Abstract
A device is described for taking sharp x-ray images of the lungs of crying and restless infants under 3 years of age. Directly before the tube opening of a condenser discharge x-ray machine a lead shutter with a transverse slit-like opening 5mm. wide is mounted to operate like a focal plane shutter. When released electrically from the control panel it falls downward 7cm. after first closing the filament and high voltage primary circuits. The exposure in any given point on the film from the resulting x-ray emission is limited by the lead shutter to between 1/200 and 1/400 of a second determined both theoretically from standard formulas and experimentally.
Test films of infants' chests were made with a full wave rectified unit (0.1 sec. exposure), a condenser discharge unit (0.05 sec. exposure) and a condenser discharge unit with a slit shutter. Details in the former films were often too indistinct for clinical evaluation whereas the details in the latter were considerably better than that obtained by conventional techniques. Improved detail in chest studies and simplicity of operation of the slit shutter should be of value in clinical and experimental medicine.
