Axial fat-saturated FSE imaging of knee: appearance of meniscal tears

Objective: To observe and describe the appearance of normal, torn, and other abnormal menisci on axial fat-saturated fast spin echo MR images of the knee. Design and patients: Two hundred and sixty-eight consecutive MR examinations of the knee were retrospectively reviewed. Fifty-five cases had surgical correlation available. The MR images were reviewed for the presence of meniscal tears and other meniscal pathology. Normal, torn, and other abnormal menisci were qualitatively assessed to develop descriptive criteria for the respective findings on axial fat-saturated fast spin echo images of the knee. Results: Fifty-nine meniscal tears were found at arthroscopy among the 110 menisci. Normal and abnormal menisci had definable appearances on axial MR images. Axial images showed vertical tears and displaced meniscal fragments well, whereas horizontal tears appeared subtle. Examples of various tears and other pathology demonstrated by axial images were collected. Descriptions for the various tears are proposed based on these findings. Conclusion: Axial fat-saturated fast spin echo images can show a variety of meniscal tears in definable patterns and may potentially provide additional characterization of meniscal tears. Further evaluation is needed to validate the proposed criteria for meniscal tears and to study the accuracy of axial images in the detection and characterization of meniscal tears.