Does alginate packing affect scan results?
A study examined the CT and MR appearances of four packing materials commonly used in otolaryngologic surgery. Bismuth and iodoform paraffin paste, aqueous betadine gauze, calcium sodium alginate, and triadocortyl cream were examined. CT attenuation values were measured using phantoms containing packing materials; MR characteristics were examined by packing the external auditory meati of volunteers. Two illustrative case reports also are presented. Bismuth and iodoform paraffin paste has a high CT attenuation (> 3000 Hounsfield units) resulting in severe image degradation attributable to streak artifact. Aqueous betadine gauze was of high attenuation (258 Hounsfield units; SD, 16.5) but did not cause image degradation. The attenuation value of calcium sodium alginate coincided with that of muscle, and the attenuation value of triadocortyl creme coincided with that of fat. On MR, calcium sodium alginate and bismuth and iodoform paraffin paste had imaging characteristics similar to muscl
