Imaging center operator Akumin Inc. has announced the departure of Chief Executive Officer Rhonda Longmore-Grund effective March 18.

The publicly traded radiology firm closed its $820 million purchase of Akumin Healthcare Services in September. Following the deal, the combined company had operated under a co-CEO arrangement, with Akumin leader Riadh Zine and Alliance chief Longmore-Grund sharing the role. However, its board of directors has decided to end the power-sharing agreement, with Zine remaining in the role following her departure.

“On behalf of the board of directors of Akumin, I would like to thank Rhonda for her dedication and contributions to date,” he said in a statement issued late Friday. “Rhonda successfully assisted us through a period of transition following our acquisition of Alliance, which has secured Akumin’s position as one of the most comprehensive radiology and oncology solutions providers in the United States. We wish her the very best in her next endeavors.”

The decision comes after Akumin recently announced its first quarterly earnings results as a combined company. Zine and colleagues said they saw strong same-store performance, including increases in MRI (6%), PET/CT (4%), and total radiology procedures (3%). Altogether, Akumin reported $179.4 million in revenue for Q4 of 2021, up 168% compared to the same period the previous year without Alliance Healthcare’s contributions. Adjusted earnings were more than $27.5 million in the fourth quarter, a nearly 104% uptick over the previous year, the company said March 16.

Based in Plantation, Florida, Akumin owns or operates more than 200 outpatient imaging locations.