Ultra-short TE (UTE) and Zero TE (ZTE) MR pulse sequences provide unique capabilities for imaging short-lived tissues (i.e. T2 < 1ms) which are otherwise invisible using conventional MR imaging with echo times (TE) in the milliseconds range. The presentation will first review 2D and 3D UTE imaging using center-out (typically radial) k-space sampling. Subsequently, ZTE imaging will be described highlighting its unique features regarding RF excitation and silent imaging. At the end of the presentation related methods like SWIFT and Looping Star will be briefly mentioned as well.
Ultra-short TE (UTE) and Zero TE (ZTE) MR pulse sequences provide unique capabilities for imaging short-lived tissues (i.e. T2 < 1ms) which are otherwise invisible using conventional MR imaging with echo times (TE) in the milliseconds range (1–8).
The presentation will first review 2D and 3D UTE imaging using center-out (typically radial) k-space sampling (1,2,9,3). Subsequently, ZTE imaging will be described highlighting its unique features regarding RF excitation and silent imaging (4–8). Imaging characteristic related to center-out radial sampling (i.e. point spread function, motion properties, …) will be discussed as well (10–12).
Both, UTE and ZTE results in spoiled gradient echo type steady-state signal response; primarily capturing proton density (PD) and T1 relaxation contrast. Preparation pulses can be used to generate additional contrasts (i.e. T1(r), T2, MT, …), or to saturate long T2 and/or off-resonance fat. Similarly, multi-gradient echo readouts can be used for suppression of long T2 tissues and/or Dixon-type fat/water chemical shift separation (13).
At the end of the presentation, more advanced methods including SWIFT (14), and Looping Star (15) (for silent T2* weighted imaging) will be described.
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