Herndon, VA-based Guardian Technologies today completed the second and final closing of a $5.2 million private placement, for which Midtown Partners & Co. acted as the agent. A good chunk of the money will be put toward development of the firm’s threat detection technology for improved airport security, called PinPoint, but Guardian president Bill Donovan said in a statement that the funds also would be used “for continued investment in the development of sophisticated image clarification, tissue characterization and computer-aided detection technologies for medical applications.” The firm’s Signature Mapping CAD technology improves imaging diagnosis and therapy through image clarification, computer-aided visualization, detection and diagnosis, and tissue characterization. Guardian also makes Flow Point, a Web-based system for managing images, radiology workflow and archives.