Avid Radiopharmaceuticals, a Philadelphia-based maker of “molecular imaging agents” that help highlight diseased tissue in various medical scans, raised $26 million in a third round to develop early-detection products for Alzheimer’s and Parkinson’s disease.

AllianceBernstein and Safeguard Scientifics led the round. Previous investors including Pfizer Strategic Investments Group, the venture arm of Pfizer; Lilly Ventures, the venture arm of Eli Lilly; RK Venture Group; and BioAdvance also joined the round.

Avid’s development efforts are focused on new imaging agents for neurological problems. It recently announced initial positive results for AV-1, its lead compound for imaging the clumps of beta-amyloid protein that are often characteristic of Alzheimer’s disease.

The company’s release on the funding is here.