Special talk 2: Microwave based systems for imaging tissue

The talk will present a novel system which employs an alternate approach to imaging tissues. Conventional tomographic reconstruction systems (catscan) have traditionally employed x-rays to obtain 3D images of tissues. The use of x-rays assures excellent resolution and penetration characteristics. The disadvantages of using x-rays include the ionizing nature of the radiation employed for imaging as well the relatively low contrast obtained between healthy and cancerous tissue. A number of studies carried over the past several years have shown that the significant differences in the electrical properties associated with certain types of malignant tumors and normal tissue can be exploited as a basis for imaging tissue. The differences in electrical properties can also be utilized to selectively focus microwaves on the malignant tissue to raise its temperature as part of a hyperthermia treatment protocol, or possibly even to induce necrosis of the tissue. Most tomographic reconstruction systems also involve measurement of a series of projections obtained by rotating a source-detector pair around the patient. This requires the patient to be confined inside a tube during the scanning process. Confinement within a tube can sometimes be a challenge when the patient is too young or is claustrophobic. This talk will present a novel system which avoids the use of the traditional rotational scanning scheme and utilizes, instead, a set of electronically programmable mirrors to deflect microwaves. Microwaves deflected by the mirrors and scattered by the tissue are measured and processed to obtain a 3D image reconstruction of the tissue. The same system can be employed to as a therapy tool where the mirrors can be programmed to focus microwaves on the cancerous tissue to elevate it temperature. The talk will describe the system integration issues associated with a prototype system that is being built to validate the concept.