RESUMO
OBJECTIVE: The purpose of this study was to determine whether unenhanced MRI without sedation is a feasible substitute for dimercaptosuccinic acid (DMSA) scintigraphy in the detection of renal scars in pediatric patients. SUBJECTS AND METHODS: Patients scheduled for 99mTc-labeled DMSA scintigraphy for assessment of possible renal scars were recruited to undergo unenhanced MRI (free-breathing fat-suppressed T2-weighted single-shot turbo spin-echo and T1-weighted gradient-echo imaging, 13 minutes' total imaging time). Scintigraphic and MRI studies were evaluated by two independent blinded specialty-based radiologists. For each imaging examination, readers identified scars in upper, middle, and lower kidney zones and rated their diagnostic confidence and the quality of each study. The scintigraphic readers' consensus score opinion for the presence of scars was considered the reference standard. RESULTS: DMSA scintigraphy showed scarring in 19 of the 78 (24.4%) evaluated zones and MRI in 18 of the 78 (23.1%). The two MRI readers found mean sensitivities of 94.7% and 89.5%, identical specificities of 100%, and diagnostic accuracies of 98.7% and 97.4%. Interobserver agreement was 98.7% for MRI and 92.3% for DMSA scintigraphy. The MRI readers were significantly more confident in determining the absence rather than the presence of scars (p = 0.02). MRI readers were more likely to rate study quality as excellent (84.6%) than were the scintigraphic readers (57.7%) (p = 0.024). CONCLUSION: Unenhanced MRI has excellent sensitivity, specificity, diagnostic accuracy, and interobserver agreement for detecting renal scars in older children who do not need sedation. It may serve as a substitute modality, especially when DMSA is not available.
Assuntos
Cicatriz/diagnóstico por imagem , Nefropatias/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Cintilografia/métodos , Compostos Radiofarmacêuticos/administração & dosagem , Ácido Dimercaptossuccínico Tecnécio Tc 99m/administração & dosagem , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: The relevance of allergic sensitization, as judged by titers of serum IgE antibodies, to the risk of an asthma exacerbation caused by rhinovirus is unclear. OBJECTIVE: We sought to examine the prevalence of rhinovirus infections in relation to the atopic status of children treated for wheezing in Costa Rica, a country with an increased asthma burden. METHODS: The children enrolled (n= 287) were 7 through 12 years old. They included 96 with acute wheezing, 65 with stable asthma, and 126 nonasthmatic control subjects. PCR methods, including gene sequencing to identify rhinovirus strains, were used to identify viral pathogens in nasal washes. Results were examined in relation to wheezing, IgE, allergen-specific IgE antibody, and fraction of exhaled nitric oxide levels. RESULTS: Sixty-four percent of wheezing children compared with 13% of children with stable asthma and 13% of nonasthmatic control subjects had positive test results for rhinovirus (P< .001 for both comparisons). Among wheezing subjects, 75% of the rhinoviruses detected were group C strains. High titers of IgE antibodies to dust mite allergen (especially Dermatophagoides species) were common and correlated significantly with total IgE and fraction of exhaled nitric oxide levels. The greatest risk for wheezing was observed among children with titers of IgE antibodies to dust mite of 17.5 IU/mL or greater who tested positive for rhinovirus (odds ratio for wheezing, 31.5; 95% CI, 8.3-108; P< .001). CONCLUSIONS: High titers of IgE antibody to dust mite allergen were common and significantly increased the risk for acute wheezing provoked by rhinovirus among asthmatic children.
Assuntos
Alérgenos/imunologia , Asma/complicações , Asma/imunologia , Imunoglobulina E/sangue , Infecções por Picornaviridae/imunologia , Pyroglyphidae/imunologia , Rhinovirus , Animais , Estudos de Casos e Controles , Criança , Epitopos/imunologia , Expiração , Feminino , Humanos , Masculino , Óxido Nítrico/análise , Infecções por Picornaviridae/complicações , Infecções por Picornaviridae/diagnóstico , Sons Respiratórios/etiologia , Rhinovirus/genética , Rhinovirus/imunologia , RiscoRESUMO
OBJECTIVES: We tested the hypothesis that twice weekly prophylactic dosing of fluconazole prevents invasive candidiasis without promoting resistant Candida species in high-risk, preterm infants. STUDY DESIGN: We compared our previous dosing schedule (Group A) to a less frequent dosing schedule of twice a week (Group B) of fluconazole prophylaxis for up to 6 weeks in a prospective, randomized, double-blind clinical trial in preterm infants weighing <1000 grams at birth and with an endotracheal tube and/or central vascular catheter over a 24-month period. Weekly surveillance cultures were obtained on study patients. RESULTS: Candida colonization was documented in 5 (12%) of 41 Group A and in 4 (10%) of 40 Group B infants. Candida sepsis developed in two (5%) of Group A and one (3%) of Group B infants (risk difference, -0.02; 95% confidence interval, -0.14-0.10; P=.68). All fungal isolates remained sensitive to fluconazole, and no drug side effects were documented. CONCLUSIONS: Twice weekly dosing of prophylactic fluconazole can decrease Candida colonization and invasive infection, cost, and patient exposure in high-risk, preterm infants weighing <1000 grams at birth. We speculate that lower and less frequent dosing may delay or prevent the emergence of antifungal resistance.