MR diffusion weighted imaging study on patella cartilage applied to osteoarthritis of knee joint

Objective: To evaluate the clinical significance of quantitative measurement ADC value of patella cartilage on MR diffusion weighted imaging (DWI). Methods: Thirty-six knees of healthy volunteers and 18 of osteoarthritis(OA) were imaged with routine MR sequences and DWI. The ADC of each part of patella were measured and compared with each other. Results: In healthy volunteers, the ADCav of patella cartilage was (7.8 ±2.3) x 10-4 mm2/s and the ADCav among superior-middle-inferior portions was not significantly different (F=0.050, P=0.951). The ADCav of superior-middle-inferior portions was (7.9±2.3) x 10-4 mm2/s, (7.7±2.7) x 10-4 mm2/s, (7.9±2.5) x 10-4 mm2/s, respectively. In OA patients, the ADCav of patella cartilage was (10.5±4.1) x 10-4 mm2/s and the ADCav among superior- middle-inferior portions was not significantly different also (F=0.940, P=0.910). The ADCav of superior- middle-inferior portions was (10.8±4.1) x 10-4 mm2/s, (10.4±4.4) x 10-4 mm2/s, (10.5±4.2) x 10-4 mm2/s, respectively. The ADCav of the healthy volunteers was lower than that of the OA group(t=- 2.577, P=0.017) and the medial part showed the most different. Conclusion: DWI is a useful method in detecting early cartilage injury which can not be showed on routine sequences. (authors)