Evaluation of Dynamic Thermograms Using Semiautomatic Segmentation Software: Applied to the Diagnosis of Thyroid Cancer

Infrared thermography is an imaging technique applied in studies to aid in the diagnosis of several types of cancer, including thyroid cancer. Tumors generate changes (anatomical and vascular) that are shown in thermal images. This paper shows the creation of semiautomatic segmentation software to assist in the diagnosis of tumors in dynamic thermograms. For the beginning of the analysis, the software allows the creation of a project using the text files exported by the camera and interpreting them as a temperature matrix. Then, it allows to change the scale of the displayed image and choose the color palette used in the temperature conversion for color. The FloodFill algorithm delimits the regions of interest (area with tumor and healthy) when the user positions the cursor (seed expansion) on the tumor, and defines the threshold of difference. The extraction of data in the segmented region provides: the temperatures (maximum, minimum and average); the number of pixels involved in the segmentation area; allows the export of the data in a .cvs file (compatible with other programs, such as excel); and provides a graph with the thermal difference between the two areas analyzed (healthy and with tumor). The application of the software has been demonstrated in two thyroid tumors, one malignant and one benign. In the malignant one, it is possible to observe higher temperatures in the tumors compared to the healthy regions during the rewarming period after cold stress, different thermal behavior between benign and malignant tumors, as well as a larger number of pixels in the segmented area of the malignant tumor, when compared to benign. It is expected that the information extracted from each tumor (and surrounding healthy areas) can be useful for the clinical diagnosis in the correct indication of biopsies considering that the thermographic image contains information that goes beyond a simple temperature measurement.