| 摘要 |
In an imaging mass analysis, image information of a sample allows users to grasp specific information about the sample, such as distribution of a portion with a particular function or effect. The mass spectrum intensity data are normalized for each pixel so that the sum of the intensities over the entire mass-to-charge ratio (m/z) is one. Entropy is calculated by totaling the product of the intensity normalizing at each m/z and the logarithm of that intensity over the entire m/z range. After the entropy is calculated for each pixel, the pixels are colored according to their entropy values to display a two-dimensional color image of entropy distribution. The entropy of a cancerous portion is relatively small because of a high content of a specific kind of substance and the simplified composition of the substances. Thus, the cancerous part and the normal part of the entropy image can be distinguished.
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