Condromalácia de patela: comparação entre os achados em aparelhos de ressonância magnética de alto e baixo campo magnético

Abstract

OBJECTIVE: To compare the performance of low-field-strength and high-field-strength magnetic resonance imaging equipments for evaluation of the patella articular cartilage. MATERIALS AND METHODS: The study was developed using GRE 2D, GRE 3D, FSE T2, STIR sequences (low-field) and TSE T2 SPIR sequence. Each sequence has been separately analyzed for evaluation of the cartilage without knowledge of other sequences results or any patients data; the lesion was assigned a grade from 0 to 3 and had its location defined. Agreement and disagreement results were analyzed by Kappa and McNemar tests. RESULTS: Medial facet has presented low agreement index and disagreements showed to be significantly overestimated. Lateral facet has presented a reasonable agreement index and disagreement index was not significant. Medial ridge has presented a reasonable agreement index and disagreement index has showed to be underestimated. CONCLUSION: The STIR sequence versus TSE T2 SPIR sequence has presented the higher agreement index. High grade lesions are better characterized by low-field-strength magnetic resonance imaging equipment sequences. Areas of increased signal intensity make difficult the study of the patella medial facet cartilage in low-field-strength equipment.