Latus Sarah, Grube Sarah, Eixmann Tim, Neidhardt Maximilian, Gerlach Stefan, Mieling Robin, Huttmann Gereon, Lutz Matthias, Schlaefer Alexander
IEEE Trans Biomed Eng. 2023 Nov;70(11):3064-3072. doi: 10.1109/TBME.2023.3275539. Epub 2023 Oct 19.
Optical coherence elastography (OCE) allows for high resolution analysis of elastic tissue properties. However, due to the limited penetration of light into tissue, miniature probes are required to reach structures inside the body, e.g., vessel walls. Shear wave elastography relates shear wave velocities to quantitative estimates of elasticity. Generally, this is achieved by measuring the runtime of waves between two or multiple points. For miniature probes, optical fibers have been integrated and the runtime between the point of excitation and a single measurement point has been considered. This approach requires precise temporal synchronization and spatial calibration between excitation and imaging.
We present a miniaturized dual-fiber OCE probe of 1 mm diameter allowing for robust shear wave elastography. Shear wave velocity is estimated between two optics and hence independent of wave propagation between excitation and imaging. We quantify the wave propagation by evaluating either a single or two measurement points. Particularly, we compare both approaches to ultrasound elastography.
Our experimental results demonstrate that quantification of local tissue elasticities is feasible. For homogeneous soft tissue phantoms, we obtain mean deviations of 0.15 ms and 0.02 ms for single-fiber and dual-fiber OCE, respectively. In inhomogeneous phantoms, we measure mean deviations of up to 0.54 ms and 0.03 ms for single-fiber and dual-fiber OCE, respectively.
We present a dual-fiber OCE approach that is much more robust in inhomogeneous tissues. Moreover, we demonstrate the feasibility of elasticity quantification in ex-vivo coronary arteries.
This study introduces an approach for robust elasticity quantification from within the tissue.
光学相干弹性成像（OCE）能够对弹性组织特性进行高分辨率分析。然而，由于光在组织中的穿透深度有限，需要微型探头才能到达体内结构，如血管壁。剪切波弹性成像将剪切波速度与弹性的定量估计相关联。一般来说，这是通过测量两点或多点之间波的传播时间来实现的。对于微型探头，已集成了光纤，并考虑了激发点与单个测量点之间的传播时间。这种方法需要在激发和成像之间进行精确的时间同步和空间校准。
我们展示了一种直径为1毫米的小型化双光纤OCE探头，可实现可靠的剪切波弹性成像。剪切波速度是在两个光学元件之间估计的，因此与激发和成像之间的波传播无关。我们通过评估一个或两个测量点来量化波传播。特别地，我们将这两种方法与超声弹性成像进行了比较。
我们的实验结果表明，对局部组织弹性进行量化是可行的。对于均匀的软组织模型，单光纤和双光纤OCE的平均偏差分别为0.15毫秒和0.02毫秒。在不均匀模型中，单光纤和双光纤OCE的平均偏差分别高达0.54毫秒和0.03毫秒。
我们提出了一种双光纤OCE方法，该方法在不均匀组织中更具鲁棒性。此外，我们证明了在离体冠状动脉中进行弹性量化的可行性。
本研究介绍了一种从组织内部进行可靠弹性量化的方法。
