Ulrich V. Willi, MD (1939–2026) was a pioneering leader in pediatric radiology, shaping modern diagnostic imaging through his work in Zurich, Boston, Stanford, Johns Hopkins, and at IDKD. He combined outstanding academic achievement with global humanitarian engagement, notably his long-standing support of the Kantha Bopha Children’s Hospitals in Cambodia. A perfectionist teacher, mentor, and department chair, he trained and inspired generations of pediatric radiologists worldwide. Prof. Will has been a teacher for IDKD since 1992 and became the organizer of the pediatrics precourse which he organized till 2010.  Remembered for his deep humanity, love of the arts, and enduring friendships, his legacy continues to live on in the many colleagues, students, and patients whose lives he touched.