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With the rising participation of girls in sports at both the recreational and elite levels, there has also been increased awareness of injuries common in this athlete population. Anatomic differences between boys and girls cause girl athletes to be predisposed to certain injuries. Certain behavioral patterns, such as eating disorders, also cause problems specific to girl athletes that may result in injury. Imaging plays a large role in diagnosis and ongoing management, but there has been only scant literature dedicated to the specific topic of imaging in girl athletes. The purpose of this article is to review the imaging findings and recommendations for injuries and other conditions affecting the adolescent girl athlete. This article first provides an overview of the key anatomic differences between boys and girls, including both static and dynamic factors, as well as non-anatomic differences, such as hormonal factors, and discusses how these differences contribute to the injury patterns that are seen more typically in girls. The article then reviews the imaging findings in injuries that are commonly seen in girl athletes. There is also a discussion of the "female athlete triad," which consists of osteoporosis, disordered eating, and amenorrhea, and the role of imaging in this condition.
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Traumatismos em Atletas/diagnóstico por imagem , Sistema Musculoesquelético/diagnóstico por imagem , Sistema Musculoesquelético/lesões , Adolescente , Feminino , Síndrome da Tríade da Mulher Atleta/complicações , Síndrome da Tríade da Mulher Atleta/diagnóstico por imagem , Humanos , Fatores de RiscoRESUMO
BACKGROUND: Femoroacetabular impingement (FAI) can lead to acetabular chondrolabral damage and has been theorized as a causative factor in the development of osteoarthritis. The pathogenesis of FAI is unknown. The purpose of this study was to determine the prevalence of FAI morphology in asymptomatic adolescents. METHODS: We identified children 10 to 18 years of age who had undergone a pelvic CT between 2007 and 2012. Exclusion criteria included hip pain, any hip pathology, bone tumor, long-term steroid use, history of chemotherapy or radiation therapy, nonambulatory status, neuromuscular disorder, chromosomal abnormality, and metabolic bone disease. Multiplanar reformatted images were created from axial images to calculate α angles and lateral center-edge angles (LCEA). Cam morphology was defined as an α-angle ≥55 degrees and pincer morphology as a LCEA≥40 degrees. RESULTS: We analyzed 558 patients (1116 hips). There were 276 males and 282 females. The average age was 14.4 years (range, 10.0 to 18.2 y). The mean α-angle was 47.9 degrees (range, 25.7 to 78 degrees) and the mean LCEA was 34.4 degrees (range, 3.9 to 58.6 degrees). Males had a significantly higher mean α-angle (49.7 vs. 46.0 degrees) (P<0.0005) and females had a significantly higher mean LCEA (35.7 vs. 33.0 degrees) (P<0.0005). Ninety-four adolescents (16.8%) had an α-angle ≥55 degrees. Cam morphology was significantly more common in males (23.9% vs. 9.9%) (P<0.001). A total of 181 adolescents (32.4%) had a LCEA≥40 degrees. Pincer morphology was equally common in males and females (29.7% vs. 35.1%) (P=0.17). Thirty-four adolescents (6.1%) had mixed morphologies. Mixed morphologies were found in 21 males (7.6%) and 13 females (4.6%) (P=0.19). The prevalence of pincer morphology increased significantly with increased age in males (P<0.001). CONCLUSIONS: The prevalence of cam-type FAI morphology in asymptomatic adolescents is similar to the reported prevalence in asymptomatic adults. Pincer morphology may be more common than cam morphology in adolescents. Cam morphology is more prevalent in males, whereas pincer and mixed morphologies are equally prevalent in both sexes. LEVEL OF EVIDENCE: Level III-diagnostic.
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Doenças Assintomáticas , Impacto Femoroacetabular/diagnóstico , Articulação do Quadril/diagnóstico por imagem , Adolescente , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Prevalência , Estudos Retrospectivos , Fatores Sexuais , Tomografia Computadorizada por Raios XRESUMO
Non-accidental trauma is a significant source of morbidity and mortality in the pediatric population. Given the vulnerable state of the child, the radiologist can often provide valuable diagnostic information in the setting of suspected abuse. This review focuses on common findings of abusive trauma and serves as a guide to aid in clinical decision-making for providers of emergency medicine and pediatrics. Amid this discussion is an assessment of modern controversies regarding reported mimicking pathologies, recapitulation of the current state of evidence with respect to radiologic findings of abuse, and examination of the contribution that spine imaging may add to the diagnosis of possible abusive head trauma in the acutely injured child. Recommendations for avoiding pitfalls regarding the dating of intracranial injuries are discussed, and illustrated depictions of perpetrator-induced pathology are provided to aid in the understanding of these injuries. Through the use of the appropriate approach to imaging and evidence-based guidelines regarding radiologic findings, the role of radiology is to provide fundamental clues to diagnose and prevent recurrence of abusive injury in patients who cannot speak for themselves.
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Maus-Tratos Infantis/diagnóstico , Traumatismos Craniocerebrais/diagnóstico por imagem , Diagnóstico por Imagem , Criança , Tomada de Decisões , Diagnóstico Diferencial , HumanosRESUMO
Ultrasonography (US) is commonly used to assess the peripheral nerves of the lower extremity because of its many advantages over magnetic resonance (MR) imaging. The most obvious advantages over MR imaging are superior soft-tissue resolution, low cost, portability, lack of magnetic susceptibility artifact, and the ability to image patients who cannot undergo MR imaging. US has been shown to have equal specificity and greater sensitivity than MR imaging in the evaluation of peripheral nerves. Additional benefits are the capability of real-time and dynamic imaging, and the ability to scan an entire extremity quickly without the need for a patient to lie motionless for long periods of time, as with MR imaging. Any abnormal findings can be easily compared against the contralateral side. Published literature has shown that US has clinical utility in patients suspected of having peripheral nerve disease: US can be used to guide diagnostic and therapeutic decisions, as well as help confirm electrodiagnostic findings. Common indications for lower extremity peripheral nerve US are the evaluation for injury due to penetrating trauma, entrapment by scar tissue, or tumor. To confidently perform US of the peripheral nerves of the lower extremity, it is important to gain a thorough knowledge of anatomic landmarks and the course of each nerve. Readers who may not be familiar with US will be introduced to the basics of scanning the peripheral nerves of the lower extremity. Important anatomic landmarks and common sites of injury and entrapment will be reviewed.
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Perna (Membro)/inervação , Nervos Periféricos/diagnóstico por imagem , Doenças do Sistema Nervoso Periférico/diagnóstico por imagem , Ultrassonografia/métodos , Nervo Femoral/diagnóstico por imagem , Humanos , Perna (Membro)/diagnóstico por imagem , Imageamento por Ressonância Magnética , Neuroma Intermetatársico/diagnóstico por imagem , Traumatismos dos Nervos Periféricos/diagnóstico por imagem , Nervo Fibular/diagnóstico por imagem , Nervo Isquiático/diagnóstico por imagem , Nervo Tibial/diagnóstico por imagem , Ultrassonografia/instrumentaçãoRESUMO
BACKGROUND: MR Urography (MRU) is an increasingly used imaging modality for the evaluation of pediatric genitourinary obstruction. OBJECTIVE: To determine whether pediatric MR urography (MRU) reliably detects crossing vessels in the setting of suspected ureteropelvic junction (UPJ) obstruction. The clinical significance of these vessels was also evaluated. MATERIALS AND METHODS: We identified pediatric patients diagnosed with UPJ obstruction by MRU between May 2009 and June 2014. MRU studies were evaluated by two pediatric radiologists for the presence or absence of crossing vessels. Ancillary imaging findings such as laterality, parenchymal thinning/scarring, trapped fluid in the proximal ureter, and presence of renal parenchymal edema were also evaluated. Imaging findings were compared to surgical findings. We used the Mann-Whitney U test to compare continuous data and the Fisher exact test to compare proportions. RESULTS: Twenty-four of 25 (96%) UPJ obstructions identified by MRU were surgically confirmed. MRU identified crossing vessels in 10 of these cases, with 9 cases confirmed intraoperatively (κ = 0.92 [95% CI: 0.75, 1.0]). Crossing vessels were determined to be the primary cause of UPJ obstruction in 7/9 children intraoperatively, while in two children the vessels were deemed incidental and noncontributory to the urinary tract obstruction. There was no significant difference in age or the proportions of ancillary findings when comparing children without and with obstructing vessels. CONCLUSION: MRU allows detection of crossing vessels in pediatric UPJ obstruction. Although these vessels are the primary cause of obstruction in some children, they are incidental and non-contributory in others. Our study failed to convincingly identify any significant predictors (e.g., age or presence of renal parenchymal edema) that indicate when a crossing vessel is the primary cause of obstruction.
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Imageamento por Ressonância Magnética , Ureter/irrigação sanguínea , Ureter/patologia , Obstrução Ureteral/patologia , Adolescente , Criança , Pré-Escolar , Meios de Contraste , Feminino , Gadolínio , Compostos Heterocíclicos , Humanos , Aumento da Imagem , Imageamento Tridimensional , Lactente , Masculino , Compostos Organometálicos , Reprodutibilidade dos Testes , Estudos RetrospectivosRESUMO
Soft tissue vascular anomalies may be composed of arterial, venous, and/or lymphatic elements, and diagnosed prenatally or later in childhood or adulthood. They are divided into categories of vascular malformations and vascular tumors. Vascular malformations are further divided into low-flow and fast-flow lesions. A low-flow lesion is most common, with a prevalence of 70%. Vascular tumors may behave in a benign, locally aggressive, borderline, or malignant manner. Infantile hemangioma is a vascular tumor that presents in the neonatal period and then regresses. The presence or multiple skin lesions in an infant can signal underlying visceral vascular anomalies, and complex anomalies may be associated with overgrowth syndromes. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.
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Sociedades Médicas , Malformações Vasculares , Humanos , Malformações Vasculares/diagnóstico por imagem , Estados Unidos , Medicina Baseada em Evidências , Lactente , Neoplasias Vasculares/diagnóstico por imagem , Neoplasias de Tecidos Moles/diagnóstico por imagem , Recém-Nascido , Criança , Diagnóstico por Imagem/métodos , Hemangioma/diagnóstico por imagem , Guias de Prática Clínica como AssuntoRESUMO
Background: Clinical trials have shown success in bleed prevention with emicizumab, but real-world data on the effectiveness of emicizumab in preventing serious bleeds in the pediatric population are lacking. Objectives: To report real-world data on the effectiveness of Emicizumab in pediatric persons with hemophilia A. Methods: We completed a retrospective chart review of 37 pediatric male patients aged ≤18 years on emicizumab prophylaxis for a median duration of 30.5 months at Children's Medical Center in Dallas, Texas. Results: We identified 4 pediatric persons with severe hemophilia A with and without inhibitors who experienced a provoked or unprovoked serious bleed requiring hospitalization. Conclusion: This study highlights that serious bleeds, both provoked and unprovoked, can occur in pediatric persons with severe hemophilia A. These findings are important for clinicians to provide appropriate counseling/education and recommendation of treatment for pediatric persons with severe hemophilia A through shared decision making. Up-titration of emicizumab or factor VIII replacement needs consideration in persons with hemophilia with suboptimal bleeding control or who participate in activities categorized as moderate- to high-risk activities.
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BACKGROUND: Inflammatory bowel disease is an inflammatory disorder that primarily impacts the gastrointestinal tract, leading to malnutrition and chronic microscopic intestinal blood loss. Uncontrolled systemic inflammation can impact other parts of the body, known as extraintestinal manifestations. Up to 25% of patients with inflammatory bowel disease are reported to have these complications in their skin, joints, bones, eyes, liver, lung, and pancreas (Rogler et al. in Gastroenterology 161(4):1118-1132, 2021). Neurologic involvement as extraintestinal manifestations are less common, reported at 3-19%, including neuropathies, demyelination, and cerebrovascular events (Morís in World J Gastroenterol. 20(5):1228-1237, 2014). CASE PRESENTATION: A 13-year-old Caucasian boy presented with 1 month of progressive lower-extremity pain, weakness, and weight loss. His physical examination was notable for cachexia, lower-extremity weakness, and chorea. Labs revealed normocytic anemia and systemic inflammation. Imaging revealed symmetric abnormal marrow signal in the pelvis and upper femurs. Pathologic examination of the bone revealed chronic inflammation consistent with chronic nonbacterial osteitis. Endoscopy revealed colonic inflammation consistent with inflammatory bowel disease. CONCLUSIONS: Children and adolescents with musculoskeletal pain lasting more than 2 weeks with systemic signs or symptoms like weight loss should prompt evaluation for systemic inflammatory disorders such as chronic nonbacterial osteitis, which can occur in isolation or associated with inflammatory bowel disease. This patient also had a nonspecific neurologic abnormality, chorea, which resolved with treatment of underlying inflammatory disorder. These extraintestinal manifestations may be concurrent with or precede intestinal inflammation, requiring a high index of suspicion when investigating nonspecific systemic inflammation.
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Coreia , Doenças Inflamatórias Intestinais , Osteíte , Masculino , Criança , Adolescente , Humanos , Osteíte/patologia , Caquexia/complicações , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/patologia , Inflamação/complicações , Dor , Redução de PesoRESUMO
A team approach is optimal in the evaluation and treatment of musculoskeletal infection in pediatric patients given the complexity and uncertainty with which such infections manifest and progress, particularly among severely ill children. The team approach includes emergency medicine, pediatric intensive care, pediatric hospitalist medicine, infectious disease service, orthopaedic surgery, radiology, anesthesiology, pharmacology, and hematology. These services follow evidence-based clinical practice guidelines with integrated processes of care so that children and their families may benefit from data-driven continuous process improvement. Important principles based on our experience in the successful treatment of pediatric musculoskeletal infection include relevant information gathering, pattern recognition, determination of the severity of illness, institutional workflow management, closed-loop communication, patient and family-centered care, ongoing dialogue among key stakeholders within and outside the context of direct patient care, and periodic data review for programmatic improvement over time. Such principles may be useful in almost any setting, including rural communities and developing countries, with the understanding that the team composition, institutional capabilities or limitations, and specific approaches to treatment may differ substantially from one setting or team to another.
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Osteomielite/terapia , Equipe de Assistência ao Paciente , Choque Séptico/terapia , Criança , Humanos , Imageamento por Ressonância Magnética , Masculino , Osteomielite/complicações , Osteomielite/diagnóstico por imagem , Choque Séptico/etiologia , Tíbia/diagnóstico por imagemRESUMO
BACKGROUND: Magnetic resonance imaging (MRI) is a heavily utilized resource to evaluate children suspected to have a musculoskeletal infection. Complex interdisciplinary workflows are involved with decision-making with regard to indications, anesthesia, contrast use, and procedural timing relative to the scan. This study assesses the impact of a quality improvement endeavor on MRI workflows at a tertiary pediatric medical center. METHODS: A registry of consecutively enrolled children for a multidisciplinary musculoskeletal infection program identified those evaluated with MRI from 2012 to 2018. Annual MRI process improvement feedback was provided to the key stakeholders. Demographic characteristics, laboratory parameters, MRI indications, anesthesia use, MRI findings, final diagnoses, scan duration, imaging protocol, surgical intervention following MRI, and length of stay were retrospectively compared between the 3 cohorts (initial, middle, and final) representing 2-year increments to assess the impact of the initiative. RESULTS: There were 526 original MRI scans performed to evaluate 1,845 children with suspected musculoskeletal infection. Anesthesia was used in 401 children (76.2%). When comparing the initial, middle, and final study period cohorts, significant improvement was demonstrated for the number of sequences per scan (7.5 sequences for the initial cohort, 5.8 sequences for the middle cohort, and 4.6 sequences for the final cohort; p < 0.00001), scan duration (73.6 minutes for the initial cohort, 52.1 minutes for the middle cohort, and 34.9 minutes for the final cohort; p < 0.00001), anesthesia duration (94.1 minutes for the initial cohort, 68.9 minutes for the middle cohort, and 53.2 minutes for the final cohort; p < 0.00001), and the rate of contrast use (87.6% for the initial cohort, 67.7% for the middle cohort, and 26.3% for the final cohort; p < 0.00001). There was also a trend toward a higher rate of procedures under continued anesthesia immediately following the MRI (70.2% in the initial cohort, 77.8% in the middle cohort, and 84.6% in the final cohort). During the final 6-month period, the mean scan duration was 24.4 minutes, anesthesia duration was 40.9 minutes, and the rate of contrast administration was 8.5%. CONCLUSIONS: Progressive quality improvement through collaborative interdisciplinary communication and workflow redesign led to improved utilization of MRI and minimized contrast use for suspected musculoskeletal infection. There was a high rate of procedural intervention under continued anesthesia for children with confirmed musculoskeletal infection. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
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Hospitais Pediátricos/normas , Infecções/diagnóstico por imagem , Imageamento por Ressonância Magnética/normas , Doenças Musculoesqueléticas/diagnóstico por imagem , Melhoria de Qualidade/organização & administração , Centros de Atenção Terciária/normas , Fluxo de Trabalho , Adolescente , Criança , Pré-Escolar , Protocolos Clínicos , Meios de Contraste , Feminino , Hospitais Pediátricos/organização & administração , Humanos , Lactente , Imageamento por Ressonância Magnética/métodos , Masculino , Sistema de Registros , Estudos Retrospectivos , Centros de Atenção Terciária/organização & administração , Texas , Fatores de Tempo , Adulto JovemRESUMO
Imaging of the temporomandibular joint in pediatric patients is a critical component in the evaluation and treatment of children with temporomandibular joint symptoms. MRI can provide detailed joint anatomy and identify inflammation, sometimes before symptom onset. Ultrasound scan is a convenient emerging modality to evaluate the joint and guide therapeutic injections. Radiography and computed tomography offer osseous detail to recognize early morphologic changes of the mandibular condyle and provide operative planning. Imaging promises to direct treatment to prevent future joint destruction and maintain function.
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Diagnóstico por Imagem , Transtornos da Articulação Temporomandibular/diagnóstico por imagem , Articulação Temporomandibular/diagnóstico por imagem , Criança , HumanosRESUMO
BACKGROUND: MAG3 diuretic renal scan remains the gold standard for determination of improvement in renal drainage following pyeloplasty for ureteropelvic junction obstruction. We hypothesized that (i) a change in geometric measurements between pre-operative and post-operative renal ultrasound (RUS) images and (ii) blinded simple visual review of images both would predict pyeloplasty success. OBJECTIVE: To determine if simple visual review and/or novel geometric measurement of renal ultrasounds can detect pyeloplasty failure. STUDY DESIGN: This study was a retrospective, blinded comparison with a gold standard. Included were children aged ≤18 years undergoing pyeloplasty at our institution from 2009 to 2015. For each kidney, representative pre-operative and post-operative RUS images were chosen. Our standard for pyeloplasty success was improved drainage curve on MAG3 and lack of additional surgery. Measurements for collecting system circularity, roundness, and renal parenchymal to collecting system area ratio (RPCSR) were obtained by three raters (Figure), who were blinded to the outcome of the pyeloplasty. Changes in geometric measurements were analyzed as a diagnostic test for MAG3-defined pyeloplasty success using ROC curve analysis. In addition, six reviewers blinded to pyeloplasty success reviewed pre-operative and post-operative images visually for improved hydronephrosis and categorized pyeloplasty as success or failure based on simple visual review of RUS. RESULTS: Fifty-three repaired renal units were identified (50 children). There were five pyeloplasty failures, four of which underwent revision or nephrectomy. While all geometric measurements could discriminate pyeloplasty failure and success, the geometric measurements that discriminated best between pyeloplasty failure and success were change in collecting system roundness and change in RPCSR. Consensus opinion among six blinded reviewers using simple visual review had a sensitivity of 94% and PPV of 100% with respect to identifying pyeloplasty success (AUC 0.97 (95% CI 0.93-1.0)). This was not significantly different from AUC for change in roundness (p = 0.09) or change in RPCSR (p = 0.1). DISCUSSION: Change in collecting system roundness and change in RPCSR were the most accurate geometric measurements in predicting pyeloplasty success. Simple visual review of ultrasound images for pyeloplasty success performed as well or better than geometric measurements. However, geometric measurements remain useful as a research tool or to communicate findings between clinicians. CONCLUSIONS: Complex geometric measurements of hydronephrosis or post-operative MAG3 scans are not needed if hydronephrosis is visually significantly improved, as simple visual review is highly sensitive for detecting pyeloplasty failure.
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Hidronefrose/diagnóstico por imagem , Pelve Renal/cirurgia , Complicações Pós-Operatórias/diagnóstico por imagem , Obstrução Ureteral/cirurgia , Criança , Feminino , Humanos , Hidronefrose/etiologia , Masculino , Complicações Pós-Operatórias/etiologia , Valor Preditivo dos Testes , Estudos Retrospectivos , Falha de Tratamento , Ultrassonografia , Obstrução Ureteral/diagnóstico por imagemRESUMO
Advanced multidetector computed tomographic and magnetic resonance imaging techniques (CT and MR enterography, respectively), designed to provide detailed images of the bowel and mesentery, can be successfully performed in children of all ages, frequently without sedation. Cross-sectional enterography allows for noninvasive diagnosis, detection of various disease-related complications and extraintestinal manifestations, and monitoring of bowel-wall inflammation in pediatric inflammatory bowel disease (IBD). This article provides a contemporary review of CT and MR enterography in the pediatric population, including up-to-date techniques and clinical applications. A range of bowel abnormalities is illustrated, with an emphasis on IBD and its many abdominopelvic manifestations.
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Enteropatias/diagnóstico , Imageamento por Ressonância Magnética , Tomografia Computadorizada Multidetectores , Criança , Humanos , Imageamento por Ressonância Magnética/métodos , Tomografia Computadorizada Multidetectores/métodosRESUMO
Noninvasive, nonionizing, multiparametric magnetic resonance (MR) imaging of the pelvis using a field strength of 3 T now provides a comprehensive assessment of perineal involvement in pediatric Crohn disease. MR imaging accurately evaluates inflammatory disease activity, and allows determination of the number and course of fistula tracts as well as their relationships to vital perianal structures, including the external anal sphincter, helping to guide surgical management and improve outcomes. This article provides an up-to-date review of perineal MR imaging findings of Crohn disease in the pediatric population, including fistulous disease, abscesses, and skin manifestations. Imaging technique is also discussed.
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Canal Anal/patologia , Doença de Crohn/patologia , Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Posicionamento do Paciente/métodos , Períneo/patologia , Proctite/patologia , Adolescente , Criança , Feminino , Humanos , MasculinoRESUMO
OBJECTIVE: In evaluating the pediatric cervical spine for injury, the use of adult protocols without sufficient sensitivity to pediatric injury patterns may lead to excessive radiation doses. Data on injury location and means of detection can inform pediatric-specific guideline development. METHODS: We retrospectively identified pediatric patients with codes from the International Classification of Diseases, 9th Revision, for cervical spine injury treated between 1980 and 2000. Collected data included physical findings, radiographic means of detection, and location of injury. Sensitivity of plain x-rays and diagnostic yield from additional radiographic studies were calculated. RESULTS: Of 239 patients, 190 had true injuries and adequate medical records; of these, 187 had adequate radiology records. Patients without radiographic abnormality were excluded. In 34 children younger than 8 years, National Emergency X-Radiography Utilization Study criteria missed two injuries (sensitivity, 94%), with 76% of injuries occurring from occiput-C2. In 158 children older than 8 years, National Emergency X-Radiography Utilization Study criteria identified all injured patients (sensitivity, 100%), with 25% of injuries occurring from occiput-C2. For children younger than 8 years, plain-film sensitivity was 75% and combination plain-film/occiput-C3 computed tomographic scan had a sensitivity of 94%, whereas combination plain-film and flexion-extension views had 81% sensitivity. In patients older than 8 years, the sensitivities were 93%, 97%, and 94%, respectively. CONCLUSION: Younger children tend to have more rostral (occiput-C2) injuries compared with older children. The National Emergency X-Radiography Utilization Study protocol may have lower sensitivity in young children than in adults. Limited computed tomography from occiput-C3 may increase diagnostic yield appreciably in young children compared with flexion-extension views. Further prospective studies, especially of young children, are needed to develop reliable pediatric protocols.
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Vértebras Cervicais/diagnóstico por imagem , Medição de Risco/métodos , Traumatismos da Medula Espinal/diagnóstico por imagem , Traumatismos da Medula Espinal/epidemiologia , Adolescente , Fatores Etários , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Michigan/epidemiologia , Prevalência , Radiografia , Reprodutibilidade dos Testes , Estudos Retrospectivos , Fatores de Risco , Sensibilidade e EspecificidadeAssuntos
Broncopatias/diagnóstico por imagem , Doenças da Traqueia/diagnóstico por imagem , Adolescente , Brônquios/anormalidades , Brônquios/lesões , Broncopatias/congênito , Neoplasias Brônquicas/diagnóstico por imagem , Broncografia/métodos , Criança , Pré-Escolar , Fluoroscopia , Corpos Estranhos/diagnóstico por imagem , Humanos , Lactente , Tomografia Computadorizada por Raios X , Traqueia/anormalidades , Traqueia/diagnóstico por imagem , Traqueia/lesões , Doenças da Traqueia/congênito , Neoplasias da Traqueia/diagnóstico por imagem , Ferimentos não Penetrantes/diagnóstico por imagemRESUMO
The effects of the linker arm rigidity and size on melanocortin receptor selectivity were explored in a series of compounds using cyclic lactam alpha-melanocyte-stimulating hormone template. A variety of dicarboxylic acid linkers introduced between the alpha-amino group of His(6) and the epsilon-amino group of Lys(10) lead to high-affinity, selective human melanocortin receptor-1 and -5 (hMC1R and hMC5R) antagonists. The incorporation of hydrophilic functions into the linker arm was found to be unfavorable for both binding potency and receptor selectivity. Analogs 8 and 9 containing highly conformationally constrained hydrophobic linkers (m- and p-phthalic acids) were found to be selective nanomolar range hMC1R antagonists (IC(50) = 7 and 4 nm, respectively), whereas the employment of a small conformationally constrained linker (maleic acid) resulted in a high-affinity (IC(50) = 19 nm) and selective hMC5R antagonist (analog 12). These newly developed melanotropins will serve as critical biochemical tools for elucidating the full spectrum of functions performed by the physiologically important melanocortin-1 and -5 receptors.