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1.
Semin Ultrasound CT MR ; 31(2): 171-93, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20304324

RESUMO

Pediatric imaging has been at the forefront of radiology innovation since the days of Roentgen. In the past 2 decades, evolving computer technology and sophisticated software algorithms have rapidly advanced how pediatric radiologic examinations are acquired and displayed, interpreted and communicated, and stored and retrieved. Cost-effective use of this state of the art technology requires fundamental knowledge of the modalities, workstations, and informatics that guide advanced pediatric imaging in the current digital era. Equally important is an understanding of the advanced clinical applications and evidence supporting this use. In the first part of this review article, after a brief introduction and historical overview, technical principles are discussed. This is followed by a review of advanced clinical applications for fetal, cardiovascular, central nervous system, neck, thoracic, gastrointestinal, genitourinary, musculoskeletal, and virtual-autopsy imaging.


Assuntos
Diagnóstico por Imagem/tendências , Informática Médica , Pediatria/tendências , Difusão de Inovações , Humanos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Interface Usuário-Computador
2.
Radiology ; 250(2): 378-86, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19098225

RESUMO

PURPOSE: To compare the cost-effectiveness of different imaging strategies in the diagnosis of pediatric appendicitis by using a decision analytic model. MATERIALS AND METHODS: Approval for this retrospective study based on literature review was not required by the institutional Research Ethics Board. A Markov decision model was constructed by using costs, utilities, and probabilities from the literature. The risk of radiation-induced cancer was modeled by using the Biological Effects of Ionizing Radiation VII report, which is based primarily on data from atomic bomb survivors. The three imaging strategies were ultrasonography (US), computed tomography (CT), and US followed by CT if the initial US study was negative. The model simulated the short-term and long-term outcomes of the patients, calculating the average quality-adjusted life span and health care costs. RESULTS: For a single abdominal CT study in a 5-year-old child, the lifetime risk of radiation-induced cancer would be 26.1 per 100,000 in female and 20.4 per 100,000 in male patients. In the base-case analysis, US followed by CT was the most costly and most effective strategy, CT was the second-most costly and second-most effective strategy, and US was the least costly and least effective strategy. The incremental cost-effectiveness ratios (ICERs) of CT to US and of US followed by CT to US were both well below the societal willingness-to-pay threshold of $50,000 (in U.S. dollars). The ICER of US followed by CT to CT was less than $10,000 in both male and female patients. CONCLUSION: In a Markov-based decision model of pediatric appendicitis, the most cost-effective method of imaging pediatric appendicitis was to start with a US study and follow each negative US study with a CT examination.


Assuntos
Apendicite/diagnóstico por imagem , Árvores de Decisões , Cadeias de Markov , Tomografia Computadorizada por Raios X/economia , Ultrassonografia/economia , Apendicite/epidemiologia , Pré-Escolar , Análise Custo-Benefício , Feminino , Humanos , Incidência , Perfuração Intestinal/epidemiologia , Masculino , Neoplasias Induzidas por Radiação/epidemiologia , Prevalência , Doses de Radiação , Estudos Retrospectivos , Risco , Programa de SEER , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X/efeitos adversos
3.
Acad Radiol ; 13(7): 803-10, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16777553

RESUMO

RATIONALE AND OBJECTIVES: Quality Assessment of Diagnostic Accuracy Studies (QUADAS) is a new tool to measure the methodological quality of diagnostic accuracy studies in systematic reviews. We used data from a systematic review of magnetic resonance spectroscopy (MRS) in the characterization of suspected brain tumors to provide a preliminary evaluation of the inter-rater reliability of QUADAS. MATERIALS AND METHODS: A structured literature search identified 19 diagnostic accuracy studies. These publications were distributed randomly to primary and secondary reviewers for dual independent assessment. Reviewers recorded methodological quality by using QUADAS on a custom-designed spreadsheet. We calculated correlation, percentage of agreement, and kappa statistic to assess inter-rater reliability. RESULTS: Most studies in our review were judged to have used an accurate reference standard. Conversely, the MRS literature frequently failed to specify the length of time between index and reference tests or that the clinicians were unaware of the index test findings when reporting the reference standard. There was good correlation (rho = 0.78) between reviewers in assessment of the overall number of quality criteria met. However, mean agreement for individual QUADAS questions was only fair (kappa = 0.22) and ranged from no agreement beyond chance (kappa < 0) to moderate agreement (kappa = 0.58). CONCLUSION: Inter-rater reliability in our study was relatively low. Nevertheless, we believe that QUADAS potentially is a useful tool for highlighting the strengths and weaknesses of existing diagnostic accuracy studies. Low reliability suggests that different reviewers will reach different conclusions if QUADAS is used to exclude "low-quality" articles from meta-analyses. We discuss methods for improving the validity and reliability of QUADAS.


Assuntos
Neoplasias Encefálicas/diagnóstico , Serviços de Diagnóstico/normas , Espectroscopia de Ressonância Magnética/normas , Controle de Qualidade , Literatura de Revisão como Assunto , Inquéritos e Questionários/normas , Consenso , Medicina Baseada em Evidências , Humanos , Variações Dependentes do Observador , Revisão da Pesquisa por Pares , Reprodutibilidade dos Testes
4.
Brain Tumor Pathol ; 19(1): 15-22, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12455884

RESUMO

Ten pediatric medulloblastoma patients were analyzed for DNA content, cell cycle, expression of drug resistance, apoptosis, cell proliferation, and N-myc genes to determine their prognostic significance. Medulloblastoma patients with progressive disease had fourth ventricle foraminal extension and larger tumors in the imaging studies. Patients with aneuploid tumors responded well to treatment regimens as compared with those with diploid tumors. Cell cycle analysis showed that the patients with progressive disease had a high S-phase fraction in the tumor cell population as compared with patients with favorable response to treatment. The correlation coefficients between Bcl-2 and MRP, Bcl-2 and Bax, p53 and p21, as well as Ki67 and PCNA were positive and significant, indicating their possible coregulated expression. The relationship between these markers indicates their relative and cumulative effect on cellular drug resistance, apoptosis, and/or cell proliferation in pediatric medulloblastomas.


Assuntos
Biomarcadores Tumorais/biossíntese , Neoplasias Cerebelares/metabolismo , Meduloblastoma/metabolismo , Adolescente , Apoptose , Ciclo Celular , Neoplasias Cerebelares/genética , Neoplasias Cerebelares/patologia , Neoplasias Cerebelares/terapia , Criança , Pré-Escolar , Resistencia a Medicamentos Antineoplásicos , Feminino , Expressão Gênica , Genes myc/genética , Humanos , Lactente , Masculino , Meduloblastoma/genética , Meduloblastoma/patologia , Meduloblastoma/terapia , Reação em Cadeia da Polimerase , Fatores de Risco , Resultado do Tratamento
5.
Acad Radiol ; 10(2): 139-44, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12583564

RESUMO

RATIONALE AND OBJECTIVES: The purpose of this study was to compare the costs of voiding cystourethrography (VCUG) versus radionuclide cystography (RNC) for evaluation of vesicoureteral reflux in children. MATERIALS AND METHODS: The variable direct costs of performing 25 VCUG and 25 RNC examinations in age- and general health-matched patients suspected of having vesicoureteral reflux was determined by using time and motion analyses. All personnel directly involved in the cases were tracked, and the involvement times were recorded to the nearest minute. All material items used during the procedures were recorded. The cost of labor was determined from personnel reimbursement data, and the cost of materials, from vendor pricing. The fixed direct costs were assessed from hospital accounting records. Mean, standard deviation, and 95% confidence interval (CI) were determined for all direct (fixed and variable) costs. The total costs were determined for each procedure and compared by using the Student t test. RESULTS: There was a significant difference (P < .0001) between the mean total direct cost of VCUG ($112.17 +/- 10.33) and that of RNC ($64.58 +/- 1.91). VCUG examination for vesicoureteral reflux in children cost 1.74 times more than RNC examination (95% CI: 1.28, 2.36). CONCLUSION: When the technique is clinically appropriate, institutions may obtain substantial cost savings by using RNC in place of VCUG for examining children suspected of having vesicoureteral reflux.


Assuntos
Urografia/economia , Refluxo Vesicoureteral/diagnóstico por imagem , Criança , Pré-Escolar , Custos e Análise de Custo , Feminino , Humanos , Masculino , Cintilografia , Sensibilidade e Especificidade
6.
Neuroimaging Clin N Am ; 13(2): 157-65, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-13677798

RESUMO

Society is increasingly demanding proof that imaging has an impact on patient outcome and questioning its cost on the health care delivery system. Radiologists should provide the following three key components in their research publications: (1) the statistical power and confidence intervals of the results obtained; (2) the diagnostic performance of the tests, including sensitivity, specificity, and ROC curves; and (3) comprehensive decision analysis and cost-effectiveness analysis to determine the impact that imaging has on health outcome, cost, and quality of life. Strict adherence to these evidence-based medicine principles would help advance the field and provide the best health care for patients.


Assuntos
Diagnóstico por Imagem , Medicina Baseada em Evidências , Doenças do Sistema Nervoso/diagnóstico por imagem , Doenças do Sistema Nervoso/patologia , Humanos , Radiografia
7.
Neuroimaging Clin N Am ; 13(2): 225-35, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-13677803

RESUMO

Headache represents one of the most common complaints in the outpatient and emergency room setting [1]. Most causes of headache are benign and do not require emergent imaging or intervention. The authors' review of the diagnostic tests does not offer absolute indications for neuroimaging because most of the evidence is based on studies that are not randomized controlled trials. Imaging guidelines for adults and children, however, have emerged based on the available level 2 and 3 literature. CT imaging remains the initial test of choice for new-onset headache in adults and headache suggestive of SAH. Most of the available literature also recommends performing lumbar puncture when CT is equivocal in ruling out SAH [1]. The sensitivity of MR imaging appears to be less than CT for SAH [1]. Newer MR imaging techniques need to be tested and developed to determine if they have higher sensitivity than CT or lumbar puncture in the detection of SAH. In adults with suspected brain metastatic disease, contrast-enhanced MR imaging is the imaging study of choice [38,39]. Contrast-enhanced MR imaging is the examination of choice for brain metastatic lesions less than 2 cm [39]. CT angiography and MR angiography have sensitivities greater than 85% for brain aneurysms larger than 5 mm [43]. If clinically warranted, aneurysms smaller than 5 mm may require digitally subtracted angiography because of the low sensitivity of MR and CT angiography. In children, the choice of diagnostic test strategy depends on the risk group. In high-risk patients, MR imaging is the test of choice whereas in low-risk patients, close clinical observation with periodic reassessment is the best strategy [44]. Clinical diagnosis will always play a key role in the evaluation of headache disorders; however, for the small subset of patients who present with headache secondary to an intracranial space-occupying lesion, bleeding, or SAH, making the diagnosis is crucial to decreasing morbidity and mortality. CT, MR imaging, and lumbar puncture play important roles in the assessment of headache disorders, but their future roles will continue to evolve as the technology becomes more sophisticated and robust, and physicians become more expert with their use [1].


Assuntos
Medicina Baseada em Evidências , Cefaleia/diagnóstico por imagem , Cefaleia/patologia , Adulto , Angiografia Cerebral , Criança , Cefaleia/etiologia , Humanos , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X
8.
Neuroimaging Clin N Am ; 13(2): 327-34, xii, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-13677810

RESUMO

This article reviews the scientific evidence behind the diagnostic tools available for the appropriate workup and management of patients with occult spinal dysraphism (OSD). The diagnostic tools include the use of detailed history and physical examination, plain films, ultrasound, MR imaging, and neurophysiologic tests. In addition, the article discusses the epidemiology of the most common causes of OSD in children, which will allow physicians caring for children to develop a pretest probability of disease and make a more educated decision as to when additional diagnostic testing is required.


Assuntos
Medicina Baseada em Evidências , Espinha Bífida Oculta/diagnóstico , Espinha Bífida Oculta/terapia , Humanos
10.
AJNR Am J Neuroradiol ; 34(5): 1004-9, S1-2, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23391843

RESUMO

BACKGROUND AND PURPOSE: Patients with focal intractable epilepsy and normal MR imaging findings frequently undergo further diagnostic tests to localize the epileptogenic zone. The aim of this study was to determine the cost-effective diagnostic strategy that will identify the epileptogenic zone in patients with suspected focal intractable epilepsy and normal MR imaging findings by using decision analysis. MATERIALS AND METHODS: A Markov decision model was constructed by using sensitivities and specificities of test strategies, seizure outcomes following surgical and medical treatment, cost, utilities, probabilities, and standardized mortality ratios. We compared 6 diagnostic test strategies: PET, ictal SPECT, and MEG individually; and combinations of PET+SPECT, PET+MEG, and SPECT+MEG. The outcomes measured were health care costs, QALY, and ICER. One-way and probabilistic sensitivity analyses were conducted to adjust for uncertainties in model parameters. RESULTS: The preferred strategies were PET+MEG and SPECT. The health care cost of the baseline strategy (PET+MEG) was $95,612 with 16.30 QALY gained. SPECT cost $97,479 with 16.45 QALY gained and an ICER of $12,934/QALY gained compared with those in PET+MEG. One-way sensitivity analyses showed that the decisions of the model were sensitive to variations in sensitivity and specificity of the test strategies. Probabilistic sensitivity analysis showed that when the willingness to pay was <$10,000, PET+MEG was the favored strategy, but the favored strategy changed to SPECT when the willingness to pay was >$10,000. CONCLUSIONS: PET+MEG and SPECT were the preferred strategies in the base case. The choice of test was dependent on the sensitivity and specificity of test strategies and willingness to pay. Further study with a larger sample size is needed to obtain better estimates of sensitivity and specificity of diagnostic tests.


Assuntos
Sistemas de Apoio a Decisões Clínicas , Técnicas de Apoio para a Decisão , Epilepsia/diagnóstico , Epilepsia/economia , Imageamento por Ressonância Magnética/economia , Magnetoencefalografia/economia , Cintilografia/economia , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Análise Custo-Benefício , Epilepsia/mortalidade , Feminino , Custos de Cuidados de Saúde , Humanos , Imageamento por Ressonância Magnética/estatística & dados numéricos , Magnetoencefalografia/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Ontário , Prevalência , Cintilografia/estatística & dados numéricos , Reprodutibilidade dos Testes , Medição de Risco , Sensibilidade e Especificidade , Análise de Sobrevida , Taxa de Sobrevida
11.
Radiology ; 244(2): 331-6, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17641360

RESUMO

Evidence-based radiology (EBR) is an important tool for the practice of radiology. The user of the EBR approach identifies evidence in a systematic fashion and then assimilates information through in-depth, explicit critical review of the best-designed and most recent literature on the subject in question. Clinical decision making is then based on the best current evidence, clinical expertise, and patient values. Substantial progress has been made in the review and dissemination of EBR. Dissemination of EBR within radiology has two critical aspects. The first is increased understanding of the methods required for EBR and of the appropriate use of EBR. The second important component is the dissemination of the data and critical literature reviews necessary to allow use of the EBR approach. Resources available for both EBR methods and EBR data in radiology include societies, journals, medical meetings, Web sites, and textbooks. Although radiology has made important progress in this field in recent years, the specialty is still behind other specialties that have been at the forefront of evidence-based medicine in the past decade.


Assuntos
Diagnóstico por Imagem/tendências , Medicina Baseada em Evidências , Radiologia/tendências , Pesquisa Biomédica/métodos , Pesquisa Biomédica/tendências , Ensaios Clínicos como Assunto/métodos , Ensaios Clínicos como Assunto/tendências , Difusão de Inovações , Educação Médica/métodos , Educação Médica/tendências , Medicina Baseada em Evidências/educação , Medicina Baseada em Evidências/métodos , Medicina Baseada em Evidências/tendências , Humanos , Competência Profissional , Radiologia/educação , Radiologia/métodos , Sociedades Médicas , Avaliação da Tecnologia Biomédica
12.
Radiology ; 242(1): 94-100, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17185662

RESUMO

PURPOSE: To determine the role of functional magnetic resonance (MR) imaging in assessing hemispheric language dominance in epilepsy and nonepilepsy populations. MATERIALS AND METHODS: A Bayesian analysis study was performed. The study was based on data from the published literature; thus, institutional review board approval was not required. The literature was reviewed to obtain pretest probabilities and likelihood ratios, which were analyzed to determine the posttest probability of language dominance by using functional MR imaging. Pretest probabilities of different hand dominances in epilepsy and nonepilepsy populations were obtained from the largest studies available in the literature. Likelihood ratios were derived from the sensitivity and specificity of functional MR imaging by using electrocortical stimulation (ECS) and the Wada test as reference standards. RESULTS: Likelihood ratios for functional MR in determining language dominance were 9.3 and 12.3 with ECS and the Wada test as reference standards, respectively. Use of functional MR increased the final posttest probabilities of hemispheric language dominance in epilepsy and nonepilepsy populations. In the nonepilepsy population, regardless of hand dominance, there was very high posttest probability (>or=96%) of a correlation between functional MR hemisphere activation and definite left-hemisphere language dominance. In the epilepsy population with right-hand dominance or ambidexterity, there was very high posttest probability (>or=95%) of a correlation between functional MR hemisphere activation and definite left-hemisphere language dominance. In the left-handed nonepileptic subjects, there was high posttest probability (81%-83%) of a correlation between functional MR hemisphere activation and definite right-hemisphere language dominance. In the left-handed epilepsy population, there was high posttest probability (80%-97%) of a correlation between functional MR hemisphere activation and definite left-hemisphere language dominance. In the epilepsy population with ambidexterity, there was high posttest probability (80%-87%) of correlations between functional MR hemisphere activation and both definite right-hemisphere and bilateral language dominance. CONCLUSION: Use of functional MR increases importantly the posttest probabilities of hemispheric language dominance in multiple subgroups of individuals with and without epilepsy.


Assuntos
Mapeamento Encefálico/métodos , Encéfalo/fisiopatologia , Dominância Cerebral , Epilepsia/diagnóstico , Epilepsia/fisiopatologia , Idioma , Imageamento por Ressonância Magnética/estatística & dados numéricos , Teorema de Bayes , Ensaios Clínicos como Assunto/estatística & dados numéricos , Epilepsia/epidemiologia , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
13.
Pediatr Radiol ; 37(6): 556-60, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17450353

RESUMO

BACKGROUND: Appropriate differentiation between epidermoid-dermoid and arachnoid cysts is important for patient management. MRI has had limitations in differentiating these two types of cysts, especially in the region of the spinal cord. OBJECTIVE: To evaluate the role of diffusion-weighted (DW) MRI for differentiation between spinal arachnoid and epidermoid-dermoid cysts. MATERIALS AND METHODS: Four children underwent conventional and DW MRI. Turbo spin-echo imaging was used to obtain DW images. RESULTS: On conventional MRI, low T1-W and high T2-W signal was present in all lesions. DW imaging showed restricted diffusion in two patients with epidermoid-dermoid cysts and no water restriction in two patients with arachnoid cysts. Three of four children had extramedullary lesions and one patient had an intramedullary lesion. Three children had surgery, two with epidermoid-dermoid cysts and one with arachnoid cyst. Diagnosis was confirmed by histopathology. One child with a thoracic arachnoid cyst had stable clinical imaging findings during a follow-up of 21 months. CONCLUSION: On conventional MRI, epidermoid-dermoid and arachnoid cysts have similar signal characteristics. Initial experience with spine DW imaging shows promise in differentiating epidermoid-dermoid cysts from arachnoid cysts. Preoperative differentiation is important because it changes management and surgical approach.


Assuntos
Cistos Aracnóideos/patologia , Imagem de Difusão por Ressonância Magnética , Cisto Epidérmico/patologia , Doenças da Medula Espinal/diagnóstico , Adolescente , Criança , Pré-Escolar , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Estudos Retrospectivos
14.
J Am Coll Radiol ; 3(7): 505-9, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17412113

RESUMO

The ACR Appropriateness Criteria are an important effort aimed at establishing when imaging should be used in medicine. However, substantial improvements in the Appropriateness Criteria are necessary for them to meet current standards for evidence-based guidelines. In this article, we provide concrete suggestions for improving the evidence basis of the Appropriateness Criteria.


Assuntos
Diagnóstico por Imagem/normas , Diagnóstico por Imagem/tendências , Medicina Baseada em Evidências , Guias de Prática Clínica como Assunto , Radiologia/normas , Sociedades Médicas , Pesquisa Biomédica/métodos , Pesquisa Biomédica/tendências , Ensaios Clínicos como Assunto/métodos , Ensaios Clínicos como Assunto/tendências , Medicina Baseada em Evidências/normas , Humanos , Avaliação da Tecnologia Biomédica/normas , Estados Unidos
15.
Pediatr Radiol ; 36(12): 1295-9, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17028853

RESUMO

BACKGROUND: Detailed evaluation of a brachial plexus birth injury is important for treatment planning. OBJECTIVE: To determine the diagnostic performance of MRI and MR myelography in infants with a brachial plexus birth injury. MATERIALS AND METHODS: Included in the study were 31 children with perinatal brachial plexus injury who underwent surgical intervention. All patients had cervical and brachial plexus MRI. The standard of reference was the combination of intraoperative (1) surgical evaluation and (2) electrophysiological studies (motor evoked potentials, MEP, and somatosensory evoked potentials, SSEP), and (3) the evaluation of histopathological neuronal loss. MRI findings of cord lesion, pseudomeningocele, and post-traumatic neuroma were correlated with the standard of reference. Diagnostic performance characteristics including sensitivity and specificity were determined. RESULTS: From June 2001 to March 2004, 31 children (mean age 7.3 months, standard deviation 1.6 months, range 4.8-12.1 months; 19 male, 12 female) with a brachial plexus birth injury who underwent surgical intervention were enrolled. Sensitivity and specificity of an MRI finding of post-traumatic neuroma were 97% (30/31) and 100% (31/31), respectively, using the contralateral normal brachial plexus as the control. However, MRI could not determine the exact anatomic area (i.e. trunk or division) of the post-traumatic brachial plexus neuroma injury. Sensitivity and specificity for an MRI finding of pseudomeningocele in determining exiting nerve injury were 50% and 100%, respectively, using MEP, and 44% and 80%, respectively, using SSEP as the standard of reference. MRI in infants could not image well the exiting nerve roots to determine consistently the presence or absence of definite avulsion. CONCLUSION: In children younger than 18 months with brachial plexus injury, the MRI finding of pseudomeningocele has a low sensitivity and a high specificity for nerve root avulsion. MRI and MR myelography cannot image well the exiting nerve roots to determine consistently the presence or absence of avulsion of nerve roots. The MRI finding of post-traumatic neuroma has a high sensitivity and specificity in determining the side of the brachial plexus injury but cannot reveal the exact anatomic area (i.e. trunk or division) involved. The information obtained is, however, useful to the surgeon during intraoperative evaluation of spinal nerve integrity for reconstruction.


Assuntos
Traumatismos do Nascimento/diagnóstico , Neuropatias do Plexo Braquial/diagnóstico , Plexo Braquial/lesões , Imageamento por Ressonância Magnética/métodos , Neuroma/diagnóstico , Neoplasias do Sistema Nervoso Periférico/diagnóstico , Traumatismos do Nascimento/cirurgia , Plexo Braquial/patologia , Plexo Braquial/cirurgia , Neuropatias do Plexo Braquial/cirurgia , Eletrofisiologia/métodos , Potencial Evocado Motor , Potenciais Somatossensoriais Evocados , Feminino , Humanos , Lactente , Masculino , Neuroma/etiologia , Neuroma/cirurgia , Neoplasias do Sistema Nervoso Periférico/etiologia , Neoplasias do Sistema Nervoso Periférico/cirurgia , Valor Preditivo dos Testes , Estudos Prospectivos , Padrões de Referência , Sensibilidade e Especificidade
16.
Radiology ; 236(1): 247-53, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15987978

RESUMO

PURPOSE: To prospectively evaluate effect of functional magnetic resonance (MR) imaging on diagnostic work-up and treatment planning in patients with seizure disorders who are candidates for surgical treatment. MATERIALS AND METHODS: Institutional review board approval was obtained; informed consent was obtained either from the patient or the parent or guardian in all patients. This study was conducted with Health Insurance Portability and Accountability Act compliance. Sixty consecutively enrolled patients (33 males, 27 females; mean age, 15.8 years +/- 8.7 [standard deviation]; range, 6.8-44.2 years) were prospectively examined. Forty-five (75%) patients were right handed, nine (15%) were left handed, and six (10%) had indeterminate hand dominance. Prospective questionnaires were used to evaluate diagnostic work-up, counseling, and treatment plans of the seizure team before and after functional MR imaging. Confidence level scales were used to determine effect of functional MR imaging on diagnostic and therapeutic thinking. Paired t test and 95% confidence interval analyses were performed. RESULTS: In 53 patients, language mapping was performed; in 33, motor mapping; and in seven, visual mapping. The study revealed change in anatomic location or lateralization of language-receptive (Wernicke) (28% of patients) and language-expressive (Broca) (21% of patients) areas. Statistically significant increases were found in confidence levels after functional MR imaging in regard to motor and visual cortical function evaluation. In 35 (58%) of 60 patients, the seizure team thought that functional MR imaging results altered patient and family counseling. In 38 (63%) of 60 patients, functional MR imaging results helped to avoid further studies, including Wada test. In 31 (52%) and 25 (42%) of 60 patients, intraoperative mapping and surgical plans, respectively, were altered because of functional MR imaging results. In five (8%) patients, two-stage surgery with extra-operative direct electrical stimulation mapping was averted, and resection was accomplished in one stage. In four (7%) patients, extent of surgical resection was altered because eloquent areas were identified close to seizure focus. CONCLUSION: Functional MR imaging results influenced diagnostic and therapeutic decision making of the seizure team; results indicated language dominance changed, confidence level in identification of critical brain function areas increased, patient and family counseling were altered, and intraoperative mapping and surgical approach were altered.


Assuntos
Epilepsia/diagnóstico , Imageamento por Ressonância Magnética/métodos , Adolescente , Adulto , Criança , Epilepsia/fisiopatologia , Epilepsia/cirurgia , Feminino , Humanos , Masculino , Planejamento de Assistência ao Paciente , Estudos Prospectivos , Inquéritos e Questionários
17.
Radiology ; 226(2): 297-301, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12563116

RESUMO

In radiology, appropriate diagnoses are often based on quantitative data. However, these data contain inherent variability. Radiologists often see P values in the literature but are less familiar with other ways of reporting statistics. Statistics such as the SD and standard error of the mean (SEM) are commonly used in radiology, whereas the CI is not often used. Because the SEM is smaller than the SD, it is often inappropriately used in order to make the variability of the data look tighter. However, unlike the SD, which quantifies the variability of the actual data for a single sample, the SEM represents the precision for an estimated mean of a general population taken from many sample means. Since readers are usually interested in knowing about the variability of the single sample, the SD often is the preferred statistic. Statistical calculations combine sample size and variability (ie, the SD) to generate a CI for a population proportion or population mean. CIs enable researchers to estimate population values without having data from all members of the population. In most cases, CIs are based on a 95% confidence level. The advantage of CIs over significance tests (P values) is that the CIs shift the interpretation from a qualitative judgment about the role of chance to a quantitative estimation of the biologic measure of effect. Proper understanding and use of these fundamental statistics and their calculations will allow more reliable analysis, interpretation, and communication of clinical information among health care providers and between these providers and their patients.


Assuntos
Intervalos de Confiança , Interpretação Estatística de Dados , Radiologia , Humanos
18.
Pediatr Radiol ; 32(11): 755-64, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12389101

RESUMO

PURPOSE: To describe the resources and strategies required to establish a health outcomes and economics center in radiology. METHODS: Human and nonhuman resources required to perform sound outcomes and economics studies in radiology are reviewed. RESULTS: Human resources needed include skilled medical and nonmedical staff. Nonhuman resources required are: (1). communication and information network; (2). education tools and training programs; (3). budgetary strategies; and (4). sources of income. Effective utilization of these resources allows the performance of robust operational and clinical research projects in decision analysis, cost-effectiveness, diagnostic performance (sensitivity, specificity, and ROC curves), and clinical analytical and experimental studies. CONCLUSION: As new radiologic technology and techniques are introduced in medicine, society is increasingly demanding sound clinical studies that will determine the impact of radiologic studies on patient outcome. Health-care funding is scarce, and therefore third-party payers and hospitals are demanding more efficiency and productivity from radiologic service providers. To meet these challenges, radiology departments could establish health outcomes and economics centers to study the clinical effectiveness of imaging and its impact on patient outcome.


Assuntos
Avaliação de Resultados em Cuidados de Saúde , Serviço Hospitalar de Radiologia/economia , Orçamentos , Redes de Comunicação de Computadores , Análise Custo-Benefício , Eficiência Organizacional , Humanos , Armazenamento e Recuperação da Informação , Sistemas de Informação em Radiologia
19.
Int J Neurosci ; 114(5): 661-80, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15204072

RESUMO

The purpose of this study was to find a robust nonverbal paradigm to obtain reliable, reproducible auditory activation and characterize the nonverbal activation of the auditory cortex in regard to the Brodmann regions. The extent of localization and lateralization of activation was investigated utilizing functional magnetic resonance (fMR). Two tasks were used: monotonous repetitive stimuli of "double octaves" (DO) consisting of alternating four A with four C piano notes and a variated string of "sequential notes" (SN), which was a fast nonrepetitive sequence of piano notes. Eleven volunteers were investigated. The activation periods had a duration of 30 s, and presented every 30 s. All subjects demonstrated fMRI signal activity in the superior temporal gyrus (STG) involving the primary and secondary auditory cortex except one subject who showed no activation with the DO stimulus. SN elicited more activation than DO (p =<.03). The bulk activation for SN and DO was slightly greater in the right hemisphere, although the primary auditory area (Brodmann's 41) was better activated on the left p =<.001. Brodmann's area 22 was most frequently right-side dominant (p =.015, p =.017 for DO and SN, respectively). These findings appear to have implications in the examination of preverbal subjects.


Assuntos
Córtex Auditivo/fisiologia , Lateralidade Funcional/fisiologia , Imageamento por Ressonância Magnética , Estimulação Acústica/métodos , Adolescente , Adulto , Limiar Auditivo , Mapeamento Encefálico , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Reprodutibilidade dos Testes
20.
AJR Am J Roentgenol ; 179(1): 215-21, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12076939

RESUMO

OBJECTIVE: Our purpose was to evaluate the clinical and economic impact of three evaluation strategies in children at different risks of craniosynostosis. MATERIALS AND METHODS: A decision-analytic and cost-effectiveness model was constructed to compare three evaluation in strategies in children with suspected synostosis: no imaging, radiography (if abnormal, followed by three-dimensional CT [3D CT]), and 3D CT. Three risk groups were analyzed on the basis of the prevalence (pretest probability) of disease: low (completly healthy children; prevalence, 34/100,000), intermediate (healthy children with head deformity; prevalence, 1/115), and high risk (children with syndromic craniofacial disorders [i.e., Crouzon's syndrome or Apert's syndrome]; prevalence, 9-10/10). Test performance (sensitivity and specificity) of the evaluation strategies was obtained from the literature. Costs (not charge) estimates were obtained from the hospital cost-accounting database and from the Medicaid fee schedule. RESULTS: In the low-risk group, the radiographic and 3D CT strategies resulted in a cost per quality-adjusted life year (QALY) gained of more than $560,000. In the intermediate-risk group, the radiographic strategy resulted in a cost per QALY gained of $54,600. Three-dimensional CT was more effective than the two other strategies but at a higher cost-hence, with a cost per QALY gained of $374,200. In the high-risk group, 3D CT was the most effective strategy with a cost per QALY gained of $33,800. Less experienced radiologists and poor-quality studies increased the evaluation cost per QALY gained for all of the risk groups because of decreased effectiveness. CONCLUSION: Radiologic screening of completely healthy children (low risk) for synostosis is not warranted because of the high cost per QALY gained of the radiographic and 3D CT strategies. In healthy children with head deformity (intermediate risk), the radiographic strategy had a reasonable cost per QALY gained. Three-dimensional CT was more effective but had a high cost per QALY gained. In children with syndromic craniofacial disorders (high risk), 3D CT was the most effective strategy and had a reasonable cost per QALY gained. Selection of children with suspected craniosynostosis based on their risk group and use of the most appropriate evaluation strategy could maximize clinical and economic outcomes for these patients.


Assuntos
Craniossinostoses/diagnóstico , Craniossinostoses/economia , Técnicas de Apoio para a Decisão , Imageamento Tridimensional/economia , Radiografia/economia , Tomografia Computadorizada por Raios X/economia , Criança , Análise Custo-Benefício/economia , Craniossinostoses/etiologia , Humanos , Avaliação de Resultados em Cuidados de Saúde , Anos de Vida Ajustados por Qualidade de Vida , Fatores de Risco , Sensibilidade e Especificidade
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