**3.1 RARE 2D**

T2-weighted sequences are the most widely used for imaging-based tumor detection. These are accelerated spin-echo sequences (RARE, or Rapid Acquisition with Refocused Echoes) which are generally acquired in two dimensions (2D), in multi-slice mode. When these sequences are used for clinical imaging, pulses are often added to suppress fluid signals (FLAIR, or Fluid-Attenuated Inversion Recovery).

To image small animals, the following parameters are used: in 2D

TE/TR = 70/5,000 ms; FOV: 22.5 x 22.5 mm; matrix: 192 x 128; spatial resolution: 117 x 175 µm; slice thickness: 750 µm; excitation pulse: Hermite 1 ms, 90°; refocusing pulse: Hermite 1 ms, 180°; reception bandwidth: 260 Hertz/pixel; RARE factor: 32; number of averages: 32, total acquisition time: 10 min 40 sec; transverse orientation.
