Identify paraffin-embedded brain glioma using terahertz pulsed spectroscopy

Abstract

Abstract The refractive indices, absorption coefficients and complex dielectric constants spectra of paraffin-embedded brain glioma and normal brain tissues have been measured by a terahertz time domain spectroscopy (THz-TDS) system in the range of 0.2 – 2.0 THz. The spectral differences between glioma and normal brain tissues were obtained. Our results indicate that, compared with normal tissue, glioma had higher refractive index, absorption coefficient, and dielectric constant. Based on these results, the suitable frequency components for different methods of glioma imaging (intensity imaging, coherent imaging and terahertz pulsed imaging) are analyzed. Keywords: spectroscopy, terahertz, tissue diagnostics. 1. Introduction Brain gliomas are the most common and deadly malignant brain tumors. 1 Gliomas are the leading cause of death by brain diseases in both children and adults 2 , and the median survival for patients with brain gliomas is a mere 12 to 15 months 3 . An accurate, early clinical diagnosis of br ain gliomas is crucial for patients’ treat ment, in which microscopic pathology is the most commonly used technique for tissue analysis. Embedding brain gliomas in paraffin is a widely used first step in microscopic pathology analysis owing to its better storage and long-term tissue morphology preservation in clinical settings