Framework for estimating tumour parameters using thermal imaging.

Background & objectives: Non-invasive and non-ionizing medical imaging techniques are safe as these can be repeatedly used on as individual and are applicable across all age groups. Breast thermography is a non-invasive and non-ionizing medical imaging that can be potentially used in breast cancer detection and diagnosis. In this study, we used breast thermography to estimate the tumour contour from the breast skin surface temperature. Methods: We proposed a framework called infrared thermography based image construction (ITBIC) to estimate tumour parameters such as size and depth from cancerous breast skin surface temperature data. Markov Chain Monte Carlo method was used to enhance the accuracy of estimation in order to reflect clearly realistic situation. Results: We validated our method experimentally using Watermelon and Agar models. For the Watermelon experiment error in estimation of size and depth parameters was 1.5 and 3.8 per cent respectively. For the Agar model it was 0 and 8 per cent respectively. Further, thermal breast screening was done on female volunteers and compared it with the magnetic resonance imaging. The results were positive and encouraging. Interpretation & conclusions: ITBIC is computationally fast thermal imaging system and is perhaps affordable. Such a system will be useful for doctors or radiologists for breast cancer diagnosis.

Potassium homeostasis during & after cardiopulmonary bypass.

Potassium homeostasis was studied in 30 patients undergoing cardiac surgery by employing cardiopulmonary bypass (CPB) and moderate hypothermia, and using morphine, N2O, relaxant anaesthesia. There was a trend for hypokalemia, and for maintaining a K+ level of 4-4.5 mmol/l, K+ infusion was required during CPB (9.017 mmol/m2 BSA/h). K+ infusion required in the post-operative period was considerably less (1.532 mmol/m2 BSA/h). There was no significant difference in the K+ levels of patients receiving preoperative diuretic therapy, as compared to those not receiving such therapy. Potassium requirement was significantly higher in patients under-going CABG and valvular heart disease, as compared to congenital heart disease. The mean urinary loss of K+ during bypass was found to be 2.95 mmol/m2 BSA/h, which was only 32 per cent of that required to be infused (9.017 mmol/m2 BSA/h). The mean excretion of K+ in the post operative period was significantly higher (4.53 mmol/m2 BSA/h) than K+ required to be infused during this period (1.532 mmol/m2 BSA/h).