RESUMO
INTRODUCTION: Vestibular neuritis is the second cause of vertigo and new imaging protocols using delayed FLAIR with double-dose of gadolinium are proposed for its diagnosis. Our aim is to demonstrate that a single dose of gadolinium is sufficient. METHODS: Thirty-three patients with a unilateral vestibular neuritis are compared to a control group. All patients underwent a FLAIR sequence, 1 hour after intravenous injection of a single dose of gadolinium, on a 1.5 Tesla MRI. Two radiologists analyzed the enhancement intensity of the superior (sup VN) and inferior vestibular nerve (inf VN) and ratios to the signal of the cerebellum were calculated (supVN/C). The statistics were performed using Bayesian analysis. RESULTS: A strong enhancement of the sup VN was observed on the pathological side in 85% of patients with vestibular neuritis. The average signal intensity of the pathological sup VN (139 units ± 44) was more than two times the average intensity in the control group (58.5 units ± 5). The average ratios supVN/C were significantly different between the pathological side in vestibular neuritis (2.43 units ± 0.63) and the control group [1.16 ± 0.14 (Pr(diff > 0) = 1)]. A delayed enhancement > 71.5 units had a sensitivity of 96% and a specificity of 100% for the diagnosis of superior vestibular neuritis. CONCLUSION: A delayed FLAIR sequence, acquired 1 hour after a single dose of gadolinium injection, is a useful method for the diagnosis of vestibular neuritis. An enhancement of the sup VN > 71.5 units was in favor of the diagnosis.
Assuntos
Gadolínio DTPA/administração & dosagem , Imageamento por Ressonância Magnética/métodos , Nervo Vestibular/diagnóstico por imagem , Neuronite Vestibular/diagnóstico , Adulto , Idoso , Teorema de Bayes , Estudos de Casos e Controles , Meios de Contraste , Feminino , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Vertigem/etiologia , Testes de Função Vestibular , Nervo Vestibular/patologia , Neuronite Vestibular/diagnóstico por imagemRESUMO
The Hourglass sign is a useful imaging clue for diagnosing diaphragmatic ruptures with viscera herniation on multidetector CT, with a sensitivity ranging from 16% to 63% and a specificity around 98%-100%. This sign is also commonly found in the literature under the name "Collar sign," first described in 1995 by Worthy et al. It refers to the waistlike constriction of the herniated structure at the site of the diaphragmatic rupture.
