1. A diagnosis processing device for diagnosing a target for abnormality by use of a neural network, the diagnosis processing device comprising: learning pattern creating means for creating a learning pattern by (i) digitalizing a learning image into digital data, the learning image being an image in which abnormality information indicating a substantive feature of abnormality of the target is pre-known, and (ii) sampling data from the digital data of the learning image by use of a predetermined sampling method, the learning pattern indicating a data sequence of a sample data row of the data thus sampled; learning processing means for causing the neural network to learn, by use of two or more learning patterns created as above by the learning pattern creating means; diagnostic pattern creating means for creating a diagnostic pattern by (iii) digitalizing a diagnostic image into digital data, the diagnostic image being an image in which abnormality information is unknown, and (iv) sampling data from the digital data of the diagnostic image by use of the predetermined sampling method, the diagnostic pattern indicating a data sequence of a sample data row of the data thus sampled; and determining means for determining a substantive feature of the abnormality of the target indicated in the abnormality information in the diagnostic image, based on an output value outputted, in response to an input of the diagnostic pattern, from a learned neural network which is the neural network subjected to learning.