top of page
Artboard 1 copy@4x-8.png
Picture Dr. R. cover 2009.jpg


Co-Founder & Senior Orthopedic Radiologist

Dr. Rosengarten was fellowship trained in MSK/Orthopedic Radiology and his passion in this practice segment is evident. During his first 15 years in academic practice, he won several awards for resident education, published multiple papers, and was the primary investigator or sub-investigator for over 50 research projects. He mentored over 50 residents, fellows and medical students. For 35 years he has had numerous academic appointments including at Northwestern University, The University of Illinois, and The Chicago Medical School at Rosalind Franklin University.

Dr. Rosengarten formed three independent radiology practices, built over 20 imaging centers, and co-founded or helped build several medical companies over the last 2 decades. As an entrepreneur, he participated in multiple projects on behalf of academic and community hospitals as well as his own and other radiology groups.

Dr. Rosengarten feels strongly about 2 practices that have helped ensure success throughout his business career: 1) Empowering coworkers at all levels so they feel as though they have control over their work lives; 2) Building a culture that encourages enjoyment at work.

All three of Dr. Rosengarten’s children have followed his footsteps into medicine and radiology, in particular based on the passion that they observed their father maintain through both good times and challenging situations. Dr. Rosengarten feels that support he has received from the people that he loves—family and friends—is most responsible for his personal success.

He loves world travel, meeting and learning from all people, experiencing new and varied cultures, and feels that lifelong learning is vital.

“I never thought that I would be saying that I have been practicing radiology for 35 years. I am still passionate about the same things 35 years later: patient centered care, with the highest quality, best service, and the lowest possible cost. That’s it! That equals the best value for the patient!”

Michael Timins 2015.jpg


Director of Orthopedic Radiology

Dr. Timins has practiced Musculoskeletal Radiology for 30 years after completing his residency at Northwestern University where he was chief resident. Dr. Timins completed his fellowship at the Medical College of Wisconsin (MCW) and attained a master’s degree at the University of Chicago. Before his tenure at Diaspora Radiology, Dr. Timins was an academic radiologist at MCW where he won multiple teaching awards. Dr. Timins has written and published many articles in peer-reviewed journals. He is known for his personable manner, his gratitude and friendliness in caring for the patients and the clinicians that treat them, and the dedicated care with which he interprets each and every imaging study that he reads.

Kalmar- uncropped web-490x248.jpg


Director or Body Imaging and Oncologic Imaging

Dr. Kalmar has over 20 years’ experience in all aspects of radiology, with a strong interest and subspecialty fellowship training in body imaging and musculoskeletal imaging.  Dr. Kalmar approaches every imaging case as if it were his mother’s and treats every referring physician as if they were a sibling, providing very thorough, thoughtful, and well-researched interpretations that aid in narrowing the differential of sometimes tricky diagnoses. 

Numerous daily phone consultations with referring physicians have made Dr. Kalmar’s career a more palpable and personally satisfying experience which is not often the case for a radiologist who sits in front of a computer monitor all day.  Whether he is interpreting the cases of thousands of NFL, NBA, MLB, PGA, Big Ten and Olympic athletes or injecting pain-relieving steroids into the hip of a 90-year-old woman, every one of Dr. Kalmar’s patients is seen and treated with equal optics and provided with the highest quality diagnostic interpretations and treatment.

WKM photo 3-2021.jpg


Director of Neuroradiology

Dr. Manness has practiced Neuroradiology exclusively for over 20 years. He is fellowship-trained and has extensive experience and expertise interpreting exams of the head, neck, and spine. He eagerly embraces new and innovative imaging techniques and equipment, such as 3T MRI. Dr. Manness enjoys professional collaboration with specialists to help them with their patients' diagnoses and treatments. His emphasis on patient care, accurate interpretation of exams, and high-quality service has made him a reliable source for clinician consults, especially for their most challenging neurological cases. In his time off, Dr. Manness enjoys spending time with his wife and 3 boys, coaching youth sports, travelling, and playing tennis.

Zach Rosen.jpg


Resident & Fellow Liaison

Dr. Zach Rosengarten is a board-certified musculoskeletal radiologist, having completed his Orthopedic/ MSK fellowship training at UC- Irvine/ Long Beach VA Hospital in 2022 and his Diagnostic Radiology residency training at Lenox Hill Hospital in New York City in 2021.  Zach's MD was granted from the Chicago Medical School, after undergraduate study at the University of Wisconsin. 


Zach has spent the last 10 years building friendships and teams to navigate the various requirements of medical training, passing exams, and learning the intricacies of the medical profession. During this time, he met the love of his life, Dr. Hannah Ahmed, and enjoyed invaluable family support. Zach's passion is to provide the highest quality and most affordable radiology services.


Zach is especially curious about the business and investing world. He is excited to help drive the creation of Smart Scan Medical Imaging with the goals of helping to control the cost of healthcare, at a time when medical costs are getting out of hand. Zach has dabbled in investing in early start-up companies, in areas such as healthcare, tech, and software. Zach has also examined the philosophy of money via an investment in bitcoin. To relax, Zach likes to yell at his favorite sports teams through the TV, mainly the Packers and Badgers.



Community Pediatrician & Medical Advisor

Hannah Ahmed is a community pediatrician who completed her training at Weill Cornell Medical Center/ New York Presbyterian in New York City. She attended college at the University of California- Los Angeles, where she received her bachelor’s in Anthropology, and worked to produce one of the largest music festivals in the city. While backpacking abroad after graduating, she discovered her love for teaching, which she did both internationally and locally in Oakland, CA.


This diverse passion for working at the crossroads of education, public health and medicine led her to apply to medical school. She was granted her MD at Chicago Medical School, where she met her love and life partner, Dr. Zach Rosengarten. 


Hannah continues to be inspired by her love of travel, music, art, and the power of aesthetics. Hannah makes it her life goal to improve health outcomes of the patients she serves, in particular through optimizing wellness and reducing disparities. 

Maria photo.jpg

Maria Corona

Senior Director

Maria Corona has 17 years experience in Healthcare Operations roles.  She began her career in the field as a front desk staff member while completing her degree in Economics at DePaul University. While working at GRC, LLC (a successful group of freestanding imaging centers), Northwestern Memorial Hospital (North Market), and Smart Scan MRI (a prior startup imaging center), she's held the position of Vice President of Operations, Manager of Imaging Satellites, and Executive Director.  At Diaspora Radiology Maria has assumed the role of Practice Manager and Administrative Director.  

bottom of page