athenahealth, Inc., the premier provider of revenue cycle optimization services for medical practices, today announced that Horizon Medical Group, a group of nationwide state-of-the-art open MRI clinics, has selected athenahealth at its Web-based revenue cycle management services partner. athenahealth offers comprehensive workflow technology, central billing and reimbursement services. athenahealth’s services provide clinicians and their staff with a solution that puts procedure and insurance information at their fingertips, while the patient is still in the office.