1980s    
Alliance Imaging Inc. was founded in 1983 as a shared mobile CT provider.     

Shortly after the introduction of clinical MRI, Alliance Imaging purchased its first mobile MRI system.  Two of the first MRI technologists in clinical practice in the United States were hired to operate the unit in Southern California.  Over the next few years Alliance grew rapidly, expanding its MRI services into Northern California, and then the central and eastern regions of the United States.

1990s
Alliance continued its rapid growth through purchasing additional imaging systems and making a series of thirteen strategic acquisitions.

By the end of 1998, Alliance had acquired 250 mobile MRI systems and serviced clients nationwide.  In December 1998, Alliance became the first national provider of shared imaging services to receive accreditation from the Joint Commission.

In November 1999, an affiliate of Kohlberg, Kravis, Roberts & Company (KKR) acquired a majority ownership of the company.

2001
Alliance made a public offering on the New York Stock Exchange, under the symbol AIQ.

2003
Alliance adopted a new strategic growth plan focused on introducing PET technology and Fixed Site Imaging Centers into their service lines.

2005
Alliance Imaging acquired PET Scans of America and ADC, strengthening the PET, PET/CT and Fixed Site Imaging Center segments of the Company’s business.

Alliance Oncology, a joint venture with the University of Pittsburgh Medical Center, was formed.  Alliance Oncology partners with hospitals to build and operate radiation oncology centers with an emphasis on intensity modulated radiation therapy (IMRT) and image guided radiation therapy (IGRT).  Alliance owns 80% of Alliance Oncology. 

2007
In April 2007, funds managed by Oaktree Capital Management, LLC (Oaktree) and MTS Health Investors, LLC (MTS) purchased a significant interest in Alliance from funds managed by an affiliate of KKR.

Alliance Imaging acquired New England Health Imaging and Bethesda Regional Cancer Treatment Centers. These strengthen the Fixed Site Imaging Center and Radiation Oncology segments of the Company's business. 

Today
Alliance Imaging operates 500 imaging and radiation therapy systems, including 314 MRI systems and 81 PET or PET/CT systems, and serves over 1,000 clients in 44 states.  Alliance operates 88 fixed-site imaging centers and 18 radiation therapy centers and stereotactic radiosurgery facilities.  The company provides MRI, PET, PET/CT, CT and Radiation Therapy services through Fixed Site Imaging Centers and Shared Mobile Services.