Doheny Image Reading Center, Doheny Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, California 90033, USA.
Invest Ophthalmol Vis Sci. 2010 Feb;51(2):1071-8. doi: 10.1167/iovs.09-4325. Epub 2009 Sep 24.
To investigate the relationship between B-scan density and retinal thickness measurements obtained by spectral domain optical coherence tomography (SDOCT) in eyes with retinal disease.
Data were collected from 115 patients who underwent volume OCT imaging with Cirrus HD-OCT using the 512 x 128 horizontal raster protocol. Raw OCT data, including the location of the automated retinal boundaries, were exported from the Cirrus HD-OCT instrument and imported into the Doheny Image Reading Center (DIRC) OCT viewing and grading software, termed "3D-OCTOR." For each case, retinal thickness maps similar to those produced by Cirrus HD-OCT were generated using all 128 B-scans, as well as using less dense subsets of scans, ranging from every other scan to every 16th scan. Retinal thickness measurements derived using only a subset of scans were compared to measurements using all 128 B-scans, and differences for the foveal central subfield (FCS) and total macular volume were computed.
The mean error in FCS retinal thickness measurement increased as the density of B-scans decreased, but the error was small (<2 microm), except at the sparsest densities evaluated. The maximum error at a density of every fourth scan (32 scans spaced 188 microm apart) was <1%.
B-scan density in volume SDOCT acquisitions can be reduced to 32 horizontal B-scans (spaced 188 microm apart) with minimal change in calculated retinal thickness measurements. This information may be of value in design of scanning protocols for SDOCT for use in future clinical trials.
研究眼底病变患者的光谱域光相干断层扫描（SDOCT）B 扫描密度与视网膜厚度测量值之间的关系。
共纳入 115 例接受 Cirrus HD-OCT 容积 OCT 成像的患者，采用 512 x 128 水平光栅方案。将 Cirrus HD-OCT 仪器中导出的原始 OCT 数据（包括自动视网膜边界的位置）导入 Doheny 图像阅读中心（DIRC）OCT 观察和分级软件（称为“3D-OCTOR”）。对于每个病例，使用所有 128 个 B 扫描以及从每隔一个扫描到每隔 16 个扫描的密度较低的 B 扫描子集生成类似于 Cirrus HD-OCT 生成的视网膜厚度图。仅使用扫描子集获得的视网膜厚度测量值与使用所有 128 个 B 扫描获得的测量值进行比较，并计算中央凹中心小区域（FCS）和全黄斑体积的差异。
随着 B 扫描密度的降低，FCS 视网膜厚度测量的平均误差增加，但误差较小（<2 微米），除了评估的最稀疏密度之外。在密度为每四个扫描（间隔 188 微米的 32 个扫描）时，最大误差<1%。
在体积 SDOCT 采集时，B 扫描密度可以降低到 32 个水平 B 扫描（间隔 188 微米），而计算的视网膜厚度测量值几乎没有变化。该信息可能对 SDOCT 扫描方案的设计具有重要价值，用于未来的临床试验。
