Diffusion Weighted whole body Imaging with body Background signal Suppression.
Whole-body DWI requires consistent high-quality fat suppression so that residual fat signal is not superimposed over signal from lesions. DWIBS combines STIR fat suppression – which works well over large fields-of-view – with single-shot EPI readout. Parallel imaging keeps the EPI shot short, to minimise blurring and image distortion.
The presence of tumours is denoted by high signal on high b-value (800-1000 s/mm2) diffusion weighted images. The signal from tumours remains high because of their high cellularity. DWIBS is a free-breathing acquisition; motion artefacts are suppressed via the acquisition of multiple signal averages.
From the multiple 2D-slice DWIBS source data, a 3D maximum-intensity projection is created which is then grey-scale inverted to present the image in a similar way to that used traditionally for nuclear medicine studies.