Figure 16b.  (a) LFJ arthrogram obtained at the beginning of opacification demonstrates a cyst located superiorly (arrow). (b) LFJ arthrogram obtained at the end of contrast material injection shows leakage with opacification of the soft tissues surrounding the facet joint (arrowhead). Such leakage has no adverse effects and may even result in complete resolution of the lesion if it occurs at the level of a cyst or diverticulum.