Medical Physics remembers ultrasound phantom pioneer, Ernest L. Madsen, PhD

Ernest L. Madsen, PhD

Ernest L. Madsen, emeritus professor of medical physics at the University of Wisconsin–Madison, died on Aug. 24, 2024. He was 87.

Madsen was born in Sparta, Wisconsin in 1936. He arrived at the University of Wisconsin–Madison in 1976 in a postdoctoral role after receiving a PhD in Physics from the Catholic University of America in Washington DC in 1968. Before coming to Madison he taught physics at the University of Wisconsin River Falls and at Pembroke State University. He would quickly become a pioneer in the development of ultrasound imaging phantoms and in quantitative ultrasound research.

A breast-mimicking phantom for testing a whole-breast imaging system.

At that time, diagnostic ultrasound practitioners were looking for a way to better assess the capabilities of ultrasound devices. The standard tool included stainless steel rods immersed in a water-alcohol mixture that lacked speckle-generating properties. They were looking for an option that would more closely mimic biological tissue.

Madsen and colleagues began exploring water-based gels suspending tiny particles that contributed to ultrasound scattering and attenuation. The goal was to discover materials with sound speed and attenuation coefficients that mimic soft tissues. Their breakthrough work was published in the September 1978 edition of Medical Physics. And the use of graphite-in-gel materials was patented by the Wisconsin Alumni Research Foundation in 1981. Many manufacturers of test tools used by clinical physicists and engineers for routine assessments of ultrasound scanners incorporate the concepts and methods described in these documents in their commercial phantoms. This research then led to the development of the first anthropomorphic breast phantom in 1982.

Through the years, Ernie and close colleague Gary Frank continued and expanded their phantom designs, creating a phantom lab that would become a worldwide reference for ultrasound phantom research and would provide the ultrasound industry, clinical, and academic communities with phantoms for decades to come. Madsen became known as the “go-to” person for custom phantoms and created many one-of-a-kind items over his career.

Madsen (left) and Frank (right) working on an early breast phantom – 1979

Madsen’s accomplishments include 15 patents primarily related to phantom development, and over 150 scientific papers. He led many ultrasound physics students who were developing methods for rigorous analysis of data derived from ultrasound instruments. This work has also contributed to ongoing efforts to incorporate advanced data processing apps on clinical ultrasound machines. Ernie was elected Fellow of the American Institute of Ultrasound in Medicine in 1988, and Fellow of the American Association of Physicists in Medicine in 2001. He also was honored to receive AIUM’s Joseph Holmes Pioneer Award in 2007.

“Ernie was the most intelligent, hardworking and creative person I’ve ever met and I was lucky enough to witness this daily for 37 years,” says close colleague and friend Gary Frank. “I always told others he was an idea machine. He was a father figure to me whether he knew it or not. His advice helped shape my life in many ways and I will always be grateful. He will be missed!”

Funeral services for Dr. Madsen will be held at Covenant Presbyterian Church on Saturday, September 14 at 4 p.m. with visitation beginning at 3 p.m.