On today's Please Explain, we'll answer your questions about radiology. Ever wondered how doctors read X-rays? or how MRIs render images of your brain? Leonard talks to Dr. Robert Zimmerman of the Department of Radiology at Weill Medical College, and director of Diagnostic Radiology at New York Presbyterian Hospital. Also, Dr. Jonathan Susman, clinical director of Vascular and Interventional Radiology at New York Presbyterian of the Columbia University Medical Center.