Oregon Health and Science University, Department of Biomedical Engineering, 3303 South West Bond Avenue, Portland, Oregon 97237, USA.
J Biomed Opt. 2010 Mar-Apr;15(2):026011. doi: 10.1117/1.3369811.
We present high-resolution wide-field imaging of retinal and choroidal blood perfusion with optical microangiography (OMAG) technology. Based on spatial frequency analysis, OMAG is capable of visualizing the vascular perfusion map down to capillary-level resolution. An OMAG system operating at 840 nm is used with an A-scan rate of 27,000 Hz, axial resolution of 8 mum, and sensitivity of 98 dB. To achieve wide-field imaging, we capture 16 optical coherence tomography (OCT) 3-D datasets in a sequential order, which together provide an area of approximately 7.4 x 7.4 mm(2) at the posterior segment of the human eye. For each of these datasets, the bulk tissue motion artifacts are eliminated by applying a phase compensation method based on histogram estimation of bulk motion phases, while the displacements occurring between adjacent B-frames are compensated for by 2-D cross correlation between two adjacent OMAG flow images. The depth-resolved capability of OMAG imaging also provides volumetric information on the ocular circulations. Finally, we compare the clinical fluorescein angiography and indocyanine green angiography imaging results with the OMAG results of blood perfusion map within the retina and choroid, and show excellent agreement between these modalities.
我们提出了一种基于光学微血管造影（OMAG）技术的高分辨率宽场视网膜和脉络膜血流灌注成像方法。基于空间频率分析，OMAG 能够可视化血管灌注图，达到毛细血管水平的分辨率。我们使用工作在 840nm 波长、轴向分辨率为 8μm、灵敏度为 98dB 的 OMAG 系统，以 27,000Hz 的 A 扫描速率进行采集。为了实现宽场成像，我们以连续的顺序捕获 16 个光学相干断层扫描（OCT）3D 数据集，这些数据集共同提供了人眼后节约 7.4 x 7.4mm(2)的区域。对于这些数据集的每一个，通过应用基于体相运动相位直方图估计的相位补偿方法，可以消除大块组织运动伪影，而相邻 B 帧之间的位移则通过两个相邻 OMAG 血流图像之间的 2D 互相关来补偿。OMAG 成像的深度分辨能力还提供了关于眼循环的体积信息。最后，我们将临床荧光素血管造影和吲哚菁绿血管造影成像结果与 OMAG 对视网膜和脉络膜内血液灌注图的结果进行了比较，并显示这些模态之间具有极好的一致性。
