Roy Ranadhir, Godavarty Anuradha, Sevick-Muraca Eva M
Mathematics Department University of Texas-Pan American Edinburg, TX 78541, USA.
Phys Med Biol. 2007 Jul 21;52(14):4155-70. doi: 10.1088/0031-9155/52/14/009. Epub 2007 Jun 15.
Near-infrared fluorescence optical imaging has the unique opportunity of differentiating diseased lesions from normal lesions based upon environmentally indicated changes in the lifetime of a fluorescent imaging agent. In this paper, we demonstrate three-dimensional lifetime tomography using the gradient-based penalty modified barrier function with simple bounds truncated Newton with trust region method to reconstruct lifetime maps in a clinically relevant, single breast-shaped ( approximately 1081 cm(3)) phantom from point-frequency-domain photon migration measurements at 100 MHz. A reverse differentiation technique is used to calculate the gradients. This algorithm is desirable because the storage benefit from the use of the truncated Newton method and the reverse differentiation technique increase the speed. Two fluorescent contrast agents, indocyanine green and 3-3'-diethylthiatricarbocyanine iodide which differed in their fluorescence lifetimes by 0.62 ns, were used. Images of targets at a depth of 2.0 cm and target-to-background ratios (T:B) of 212:1 and 70:1 in fluoroscence absorption and 1:2.1 and 2.1:1 in lifetimes are successfully reconstructed. Our results show that image reconstruction is possible when there is (i) a longer lifetime in a target than the background and (ii) a shorter lifetime in a target than the background.
近红外荧光光学成像有独特的机会，可基于荧光成像剂寿命的环境指示变化来区分病变与正常组织。在本文中，我们展示了使用基于梯度的罚函数修正障碍函数结合带信赖域方法的简单边界截断牛顿法进行三维寿命断层成像，以从100 MHz的点频域光子迁移测量中重建具有临床相关性的单个乳房形状（约1081立方厘米）体模中的寿命图。采用反向微分技术来计算梯度。该算法是可取的，因为使用截断牛顿法和反向微分技术带来的存储优势提高了速度。使用了两种荧光造影剂，吲哚菁绿和3,3'-二乙基硫代三碳菁碘化物，它们的荧光寿命相差0.62纳秒。成功重建了深度为2.0厘米、荧光吸收中靶与背景比（T:B）为212:1和70:1以及寿命中为1:2.1和2.1:1的目标图像。我们的结果表明，当（i）目标中的寿命比背景长以及（ii）目标中的寿命比背景短时，图像重建是可行的。
