脂肪抑制併用造影T_1強調画像での表示法に関する検討

摘要

今回，乳房においてT_1WIとFS-T_1WIの乳腺内腫瘤と脂肪内腫瘤で表示上の造影効果について検討を行っ た．結果，造影前が高輝度となるFS-T_1WIの脂肪内腫瘤のみ，造影効果を識別できない可能性があった．脂 肪抑制法の適応である脂肪内腫瘤は多くの部位に存在 するので，FS-T_1WIによる造影効果の判別が重要とな る．レシーバーゲイン固定と同一表示設定による表示 は，造影前後において造影効果のみ輝度差となる方法 で，脂肪内腫癌での造影効果の判別には有効であると 思われた．%The effects of imaging conditions and measures for their improvement were examined with regard to recognition of the effects of contrast on images when T_1-weighted imaging with selective fat suppression was applied. Method: Luminance at the target region was examined before and after contrast imaging using phantoms assuming pre- and post-imaging conditions. A clinical examination was performed on tumors revealed by breast examination, including those surrounded by mammary gland and by fat tissue. Results: When fat suppression was used and imaging contrast was enhanced, the luminance level of fat tumors with the same structure as the prepared phantoms appeared to be high both before and after contrast imaging, and the effects of contrast were not distinguishable. This observation is attributable to the fact that the imaging conditions before and after contrast imaging were substantially different. To make a comparison between pre-and post-contrast images, it is considered necessary to perform imaging with fixed receiver gain and to apply the same imaging method for pre- and post-contrast images by adjusting post-contrast imaging conditions to those of pre-contrast imaging.