Donald B. Twieg, Ph.D.

Donald B. Twieg, Ph.D. (December 8, 1944 – April 28, 2025)

Those who knew Don were deeply saddened to hear of his passing in Denver, Colorado, on April 28, 2025, following a brief illness.

Dr. Twieg received his undergraduate training in physics from Rice University and his Ph.D. degree from a joint Southern Methodist University – University of Texas Southwestern Medical School graduate program in biomedical engineering. Following a brief employment with Boeing in Huntsville, Alabama, Dr. Twieg completed his Ph.D. degree and joined the Department of Radiology at the University of Texas Medical School in Dallas. His initial research in the early days of nuclear medicine resulted in a number of publications in that field. He made contributions in cardiovascular nuclear medicine that included diagnostic tests for several cardiac functions.

In the early 1980s, Dr. Twieg became involved in MRI at UT Southwestern in the days when the term, “NMR imaging” was still used. In 1983 he published a paper on fundamental work he was doing on characterizing and analyzing the signal and image formation process involved in MR imaging. His insight led to his founding paper in 1983 revealing an innovation that he coined, “the k-trajectory formulation of the NMR imaging process,” an analytical approach for characterizing and synthesizing the MR imaging method. This breakthrough in developing a mathematical approach to MR image creation and analysis was quickly adopted by the MRI community. It led to Dr. Twieg sometimes being referred to as “Mr. k-space.”

Dr. Twieg’s career path eventually took him to the Phillips Research Laboratory in Germany where he spent a year before joining the medical imaging group at the University of San Francisco. In 1990 he joined the imaging group at the Center for Nuclear Imaging Research (CNIR) at the University of Alabama at Birmingham (UAB) where one of the first high-field (4.1T) whole-body imaging systems was located. At UAB Dr. Twieg was a friend and close colleague to many in the CNIR and the UAB School of Engineering. He authored a number of publications while at UAB and was co-author on the papers of many others. He also mentored 19 M.S. and Ph.D. students. At both the San Francisco Veterans Administration and the University of Alabama at Birmingham, Dr. Twieg was responsible for inspiring and training a generation of investigators who continued his groundbreaking work in spectroscopic imaging and popularized its use in the human brain.

While still working, Dr. Twieg often spoke wistfully of his visits as a boy to Colorado with his father and grandfather. Following his retirement from UAB, he and his wife, Kathy, moved to Evergreen, Colorado. He achieved his goal of returning there in his retirement. Don Twieg will be missed by his wife Kathy, his son Danny, daughter Elizabeth, and many colleagues and friends.

Ernest Stokely, Ph.D.