Verkruysse Wim, Choi Bernard, Zhang Jenny R, Kim Jeehyun, Nelson J Stuart
Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA 92612, USA.
Phys Med Biol. 2008 Mar 7;53(5):1463-74. doi: 10.1088/0031-9155/53/5/019. Epub 2008 Feb 19.
Pulsed photo-thermal radiometry (PPTR) is a non-invasive, non-contact diagnostic technique used to locate cutaneous chromophores such as melanin (epidermis) and hemoglobin (vascular structures). Clinical utility of PPTR is limited because it typically requires trained user intervention to regularize the inversion solution. Herein, the feasibility of automated regularization was studied. A second objective of this study was to depart from modeling port wine stain PWS, a vascular skin lesion frequently studied with PPTR, as strictly layered structures since this may influence conclusions regarding PPTR reconstruction quality. Average blood vessel depths, diameters and densities derived from histology of 30 PWS patients were used to generate 15 randomized lesion geometries for which we simulated PPTR signals. Reconstruction accuracy for subjective regularization was compared with that for automated regularization methods. The objective regularization approach performed better. However, the average difference was much smaller than the variation between the 15 simulated profiles. Reconstruction quality depended more on the actual profile to be reconstructed than on the reconstruction algorithm or regularization method. Similar, or better, accuracy reconstructions can be achieved with an automated regularization procedure which enhances prospects for user friendly implementation of PPTR to optimize laser therapy on an individual patient basis.
脉冲光热辐射测量法（PPTR）是一种非侵入性、非接触式诊断技术，用于定位皮肤中的发色团，如黑色素（表皮）和血红蛋白（血管结构）。PPTR的临床应用受到限制，因为它通常需要经过训练的用户干预来规范反演解决方案。在此，研究了自动正则化的可行性。本研究的第二个目标是不再将葡萄酒色斑（PWS）——一种经常用PPTR研究的皮肤血管病变——建模为严格的分层结构，因为这可能会影响有关PPTR重建质量的结论。利用30例PWS患者组织学得出的平均血管深度、直径和密度，生成了15种随机病变几何形状，并对其PPTR信号进行了模拟。将主观正则化的重建精度与自动正则化方法的重建精度进行了比较。客观正则化方法表现更好。然而，平均差异远小于15个模拟剖面之间的变化。重建质量更多地取决于要重建的实际剖面，而不是重建算法或正则化方法。使用自动正则化程序可以实现相似或更好的精度重建，这增强了PPTR在用户友好型实施方面的前景，以便在个体患者基础上优化激光治疗。
