University of Texas at Arlington, Bioengineering Department, Arlington, Texas 76010, USA.
J Biomed Opt. 2010 Jan-Feb;15(1):016015. doi: 10.1117/1.3299728.
Surgeons often cannot see major vessels embedded in adipose tissue and inadvertently injure them. One such example occurs during surgical removal of the gallbladder, where injury of the nearby common bile duct leads to life-threatening complications. Near-infrared imaging of the intraoperative field may help surgeons localize such critical tissue-embedded vessels. We have investigated how continuous-wave (CW) imaging performs relative to time-gated wide-field imaging, presently a rather costly technology, under broad Gaussian beam-illumination conditions. We have studied the simplified case of an isolated cylinder having bile-duct optical properties, embedded at different depths within a 2-cm slab of adipose tissue. Monte Carlo simulations were preformed for both reflectance and transillumination geometries. The relative performance of CW versus time-gated imaging was compared in terms of spatial resolution and contrast-to-background ratio in the resulting simulated images. It was found that time-gated imaging offers superior spatial resolution and vessel-detection sensitivity in most cases, though CW transillumination measurements may also offer satisfactory performance for this tissue geometry at lower cost. Experiments were performed in reflectance geometry to validate simulation results, and potential challenges in the translation of this technology to the clinic are discussed.
外科医生在手术过程中常常无法看到嵌入脂肪组织中的主要血管，从而无意中损伤它们。例如，在胆囊切除手术中，附近的胆总管损伤会导致危及生命的并发症。术中现场的近红外成像可能有助于外科医生定位这些关键的组织内血管。我们研究了连续波（CW）成像在广泛高斯光束照射条件下相对于时间门控宽场成像的性能，目前后者是一种相当昂贵的技术。我们研究了一个简化的情况，即一个具有胆管光学特性的孤立圆柱体，以不同的深度嵌入在 2 厘米厚的脂肪组织平板中。分别针对反射和透射几何结构进行了蒙特卡罗模拟。在模拟图像中，根据空间分辨率和对比度与背景比，比较了 CW 与时间门控成像的相对性能。结果发现，在大多数情况下，时间门控成像在空间分辨率和血管检测灵敏度方面具有优势，尽管 CW 透射测量在这种组织几何结构下也可以以较低的成本提供令人满意的性能。在反射几何结构中进行了实验以验证模拟结果，并讨论了将该技术转化为临床应用的潜在挑战。
