Fundamento: Há poucos dados sobre a definição de parâmetros simples e robustos para predizer artefato de imagem em tomografia computadorizada (TC) cardíaca. Objetivos: Avaliar o valor da simples medida da espessura do tecido subcutâneo (espessura pele-esterno) como preditor de artefato de imagem em TC cardíaca. Métodos: O estudo avaliou 86 pacientes submetidos a angiotomografia computadorizada cardíaca (ATCC) com sincronização prospectiva com ECG e avaliação de escore de cálcio coronário com 120 kV e 150 mA. A qualidade da imagem foi medida objetivamente pelo artefato de imagem na aorta em ATCC, sendo 'artefato baixo' definido como aquele < 30 UH. Os diâmetros torácicos anteroposterior e laterolateral, o artefato de imagem na aorta e a espessura pele-esterno foram medidos como preditores de artefato em ATCC. A associação de preditores e artefato de imagem foi avaliada usando-se correlação de Pearson. Resultados: A dose média de radiação foi 3,5 ± 1,5 mSv. O artefato de imagem médio na ATCC foi de 36,3 ± 8,5 UH, sendo o artefato de imagem médiona fase sem contraste do exame de 17,7 ± 4,4 UH. Todos os preditores foram independentemente associados com artefato em ATCC. Os melhores preditores foram espessura pele-esterno, com correlação de 0,70 (p < 0,001), e artefato de imagem na fases em contraste,com correlação de 0,73 (p < 0,001). Ao avaliar a habilidade de predizer artefato de imagem baixo, as áreas sob a curva ROC para o artefato de imagem na fases em contraste e para a espessura pele-esterno foram 0,837e 0,864, respectivamente. Conclusão: Tanto espessura pele-esterno quanto artefato de escore de cálcio são preditores simples e precisos de artefato de imagem em ATCC. Tais parâmetros podem ser incorporados aos protocolos de TC padrão para ajustar adequadamente a exposição à radiação.

Background: Few data on the definition of simple robust parameters to predict image noise in cardiac computed tomography (CT) exist. Objectives: To evaluate the value of a simple measure of subcutaneous tissue as a predictor of image noise in cardiac CT. Methods: 86 patients underwent prospective ECG-gated coronary computed tomographic angiography (CTA) and coronary calcium scoring (CAC) with 120 kV and 150 mA. The image quality was objectively measured by the image noise in the aorta in the cardiac CTA, and low noise was defined as noise < 30HU. The chest anteroposterior diameter and lateral width, the image noise in the aorta and the skin-sternum (SS) thickness were measured as predictors of cardiac CTA noise. The association of the predictors and image noise was performed by using Pearson correlation. Results: The mean radiation dose was 3.5 ± 1.5 mSv. The mean image noise in CT was 36.3 ± 8.5 HU, and the mean image noise in non-contrast scan was 17.7 ± 4.4 HU. All predictors were independently associated with cardiac CTA noise. The best predictors were SS thickness, with a correlation of 0.70 (p < 0.001), and noise in the non-contrast images, with a correlation of 0.73 (p < 0.001). When evaluating the ability to predict low image noise, the areas under the ROC curve for the non-contrast noise and for the SS thickness were 0.837 and 0.864, respectively. Conclusion: Both SS thickness and CAC noise are simple accurate predictors of cardiac CTA image noise. Those parameters can be incorporated in standard CT protocols to adequately adjust radiation exposure.

INTRODUCTION: Sudden hearing loss (SHL) is an ENT emergency defined as sensorineural hearing loss (SNHL) > 30 dB HL affecting at least 3 consecutive tonal frequencies, showing a sudden onset, and occurring within 3 days. In cases of SHL, a detailed investigation should be performed in order to determine the etiology and provide the best treatment. Otoacoustic emission (OAE) analysis, electronystagmography (ENG), bithermal caloric test (BCT), and vestibular evoked myogenic potential (VEMP) assessments may be used in addition to a number of auxiliary methods to determine the topographic diagnosis. OBJECTIVE: To evaluate the contribution of OAE analysis, BCT, VEMP assessment, and magnetic resonance imaging (MRI) to the topographic diagnosis of SHL. METHOD: Cross-sectional and retrospective studies of 21 patients with SHL, as defined above, were performed. The patients underwent the following exams: audiometry, tympanometry, OAE analysis, BCT, VEMP assessment, and MRI. Sex, affected side, degree of hearing loss, and cochleovestibular test results were described and correlated with MRI findings. Student's t-test was used for analysis of qualitative variables (p < 0.05). RESULTS: The mean age of the 21 patients assessed was 52.5 ± 15.3 years; 13 (61.9%) were women and 8 (38.1%) were men. Most (55%) had severe hearing loss. MRI changes were found in 20% of the cases. When the audiovestibular test results were added to the MRI findings, the topographic SHL diagnosis rate increased from 20% to 45%. CONCLUSION: Only combined analysis via several examinations provides a precise topographic diagnosis. Isolated data do not provide sufficient evidence to establish the extent of involvement and, hence, a possible etiology.