text: An<unk>  <unk> , sometimes called a C-Arm, refers to a special<unk><unk>  device used in medical<unk> ng involving x rays.  It consists of an input window, input phosphor, photocathode, vacuum and electron optics, output phosphor and output window.  It allows for lower x-ray doses to be used on patients by magnifying the intensity produced in the output<unk> , enabling the viewer to easily see the structure of the object being<unk> d.  They were introduced by Philips in 1955.
option_0: X-ray image intensifier
option_1: Chest x ray template
option_2: Farmer's lung physical examination
option_3: Cough physical examination
option_4: Altitude sickness x-ray
option_5: Burn physical examination
option_6: Echocardiography or ultrasound template
option_7: French catheter scale