• Willard Hennemann, PhD, has been named VP of new product and business development at BioSphere Medical (Rockland, Massachusetts). Hennemann previously was VP of R&D/Interventional Vascular at CryoCath Technologies. BioSphere uses bioengineered microspheres to treat uterine fibroids, hypervascularized tumors, and vascular malformations by a minimally invasive, image-guided medical procedure called embolotherapy.

• DaVita (El Segundo, California) said that Richard Whitney has rejoined the company and will be appointed CFO, effective March, 1. Whitney will work with DaVita in a part-time role for one to two years. Currently, Whitney is founder and managing member of Whitney Capital. DaVita is a provider of kidney care.

• Mobile Imaging Development (Las Vegas) said that its limited partnership, Mobile Diagnostic Centers, has named John Nichols, MD, medical director. The company said that Nichols is a “recognized expert in radiology with over 25 years of experience.” Mobile Imaging is a healthcare management company.

• NightHawk Radiology Holdings (Coeur D’ Alene, Idaho) said that Tim Mayleben, NightHawk’s president/COO, will be leaving the company for personal reasons. Mayleben will remain with NightHawkthrough the end of February and is expected to resign from the board of directors as well. Jon Berger will serve as interim COO. The company also reported that senior VP and CFO Glenn Cole will be stepping down, most likely sometime in the second quarter. Cole will remain until a new CFO is named and through a transition period. NightHawk is a provider of radiology services.