Ultra-Short Echo Time (UTE) imaging, characterized by acquisition schemes with Echo Times (TE) of < 1 msec, have enabled new applications of pediatric musculoskeletal (MSK) MRI including cortical bone, tendons and ligaments. The protons in the bone collagen matrix have an effective T2* on the order of 20 – 80 µsec. The UTE sequence consists of a 40 µs long non-selective RF pulse followed by transmit/receive switch time and a 100% asymmetric data, i.e. free induction decay, acquisition from the center to the surface of a sphere. In order to achieve the shortest possible TE, data acquisition starts already during ramp-up time of the readout gradient. The aim of our study was to assess the feasibility and compare two UTE sequences, a prototype 3D UTE with radial koosh-ball acquisition and clinically available pointwise encoding time reduction with radial acquisition (PETRA), in pediatric patients referred for clinical MSK studies.
SPR 2020 Annual Meeting & Postgraduate Course
Liu Ke Cheng,