Monte carlo simulation of laser radiation propagation in the multilayers model of head and brain tissues in health and in the presence of intracranial hematoma

Background and Objectives: Development of new optical methods of non-contact express diagnostics of intracranial hematoma remains an actual task. The development of optical model of the head in norm and in the presence of intracranial hematoma is the aim of the present study. Influence of the dimensions of the head tissues with and without hematoma on distribution of the backscattered laser radiation intensity is discussed. Materials and Methods: The optical model of the head and brain tissues in norm and in the presence of intracranial hematoma is developed. The computer simulations (Monte Carlo method) of the laser radiation propagation (wavelengths of 0.730 $\mu$m, 0.805 $\mu$m and 0.980 $\mu$m) were performed with the help of the developed model. Results: In case of hematoma the “ring” structure of the backscattered laser radiation intensity distribution is observed on the surface of the scalp. The influence of the skin thickness of the head (scalp), skull thickness and hematoma thickness on the difference in the power for backscattered laser radiation on the surface of the scalp in health and in the presence of hematoma is discussed. It is shown that this difference is maximal at the wavelength of laser radiation equal to 0.805 $\mu$m. The smaller thickness of the scalp and the bones of the skull the greater this difference. It is shown that this difference is maximal at the wavelength of laser radiation of 0.805 $\mu$m. The smaller the thickness of the skin of the head (scalp) and the bones of the skull the greater this difference. Conclusion: It was established that difference in the power of backscattered laser radiation on the surface of the scalp in health and in the presence of hematoma increases nonlinearly while increasing of the hematoma thickness.