The purpose of this study is to compare the yield of two methods for obtaining a lung tissue sample: Procedure #1: standard fiberoptic bronchoscopy (FB) with fluoroscopy, and Procedure #2: ultrathin bronchoscope procedure with fluoroscopy and radial endobronchial ultrasound (R-EBUS). These two procedures are similar in that they both: (1) enable your doctor to look inside your lungs with a device called a bronchoscope, and (2) Use fluoroscopy, which is a technique that uses X-rays to see your lungs.