A hand-held scanner, reminiscent of the fictional Star Trek medical Tricorder, images blood vessels through the skin and projects a map onto the skin showing nurses exactly where to insert a needle. A pocket-sized device checks blood sugar levels through the skin of people with diabetes — no pinprick or blood sample needed. Those innovations are among a new genre of medical imaging technology that's giving doctors and scientists noninvasive views into the body to diagnose and study diseases. A report on the topic appears in the current edition of Chemical & Engineering News (C&EN), the weekly newsmagazine of the American Chemical Society, the world’s largest scientific society.