Usefulness of administration of SPIO prior to RF ablation for evaluation of the therapeutic effect: an experimental study using miniature XXXX .

@entity1707 @entity548 @entity39 @entity75 @entity96 @entity409 @entity406 @entity1933
OBJECTIVES: To evaluate the usefulness of administration of superparamagnetic @entity1933 (SPIO) and magnetic resonance (MR) imaging for assessing the efficacy of radiofrequency (RF) liver ablation. MATERIAL AND METHODS: Using a protocol approved by the animal research committee of our university, nine RF liver ablations were performed in three miniature @entity1707 . Six ablations were performed after administration of SPIO in two @entity1707 (group A). Three ablations were performed in the other @entity1707 without administration of SPIO (group B). All @entity1707 were sacrificed 4 days after the procedure. Harvested livers were scanned with a 1.5T MR system before and after fixation with 10% buffered @entity406 , and MR images were precisely compared with histological specimens. RESULTS: There were no histological differences between the two groups. All ablated @entity409 showed coagulation @entity39 at the external layer. There were no viable cells inside the coagulation @entity39 . All @entity75 had a hypointense rim on fast low angle shot (FLASH) images. The rims of group A were thicker than those of group B. The rims of group B corresponded histologically to congestion and @entity548 @entity39 area. The rims of the group A corresponded to @entity548 @entity39 and coagulation @entity39 areas. In group A, the hypointense rim reflected @entity39 Kupffer cells that took up SPIO before RF liver ablation. CONCLUSION: Administration of SPIO made it possible to precisely evaluate ablated liver parenchyma by hypointense rim on FLASH images. This method is helpful for the evaluation of safety margin after RF ablation for @entity96 .
