Terahertz pulsed imaging and spectroscopy of breast tumors

We have developed a portable terahertz pulsed imaging system (TPI Imaga1000) for use in a clinical environment. The system uses photoconduction to generate and detect terahertz radiation with frequency content from 0.1-4 THz. Here, we report on a study using TPI for imaging breast tumours ex vivo. Several breast samples were imaged and parameters from the time domain impulse functions were used to provide contrast. The size and shape of tumour regions in the terahertz images were compared with the corresponding histology section. Good correlation was found for area and shape of rumour in the THz images compared to that of histology. In addition, we have also performed spectroscopy study comparing the terahertz properties (absorption coefficient and refractive index) of excised normal breast skin and breast tumor. Both the absorption coefficient and refractive index were higher for tissue containing tumor compared to normal. These changes are consistent with higher water content and structural changes, like increased cell and protein density. This study demonstrates the potential of TPI to image both invasive breast carcinomas and ductal carcinoma in situ using THz and encourages further studies.