Shots - Health News Shots - Health News Health News From NPR

Researchers at the U.S. Geological Survey National Wildlife Health Center in Madison, Wis., use eggs to see if the Asian strain of the H5N1 bird flu virus has entered the U.S. in this photo from 2006. Andy Manis/AP hide caption

itoggle caption Andy Manis/AP

Mosquitoes like this one can carry the virus that causes dengue fever, which may become a bigger problem in some regions as biodiversity is lost. James Gathany/CDC Public Health Image Library hide caption

itoggle caption James Gathany/CDC Public Health Image Library

John Kelly and Dr. Marcia Angell were advocates on opposing sides of a Massachusetts measure to legalize physician-assisted suicide. Jesse Costa/Jesse Costa/WBUR hide caption

itoggle caption Jesse Costa/Jesse Costa/WBUR

Dr. Jame Abraham used positron emission tomography, or PET, scans to understand differences in brain metabolism before and after chemotherapy. Dr. Jame Abraham hide caption

itoggle caption Dr. Jame Abraham

The number of new drug shortages each year in the U.S., from 2001 through Dec. 21, 2012. University of Utah hide caption

itoggle caption University of Utah

Brain scans using Amyvid dye to highlight beta-amyloid plaques in the brain. Clockwise from top left: a cognitively normal subject; an amyloid-positive patient with Alzheimer's disease; a patient with mild cognitive impairment who progressed to dementia during a study; and a patient with mild cognitive impairment. Slide courtesy of the journal Neurology hide caption

itoggle caption Slide courtesy of the journal Neurology

An overweight child reads her part during a skit that was in a 2010 program promoting healthy lifestyles sponsored by Children's Hospital near Denver. John Moore/Getty Images hide caption

itoggle caption John Moore/Getty Images

Doctors used a type of MRI test to look at the blood vessels in the brain of a woman with dystextia. The test confirmed she was suffering from a stroke on the right side of her brain Archives of Neurology hide caption

itoggle caption Archives of Neurology

Doctors use tissue slides like this one of the ovary's outer cortex to confirm a woman's ovarian reserve. It's also the the ovary tissue that's removed in an ovarian transplant. Courtesy of the Infertility Center of St. Louis hide caption

itoggle caption Courtesy of the Infertility Center of St. Louis

According to a study published in Pediatrics, boys are entering puberty six months to two years earlier than they did in past studies. iStockphoto.com hide caption

itoggle caption iStockphoto.com

Kristen Miller, a colonoscopy patient, sits with Dr. Stephen Hanauer at the University of Chicago Medical Center in Chicago in 2010. They're looking at an interactive computer program describing benefits and risks of the procedure. Brian Kersey/AP hide caption

itoggle caption Brian Kersey/AP