Meet Our Chief Residents
Irvin Calderon, MD
Irvin is a first-generation student who grew up in inland southern California. After having completed his undergraduate degrees in neuroscience and biochemistry at UCLA, he returned home to earn his medical degree from UC Riverside where he met his wife. He completed a surgical internship year at Kaiser Permanente Los Angeles Medical Center (earning "intern of the year") before starting radiology residency at UCLA. When he is not in the reading room or moonlighting, Irvin loves going out dancing with his wife and exploring the multicultural LA food scene, and he commutes regularly to the Inland Empire to be with family. Irvin is honored to serve as Chief Resident alongside Amy, Hiro, Keon, and Kat, and looks forward to supporting his coresidents’ training experience. Following residency, he plans to continue his training with a fellowship in neuroradiology.
Kathryn Champ, MD
Kat was born in New York but was raised as an Angelino in the LA suburb of La Canada Flintridge. She then moved to Baltimore, MD which became her home for nearly 10 years where she completed her undergraduate degree in chemistry at Johns Hopkins University, medical school at University of Maryland, and transitional year at University of Maryland Midtown Campus before deciding she missed the sun and sushi of LA too much. During residency Kat was a leader in our resident union, CIR, representing her colleagues as a member of the contract bargaining team (twice!) and as a national delegate for UCLA (three times!) while also serving as the radiology moonlighting chief for three years. When she's not dictating cases or moonlighting, you can find Kat smashing golf balls at the driving range, doodling in her journal, or trying everything on the menu at a new restaurant somewhere around LA.
After residency, Kat will return to Baltimore as an ER and Trauma Imaging fellow at the R Adams Cowley Shock Trauma Center at the University of Maryland. She is thrilled to work with her dream team of co-chiefs to support her fellow residents' professional and personal growth and help recruit a fantastic group of new UCLA radiology residents.
Keon Mahmoudi, MD
Keon was born and raised in the Atlanta area. He studied Biology at Georgia Tech where he first developed an interest in novel brain tumor treatments and detection. He then moved to New York City to pursue his research interests and stayed to obtain his medical degree at Icahn School of Medicine at Mount Sinai. Drawn to radiology and the great state of California, he matched at UCLA for residency and has enjoyed every moment. In his free time, he can be found running with local run clubs, playing tennis, hiking, catching the sunset, sitting on the 405, and avoiding the pickleball kitchen. Keon is delighted to serve alongside his co-chiefs and looks forward to supporting his peers and enhancing the residency experience. After residency, he plans to pursue a fellowship in neuroradiology.
Hiro Sparks, MD
Hiro grew up in Walnut Creek, California, before heading down the coast to attend the University of California, Santa Barbara, where he enjoyed the perfect mix of academia and ocean waves. He then pursued his medical degree at UCLA, where he was awarded the Dean’s Leadership in Health Science Scholarship, allowing him to spend a year conducting research in neuroelectrophysiology. After medical school, he completed a General Surgery internship at UCLA before continuing his training as an Integrated Interventional Radiology/Diagnostic Radiology (IR/DR) resident at UCLA. His passion lies in developing and mastering innovative procedures that achieve maximum clinical impact with minimal invasiveness.
When he's not in the hospital, Hiro can be found surfing, working out, or finding new ways to challenge himself both mentally and physically. As chief resident, he is committed to enhancing resident education and fostering camaraderie within the program. He looks forward to building a supportive and collaborative environment where residents can thrive both professionally and personally.
Amy Zhang, MD
Amy grew up in the Greater Boston area. She completed her undergraduate studies at MIT, where she majored in Biology and minored in Literature. She subsequently attended medical school at Yale School of Medicine in New Haven. After many years in New England, she was excited to journey west and continue her training at UCLA for radiology residency. Besides appreciating the sunny LA weather, she enjoys reading, baking, and exploring the diverse local food scene in her free time. After residency, she plans to pursue a fellowship in musculoskeletal radiology. Amy is honored to have the opportunity to work with her wonderful co-chiefs to support her fellow residents and their training experience.
