Desenvolvimento de técnica de análise de imagens digitais para avaliação do estágio da fibrose em biópsias hepáticas de pacientes portadores de hepatite crônica por vírus da hepatite B e C

• Autor(a) principal: Campos, Carlos Frederico Ferreira
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/8697
• topic: Chronic viral hepatitis; Hepatic Fibrosis; Semi-quantitative Scores; Digital Image Analysis; Hepatites crônicas virais; Fibrose hepática; Escores semiquantitativos; Análise de imagens digitais; CNPQ::CIENCIAS DA SAUDE::MEDICINA::ANATOMIA PATOLOGICA E PATOLOGIA CLINICA

The hepatitis caused by viruses are the most frequent, principally the virus B (HBV) and C (HCV) hepatitis. The anatomopathologic study of the liver biopsy is considered the gold standard for the evaluation of architectural distortion and degree o fibrosis of the liver s parenchyma, important prognostic factors for the patients with chronic viral hepatitis. In the actual histopathological evaluation, in addition to subjective reports of histological alterations, semiquantitative scores that correlate morphological findings with numeric degrees are used, such as the renowned Ishak and METAVIR scores. However, in all of these systems there is the disadvantage of the subjectiveness of the examinator and the incorporation of categorical description of architectural changes without reference to quantitative changes in liver collagen. Digital Image Analysis techniques (DIA) that provide objective quantification of the degrees of liver fibrosis in histological samples have been developed. But the high cost and worldwide unavailability of the technologies described restrained their use to a few specialized centers. This study aims at developing an affordable technique for liver s fibrosis DIA in chronic viral hepatitis. Three hundred and four core needle biopsies obtained by Menghini needles from patients with virus B and virus C hepatitis were studied. All samples had at least 15 mm in length or five complete portal tracts and were stained with the Masson s Trichrome Method. The staging by Ishak s and METAVIR s scores was done by a single experienced hepatopathologist, without the knowledge patient s clinical data. The microscopic images were digitalized. The fibrosis indexes were calculated in an automated way by a new technique developed in the Adobe® Photoshop® software. For the Ishak score the following median Fibrosis Indexes (FI) were observed: 0,8% ± 0,0 (stage 0), 2.4% ± 0,6 (stage 1), 4,7% ± 1,6 (stage 2), 7,4% ± 1.4 (stage 3), 14,9% ± 3.7 (stage 4), 23,4% ± 2.9 (stage 5) e 34,5% ± 1,5 (stage 6). For the METAVIR classification: 0,8% ± 0,1 (stage F0), 3,8% ± 1.8 (stage F1), 7,4% ± 1.4 (stage F2), 20,4% ± 5,2 (stage F3) e 34,5% ± 1,5 (stage F4). We found an excellent correlation between the DIA fibrosis indexes and the Ishak´s (r=0.94; p<0.001) and METAVIR (r=0.92; p<0.001) stages. In relation to the indication for antiviral treatment, the mean FI observed was 16.4% for both classifications. In relation to cirrhosis s diagnosis, the mean FI observed was 26.9% for Ishak s score, and 34.5% for METAVIR s classification. There was excellent intraobserver reproducibility. This new method of digital image analysis for liver fibrosis quantification is affordable and was developed using technology that is available worldwide, allowing the precise identification of all the stages of fibrosis in the group of patients studied, with excellent intraobserver reproducibility.