Table 2.

Summary of MRI sequences on 1.5-T magnet for imaging ocular melanoma metastasis in the abdomen

Sequence	Comments
Multiplanar survey, using balanced steady-state free precession or other techniques
T2 weighted fast spin echo axial and coronal planes	Two sequences of axial images with TE of 80 and 200 ms are helpful. The higher TE value differentiates cysts from solid masses whereas the lower TE sequence demonstrates metastasis better
Dual-echo fat-water in-phase and opposed-phase gradient echo images	On 1.5 T: TE of 2.2 and 4.4 ms (On 3 T: TE of 1.1 and 2.2 ms) If possible, this can be obtained using 3D Dixon fat-water separation technique to yield fat-suppressed images (examples of such sequences include LAVA-flex, mDixon or VIBE-Dixon based on the vendor)
Multiphasic 3D fat-suppressed gradient echo images following contrast administration	Shortest possible TR and TE, and overlapping thinnest possible slices, within MRI unit capabilities. Hepatobiliary phase (10–20 min) obtained with hepatocyte-avid agent is extremely useful
Diffusion-weighted sequence	B-values of 800 and 20–50 These are highly useful if contrast cannot be administered

3D, three-dimensional; LAVA-flex, liver acquisition with volume acquisition with Dixon method of water–fat separation; mDixon, multipoint Dixon; TE, echo time; TR, repetition time; VIBE-Dixon, volume interpolated body examination with Dixon method of water–fat separation.