MRI of Paraspinal Gossypiboma: Look for the Barium Sulfate Filament.

Gossypiboma is a rare post-surgical complication comprising a retained surgical gauze surrounded by a foreign body reaction. Although usually presenting on magnetic resonance imaging (MRI) with low T1 signal, high central and low peripheral signal on T2, and bandlike peripheral enhancement, MR appearance is often non-specific. The barium sulphate filament within a surgical gauze presents on MR as a curvilinear thread which is dark on both T1 and T2 sequences. Scrutinizing the MR images is critical to identify the filament and to pinpoint the diagnosis of gossypiboma. Teaching Point: A paraspinal mass on postoperative spine MRI should be carefully searched for a hypointense contorted wire (the barium sulfate filament), as it may be the characteristic finding to evocate the diagnosis of gossypiboma.