Application of thermography for non-invasive diagnosis of thyroid gland disease.

Application of thermography for non-invasive diagnosis of thyroid gland disease.
Helmy A1, Holdmann M, Rizkalla M.

Abstract
In this paper, a computer-based prototype device was designed based on an economical noninvasive system that could detect and display the relative skin temperature variations present in human patients suffering from thyroid disorders. Such a system could be used to augment the normal procedures followed by the physician in diagnosing the thyroid to detect areas of hyperactivity within the gland. Because a hyperactive nodule is a center of increased blood flow and chemical activity, it might be also a center of heat production that is detectable by thermal sensing. This paper also presents a finite-element analysis (FEA) of a hot thyroid nodule that is used for investigating the temperature distribution in conjunction with the prototype. The instrumentation model built was based on actual dimensional human model for thyroid nodules obtained from various patients. A software program was written in Visual Basic to detect the temperature distribution around the hot spot. The software also incorporates means to minimize the thermal noise associated with the body temperature. The FEA utilizes the same boundary values used in the practical settings. This includes initial values of temperatures for the hot spot and its surroundings. The results of the finite-element simulation assisted in the selection of the solid state sensors that were used in the instrumentation of the thermographic system. The selected sensors were calibrated for their functionality and dynamic performance according to the specifications. The new noninvasive diagnostic technique was applied to patients having Graves' diseases at the Indiana University (IU) Hospital, and compared with the existing scheme that utilizes I Scan. The results of the new diagnostic method were in good agreement with the current existing method.

Thyroid diagnosis by thermogram sequence analysis.

Thyroid diagnosis by thermogram sequence analysis.
Chan FH, So AT, Kung AW, Lam FK, Yip HC. Source Department of Electrical and Electronic Engineering, University of Hong Kong, Hong Kong.

Abstract
A computerized thermal imaging system for thyroid diagnosis was developed by the authors and it was discovered that the rate of changes of temperature, rather than the absolute values, associated with a sequence of thermograms could help the medical doctors to identify clinical disorders. In order to further enhance the diagnostic capabilities and speed, a new method for medical thermogram analysis has been developed that compresses a sequence of thermograms into one thermogram while retaining the important information such as the geometrical patterns of the objects and the rate of temperature changes of each pixel within the images. As motion artifacts are unavoidable when a patient undergoes minutes of thermogram recording, direct comparison between images is deemed impossible. A high speed image matching algorithm has been developed to provide an absolute geometrical foundation for pixel-to-pixel comparison. The rate of change of temperature of a particular pixel along the sequence is represented by one single parameter after a process of temperature integration which can then be converted into a corresponding gray level for display. The resultant compressed thermogram can give a clear distinction between problem areas and normal ones. Although our emphasis is on thyroid diagnosis, it is anticipated that this new technique can be applicable to other areas of a human body.