Dr.Chang studied for a year at National Taiwan University in the Department of Endocrinology and Metabolism and another one year at UCLA in the United States. He has served as the Director of the Endocrinology and Metabolism Department and the Deputy Director of the Internal Medicine Department at China Medical University Hospital. Dr. Chang's clinical and research interests include the treatment of diabetes and thyroid diseases, particularly the clinical interpretation of thyroid ultrasound for predicting malignant tumors.