Abstract: A method of investigating a sample (breast tissue) (27), the sample comprising at least a first material (normal breast tissue) in order to determine they presence of at least one further material (cancerous tissue), the method comprising the steps of: Irradiating the sample with electromagnetic radiation in the range from 25 GHz to 100 THz; Detecting radiation reflected from the sample; Determining a parameter related to the amplitude of the radiation, which is reflected from the sample, in the time domain; Analysing the parameter derived in step (c) in order to determine if the sample further comprises the at least one further material wherein the irradiating and reflected radiation passes through a (z-cut quartz) window member (43) having a refractive index that falls between the refractive indices of the at least first and at least one further materials

Abstract: A method of imaging a sample, the method comprising: (a) irradiating a sample with a pulse of electromagnetic radiation, said pulse having a plurality of frequencies in the range from 25 GHz to 100 THz; (b) determining a first parameter related to the amplitude of the radiation, which is either reflected from and/or transmitted by the sample, in the time domain; (c) calculating the value of the first parameter at a first time value relative to the value of the first parameter at a second time value which coincides with a physical feature of the dataset of the first parameter with respect to time; and (d) generating an image by plotting the value calculated in step (c) for different points of the sample.