Pohang University of Science and Technology, Medical Device Innovation Center, Department of Creative IT Engineering, Pohang, Republic of Korea.
J Biomed Opt. 2017 Jul 1;22(7):76005. doi: 10.1117/1.JBO.22.7.076005.
Vulnerable plaques are the major cause of cardiovascular disease, but they are difficult to detect with conventional intravascular imaging techniques. Techniques are needed to identify plaque vulnerability based on the presence of lipids in plaque. Thermal strain imaging (TSI) is an imaging technique based on ultrasound (US) wave propagation speed, which varies with the medium temperature. In TSI, the strain that occurs during tissue temperature change can be used for lipid detection because it has a different tendency depending on the type of tissue. Here, we demonstrate photothermal strain imaging (pTSI) using an intravascular ultrasound catheter. pTSI is performed by slightly and selectively heating lipid using a relatively inexpensive continuous laser source. We applied a speckle-tracking algorithm to US B-mode images for strain calculations. As a result, the strain produced in porcine fat was different from the strain produced in water-bearing gelatin phantom, which made it possible to distinguish the two. This suggests that pTSI could potentially be a way of differentiating lipids in coronary artery.
易损斑块是心血管疾病的主要原因，但它们很难用传统的血管内成像技术检测到。需要根据斑块中脂质的存在来识别斑块的脆弱性。热应变成像（TSI）是一种基于超声波（US）波传播速度的成像技术，该速度随介质温度而变化。在 TSI 中，组织温度变化过程中产生的应变可用于脂质检测，因为它的变化趋势取决于组织的类型。在这里，我们使用血管内超声导管演示了光热应变成像（pTSI）。pTSI 通过使用相对廉价的连续激光源对脂质进行轻微且选择性的加热来实现。我们将斑点跟踪算法应用于 US B 模式图像以进行应变计算。结果表明，在猪脂肪中产生的应变与在含胶态水的明胶体模中产生的应变不同，这使得两者能够区分开来。这表明 pTSI 有可能成为区分冠状动脉中脂质的一种方法。
