Improved contrast in special procedures using a rotating aperture wheel (RAW) device.

A new scatter control technology consisting of multiple rotating aperture wheels (RAWs) is being developed to provide improved radiographic contrast and/or reduced patient dose in both single frame and dynamic procedures. The unique geometry of this system allows the conventional source-patient-image receptor geometric relationship to remain unchanged so that the device can be added to existing radiographic, fluoroscopic, and conventional tomographic installations. A prototype RAW device has been used with a rapid film changer for simulated abdominal angiography. The resulting images show improved contrast over those obtained with a standard 12:1 fixed grid.