Search

Chest radiography is the modality of choice for the identification of rib fractures in young children and there is value for the development of computer-aided rib fracture detection in this age group. However, the automated identification of rib fractures on chest radiographs can be challenging due to the need for high spatial resolution in deep learning frameworks. A patch-based deep learning algorithm was developed to automatically detect rib fractures on frontal chest radiographs in children under 2 years old. A total of 845 chest radiographs of children 0-2 years old (median: 4 months old) were manually segmented for rib fractures by radiologists and served as the ground-truth labels. Image analysis utilized a patch-based sliding-window technique, to meet the high-resolution requirements for fracture detection. Standard transfer learning techniques used ResNet-50 and ResNet-18 architectures. Area-under-curve for precision-recall (AUC-PR) and receiver-operating-characteristic (AUC-ROC), along with patch and whole-image classification metrics, were reported. On the test patches, the ResNet-50 model showed AUC-PR and AUC-ROC of 0.25 and 0.77, respectively, and the ResNet-18 showed an AUC-PR of 0.32 and AUC-ROC of 0.76. On the whole-radiograph level, the ResNet-50 had an AUC-ROC of 0.74 with 88% sensitivity and 43% specificity in identifying rib fractures, and the ResNet-18 had an AUC-ROC of 0.75 with 75% sensitivity and 60% specificity in identifying rib fractures. This work demonstrates the utility of patch-based analysis for detection of rib fractures in children under 2 years old. Future work with large cohorts of multi-institutional data will improve the generalizability of these findings to patients with suspicion of child abuse., (© 2023. The Author(s) under exclusive licence to Society for Imaging Informatics in Medicine.) more...

Measurement of angles on foot radiographs is an important step in the evaluation of malalignment. The objective is to develop a CNN model to measure angles on radiographs, using radiologists' measurements as the reference standard. This IRB-approved retrospective study included 450 radiographs from 216 patients (< 3 years of age). Angles were automatically measured by means of image segmentation followed by angle calculation, according to Simon's approach for measuring pediatric foot angles. A multiclass U-Net model with a ResNet-34 backbone was used for segmentation. Two pediatric radiologists independently measured anteroposterior and lateral talocalcaneal and talo-1 st metatarsal angles using the test dataset and recorded the time used for each study. Intraclass correlation coefficients (ICC) were used to compare angle and paired Wilcoxon signed-rank test to compare time between radiologists and the CNN model. There was high spatial overlap between manual and CNN-based automatic segmentations with dice coefficients ranging between 0.81 (lateral 1 st metatarsal) and 0.94 (lateral calcaneus). Agreement was higher for angles on the lateral view when compared to the AP view, between radiologists (ICC: 0.93-0.95, 0.85-0.92, respectively) and between radiologists' mean and CNN calculated (ICC: 0.71-0.73, 0.41-0.52, respectively). Automated angle calculation was significantly faster when compared to radiologists' manual measurements (3 ± 2 vs 114 ± 24 s, respectively; P < 0.001). A CNN model can selectively segment immature ossification centers and automatically calculate angles with a high spatial overlap and moderate to substantial agreement when compared to manual methods, and 39 times faster., (© 2023. The Author(s) under exclusive licence to Society for Imaging Informatics in Medicine.) more...

The COVID-19 pandemic has challenged organizations to adapt under uncertainty and time pressure, with no pre-existing protocols or guidelines available. For organizations to learn to adapt effectively, there is a need to understand the perspectives of the frontline workforce involved in everyday operations. This study implemented a survey-tool to elicit narratives of successful adaptation based on the lived experiences frontline radiology staff at a large multispecialty pediatric hospital. Fifty-eight members of the radiology frontline staff responded to the tool between July and October of 2020. Qualitative analysis of the free-text data revealed five categories of themes that underpinned adaptive capacity of the radiology department during the pandemic: information flow, attitudes and initiative, new and adjusted workflows, availability and utilization of resources, and collaboration and teamwork. Enablers of adaptive capacity included timely and clear communication about procedures and policies from the leadership to frontline staff, and revised workflows with flexible work arrangements, such as remote patient screening. Responses to multiple choice questions in the tool helped identify the main categories of challenges faced by staff, factors that enabled successful adaptation, and resources used. The study demonstrates the use of a survey-tool to proactively identify frontline adaptations. The paper also reports a system-wide intervention resulting directly from a discovery enabled by the findings based on the use of RETIPS in the radiology department. In general, the tool could be used in concert with existing learning mechanisms, such as safety event reporting systems, to inform leadership-level decisions to support adaptive capacity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.) more...

Objective: To describe the development and implementation of a process for creating accurate Pediatric genitourinary 3D modeling and printing with multiphase postcontrast imaging for surgical planning., Materials and Methods: Additive manufacturing and 3D model present opportunities to support clinical planning, this manuscript's specific process and considerations for creating pediatric genitourinary 3D modeling to support urology. The process for creating the 3D models and prints covers 3 key aspects from image acquisition, imaging review and selection, and segmentation and modification (as needed). Each step is outlined with the key roles and procedures., Results: The described case had digital and printed models prepared with references to the optimized imaging sequence for 3D modeling of Pediatric genitourinary. Case shared include complex genitourinary reconstruction and Kideny with Wilms tumors., Conclusion: The processes described have become a standard of practice for complex kidney tumors and exstrophy planning. The team continues to work on ever-changing improvements to make the best possible models to support clinical and surgical planning., (Copyright © 2023 Elsevier Inc. All rights reserved.) more...

Rationale and Objectives: Artificial intelligence (AI) holds enormous potential for improvements in patient care, efficiency, and innovation in pediatric radiology practice. Although there is a pressing need for a radiology-specific training curriculum and formalized AI teaching, few resources are available. The purpose of our study was to perform a needs assessment for the development of an AI curriculum during pediatric radiology training and continuing education., Materials and Methods: A focus group study using a semistructured moderator-guided interview was conducted with radiology trainees' and attending radiologists' perceptions of AI, perceived competence in interpretation of AI literature, and perceived expectations from radiology AI educational programs. The focus group was audio-recorded, transcribed, and thematic analysis was performed., Results: The focus group was held virtually with seven participants. The following themes we identified: (1) AI knowledge, (2) previous training, (3) learning preferences, (4) AI expectations, and (5) AI concerns. The participants had no previous formal training in AI and variability in perceived needs and interests. Most preferred a case-based approach to teaching AI. They expressed incomplete understanding of AI hindered its clinical applicability and reiterated a need for improved training in the interpretation and application of AI literature in their practice., Conclusion: We found heterogeneity in perspectives about AI; thus, a curriculum must account for the wide range of these interests and needs. Teaching the interpretation of AI research methods, literature critique, and quality control through implementation of specific scenarios could engage a variety of trainees from different backgrounds and interest levels while ensuring a baseline level of competency in AI., (Copyright © 2022 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.) more...

Background: Exercise has been demonstrated to be safe and well-tolerated in individuals with multiple sclerosis (MS). Physical activity has been shown to enhance the therapeutic effects of transcranial direct current stimulation (tDCS). This study aimed to determine the efficacy of intermittent tDCS combined with riding a stationary bicycle to improve walking capacity in individuals with MS., Methods: This double-blind randomized controlled trial enrolled 50 eligible participants. Thirty-nine participants completed the study: 21 in the active group and 18 in the control group. Participants were assigned randomly to exercise on a stationary bike in conjunction with anodal tDCS or to exercise combined with a sham tDCS protocol. Walking capacity tests (2-Minute Walk Test, 5-Meter Walk Test, Timed Up and Go test), manual muscle testing, the Fatigue Severity Scale, and the Multiple Sclerosis Quality of Life-54 were used to determine outcomes., Results: In terms of observed changes in 2-Minute Walk Test and 5-Meter Walk Test values, the exercise + tDCS group achieved significantly higher posttreatment values than the exercise + sham tDCS group. After the intervention and 1 month later, the intervention group's mean Timed Up and Go test value decreased significantly ( P = .002) compared with that of the control group. There was no difference in Fatigue Severity Scale score, Multiple Sclerosis Quality of Life-54 score, or manual muscle testing improvement between the 2 groups., Conclusions: Nonconsecutive sessions of anodal tDCS combined with stationary cycling may have a greater effect on the walking capacity of individuals with MS than exercise alone., Competing Interests: FINANCIAL DISCLOSURES: The authors have disclosed no relevant financial relationships., (© 2022 Consortium of Multiple Sclerosis Centers.) more...

Background: Abdominal emergencies in neonates require surgical management in almost all cases and complications may include bowel perforation, sepsis, shock, and even death. Radiological imaging has become a very important aid in the clinical setting as it shortens time to diagnosis., Objective: The objective of this review is to discuss the more prevalent neonatal gastrointestinal emergencies, review appropriate imaging options, and illustrate common radiological presentations of these entities., Conclusion: Despite advancements in imaging techniques, it is important to keep in mind that neonates have a higher susceptibility to the adverse effects of ionizing radiation, and therefore radiography and ultrasonography remain the main diagnostic modalities for ruling out the diseases with the worst prognosis. Other modalities (fluoroscopy, computed tomography, and magnetic resonance imaging) may have limited use in very specific conditions. All providers in an emergency department should be familiar with the basic radiological findings that may indicate a gastrointestinal emergency, especially in health institutions that do not have 24-h radiologist coverage., Competing Interests: Conflict of interest statement None declared., (Copyright © 2022 French Society of Pediatrics. Published by Elsevier Masson SAS. All rights reserved.) more...

The COVID-19 pandemic produced unprecedented challenges to healthcare and medical device manufacturing (e.g. personal protective device and replacement part shortages). Additive manufacturing, 3D printing, and the maker community were uniquely positioned to respond to these needs by providing in-house design and manufacturing to meet the needs of clinicians and hospitals. This paper reviews the pandemic response of Children's Hospital of Philadelphia CHAMP 3D Lab, a point-ofcare3D printing team that supports clinical and research projects across the hospital network. The CHAMP team responded to a variety of COVID-19 healthcare needs including providing protective eyewear and ventilator components, creating a transport hook, and designing a novel transparent facemask. This case series details our response to these needs, describing challenges experienced and lessons learned in overcoming them so that others may learn from our experiences. Challenges to responding to the pandemic included the need to handle urgent pandemic related requests in addition to our standard fare. This required us to not only expand our capacity without additional resources, but also to develop a system of prioritization. Specific changes made included: streamlining workflows, identifying safety review processes, and developing/enlisting a network of collaborators. Further, we consider how to transition to a future, post-pandemic world without losing the cohesive drive of emergency-induced innovation. This paper aims to share what we have learned and to encourage both teams currently engaged in the printing community and those looking to join it., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 The Authors.) more...

Purpose: The aim of this study was to solicit perspectives of pediatric emergency department physicians (PEDPs) to determine how software-based clinical decision support mechanisms (CDSMs) may integrate with existing imaging clinical decision support (ICDS) to optimize imaging utilization at the authors' institution., Methods: Through qualitative interviews, the authors explored how PEDPs define ICDS, how they seek and obtain radiologist consultation, and how the rollout of CDSMs at the institution may potentially affect clinical practice. Codes were developed and explicitly defined through literature review and analysis of a subset of interviews. Coding results informed thematic categories used to develop an explanatory model., Results: Analysis revealed three major thematic categories: (1) common influences on the decision process, (2) radiology consultation experience, and (3) PEDPs' perspectives on CDSMs. PEDPs described radiologist consultation as a valuable component of ICDS but reported difficulty in coordinating imaging strategies with radiologists and other subspecialists. PEDPs described the exchange of ideas as especially worthwhile for scenarios that do not fit neatly into clinical pathways. Barriers to radiologist consultation include time, access to radiologists, and not wanting to disrupt radiologists' workflow. PEDPs expressed optimism that CDSMs may improve their workflow and facilitate effective interaction with radiologists., Conclusions: PEDPs suggested that radiologist consultation will continue to be a valuable component of ICDS after the implementation of CDSMs by providing discussion-driven guidance to complement CDSM recommendations. The results also indicate that radiologists may consider strategies to facilitate effective interaction with PEDPs and reconcile conflicts of CDSMs with clinical practice., (Copyright © 2019 American College of Radiology. Published by Elsevier Inc. All rights reserved.) more...

Purpose: This paper presents new quantitative data on a signal-to-noise ratio (SNR) study, distortion study, and targeting accuracy phantom study for our patient-mounted robot (called Arthrobot). Arthrobot was developed as an MRI-guided needle placement device for diagnostic and interventional procedures such as arthrography., Methods: We present the robot design and inverse kinematics. Quantitative assessment results for SNR and distortion study are also reported. A respiratory motion study was conducted to evaluate the shoulder mounting method. A phantom study was conducted to investigate end-to-end targeting accuracy. Combined error considering targeting accuracy, respiratory motion, and structure deformation is also reported., Results: The SNR study showed that the SNR changes only 2% when the unpowered robot was placed on top of a standard water phantom. The distortion study showed that the maximum distortion from the ground truth was 2.57%. The average error associated with respiratory motion was 1.32 mm with standard deviation of 1.38 mm. Results of gel phantom targeting studies indicate average needle placement error of 1.64 mm, with a standard deviation of 0.90 mm., Conclusions: Noise and distortion of the MR images were not significant, and image quality in the presence of the robot was satisfactory for MRI-guided targeting. Combined average total error, adding mounting stability errors and structure deformation errors to targeting error, is estimated to be 3.4 mm with a standard deviation of 1.65 mm. In clinical practice, needle placement accuracy under 5 mm is considered sufficient for successful joint injection during shoulder arthrography. Therefore, for the intended clinical procedure, these results indicate that Arthrobot has sufficient positioning accuracy. more...

A new version of our compact and lightweight patient-mounted MRI-compatible 4 degree-of-freedom (DOF) robot for MRI-guided arthrography procedures is introduced. This robot could convert the traditional two-stage arthrography procedure (fluoroscopy-guided needle insertion followed by a diagnostic MRI scan) to a one-stage procedure, all in the MRI suite. The results of a recent accuracy study are reported. A new mounting technique is proposed and the mounting stability is investigated using optical and electromagnetic tracking on an anthropomorphic phantom. Five volunteer subjects including 2 radiologists were asked to conduct needle insertion in 4 different random positions and orientations within the robot's workspace and the displacement of the base of the robot was investigated during robot motion and needle insertion. Experimental results show that the proposed mounting method is stable and promising for clinical application. more...

A novel compact and lightweight patient-mounted MRI-compatible robot has been designed for MRI image-guided interventions. This robot is intended to enable MRI-guided needle placement as done in shoulder arthrography. The robot could make needle placement more accurate and simplify the current workflow by converting the traditional two-stage arthrography procedure (fluoroscopy-guided needle insertion followed by a diagnostic MRI scan) to a one-stage procedure (streamlined workflow all in MRI suite). The robot has 4 degrees of freedom (DOF), two for orientation of the needle and two for needle positioning. The mechanical design was based on several criteria including rigidity, MRI compatibility, compact design, sterilizability, and adjustability. The proposed workflow is discussed and initial MRI compatibility experiments are presented. The results show that artifacts in the region of interest are minimal and that MRI images of the shoulder were not adversely affected by placing the robot on a human volunteer. more...

Down syndrome, the most common single cause of human birth defects, produces alterations in physical growth and mental retardation. If missed before birth, the early detection of Down syndrome is crucial for the management of patients and disease. However, the diagnostic accuracy for pediatricians prior to cytogenetic results is moderate and the access to specialists is limited in many social and low-economic areas. In this study, we propose a simple, non-invasive and automated framework for Down syndrome detection based on disease-specific facial patterns. Geometric and local texture features are extracted based on automatically detected anatomical landmarks to describe facial morphology and structure. To accurately locate the anatomical facial landmarks, a hierarchical constrained local model using independent component analysis (ICA) is proposed. We also introduce a data-driven ordering method for selecting dominant independent components in ICA. The hierarchical structure of the model increases the accuracy of landmark detection by fitting separate models to different groups. Then the most representative features are selected and we also demonstrate that they match clinical observations. Finally, a variety of classifiers are evaluated to discriminate between Down syndrome and healthy populations. The best performance achieved 0.967 accuracy and 0.956 F1 score using combined features and linear discriminant analysis. The method was also validated on a dataset with mixed genetic syndromes and high performance (0.970 accuracy and 0.930 F1 score) was also obtained. The promising results indicate that our method could assist in Down syndrome screening effectively in a simple, non-invasive way, and extensible to detection of other genetic syndromes., (Copyright © 2014 Elsevier B.V. All rights reserved.) more...

Background: In a malaria-endemic area the distribution of patients is neither constant in time nor homogeneous in space. The WHO recommends the stratification of malaria risk on a fine geographical scale. In the village of Cacao in French Guiana, the study of the spatial and temporal distribution of malaria cases, during an epidemic, allowed a better understanding of the environmental factors promoting malaria transmission., Methods: A dynamic cohort of 839 persons living in 176 households (only people residing permanently in the village) was constituted between January 1st, 2002 and December 31st, 2007.The information about the number of inhabitants per household, the number of confirmed cases of Plasmodium vivax and house GPS coordinates were collected to search for spatial or temporal clustering using Kurlldorff's statistical method., Results: Of the 839 persons living permanently in the village of Cacao, 359 persons presented at least one vivax malaria episode between 2002 and 2007. Five temporal clusters and four spatial clusters were identified during the study period. In all temporal clusters, April was included. Two spatial clusters were localized at the north of the village near the Comté River and two others localized close to orchards., Conclusion: The spatial heterogeneity of malaria in the village may have been influenced by environmental disturbances due to local agricultural policies: deforestation, cultures of fresh produce, or drainage of water for agriculture. This study allowed generating behavioural, entomological, or environmental hypotheses that could be useful to improve prevention campaigns. more...

Conventional statistical shape models use Principal Component Analysis (PCA) to describe shape variations. However, such a PCA-based model assumes a Gaussian distribution of data. A model with Independent Component Analysis (ICA) does not require the Gaussian assumption and can additionally describe the local shape variation. In this paper, we propose a Hierarchical Constrained Local Model (HCLM) using ICA. The first or coarse level of HCLM locates the full landmark set, while the second level refines a relevant landmark subset. We then apply the HCLM to Down syndrome detection from photographs of young pediatric patients. Down syndrome is the most common chromosomal condition and its early detection is crucial. After locating facial anatomical landmarks using HCLM, geometric and local texture features are extracted and selected. A variety of classifiers are evaluated to identify Down syndrome from a healthy population. The best performance achieved 95.6% accuracy using support vector machine with radial basis function kernel. The results show that the ICA-based HCLM outperformed both PCA-based CLM and ICA-based CLM. more...

Down syndrome, the most common single cause of human birth defects, produces alterations in physical growth and mental retardation; its early detection is crucial. Children with Down syndrome generally have distinctive facial characteristics, which brings an opportunity for the computer-aided diagnosis of Down syndrome using photographs of patients. In this study, we propose a novel strategy based on machine learning techniques to detect Down syndrome automatically. A modified constrained local model is used to locate facial landmarks. Then geometric features and texture features based on local binary patterns are extracted around each landmark. Finally, Down syndrome is detected using a variety of classifiers. The best performance achieved 94.6% accuracy, 93.3% precision and 95.5% recall by using support vector machine with radial basis function kernel. The results indicate that our method could assist in Down syndrome screening effectively in a simple, non-invasive way. more...

Chinese American pregnant women and women of childbearing age face economic, cultural and linguistic barriers in accessing mainstream health care services. The Charles B. Wang Community Health Center developed a culturally and linguistically competent genetic education workshop for high-risk Chinese American prenatal patients. Patients referred for genetic counseling for thalassemia, abnormal triple screen results, and/or advanced maternal age were recruited to participate in the workshop. The workshop provided basic "genetic 101" education, focusing on topics that were directly relevant to the patients' reasons for referral. The effectiveness of the workshop was measured using a quasi-experimental design with pre-post surveys administered to intervention and control group participants. The evaluation also included a genetic counselor assessment and a pilot study of genetic counseling appointment length. Overall, workshop participants showed significant increases in knowledge, positive attitude and self-efficacy regarding genetic services as compared to their control group counterparts. The pilot appointment length study data revealed that the workshop reduced the length of the genetic counseling appointment time by 40%. These positive findings suggest that it would be worthwhile to replicate the genetic education workshop at other health agencies serving Chinese-speaking populations and that further evaluation research should be conducted. more...

Background: Pediatric endocrinologists at a children's hospital were concerned that bone age readings by radiologists frequently differed from their readings by >1 year., Objective: To compare consistency of bone age readings by endocrinologists vs. radiologists, and the Greulich and Pyle (GP) atlas vs. the recently published Gilsanz and Ratib (GR) digital atlas., Materials and Methods: Sixteen radiographs were read by seven radiologists and five endocrinologists, using both the GP and GR atlases. Time to complete all 16 readings was recorded. An intraclass correlation coefficient (ICC) was used to assess the level of agreement between the two disciplines and the use of different atlases., Results: The ICCs for the seven radiologists and five endocrinologists were both 0.95; the ICC for readings done by GP vs. GR for all raters was 0.96. The number of outlier readings was similar for radiologists and endocrinologists but was higher for GR than for GP. Radiologists spent less time (1.15 min) reading each bone age than endocrinologists (2.4 min)., Conclusion: Under controlled conditions, pediatric endocrinologists and radiologists displayed nearly identical consistencies in reading bone ages. The GR atlas performed similarly to the GP atlas, except for an increased number of outliers, and might be suitable as a replacement for GP. more...

Background: The epidemiological profiles of vector-borne diseases, such as malaria, are strongly associated with environmental conditions. An understanding of the effect of the climate on the occurrence of malaria may provide indirect insight into the anopheles mosquito vectors endemic to a particular region. The association between meteorological and hydrographical factors and the occurrence of malaria was studied in a village in French Guiana during an epidemic caused essentially by Plasmodium vivax., Methods: A cohort of confirmed cases of P. vivax malaria occurring between 2002 and 2007 was studied to search for an association between the number of new infection episodes occurring each month, mean, maximum and minimum monthly temperatures, cumulative rainfall for the month and the mean monthly height of the river bordering the village, with the aid of time series. Cross-correlation analysis revealed that these meteorological factors had large effects on the number of episodes, over a study period of 12 months., Results: Climatic factors supporting the continuance of the epidemic were identified in the short-term (low minimum temperatures during the month), medium-term (low maximum temperatures two months before) and long-term (low maximum temperatures nine months before and high lowest level of the river 12 months before). Cross-correlation analysis showed that the effects of these factors were greatest at the beginning of the short rainy season., Conclusion: The association between the river level and the number of malaria attacks provides clues to better understand the environment of malaria transmission and the ecological characteristics of the vectors in the region. more...

DNA methylation is one of the key mechanisms underlying the epigenetic regulation of gene expression. During DNA replication, the methylation pattern of the parent strand is maintained on the replicated strand through the action of Dnmt1 (DNA Methyltransferase 1). In mammals, Dnmt1 is recruited to hemimethylated replication foci by Uhrf1 (Ubiquitin-like, Containing PHD and RING Finger Domains 1). Here we show that Uhrf1 is required for DNA methylation in vivo during zebrafish embryogenesis. Due in part to the early embryonic lethality of Dnmt1 and Uhrf1 knockout mice, roles for these proteins during lens development have yet to be reported. We show that zebrafish mutants in uhrf1 and dnmt1 have defects in lens development and maintenance. uhrf1 and dnmt1 are expressed in the lens epithelium, and in the absence of Uhrf1 or of catalytically active Dnmt1, lens epithelial cells have altered gene expression and reduced proliferation in both mutant backgrounds. This is correlated with a wave of apoptosis in the epithelial layer, which is followed by apoptosis and unraveling of secondary lens fibers. Despite these disruptions in the lens fiber region, lens fibers express appropriate differentiation markers. The results of lens transplant experiments demonstrate that Uhrf1 and Dnmt1 functions are required lens-autonomously, but perhaps not cell-autonomously, during lens development in zebrafish. These data provide the first evidence that Uhrf1 and Dnmt1 function is required for vertebrate lens development and maintenance., (Copyright © 2010 Elsevier Inc. All rights reserved.) more...

Converging advances in the development of nanoparticle-based imaging probes and improved understanding of the molecular biology of brain tumors offer the potential to provide physicians with new tools for the diagnosis and treatment of these deadly diseases. However, the effectiveness of promising nanoparticle technologies is currently limited by insufficient accumulation of these contrast agents within tumors. Here a biocompatible nanoprobe composed of a poly(ethylene glycol) (PEG) coated iron oxide nanoparticle that is capable of specifically targeting glioma tumors via the surface-bound targeting peptide, chlorotoxin (CTX), is presented. The preferential accumulation of the nanoprobe within gliomas and subsequent magnetic resonance imaging (MRI) contrast enhancement are demonstrated in vitro in 9L cells and in vivo in tumors of a xenograft mouse model. TEM imaging reveals that the nanoprobes are internalized into the cytoplasm of 9L cells and histological analysis of selected tissues indicates that there are no acute toxic effects of these nanoprobes. High targeting specificity and benign biological response establish this nanoprobe as a potential platform to aid in the diagnosis and treatment of gliomas and other tumors of neuroectodermal origin. more...

Single-suture craniosynostosis is a condition of the sutures of the infant's skull that causes major craniofacial deformities and is associated with an increased risk of cognitive deficits and learning/language disabilities. In this paper we adapt to classification of synostostic head shapes a Bayesian methodology that overcomes the limitations of our previously published shape representation and classification techniques. We evaluate our approach in a series of large-scale experiments and show performance superior to those of standard approaches such as Fourier descriptors, cranial spectrum, and Euclidian-distance-based analyses. more...

The 22q11.2 deletion syndrome is characterized by wide phenotypic variability, frequently involving characteristic craniofacial features, cardiac malformations, and learning difficulties. Skeletal anomalies are also common and include an obtuse angle of the cranial base, retrognathia, and cervical spine abnormalities. Despite these anomalies, sleep-disturbed breathing is not reported frequently in patients with 22q11.2 deletion syndrome. We describe a patient with an obstructive sleep disturbance that was successfully treated with a tonsillectomy followed by mandibular distraction osteogenesis. She also had central sleep apnea, initially attributed to spinal cord impingement from cervical instability. Posterior cervical fusion was associated with a decrease in the number of central apneic events. more...

We report the development and in vitro study of a nanoconjugate serving as a targeted magnetic resonance imaging (MRI) contrast enhancement agent for detection of cancer cells overexpressing the folate receptor. The nanoconjugate was synthesized by coating superparamagnetic iron oxide nanoparticles with covalently bound bifunctional poly(ethylene glycol) (PEG), followed by conjugation with folic acid (FA). The specificity of the nanoconjugate targeting cancerous cells was demonstrated by comparative intracellular uptake of the nanoconjugate and PEG-/dextran-coated nanoparticles by human adenocarcinoma HeLa cells. Preferential targeting to cancerous cells was studied by comparing the uptake of the nanoconjugate by HeLa cells and by non-FR expressing osteosarcoma MG-63 cells. Uptake of the nanoconjugate by HeLa cells after 4 h incubation was found to be a 12-fold higher than that of PEG- or dextran-coated nanoparticles as quantified by inductively coupled plasma spectroscopy. A significant negative contrast enhancement was observed with magnetic resonance (MR) phantom imaging for HeLa cells over MG-63 cells, when both were cultured with the nanoconjugate. Specificity of the nanoconjugate for folate receptors was also verified with a competitive inhibition assay, in which HeLa cells were incubated with both NP-PEG-FA and free FA. The bifunctional PEG used has amide linkages within the PEG chains that can form interchain hydrogen bonding, leading to improved stability of the PEG coating. Self-assembled PEG can be controlled at the molecular level and are suitable for nanoscale coatings. more...

Craniosynostosis is a serious and common pediatric disease caused by the premature fusion of sutures of the skull. Although studies have shown an increase in risk for cognitive deficits in patients with isolated craniosynostosis, the causal basis for this association is still unclear. It is hypothesized that an abnormally shaped skull produces a secondary deformation of the brain that results in the disruption of normal neuropsychological development. In this paper, we conduct a comparative analysis of our newly developed shape descriptors in an attempt to understand the impact of skull deformations on neurobehavior. In particular, we show that our scaphocephaly severity indices and symbolic shape signatures are predictive of mental ability and psychomotor functions, respectively, which suggests the possibility that secondary deformation could influence neuro-developmental status. more...

A multifunctional nanoprobe capable of targeting glioma cells, detectable by both magnetic resonance imaging and fluorescence microscopy, was developed. The nanoprobe was synthesized by coating iron oxide nanoparticles with covalently bound bifunctional poly(ethylene glycol) (PEG) polymer, which were subsequently functionalized with chlorotoxin and the near-infrared fluorescing molecule Cy5.5. Both MR imaging and fluorescence microscopy showed significant preferential uptake of the nanoparticle conjugates by glioma cells. Such a nanoprobe could potentially be used to image resections of glioma brain tumors in real time and to correlate preoperative diagnostic images with intraoperative pathology at cellular-level resolution. more...

Objective: To evaluate the utility of three-dimensional (3D) computerized tomography angiography (CTA) in head and neck vascular anomalies., Design: Prospective case series., Methods: A consecutive series of cases of patients with distinct types of vascular anomalies (i.e. hemangioma, arteriovenous malformation, venous malformation and lymphatic malformation) were obtained through CT multislice scanner and analyzed with Vitrea 2 software (Vital Images Inc., Plymouth, MN)., Results: CTA was safe and successful in describing 3D vascular anatomy of a variety of vascular lesions., Conclusions: Three-dimensional CTA allows detailed description of vascular lesions of the head and neck and offers another effective means of imaging these complex lesions. more...

Craniosynostosis is a serious condition of childhood, caused by the early fusion of the sutures of the skull. The resulting abnormal skull development can lead to severe deformities, increased intra-cranial pressure, as well as vision, hearing and breathing problems. In this work we develop a novel approach to accurately classify deformations caused by metopic and isolated sagittal synostosis. Our method combines a novel set of symbolic shape descriptors and off-the-shelf classification tools to model morphological variations that characterize the synostotic skull. We demonstrate the efficacy of our methodology in a series of large-scale classification experiments that contrast the performance of our proposed symbolic descriptors to those of traditional numeric descriptors, such as clinical severity indices, Fourier-based descriptors and cranial image quantifications. more...

Purpose: To perform short echo time MR spectroscopic imaging of the lung parenchyma on normal volunteers., Materials and Methods: A short echo time projection-reconstruction spectroscopic imaging sequence was implemented on a commercial 1.5T whole body MRI scanner. Images and spectra of the lung parenchyma were obtained from five normal volunteers. Breath-held spectroscopic imaging was also performed., Results: Spectroscopic imaging of short-T2* species allows visualization of different anatomic structures based upon their frequency shifts. A characteristic peak from the parenchyma was seen at three ppm from water frequency., Conclusion: Short echo time MR spectroscopic imaging of the lung parenchyma was demonstrated in normal volunteers. This method may improve proton imaging of the lungs and add specificity to the diagnosis of pulmonary disease., (Copyright 2002 Wiley-Liss, Inc.) more...

Baller-Gerold syndrome is characterized by craniosynostosis and preaxial upper limb malformations. Wide heterogeneity exists with regard to the presence of additional anomalies. Most of the 31 reported cases involve other malformations, including cardiac, Central Nervous System (CNS), and urogenital anomalies. Baller-Gerold syndrome is thought to have autosomal recessive inheritance. However, Gripp et al. [1999: Am. J. Med. Genet. 82:170-176] recently provided the first evidence for autosomal dominant inheritance with variable expressivity and severity. A nonsense mutation was found in TWIST, a gene associated with Saethre-Chotzen syndrome (SCS). Here we report on a male Caucasian patient of nonconsanguineous parents, with synostosis of the coronal, metopic, and sagittal sutures, and bilateral radial ray hypoplasia. The patient's small, round ears with prominent crus helices, and cervical anomalies are common features of SCS. The father had very mild features of SCS. We identify direct paternal transmission of a novel missense TWIST mutation in the highly conserved Helix II domain of this bHLH-family gene. This report lends further support to the recent findings by Gripp et al. [1999]. Future TWIST mutational analysis on patients with craniosynostosis and radial ray involvement will shed light on whether Baller-Gerold syndrome should be a distinct entity or some cases should be reclassified as a heterogeneous form of SCS., (Copyright 2001 Wiley-Liss, Inc.) more...

Hemifacial hypertrophy is a rare condition characterized by unilateral enlargement of all tissues of the face. We describe three patients who exhibit hemifacial hyperplasia of the muscles of facial expression with no other organ system involvement. These three cases, in addition to six other cases identified in the literature, describe a unique constellation of characteristics that place these patients into a distinct syndrome. We suggest that the term "hemifacial myohyperplasia" be used to describe this specific and unique condition., (Copyright 2001 Wiley-Liss, Inc.) more...

We present the first report of a patient with atypical hemifacial microsomia (HFM) and unilateral aplasia of the floor of the middle cranial fossa, glenoid fossa, and portions of her posterior fossa. The patient also developed a Chiari I malformation with cervical syrinx over a 3-year interval. This case report highlights the critical role of imaging in revealing serious, but clinically occult, structural abnormalities, as well as the evolution in the pathogenetic understanding of HFM. more...

Remarkable advances in pediatric cardiology have been spurred by the explosion of technologies both in interventional and surgical techniques and the ability to manipulate the genome of experimental animals. After a brief discussion concerning the striking advances in the molecular understanding of congenital heart disease, this article focuses on clues to the diagnosis of congenital heart disease and on chest radiography and common, specific lesions of the neonate such as hypoplastic left heart, transposition of the great vessels, and severe tetralogy of Fallot. The impact of treatment protocols involving interventional cardiology in the neonate also are discussed. more...

Understanding the embryologic development, anatomic relationships, and pathologic processes of the greater omentum is critical to its complete and proper evaluation. The broad spectrum of imaging findings presented in this essay may allow readers to appreciate features that aid accurate diagnosis of omental disease. more...

Over 1/4-joule per pulse is obtained from a cable-fed uv preionized discharge device where a faster energy deposition rate compensates for a slower voltage rise time. These slower voltage rise-time devices may be scalable to high repetition rates using conventional thyratron switching techniques. more...