The aim of this study was to evaluate the precision and accuracy of linear measurements of maxillary sinus made in tomographic films, by comparing with 3D reconstructed images. Linear measurements of both maxillary sinus in computed tomography CT of 17 patients, with or without lesion by two calibrated examiners independently, on two occasions, with a single manual caliper. A third examiner has done the same measurements electronically in 3D-CT reconstruction. The statistical analysis was performed using ANOVA (analyses of variance). Intra-observer percentage error was little in both cases, with and without lesion; it ranged from 1.14% to 1.82%. The inter-observer error was a little higher reaching a 2.08% value. The accuracy presented a higher value. The perceptual accuracy error was higher in samples, which had lesion compared to that which had not. CT had provided adequate precision and accuracy for maxillary sinus analyses. The precision in cases with lesion was considered inferior when compared to that without lesion, but it can't affect the method efficacy.

ABSTRACT:The aim of this study was to evaluate the accuracy and reproducibility of computed tomography (CT) image interpretation made in axial slices (2D-CT) and 3D reconstructed images (3D-CT) of patients with craniofacial anomalies. The analyses were made by undergraduate dental students, and compared with the diagnoses considered upon surgical intervention. Computed tomography of 43 patients were analyzed independently by three calibrated examiners (undergraduate students) with, respectively, one, two, and three semesters of experience in craniofacial CT training and interpretation. The analysis of 2D-CT and 3D-CT images were performed at distinct times using an independent workstation associated with a specific computer graphics software for volumetric images. The analysis of inter-examiner agreement and of the agreement between observers and the gold standard was performed using the Kappa test. The accuracy evaluation presented a progressively higher value for examiners with progressively broader experience in 2D-CT and 3D-CT image interpretation. 3D-CT analyses allowed a higher interexaminer agreement (1 -0.896) than 2D-CT analyses (1 -0.614). 3D-CT was considered more precise and accurate than 2D-CT for all students' evaluations. The reproducibility and accuracy varied according to the experience in CT interpretation, and the most experienced student achieved results closer to the gold standard. DESCRIPTORS: Tomography; Face; Craniosynostosis; Craniofacial abnormalities. RESUMO:O propósito desta pesquisa foi avaliar a habilidade de alunos de graduação na análise de pacientes portadores de anomalias craniofaciais usando imagens de tomografia computadorizada (TC) em cortes axiais (2D-TC) e em terceira dimensão (3D-TC). A análise foi realizada por alunos de graduação em Odontologia, em comparação com o diagnóstico efetuado no ato operatório. Tomografias computadorizadas de 43 pacientes foram analisadas, independentemente, por três alunos de graduação previamente calibrados, com respectivamente um, dois e três semestres de tempo de experiência em interpretação de TC. As análises das imagens em 2D-TC e em 3D-TC foram obtidas em tempos e ocasiões distintos por meio de uma estação de trabalho independente utilizando-se um programa específico para imagens volumétricas. Para análise de concordância entre os observadores e destes com o diagnóstico definitivo foi utilizado o teste estatístico Kappa. Os valores de acurácia foram maiores quanto maior o tempo de experiência em interpretar imagens em 2D-TC e em 3D-TC. As análises em 3D-TC apresentaram indicadores mais elevados de concordância entre os examinadores (1 -0,896) que as análises em 2D-TC (1 -0,614). A 3D-TC foi considerada mais precisa e acurada em relação à 2D-TC na avaliação dos três alunos. A concordância entre os examinadores e entre estes e o diagnóstico variou de acordo com o tempo de treinamento em TC, sendo o aluno mais experiente aquele que obteve resultados mais próximos ao diagnóstico.