Tehran University of Medical Sciences Frontiers in Biomedical Technologies 2345-5837 13 1 2026 01 20 255 265 Masoumeh Mohamadian Energy Engineering and Physics Department of Amirkabir University pf Technology Masoumeh Hosseini Energy Engineering and Physics Department, Amirkabir University of Technology, Tehran, Iran 2023 12 31 2024 03 02 Background: Terahertz (THz) imaging has emerged as a promising technique for non-destructive evaluation and imaging applications, offering unique advantages over traditional imaging modalities. This paper presents an overview of the current state of Terahertz Computed Tomography (THz-CT) and highlights the challenges faced in its implementation. Objective: THz-CT utilizes electromagnetic waves in the terahertz frequency range to reconstruct three-dimensional images of objects with high resolution and penetration capabilities. The ability to visualize internal structures without the use of ionizing radiation has significant implications for various fields, including medicine, security, and material science. Materials and Methods: Despite its potential, THz-CT faces several challenges that need to be addressed for its widespread adoption. Firstly, the limited availability and complexity of THz sources and detectors hinder the practical implementation of THz-CT systems. Efforts are being made to develop compact, efficient, and cost-effective THz sources and detectors to overcome these limitations. Secondly, THz waves are highly susceptible to scattering and absorption by various materials, including water and certain organic compounds. This poses challenges in achieving accurate and artifact-free reconstructions, especially in applications involving biological samples. Researchers are exploring advanced signal processing techniques and novel imaging algorithms to mitigate these effects and enhance image quality. Results: Furthermore, the relatively long acquisition times required for THz-CT imaging limit its real-time applications. Efforts are underway to develop faster acquisition methods, such as multi-view imaging and compressed sensing, to reduce acquisition times while maintaining image quality. Lastly, the lack of standardized protocols and benchmarks for THz-CT imaging hinders the comparison and reproducibility of results across different systems and studies. Establishing common evaluation metrics and guidelines will facilitate the development and validation of THz-CT techniques. Also, in addition to its various applications, terahertz medical imaging and medical microbiological detection plays a significant role in the diagnosis of several types of cancers, including skin, oral, breast, and colon cancers. One of the key advantages of terahertz radiation is its exceptional sensitivity to water content, enabling the creation of high-contrast images that effectively differentiate between normal and cancerous tissues. This capability proves instrumental in accurately identifying and assessing the presence of cancer in affected areas. Conclusion: In conclusion, Terahertz Computed Tomography holds great promise for various imaging applications, but several challenges need to be overcome for its widespread adoption. Addressing the limitations associated with THz sources, scattering and absorption effects, acquisition times, and standardization will pave the way for the realization of the full potential of THz-CT in the future. https://fbt.tums.ac.ir/index.php/fbt/article/view/915 https://fbt.tums.ac.ir/index.php/fbt/article/download/915/550