Merging UTE Imaging, Water-Fat Separation, and T2* Mapping in a Single 3D MSK Scan

Jrgen Rahmer¹, Peter Brnert¹, Holger Eggers¹, Peter Koken¹, Jan P. Groen²

The separation of water and fat signal contributions, e.g. be achieved by chemical shift encoding, is essential for a number of MSK applications to improve image contrast for clinical diagnosis. Also, ultrashort echo time (UTE) imaging was proposed for MSK MRI, yielding extra information about short T2 species. It is the idea to incorporate both approaches into a multi-echo imaging (ME) sequence, which samples the UTE signal in the first echo and simultaneously delivers water-fat separation, T2* mapping and short T2 contrast. An efficient 3D ME approach is presented which allows the generation of water-fat separated images containing short-T2* components while extending the T2* mapping range down to ~ 1 ms. The 3D approach eases planning and bears the potential to deliver comprehensive diagnostic information by means of a single scan. We apply the technique to imaging of the knee, where short-T2 components are found in tendons, ligaments, and menisci.