Renowned Radiologist Dr. Peter Callen Passes Away at 78

Dr. Peter W. Callen, a prominent figure in the field of radiology and a long-time resident of Mill Valley, California, passed away on December 14, 2025, at the age of 78. His contributions to medicine, particularly in obstetric and gynecologic ultrasound, have left a lasting impact on both his patients and the medical community.

Born on August 8, 1947, Dr. Callen devoted his life to his family and his profession. After receiving his medical degree from the University of California, San Francisco, in 1973, he completed his residency in Diagnostic Radiology and pursued fellowship training at UCSF, where he remained for his entire career.

Throughout his professional journey, Dr. Callen became a respected radiologist, educator, and scholar. His work was pivotal in defining the field of obstetric and gynecologic ultrasound. He focused on enhancing the sonographic detection of abnormalities and minimizing false positive diagnoses, particularly in fetal imaging. Dr. Callen authored over 200 peer-reviewed articles and 65 book chapters, significantly advancing clinical knowledge for generations of healthcare professionals.

His textbook, Ultrasonography in Obstetrics and Gynecology, is widely regarded as a seminal reference and has become one of the most utilized resources in the specialty worldwide. This comprehensive work reflects his dedication to improving clinical practices and education in radiology.

Beyond his academic achievements, Dr. Callen was known for his warm personality and commitment to mentoring others. Colleagues and students cherished his generosity, kindness, and sense of humor. He had a unique ability to make those around him feel at ease, whether during clinical teaching sessions or casual conversations.

Dr. Callen is survived by his loving wife, Karen Callen, and their four children: Melanie, Brooke, Andrew, and Daniel Callen. He also leaves behind his grandchildren, Lula McMullin, Liam Callen, Jackson Callen, and Rory Callen, as well as his older brother, John Callen.

His legacy extends beyond his impressive qualifications and accolades; it resides in the many lives he touched throughout his career. A memorial service will be held in Marin County, California, with specific details to be announced by the family.

In memory of Dr. Callen, his family encourages the planting of living memorials, reflecting his commitment to nurturing others and the environment.