High-density breasts are common among Japanese women, and thus, the detection rate of lesions is low, as they are obscured by the mammary glands during mammography screening. Therefore, attempts have been made to classify mammary gland concentration and present individuals with the risk of lesion obscuration; however, a large variability remains among doctors. In this study, we attempted to objectively classify mammary gland concentration by using deep learning. We examined the parameters of the learning image using a neural network console as a deep learning creation tool. As a result, a square image with a resolution of 64 × 64 and 100 learnings had the highest classification accuracy (88%). As the mammary gland concentration classification is a classification of the mammary gland of the entire breast, it is considered that the method by reduction has obtained a certain degree of accuracy. Next, training image data were expanded to obtain the subsequent classification accuracy. For data augmentation, the values of angle, brightness, and contrast were changed such that the image was similar to that before data augmentation. The resolution of 256 × 256 and network AlexNet were optimal, and 100% classification accuracy was obtained. In other words, the data augmentation—performed such that learning is equivalent in all classes—was considered effective. Conversely, because these are input images with similar features, they may not have various features. Therefore, verification using an unknown evaluation image will be required in the future.
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