L. Santiago Medina

Acute Appendicitis in Young Children: Cost-effectiveness of US versus CT in Diagnosis—A Markov Decision Analytic Model

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

False lateralization of language cortex on functional MRI after a cluster of focal seizures

50,000 (in U.S. dollars). The ICER of US followed by CT to CT was less than

Occult spinal dysraphism: evidence-based diagnosis and treatment.

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.

Evidence-based imaging

fMRI can define language cortex but its limitations are not yet fully understood. This article describes a child in whom fMRI falsely lateralized language cortex when performed after a cluster of left temporal lobe seizures. Multiple language tasks revealed no activation over the left temporal lobe despite a normal neurologic exam at the time of the study. A second fMRI performed 2 weeks later activated sites predominantly over the left, which were confirmed by extra-operative functional language mapping. fMRI may be unhelpful after frequent seizures.

Pediatric Advanced Imaging and Informatics: State of the Art

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.

Molecular studies in pediatric medulloblastomas.

Evidence-based imaging , Evidence-based imaging , کتابخانه دانشگاه علوم پزشکی و خدمات درمانی بوشهر

Introduction to evidence-based imaging

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.

Vesicoureteral Reflux Imaging in Children: Comparative Cost Analysis

Ten pediatric medulloblastoma patients were analyzed for DNA content, cell cycle, expression of drug resistance, apoptosis, cell proliferation, andN-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 betweenBcl-2 andMRP, Bcl-2 andBax, p53 andp21, as well asKi67 andPCNA 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.

Evidence-based neuroimaging diagnosis and treatment :

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.

Diagnostic Evaluation in Patients with Intractable Epilepsy and Normal Findings on MRI: A Decision Analysis and Cost-Effectiveness Study

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 (