T2-star Relaxation as a means to diffrentiatie Cartilage Repair Tissue after Microfracturing Therapy

Introduction MR imaging of cartilage is widely accepted as a tool in the evaluation of cartilage. Originally such studies were limited to morphological sequences, but increasingly MR imaging is being used to produce parameter maps (i.e. relaxation or diffusion constants) which allows a biochemical evaluation of the cartilage. One such parameter which has been extensively used is the T2 relaxation value, where the T2 value of the cartilage is a function of collagen content, concentration and water content [1-4]. T2 maps are created using a multi-echo spin echo technique. However some problems with this technique have to be considered such as stimulated echoes create a fluctuation in the signal within the echo train, crosstalk issues and relatively long scan time. We present here the T2-star relaxation constant as an alternative to the T2 relaxation constant in a preliminary cross-sectional study of patients after cartilage repair using Microfracturing technique (MFX).