The Parts of a C-Arm Continued
X-Ray Generator
Penetration power is measured in rads and rads, as stated, incur costs. Therefore, the penetration power of your potential C-arm should not exceed that required to achieve its visualization objectives. The X-ray Generator is the C-arm component which puts out radiation, and so its specifications should be of primary concern when exercising corporate governance. Penetration power is integral to the operational capabilities of a C-arm. Furthermore, trends suggest that patients are becoming larger, and larger bodies require greater penetration power to image correctly. In general, facilities focused on the extremities have no need for higher-power generators.
X-ray generators on the market today primarily operate at 20,000 cycles per second with kVp settings from 40kV to 120kV.  During fluoroscopy examinations a tube current of 0.1mA to 6mA is common, while in radiographic mode it’s fixed between 20mA to
60mA. Other radiographic applications can widen this range, anywhere from 0.16 to 160 mA. Exposure lengths can be set anywhere from 0.1 seconds up to 4.
While the costs are there, the benefits from more rads are also evident. Higher peak throughput does allow greater flexibility in imaging, reducing exposure times and the need to re-take long-exposure shots. Flexibility increases the quality of care which can be afforded to pediatric, obese and other specialty-concern patients.
X-ray generators produce illuminating x-rays from a device known as an x-ray tube. There are two types of X-ray tubes; fixed anode and rotating anode. Fixed anode tubes can handle only roughly 1/10th the heat exposure of rotating anode tubes. Rotating anode tubes also offer a 0.3mm focal spot, far tighter than the fixed anode’s 0.5mm fluoroscopic focal spot and 1.8mm radiographic focal spot.