Final answer:
The founding date of the Canadian Society of Diagnostic Medical Sonographers is not provided in the available resources, which cover the history of Canadian nursing and notable medical professionals rather than sonography.
Step-by-step explanation:
The Canadian Society of Diagnostic Medical Sonographers (CSDMS) was established to represent the interests of sonographers in Canada. It aims to advance the profession and ensure high standards of practice. However, information about its formation date is not provided within the question's context and available resources. The provided references discuss historical aspects of Canadian healthcare providers such as nurses and doctors, detailing contributions from nursing sisters in wars and historic medical practitioners in Canada like Dr. Irma LeVasseur and Dr. Mary Lee Edward. These references, unfortunately, do not include information regarding the formation of the Canadian Society of Diagnostic Medical Sonographers.
Individuals interested in the history of Canadian healthcare may find the contributions of these early medical professionals noteworthy. The historical significance of their work is encapsulated in publications such as Canada's Nursing Sisters by Gerald W.L. Nicholson and On All Frontiers: Four Centuries of Canadian Nursing, which provide a deeper understanding of the developments in Canadian healthcare over the years.