When taking X-rays using an XDR sensor, the exposure meter (located at the bottom left of the XDR Exam screen) is your primary guide to proper exposure. For each X-ray, the meter must register within the green "GOOD" zone.
Before every exposure, adjust the exposure time on your X-ray machine. This crucial step ensures the meter reads "GOOD" and accounts for variations in:
- Area of interest: Different anatomical structures require varying exposure levels.
- Patient size: Larger patients necessitate higher exposures.
- Sensor type: Ensure compatibility between the sensor and exposure settings.
Always adhere to the ALARA principle (As Low As Reasonably Achievable). Using a single, fixed exposure time is not only unsafe for the patient due to potential overexposure but also leads to inconsistent image quality. Furthermore, underexposure can result in the need for retakes, increasing the overall radiation dose.
How to use the exposure meter:
The meter provides feedback on the previous exposure, indicating whether it was LOW, GOOD, or HIGH. This feedback loop helps you maintain ALARA and achieve diagnostically acceptable radiographs.
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Underexposure
“Grainy”, light images with poor contrast can be a sign of insufficient exposure relative to the anatomy being radiographed. |
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Proper Exposure
Clear, well-defined images with good contrast are a sign of proper exposure relative to anatomic density. |
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Overexposure
Dark images that appear “burned out” can result from excessive exposure relative to the area of anatomy being radiographed.
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Key takeaway: The black line on the exposure meter should always be within the green "GOOD" zone.
Important Note for Portable Units: Portable handheld X-ray units may exhibit lower meter readings compared to wall-mounted units. If you're using a portable unit, please contact XDR for specific instructions and calibration guidance.