講演抄録/キーワード |
講演名 |
2014-01-26 13:30
3次元OCT画像を利用した眼底面レジストレーション技術の開発 ○冨樫恭佑・坂本未来(山形大)・竹内 楽・秋葉正博(トプコン)・矢花武史・面高宗子・劉 孟林・小林 航・横山 悠(東北大)・福間康文(トプコン)・中澤 徹・湯浅哲也(東北大) MI2013-80 |
抄録 |
(和) |
緑内障診断には,光干渉断層計(Optical Coherence Tomography: OCT)による神経線維層厚の計測から神経線維の菲薄化を定量的に評価することが重要である.複数回検査したデータのフォローアップを行う場合には,測定データのレジストレーションが不可欠となる.本研究では,3次元OCT画像から作成される血管投影画像に位相限定相関法を適用した高速レジストレーション法を提案する.提案手法の有効性を示すため,健常者1名に対して,10回の繰り返し測定を行い,1回目の神経線維層厚分布を基準として,各測定における分布との差をRMS(Root Mean Square)で評価した.提案する処理の有無でRMSの平均値は,4.7±1.6 μmから2.6±0.3 μmへ改善された.さらに,処理時間は約0.3秒であり,実用上問題ないことを確認した. |
(英) |
Recently, retinal nerve fiber layer (RNFL) thickness measurement from retinal optical coherence tomography (OCT) images has been widely used as an important clinical index to indicate a glaucoma progression. While a long-term follow-up of RNFL thickness is effective tool for glaucoma diagnosis, a precise registration is indispensable for OCT images acquired at different date. In this study, we propose a registration algorithm to correct random shifts occurring whenever imaging based on a projection image generated from the 3-D OCT retinal images. For speeding-up, the algorithm was implemented by processing in Fourier space based on properties of Fourier transform with rotation and translation, which is referred to as phase-only correlation method. For the stable detection of shift, several preprocessing to raw data, such as background correction to homogenize different imaging conditions, zero-padding to resize the registration image from a rectangular to a square image size, and Hanning-windowing to suppress unnecessary higher frequency-components, were carefully applied before registration. We demonstrated the effectiveness of the proposed method using an actual retina image (512×885×64) of a healthy volunteer acquired by 3-D OCT-2000 manufactured by TOPCON, Japan. The measurement was repeated 10 times, and the degree of agreement in RNFL thickness measured was evaluated with root mean square (RMS). The average RMS before and after preregistration were 4.7±1.6 and 2.6±0.3 μm, respectively. From this result, it can be concluded that the proposed method improved the precision approximately twofold. In addition, the processing time was approximately 0.3 s for a single data set, which will fall inside a permissible range of clinical use. Proposed technique may become a useful tool for glaucoma diagnosis. |
キーワード |
(和) |
Optical Coherence Tomography / 位相限定相関法 / 緑内障 / / / / / |
(英) |
optical coherence tomography / phase-only correlation / glaucoma / / / / / |
文献情報 |
信学技報, vol. 113, no. 410, MI2013-80, pp. 133-137, 2014年1月. |
資料番号 |
MI2013-80 |
発行日 |
2014-01-19 (MI) |
ISSN |
Print edition: ISSN 0913-5685 Online edition: ISSN 2432-6380 |
著作権に ついて |
技術研究報告に掲載された論文の著作権は電子情報通信学会に帰属します.(許諾番号:10GA0019/12GB0052/13GB0056/17GB0034/18GB0034) |
PDFダウンロード |
MI2013-80 |