The use of India ink in tissue-simulating phantoms
The use of India ink in tissue-simulating phantoms
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DOI：
10.1364/oe.18.026854
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发表时间：
2010-12-20
期刊：
影响因子：
3.8
通讯作者：
Zaccanti, Giovanni
中科院分区：
文献类型：
--
作者：
Di Ninni, Paola;Martelli, Fabrizio;Zaccanti, Giovanni
研究了印度墨水在可见光和近红外波段的光学性质，印度墨水是一种经常用于制备组织模拟体模的吸收剂。消光系数是通过测量准直透过率和分光光度测量得到的，即从扩散无限介质中添加小浓度墨水的通量速率的多距离测量获得的吸收系数。对五个不同品牌的印度墨水样品进行了测量，对于一些品牌也进行了不同批次的测量。正如在以前发表的论文中所报道的，我们所获得的结果显示，吸收系数和消光系数在品牌间和批次间都有很大的变化。相反，我们的结果显示吸收系数和消光系数之比的变化很小。因此，所有样品的反照率都是相似的：在波长632.8、751和833 nm处，所有样品的平均值分别为0.161、0.115和0.115，最大偏差为0.044、0.019和0.035。这些结果表明，使用我们所获得的反照率的值，应该可以从简单的消光系数测量中获得未知墨水样品的吸收系数，其不确定度小于约4%。用测量吸收系数所需的复杂程序，不容易获得类似的精度。(C)2010年美国光学学会
The optical properties of India ink, an absorber often used in preparation of tissue simulating phantoms, have been investigated at visible and near infrared wavelengths. The extinction coefficient has been obtained from measurements of collimated transmittance and from spectrophotometric measurements, the absorption coefficient from multidistance measurements of fluence rate in a diffusive infinite medium with small concentrations of added ink. Measurements have been carried out on samples of India ink from five different brands, and for some brands also from different batches. As also reported in previously published papers the results we have obtained showed large inter-brand and inter-batch variations for both the absorption and the extinction coefficient. On the contrary, our results showed small variations for the ratio between the absorption and the extinction coefficient. The albedo is therefore similar for all samples: The values averaged over all samples investigated were 0.161, 0.115, and 0.115 at lambda = 632.8, 751, and 833 nm respectively, with maximum deviations of 0.044, 0.019, and 0.035. These results indicate that, using the values we have obtained for the albedo, it should be possible to obtain with uncertainty smaller than about 4% the absorption coefficient of a sample of unknown ink from simple measurements of extinction coefficient. A similar accuracy is not easily obtained with the complicated procedures necessary for measurements of absorption coefficient. (C) 2010 Optical Society of America