Portable X-ray Unit Guidelines
Portable X-ray Unit & XDR Sensors: Image Optimization Guidelines
Understanding Exposure Adjustments
Most Portable units, depending on the specific model being used, have an anode current of 1.7mA to 3mA. This value is very low compared to traditional wall-mounted x-ray units, which is anywhere from 6mA to 10mA. Because of the lower amount of electrons (Radiation) emanating from the portable unit, we as operators must “help” this exposure reach the sensor. This is one reason why you must be as close as possible to the patients face when taking radiographs. Given that the default exposure times on the portable units tend to be insufficient for many CMOS sensors, it is necessary to use exposure settings that are higher than the digital presets to achieve optimal image quality.
Portable Handheld Exposure Ranges with XDR Sensors
Portable Units 60-70 kVp and 1.7-3 mA
| Exposure Time (seconds) | ||
| Anatomic Area | Adult | Child |
| Anterior PA | 0.38s-0.40s | 0.17s-0.22s |
| Bitewing BW | 0.40s-0.45s | 0.22s-0.28s |
| Posterior PA | 0.45s-0.50s | 0.28s-0.30s |
Technical Guidance
Positioning X-ray Unit: To ensure adequate exposure reaches the sensor during capture, position the X-ray unit as near to the patient's face as practically possible.
Any distance between the cone and the sensor can introduce inconsistencies. Therefore, the cone should always be positioned as close as possible to the patient's face.
Holder Recommendations: Navigating positioning challenges with portable X-ray units due to shield and holder rods can be addressed in a few ways. Consider acquiring shorter aiming rods, modify your existing XDR aiming rods, or opting for a holder design that doesn't include a ring.
Stability: Keep the portable unit stable during the exposure. Any movement can result in blurred images.
Exposure Process: Maintain firm pressure on the trigger throughout the entire exposure duration. Releasing the trigger prematurely will interrupt the X-ray emission, likely resulting in an underexposed and non-diagnostic image.
Battery Check: Ensure the unit has sufficient battery charge to complete the necessary exposure without interruption. Low battery can lead to inconsistent image quality.
Following these guidelines, along with XDR's exposure recommendations, will enable you to consistently capture high-quality images with your portable X-ray unit and XDR sensors.