Software method to measure effusion-synovitis volume on MRI for knee OA

Abstract

Osteoarthritis Cartilage, 2014). In the present study, we focused on the meniscus change and osteophyte formation in early-stage knee osteoarthritis (OA). We examined whether there were any associations between the meniscus changes and the osteophyte formations, and also examined, if so, there were any site-specific differences for the associations in early-stage knee OA by using the magnetic resonance imaging (MRI)-based analyses. Methods: A total of 50 patients (mean age 59.7 years) who visited our outpatient clinic for knee pain between May and December 2012 were enrolled in this study. The severity of knee OA was classified by Kellgren-Lawrence (K/L) grading scale based on standing extended-knee Xray images. All patients showed either K/L grade 0, 1 or 2, and were also performed 3TMRI for the affected knee. Diagnosis of knee OA for the subjects with K/L 0 was conducted using 3TMRI according to the method by Shama et al (ARD 2013). Patients who showed less than 174 of femoro-tibial tibial angle (FTA) were excluded from the study. Compartments of the knee joint was divided into 14 places of areas according to WORMS using sagittal and coronal two dimensional (2D) fat suppressed and T2 weighted image fast spin-echo sequence (TR ¼ 5000ms, TE¼ 70ms, FOV 160mm, matrix ¼ 384Â307, Slice thickness ¼ 3mm, turbo-factor ¼ 17, Flip-angle ¼ 150, scan time ¼ 3:00). The severity of osteophyte and meniscus tear were semi-quantitatively evaluated according to the WORMS method. The medial meniscus extrusion distance (MMED) was also measured. Interrelatioships between the osteophyte scores in medial femoral condyle (MFC) and medial tibia plateau (MTP) and the medial meniscus (MM) tear and MMED were examined. Results: The patients showed the radiographic OA severities for K/L grade 0 (n¼3), 1 (n¼27) and 2 (n¼20), respectively. Twenty-three of fifty patients were male, while remaining twenty-seven patients were female. No significant differences of FTA were observed between the patients with three different K/L grades. While the MMEDs were not associated with the osteophyte scores in MTP, the MMEDs were associated with the osteophyte scores in MFC (r¼0.39, p<0.01). When the patients were divided into two groups in terms of the MMEDs by the cutline of 3 mm, the osteophyte scores in MFC in group 1 (MMEDs S3mm; 3.14) were significantly higher than those in group 2 (MMEDs <3mm; 1.50)(p¼0.03). On the other hand, the MM tear scores were associated with the osteophyte scores in MTP (r¼0.32, p¼0.03), while those were not associated with the osteophyte scores in MFC. In addition, when the patients were divided into two groups by the presence or absence of the MM tear, the osteophyte scores in MTP of the patients with MM tear (2.86) were significantly increased in comparison to those of the patients without MM tear (0.64, p¼0.02). Conclusions: The meniscus changes (MME and meniscus tear) were associated with the osteophyte formation in early-stage of medial knee OA. The associations were site-specific, that is; the MME were associated with t...