Abstract: This paper explored the application value of T2 mapping and diffusion-weighted imaging (DWI) imaging technology in the diagnosis of patellar cartilage injury and its correlation with injury grading. Fifty-five patients with patellar cartilage injury were selected as the research subjects. All of them underwent T2 mapping and DWI examination of the patellar cartilage, and measured the T2 and ADC value of patellar cartilage injury area and the control area. The T2 value and ADC value in the patellar cartilage injury area were higher than those in the control area (P<0.05), the T2 value and ADC value in the patellar cartilage injury area were positively correlated (r=0.713, P<0.001). The areas under the curve (AUC) through T2 value and ADC value diagnosis of patellar cartilage injury were 0.832 and 0.761, respectively, and the cut-off values were 40.73 ms and 17.13×10^-4 mm²/s, respectively. The AUC of the combined diagnosis was 0.931, the sensitivity was 85.45%, and the specificity was 85.45%, which was significantly higher than the two alone. The T2 value and ADC value of the patellar cartilage injury area were significantly correlated with the patellar cartilage injury grade. It suggested that the combination of T2 mapping and DWI was reliable in diagnosing patellar cartilage injury and evaluating the degree of injury.

Key words: magnetic resonance, T2 mapping, diffusion weighted imaging, patella cartilage injury, injury grading