ABSTRACT
In positron emission tomography (PET) studies, convolutional neural networks (CNNs) may be applied directly to the reconstructed distribution of radioactive tracers injected into the patient's body, as a pattern recognition tool. Nonetheless, unprocessed PET coincidence data exist in tabular format. This paper develops the transformation of tabular data into n-dimensional matrices, as a preparation stage for classification based on CNNs. This method explicitly introduces a nonlinear transformation at the feature engineering stage and then uses principal component analysis to create the images. We apply the proposed methodology to the classification of simulated PET coincidence events originating from NEMA IEC and anthropomorphic XCAT phantom. Comparative studies of neural network architectures, including multilayer perceptron and convolutional networks, were conducted. The developed method increased the initial number of features from 6 to 209 and gave the best precision results (79.8) for all tested neural network architectures; it also showed the smallest decrease when changing the test data to another phantom.
ABSTRACT
OBJECTIVE: The aim of our work was to make analysis of world literature that develops a problem of impact of environment on male reproductive health. PATIENTS AND METHODS: Materials and methods: We analyzed the bibliography available, until January 2020, about influence of different exogenic factors on male reproductive system. CONCLUSION: Conclusions: The biggest influence of ionizing radiation on mankind was reached after two big catastrophes: Chernobyl Nuclear Power Plant in April 1986 and an accident on the Fukushima Daiichi Nuclear Power Plant in March 2011. However, impact of ionizing radiation on male reproductive in literature still remains controversy that needs more detailed study. Lead influences on such sperm parameters, as sperm morphology, count, motility, semen volume. So, specific attention should be paid to the type of work routinely performed by man. Another one environmental factor that has negative influence is a heat. It effects on sperm morphology and motility.
