvement in high-resolution ultrasonography, more of these lesions are being diagnosed prenatally. Accurate and specific prenatal diagnosis is important because different lesions have different natural histories and prognosis. Prenatal MRI is an increasingly important adjunct for identification and differentiation of these lesions and may help determine in selected cases when and if in utero fetal intervention is indicated.

Background: Ultrasound (US) evaluation of some fetal anomalies provides limited information. Anatomic details that affect prognosis and selection for fetal therapy, such as liver herniation and pulmonary hypoplasia in congenital diaphragmatic hernia (CDH) and airway patency in giant neck masses, may be difficult to delineate using conventional sonographic methods. The authors evaluated the utility of prenatal magnetic resonance imaging (MRI) with new ultrafast imaging sequences in the diagnosis and management of fetal anomalies., Methods: From April 1996 to April 1997 45 MRI scans were performed in 31 pregnant women with an US diagnosis of a fetal anomaly. The US diagnoses included CDH, giant neck masses, lung masses, abdominal and pelvic abnormalities, twin anomalies, and central nervous system (CNS) anomalies. The fetuses ranged in age from 18 to 39 weeks' gestation (mean, 28.7 weeks). Using a 1.5-T magnet, a variety of ultrafast imaging sequences were performed including fast gradient-echo, half-fourier single shot turbo spin-echo (Haste) and echo-planar imaging yielding images with T1 to T2 type weighting., Results: With CDH, MRI demonstrated liver herniation into the chest in 11 of 14 cases. In four cases, US findings had not been definitive. In two cases of CDH detected by MRI, the primary diagnosis by US had been congenital cystic adenomatoid malformation (CCAM). With lung masses, MRI accurately distinguished between CCAM and bronchopulmonary sequestration (BPS). For giant neck masses with potential airway obstruction, MRI scans permitted differentiation of teratoma from cystic hygroma and allowed delineation of fetal airway involvement. The accurate anatomic evaluation facilitated planning for the ex utero intrapartum treatment (EXIT) procedure, a technique for securing the airway while the term fetus is still on placental support. With huge abdominal masses such as enterogenous cyst and lymphangioma, MRI scanning clarified the diagnosis. Fourteen of the 31 (45%) patients underwent fetal treatment after US and MRI evaluation., Conclusions: Prenatal MRI enhances fetal anatomic evaluation and facilitates perinatal management and family counseling. Ultrafast imaging sequence MRI is helpful to corroborate and refine US diagnoses. Fetal MRI is a valuable adjunct to US for prenatal diagnosis before fetal surgical intervention for selected life-threatening birth defects.

Objective: Our goal was to review our experience with the EXIT (ex utero intrapartum treatment) procedure in the management of five cases with life-threatening fetal neck masses., Study Design: We present a retrospective review of prenatal presentation and course, diagnostic accuracy of imaging studies, intraoperative management, complications, and outcomes., Results: Polyhydramnios was the initial presenting symptom in three of five fetuses with a mean gestational age of 25 +/- 6 weeks. Preterm labor occurred in two patients. Fetal magnetic resonance imaging provided accurate diagnosis in all four cases whereas conventional ultrasonography led to the diagnosis in four of five cases. The mean duration of EXIT was 28 +/- 22 minutes. The mean venous cord blood gas values were pH 7.22 +/- 0.05, PCO2 61 +/- 11 mm Hg, and PO2 42 +/- 8 mm Hg. In four of five cases an airway was successfully secured., Conclusions: The EXIT procedure provides up to 1 hour of good uteroplacental support and is the procedure of choice to secure an airway in the fetus with a giant neck mass.