Diagnostic performance of T2 mapping and diffusion-weighted MRI in early detection of cartilage degeneration in knee osteoarthritis

Abstract Background Early knee osteoarthritis (OA) is associated with biochemical cartilage changes that may not be visible on conventional magnetic resonance imaging (MRI) or plain radiography. Quantitative MRI techniques, including T2 mapping and diffusion-weighted imaging (DWI), may facilitate earlier detection of cartilage degeneration. Aim To assess the diagnostic performance of T2 mapping and apparent diffusion coefficient (ADC) measurements for detecting early cartilage degeneration in patients with clinically suspected knee OA and normal radiographs. Methods This prospective case–control study included 30 symptomatic patients with suspected early knee OA and 15 healthy volunteers. All subjects underwent conventional MRI, T2 mapping, and DWI with ADC analysis. Cartilage assessment was performed in tibiofemoral compartments. Quantitative parameters were compared between patients and controls. Results Conventional MRI identified osteoarthritic changes in 26 of 35 examined joints (74.3%). T2 values were significantly higher in patients than in controls across all compartments ( p < 0.001). T2 cutoff values ranged from > 38 to > 42 ms, yielding sensitivities of 87.5–93.9% and specificities of approximately 88%. ADC values were also significantly increased in patients ( p < 0.001), with cutoff values ranging from > 1.46 to > 1.54 ×10 −3 mm 2 /s and sensitivities and specificities of 81.8–88.2% and 88.2–93.8%, respectively. T2 mapping achieved the highest diagnostic accuracy (94%), followed by ADC measurements (90%) and conventional MRI (78%). Conclusions T2 mapping and DWI provide valuable quantitative biomarkers for detecting early cartilage degeneration in knee OA. T2 mapping demonstrated the best overall diagnostic performance, improving the identification of early osteoarthritic changes before structural abnormalities become evident on conventional MRI.