Delayed gadolinium enhanced MRI of menisci and cartilage (DGEMRIM/DGEMRIC) in overweight patients with knee osteoarthritis – a cross sectional study of 86 overweight patients with intraarticular administered gadolinium contrast

Purpose: Morphologic changes in the menisci are highly associated with development of knee osteoarthritis (KOA). The aim of this study was to examine the delayed gadolinium enhanced MRI of menisci (dGEMRIM) and its relationship to Kellgren-Lawrence grade (KLG) and to articular cartilage dGEMRIC in overweight patients with KOA Methods: 86 overweight patients (BMI > 27) with KOA from the CAROT-study (Clin trial id: NCT00655941) with a mean KLG of 3 had an ultrasound guided intraarticular injection of 0.1 ml negatively charged contrast agent (4 mmol/l Multihance) in 10 mL Lidocain. Four inversion times (50, 350, 650, 1410 ms) dGEMRIC and dGEMRIM was performed in a 1.5T Philips, Intera scanner with a time delay of 90–120 min. T1 relaxation time-values were calculated for posterior weight bearing femoral cartilage in the lateral knee compartment, and for the posterior meniscal horn of both lateral and medial menisci. Due to advanced medial KOA and missing cartilage, dGEMRIC in the medial compartment could not be measured. Results: For posterior femoral cartilage (N = 86) the mean T1 relaxation time was 441 ms (confidence limits of the mean (CLM) 427–455 ms). The mean T1 relaxation time in the lateral menisci (N = 85) was 498 ms (CLM 478–518 ms) and for the medial menisci (N = 62) mean T1 relaxation time was 484 (CLM 458–510 ms). A positive correlation was found between medial and lateral menisci with R = 0.62 (P < 0.0001) and a similar trend was observed between lateral cartilage and lateral with R = 0.26 (P = 0.02). Comparing meniscus T1 relaxation time-values from the most affected knee compartment to KLG showed trends toward increasing T1-values for KLG 1–3 and a decreasing T1-value for Menisci KLG 4View Large Image Figure ViewerDownload Hi-res image Download (PPT)View Large Image Figure ViewerDownload Hi-res image Download (PPT) Conclusions: The positive correlation between lateral and medial menisci may indicate a parallel degradative processes occurring in both knee compartments. The correlation between menisci and cartilage T1-values suggests concomitant, but different, degeneration in the two tissues in OA. The interpretation of the numerical, and insignificantly, inverse u-shaped relation between meniscal T1-values and KLG is in accordance with previous findings comparing various degrees of meniscal degeneration with both dGEMRIM and proteoglycans content from biopsies.