A study of the use of combined thermal and microwave modelling of body regions for microwave thermography
Microwave thermography has been used for the objective assessment of inflammation in the knee joints and wrist and finger joints of patients suffering with rheumatoid arthritis by comparison with similar information obtained from a control group of subjects. Combined microwave and thermal modelling has been used to estimate the effective blood supply to the anterior intra-articular region of the patella, and the perfusion of the quadriceps muscle in both groups. 2-D numerical modelling was compared with results obtained using 1-D modelling. Microwave thermography has also been used for the detection of breast cancer. However, problems such as high false positive detection rates have occurred due to natural cyclical breast temperature changes. The thermal behaviour of the normal breast throughout the menstrual cycle has been investigated and it is shown that microwave thermography is capable of detecting temperature variations in the female breast corresponding to the ovulatory and luteal phase of the menstrual cycle. Combined microwave and thermal modelling estimated the effective perfusion of the normal breast to be in the range 0.2 - ˜ 2 kg m-3s-1. This is consistent with previous work. Microwave thermography is a quick, simple technique which clinicians can easily use. It is non-invasive, passive and causes the patient no distress. By using combined microwave and thermal modelling it is possible to estimate tissue blood perfusions and water contents and compare them with expected values. The technique has many potential applications and will hopefully find a secure niche in clinical medicine.