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ABSTRACT: Voxelotor is an inhibitor of sickle hemoglobin polymerization that is used to treat sickle cell disease. Although voxelotor has been shown to improve anemia, the clinical benefit on the brain remains to be determined. This study quantified the cerebral hemodynamic effects of voxelotor in children with sickle cell anemia (SCA) using noninvasive diffuse optical spectroscopies. Specifically, frequency-domain near-infrared spectroscopy combined with diffuse correlation spectroscopy were used to noninvasively assess regional oxygen extraction fraction (OEF), cerebral blood volume, and an index of cerebral blood flow (CBFi). Estimates of CBFi were first validated against arterial spin-labeled magnetic resonance imaging (ASL-MRI) in 8 children with SCA aged 8 to 18 years. CBFi was significantly positively correlated with ASL-MRI-measured blood flow (R2 = 0.651; P = .015). Next, a single-center, open-label pilot study was completed in 8 children with SCA aged 4 to 17 years on voxelotor, monitored before treatment initiation and at 4, 8, and 12 weeks (NCT05018728). By 4 weeks, both OEF and CBFi significantly decreased, and these decreases persisted to 12 weeks (both P < .05). Decreases in CBFi were significantly correlated with increases in blood hemoglobin (Hb) concentration (P = .025), whereas the correlation between decreases in OEF and increases in Hb trended toward significance (P = .12). Given that previous work has shown that oxygen extraction and blood flow are elevated in pediatric SCA compared with controls, these results suggest that voxelotor may reduce cerebral hemodynamic impairments. This trial was registered at www.ClinicalTrials.gov as #NCT05018728.
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Anemia Falciforme , Circulação Cerebrovascular , Oxigênio , Humanos , Anemia Falciforme/sangue , Criança , Adolescente , Masculino , Feminino , Oxigênio/sangue , Oxigênio/metabolismo , Pré-Escolar , Imageamento por Ressonância Magnética/métodos , Pirazinas/uso terapêutico , Pirazinas/administração & dosagem , Projetos Piloto , Benzaldeídos/uso terapêutico , Benzaldeídos/farmacologia , Benzaldeídos/administração & dosagem , Espectroscopia de Luz Próxima ao Infravermelho/métodos , PirazóisRESUMO
In this article, the authors discuss the development and current curriculum of the Art in Medicine course at the University of Colorado School of Medicine (CUSOM), developed in collaboration with the Centre for Bioethics and Humanities, and the Denver Art Museum. Examples of art museum-based techniques implemented with medical students are discussed with objectives, methods, and pedagogy highlighted. Translational skillsets for medical professionals, including empathy, tolerance of ambiguity, perspective taking, bias, and communication are emphasised through practice in engagement in visual arts with facilitation by medical faculty and art museum educators. Following the discussion of classroom based activities, two of the co-authors, physician-educators from the CUSOM Departments of Medicine and Radiology, discuss the direct applications and importance of these skillsets in the context of the exam room and the reading room respectively.
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Educação de Graduação em Medicina , Medicina , Humanos , Ciências Humanas/educação , Currículo , EmpatiaRESUMO
BACKGROUND: The rate of anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) in ovarian teratomas is unknown. We aim to identify the prevalence of NMDARE as well as volumetric and histopathologic characteristics of ovarian teratomas in patients with versus without. METHODS: We performed a retrospective cohort study to identify patients with confirmed ovarian teratomas and the characteristics of teratomas in NMDARE compared with non-NMDARE patients. Patients aged between 0 and 21 years with confirmed histopathological diagnosis of ovarian teratoma after resection were included. The rate of NMDARE in ovarian teratomas was identified. Moreover, volumes of ovarian teratomas and the frequency of neuronal glial elements on histopathology in NMDARE versus non-NMDARE patients were assessed. RESULTS: Five out of one-hundred-and-sixty-three (3.07%) patients with histopathology confirmed ovarian teratomas were diagnosed with NMDARE. Age was not different between the NMDARE (mean: 13.8 years, standard deviation: 3.9) and non-NMDARE groups (median: 14, interquartile range [IQR]: 5). Teratoma volumes from NMDARE patients were smaller than those of non-NMDARE patients (median 28.3 cm3 with IQR of 431.2 and median 182.8 with IQR of 635.0, respectively). Both age and NMDARE diagnosis were statistically significant variables in the analysis of variance on a multiple linear regression model. Age (p = 0.013) had a positive correlation with teratoma size, whereas presence of NMDARE had a negative correlation (p = 0.008). CONCLUSION: The rate of NMDARE in ovarian teratomas is low and NMDARE patients have smaller teratomas than non-NMDARE. Further studies are needed to understand the timing of anti-NMDA receptor antibodies in teratomas and the development of NMDARE.
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Encefalite Antirreceptor de N-Metil-D-Aspartato , Neoplasias Ovarianas , Teratoma , Adolescente , Encefalite Antirreceptor de N-Metil-D-Aspartato/diagnóstico , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Neoplasias Ovarianas/diagnóstico por imagem , Receptores de N-Metil-D-Aspartato , Estudos Retrospectivos , Teratoma/diagnóstico por imagem , Adulto JovemRESUMO
Background Previous studies suggest that use of artificial intelligence (AI) algorithms as diagnostic aids may improve the quality of skeletal age assessment, though these studies lack evidence from clinical practice. Purpose To compare the accuracy and interpretation time of skeletal age assessment on hand radiograph examinations with and without the use of an AI algorithm as a diagnostic aid. Materials and Methods In this prospective randomized controlled trial, the accuracy of skeletal age assessment on hand radiograph examinations was performed with (n = 792) and without (n = 739) the AI algorithm as a diagnostic aid. For examinations with the AI algorithm, the radiologist was shown the AI interpretation as part of their routine clinical work and was permitted to accept or modify it. Hand radiographs were interpreted by 93 radiologists from six centers. The primary efficacy outcome was the mean absolute difference between the skeletal age dictated into the radiologists' signed report and the average interpretation of a panel of four radiologists not using a diagnostic aid. The secondary outcome was the interpretation time. A linear mixed-effects regression model with random center- and radiologist-level effects was used to compare the two experimental groups. Results Overall mean absolute difference was lower when radiologists used the AI algorithm compared with when they did not (5.36 months vs 5.95 months; P = .04). The proportions at which the absolute difference exceeded 12 months (9.3% vs 13.0%, P = .02) and 24 months (0.5% vs 1.8%, P = .02) were lower with the AI algorithm than without it. Median radiologist interpretation time was lower with the AI algorithm than without it (102 seconds vs 142 seconds, P = .001). Conclusion Use of an artificial intelligence algorithm improved skeletal age assessment accuracy and reduced interpretation times for radiologists, although differences were observed between centers. Clinical trial registration no. NCT03530098 © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Rubin in this issue.
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Determinação da Idade pelo Esqueleto/métodos , Inteligência Artificial , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Radiografia/métodos , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Estudos Prospectivos , Radiologistas , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Child abuse is a global public health concern. Injuries from physical abuse may be clinically occult and not appreciable on physical examination. Imaging is therefore critical in identifying and documenting such injuries. The radiologic approach for a child who has potentially been abused has received considerable attention and recommendations according to decades of experience and rigorous scientific study. Nonetheless, fringe beliefs describing alternative explanations for child abuse-related injuries have emerged and received mainstream attention. Subsequently, imaging findings identified in abused children have been attributed to poorly supported underlying medical conditions, clouding the evidence basis for radiologic findings indicative of nonaccidental trauma. Fringe beliefs that attribute findings seen in child abuse to alternate pathologies such as genetic disorders, birth trauma, metabolic imbalances, vitamin D deficiency, and short-distance falls typically have limited evidence basis and lack professional society support. Careful review of the scientific evidence and professional society consensus statements is important in differentiating findings attributable to child abuse from fringe beliefs used to discount the possibility that a child's constellation of injuries is consistent with abuse. This review refutes fringe beliefs used to provide alternative explanations in cases of suspected child abuse and reinforces the key literature and scientific consensus regarding child abuse imaging.
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Maus-Tratos Infantis/diagnóstico , Diagnóstico por Imagem/métodos , Negação em Psicologia , Feminino , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , Radiologia , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND: Artificial intelligence models have been successful in analyzing ordinary photographic images. One type of artificial intelligence model is object detection, where a labeled bounding box is drawn around an area of interest. Object detection can be applied to medical imaging tasks. OBJECTIVE: To demonstrate object detection in identifying rickets and normal wrists on pediatric wrist radiographs using a small dataset, simple software and modest computer hardware. MATERIALS AND METHODS: The institutional review board at Children's Healthcare of Atlanta approved this study. The radiology information system was searched for radiographic examinations of the wrist for the evaluation of rickets from 2007 to 2018 in children younger than 7 years of age. Inclusion criteria were an exam type of "Rickets Survey" or "Joint Survey 1 View" with reports containing the words "rickets" or "rachitic." Exclusion criteria were reports containing the words "renal," "kidney" or "transplant." Two pediatric radiologists reviewed the images and categorized them as either rickets or normal. Images were annotated by drawing a labeled bounding box around the distal radial and ulnar metaphases. The training dataset was created from images acquired from Jan. 1, 2007, to Dec. 31, 2017. This included 104 wrists with rickets and 264 normal wrists. This training dataset was used to create the object detection model. The testing dataset consisted of images acquired during the 2018 calendar year. This included 20 wrists with rickets and 37 normal wrists. Model sensitivity, specificity and accuracy were measured. RESULTS: Of the 20 wrists with rickets in the testing set, 16 were correctly identified as rickets, 2 were incorrectly identified as normal and 2 had no prediction. Of the 37 normal wrists, 33 were correctly identified as normal, 2 were incorrectly identified as rickets and 2 had no prediction. This yielded a sensitivity and specificity of 80% and 95% for wrists with rickets and 89% and 90% for normal wrists. Overall model accuracy was 86%. CONCLUSION: Object detection can identify rickets on pediatric wrist radiographs. Object detection models can be developed with a small dataset, simple software tools and modest computing power.
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Raquitismo , Punho , Inteligência Artificial , Criança , Humanos , Radiografia , Raquitismo/diagnóstico por imagem , Articulação do PunhoRESUMO
BACKGROUND: Although the radiographic features of coronavirus disease 2019 (COVID-19) in children have been described, the distinguishing features of multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19 are not well characterized. OBJECTIVE: We compared the chest radiographic findings of MIS-C with those of COVID-19 and described other distinguishing imaging features of MIS-C. MATERIALS AND METHODS: We performed a retrospective case series review of children ages 0 to 18 years who were hospitalized at Children's Healthcare of Atlanta from March to May 2020 and who either met the Centers for Disease Control and Prevention (CDC) case definition for MIS-C (n=11) or who had symptomatic, laboratory-confirmed COVID-19 (n=16). Two radiologists reviewed the most severe chest radiographs for each patient. The type and distribution of pulmonary opacities and presence or absence of pleural effusions were recorded. The chest radiographs were categorized based on potential COVID-19 imaging findings as typical, indeterminate, atypical or negative. An imaging severity score was also assigned using a simplified version of the Radiographic Assessment of Lung Edema Score. Findings were statistically compared between patients with MIS-C and those with COVID-19. Additional imaging findings of MIS-C were also described. RESULTS: Radiographic features of MIS-C included pleural effusions (82% [9/11]), pulmonary consolidations (73% [8/11]) and ground glass opacities (91% [10/11]). All of the lung opacities (100% [10/10]) were bilateral, and the majority of the pleural effusions (67% [6/9]) were bilateral. Compared to children with COVID-19, children with MIS-C were significantly more likely to develop pleural effusions on chest radiograph (82% [9/11] vs. 0% [0/0], P-value <0.01) and a lower zone predominance of pulmonary opacifications (100% [10/10] vs. 38% [5/13], P-value <0.01). Children with MIS-C who also had abdominal imaging had intra-abdominal inflammatory changes. CONCLUSION: Key chest radiographic features of MIS-C versus those of COVID-19 were pleural effusions and lower zone pulmonary opacifications as well as intra-abdominal inflammation. Elucidating the distinguishing radiographic features of MIS-C may help refine the case definition and expedite diagnosis and treatment.
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COVID-19/diagnóstico por imagem , COVID-19/patologia , Pulmão/diagnóstico por imagem , Pulmão/patologia , Radiografia Torácica/métodos , Síndrome de Resposta Inflamatória Sistêmica/diagnóstico por imagem , Síndrome de Resposta Inflamatória Sistêmica/patologia , Adolescente , Criança , Pré-Escolar , Diagnóstico Diferencial , Feminino , Humanos , Lactente , Masculino , Estudos Retrospectivos , SARS-CoV-2RESUMO
BACKGROUND: Ileocolic intussusception is a common cause of intestinal obstruction in young children. Radiographs may be of limited value in the diagnosis of intussusception and are sometimes utilized primarily to exclude pneumoperitoneum before therapeutic enema reduction. OBJECTIVE: The goal of this study was to determine if radiographic findings in ileocolic intussusception can offer prognostic information regarding the outcome of therapeutic air enema and, for those requiring surgical intervention, surgical outcomes and/or complications. MATERIALS AND METHODS: A single institution retrospective study was performed including all enemas for intussusception performed during a 5-year period from September 2012 to August 2017. Radiographs obtained before therapeutic enema, including our institution radiographs, outside facility radiographs, or scout images obtained during fluoroscopy or computed tomography (CT), were independently scored by two pediatric radiologists for normal bowel gas pattern, soft-tissue mass, paucity of bowel gas, meniscus sign and bowel obstruction. The reviewers were blinded to enema and surgical outcomes at the time of review. Differences were resolved by consensus. Cases were excluded in which there was no adequate pre-procedure radiograph. In total, 182 cases were reviewed. The medical records were reviewed for enema and surgical outcomes. RESULTS: Radiographic findings included normal bowel gas pattern in 13%, soft-tissue mass in 26%, paucity of bowel gas in 65%, meniscus sign in 12% and obstruction in 10% of the cases, with 17.5% of patients having more than one finding. In patients with bowel obstruction on radiographs, there was a statistically significant decrease in success of therapeutic enema (83% vs. 21%, P=0.0001), increase in complicated surgical reductions (47% vs. 4%, P=0.0012), and increase in bowel resection (42% vs. 4%, P=0.003) compared to patients with normal bowel gas pattern. CONCLUSION: Radiographs can offer prognostic information regarding the potential for therapeutic enema success, as well as potential surgical outcomes in patients failing enema reduction. Particularly, bowel obstruction significantly decreases the success of therapeutic enema and increases the need for bowel resection.
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Doenças do Íleo/diagnóstico por imagem , Doenças do Íleo/terapia , Intussuscepção/diagnóstico por imagem , Intussuscepção/terapia , Ar , Pré-Escolar , Enema , Feminino , Fluoroscopia , Humanos , Lactente , Masculino , Valor Preditivo dos Testes , Prognóstico , Estudos Retrospectivos , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND: Hypertrophic pyloric stenosis (HPS) is a common cause of gastric outlet obstruction in young infants. Infants with HPS present with projectile vomiting, sometimes have electrolyte abnormalities and typically undergo pyloromyotomy to alleviate the obstruction. Abdominal US is the gold standard imaging study for diagnosis. Case reports of incidental hepatic portal venous gas have been reported in infants with HPS; however, no large studies have been conducted to determine the incidence or possible clinical implications of this finding. OBJECTIVE: To assess the incidence of portal venous gas in infants with HPS and to determine whether the presence of this gas in infants with HPS indicates a more unstable patient, increased length of stay or worse outcome. MATERIALS AND METHODS: We conducted a retrospective review of sonographic reports containing "pyloric stenosis," excluding negative descriptor, at a tertiary-care children's hospital from November 2010 to September 2017. Data collected included pyloric thickness/length, liver evaluation, portal venous gas, any additional imaging, demographics, symptomatology days, electrolyte abnormality, and length of hospital stay. RESULTS: In a 7-year period, 545 US exams were positive for HPS. Of these, 334 exams included enough hepatic parenchyma to evaluate for portal venous gas. Infants in 6 of the 334 exams demonstrated portal venous gas (1.8%). Clinical presentation (length of symptoms and electrolyte abnormalities), demographics (male predominance and age at presentation) and imaging characteristics (pyloric thickness and length) were similar for the HPS groups with and without portal venous gas. There was no significant difference in outcome or length of hospital stay. CONCLUSION: Visualization of portal venous gas in infants with HPS is not rare and appears benign, without need for further imaging. Portal venous gas in infants with HPS does not portend a more severe patient presentation or outcome.
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Veia Porta/diagnóstico por imagem , Estenose Pilórica Hipertrófica/diagnóstico por imagem , Ultrassonografia/métodos , Feminino , Gases , Hospitais Pediátricos , Humanos , Incidência , Achados Incidentais , Lactente , Recém-Nascido , Masculino , Estudos RetrospectivosRESUMO
Pediatric radiology is an immensely rewarding career choice. Eight pediatric radiologists, enthusiastic for their profession, were asked six questions about their career choice. Their responses illustrate the common virtues of pediatric radiology and also demonstrate the diverse paths and activities that pediatric radiologists take and pursue.
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Atitude do Pessoal de Saúde , Escolha da Profissão , Pediatria/métodos , Radiologistas/psicologia , Radiologia/métodos , HumanosRESUMO
Congenital limb length discrepancy disorders are frequently associated with a variety of vascular anomalies and have unique genetic and phenotypic features. Many of these syndromes have been linked to sporadic somatic mosaicism involving mutations of the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway, which has an important role in tissue growth and angiogenesis. Radiologists who are aware of congenital limb length discrepancies can make specific diagnoses based on imaging findings. Although genetic confirmation is necessary for a definitive diagnosis, the radiologist serves as a central figure in the identification and treatment of these disorders. The clinical presentations, diagnostic and imaging workups, and treatment options available for patients with Klippel-Trenaunay syndrome, CLOVES (congenital lipomatous overgrowth, vascular anomalies, epidermal nevi, and scoliosis/spinal deformities) syndrome, fibroadipose vascular anomaly, phosphatase and tensin homolog mutation spectrum, Parkes-Weber syndrome, and Proteus syndrome are reviewed. ©RSNA, 2019.
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Anormalidades Múltiplas/diagnóstico por imagem , Deformidades Congênitas dos Membros/diagnóstico por imagem , Extremidade Inferior/diagnóstico por imagem , Malformações Vasculares/diagnóstico por imagem , Feminino , Humanos , Síndrome de Klippel-Trenaunay-Weber/diagnóstico por imagem , Lipoma/diagnóstico por imagem , Masculino , Anormalidades Musculoesqueléticas/diagnóstico por imagem , Nevo/diagnóstico por imagem , Síndrome de Proteu/diagnóstico por imagem , Síndrome de Sturge-Weber/diagnóstico por imagem , SíndromeRESUMO
PURPOSE: Familial dysautonomia (FD) is a rare autosomal recessive disease that affects the development of sensory and autonomic neurons, including those in the cranial nerves. We aimed to determine whether conventional brain magnetic resonance imaging (MRI) could detect morphologic changes in the trigeminal nerves of these patients. METHODS: Cross-sectional analysis of brain MRI of patients with genetically confirmed FD and age- and sex-matched controls. High-resolution 3D gradient-echo T1-weighted sequences were used to obtain measurements of the cisternal segment of the trigeminal nerves. Measurements were obtained using a two-reader consensus. RESULTS: Twenty pairs of trigeminal nerves were assessed in ten patients with FD and ten matched controls. The median (interquartile range) cross-sectional area of the trigeminal nerves in patients with FD was 3.5 (2.1) mm2, compared to 5.9 (2.0) mm2 in controls (P < 0.001). No association between trigeminal nerve area and age was found in patients or controls. CONCLUSIONS: Using conventional MRI, the caliber of the trigeminal nerves was significantly reduced bilaterally in patients with FD compared to controls, a finding that appears to be highly characteristic of this disorder. The lack of correlation between age and trigeminal nerve size supports arrested neuronal development rather than progressive atrophy.
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Disautonomia Familiar/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Nervo Trigêmeo/diagnóstico por imagem , Adolescente , Adulto , Criança , Estudos Transversais , Disautonomia Familiar/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Método Simples-Cego , Nervo Trigêmeo/fisiopatologia , Adulto JovemAssuntos
Gastos em Saúde , Pediatria , Radiologia , Estados Unidos , Humanos , Pediatria/economia , Radiologia/economia , CriançaRESUMO
BACKGROUND: Many patients at our pediatric hospital have had a contrast-enhanced CT of the abdomen and pelvis performed by an outside imaging facility before admission. We have noticed that many of these exams are multiphase, which may contribute to unnecessary radiation dose. OBJECTIVE: To determine the frequency of multiphase acquisitions and radiation dose indices in contrast-enhanced CTs of the abdomen and pelvis performed by outside imaging facilities in patients who were subsequently transferred to our pediatric hospital for care, and compare these metrics to contrast-enhanced CTs of the abdomen and pelvis performed internally. MATERIALS AND METHODS: A retrospective analysis was performed of contrast-enhanced CTs of the abdomen and pelvis from outside imaging facilities uploaded to our picture archiving and communication system (PACS) between January 1, 2012, and December 31, 2015. CT images and dose pages were reviewed to determine the number of phases and dose indices (CT dose index-volume [CTDIvol], dose-length product, size-specific dose estimate). Exams for abdominal or pelvic mass, trauma or urinary leak indications were excluded. Data were compared to internally acquired contrast-enhanced CTs of the abdomen and pelvis by querying the American College of Radiology (ACR) Dose Index Registry. This review was institutional review board and HIPAA compliant. RESULTS: There were 754 contrast-enhanced CTs of the abdomen and pelvis from 104 outside imaging facilities. Fifty-three percent (399/754) had 2 phases, and 2% (14/754) had 3 or more phases. Of the 939 contrast-enhanced CTs of the abdomen and pelvis performed internally, 12% (115) were multiphase exams. Of 88% (664) contrast-enhanced CTs of the abdomen and pelvis from outside imaging facilities with dose data, CTDIvol was 2.7 times higher than our institution contrast-enhanced CTs of the abdomen and pelvis (939) for all age categories as defined by the ACR Dose Index Registry (mean: 9.4 vs. 3.5 mGy, P<0.0001). The majority (74%) of multiphase exams were performed by 9 of 104 outside imaging facilities. CONCLUSION: Multiphase acquisitions in routine contrast-enhanced CT of the abdomen and pelvis exams at outside imaging facilities are more frequent than those at a dedicated pediatric institution and contribute to unnecessary radiation dose. A contrast-enhanced CT of the abdomen and pelvis exam from an outside imaging facility with two passes may have as much as four times to six times the dose as the same exam performed with a single pass at a pediatric imaging center. We advocate for imaging facilities with high multiphase rates to eliminate multiple phases from routine contrast-enhanced CT of the abdomen and pelvis exams in children.
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Padrões de Prática Médica/estatística & dados numéricos , Doses de Radiação , Radiografia Abdominal/métodos , Tomografia Computadorizada por Raios X/métodos , Procedimentos Desnecessários , Adolescente , Criança , Pré-Escolar , Meios de Contraste , Feminino , Hospitais Pediátricos , Humanos , Lactente , Recém-Nascido , Masculino , Melhoria de Qualidade , Estudos Retrospectivos , Adulto JovemRESUMO
White matter microstructural changes during the first three years of healthy brain development are characterized using two different models developed for limited clinical diffusion data: White Matter Tract Integrity (WMTI) metrics from Diffusional Kurtosis Imaging (DKI) and Neurite Orientation Dispersion and Density Imaging (NODDI). Both models reveal a non-linear increase in intra-axonal water fraction and in tortuosity of the extra-axonal space as a function of age, in the genu and splenium of the corpus callosum and the posterior limb of the internal capsule. The changes are consistent with expected behavior related to myelination and asynchrony of fiber development. The intra- and extracellular axial diffusivities as estimated with WMTI do not change appreciably in normal brain development. The quantitative differences in parameter estimates between models are examined and explained in the light of each model's assumptions and consequent biases, as highlighted in simulations. Finally, we discuss the feasibility of a model with fewer assumptions.
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Modelos Neurológicos , Substância Branca/anatomia & histologia , Envelhecimento/fisiologia , Axônios/fisiologia , Simulação por Computador , Corpo Caloso/crescimento & desenvolvimento , Corpo Caloso/fisiologia , Imagem de Difusão por Ressonância Magnética , Feminino , Humanos , Lactente , Recém-Nascido , Cápsula Interna/crescimento & desenvolvimento , Cápsula Interna/fisiologia , Masculino , Bainha de Mielina/fisiologia , Fibras Nervosas Mielinizadas/fisiologia , Neuritos/fisiologia , Substância Branca/crescimento & desenvolvimentoRESUMO
BACKGROUND: Rapid and accurate diagnosis of appendicitis, particularly with respect to the presence or absence of perforation, is essential in guiding appropriate management. Although many studies have explored sonographic findings associated with acute appendicitis, few investigations discuss specific signs that can reliably differentiate perforated appendicitis from acute appendicitis prior to abscess formation. OBJECTIVE: The purpose of our study was to identify sonographic findings that improve the specificity of US in the diagnosis of perforated appendicitis. Our assessment of hepatic periportal echogenicity, detailed analysis of intraperitoneal fluid, and formulation of select constellations of sonographic findings expands upon the literature addressing this important diagnostic challenge. MATERIALS AND METHODS: We retrospectively reviewed 116 abdominal US examinations for evaluation of abdominal pain in children ages 2 to 18 years from January 2008 to September 2011 at a university hospital pediatric radiology department. The study group consisted of surgical and pathology proven acute appendicitis (n = 51) and perforated appendicitis (n = 22) US exams. US exams without a sonographic diagnosis of appendicitis (n = 43) confirmed by follow-up verbal communication were included in the study population as the control group. After de-identification, the US exams were independently reviewed on a PACS workstation by four pediatric radiologists blinded to diagnosis and all clinical information. We recorded the presence of normal or abnormal appendix, appendicolith, appendiceal wall vascularity, thick-walled bowel, dilated bowel, right lower quadrant (RLQ) echogenic fat, increased hepatic periportal echogenicity, bladder debris and abscess or loculated fluid. We also recorded the characteristics of intraperitoneal fluid, indicating the relative quantity (number of abdominal regions) and quality of the fluid (simple fluid or complex fluid). We used logistic regression for correlated data to evaluate the association of diagnosis with the presence versus absence of each US finding. We conducted multivariable analysis to identify constellations of sonographic findings that were predictive of perforated appendicitis. RESULTS: The individual US findings of abscess/loculated fluid, appendicolith, dilated bowel and increased hepatic periportal echogenicity were significantly associated with perforated appendicitis when compared with acute appendicitis (P < 0.01). The sonographic observation of increased hepatic periportal echogenicity demonstrated a statistically significant association with perforated appendicitis compared with acute appendicitis (P < 0.01). The presence of complex fluid yielded a specificity of 87.7% for perforated appendicitis compared with the acute appendicitis group. The US findings of ≥2 regions or ≥3 regions with fluid had specificity of 87.3% and 99.0%, respectively, for perforated appendicitis compared with the acute appendicitis group. Select combinations of sonographic findings yielded high specificity in the diagnosis of perforated appendicitis compared with acute appendicitis. These constellations yielded higher specificity than that of each individual finding in isolation. The constellation of dilated bowel, RLQ echogenic fat, and complex fluid had the highest specificity (99.5%) for perforated appendicitis (P < 0.01). CONCLUSION: Our study demonstrates that identification of select constellations of findings using abdominal sonography, in addition to focused US examination of the right lower quadrant, can improve sonographic diagnosis of perforated appendicitis in the pediatric population.
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Apendicite/diagnóstico por imagem , Adolescente , Criança , Pré-Escolar , Diagnóstico Diferencial , Feminino , Humanos , Lactente , Masculino , Estudos Retrospectivos , Sensibilidade e Especificidade , UltrassonografiaRESUMO
OBJECTIVES: The rapid growth of computed tomography (CT) has resulted in increased concerns of ionizing radiation exposure and its subsequent risk of cancer development. We evaluated the impact of a new protocol using rapid sequence magnetic resonance imaging (rsMRI) instead of CT in children presenting with possible ventriculoperitoneal shunt (VPS) malfunction to promote patient safety. METHODS: This is a retrospective case series of pediatric patients who received a neuroimaging study for emergency evaluation of possible VPS malfunction at New York University's Tisch Hospital Emergency Department between January 2010 and July 2011. Radiology Charge Master was queried to identify the patient database. The trend in the use of rsMRI and CT was calculated for 3 patient age groups and compared across 3 chronological intervals. The effective dose of ionizing radiation per CT scan was calculated using the CT dose index and dose-length product for each patient. RESULTS: Total of 365 patients with the mean age of 8.87 years received either rsMRI or CT study during the study period. One hundred forty-four of these patients required the imaging studies because of VPS malfunction. Overall, 62% of all VPS malfunction cases used rsMRI instead of CT. The ratio of the number of patients receiving rsMRI divided by CT studies has progressively increased from 1.4:1 to 2.1:1 over 3 chronologic periods. CONCLUSIONS: Children with VPS are subject to multiple neuroimaging studies throughout their lifetime. Rapid sequence MRI is an effective alternative to CT while providing no ionizing radiation exposure or risk of developing radiation-induced cancer.