The Role of the Radiography Technician#
Quality radiographic images are critical for accurate diagnosis. The technician is responsible for positioning, technical settings, and radiation safety.
Basic Positioning Standards#
Thoracic Radiography#
- Lateral: Equal distance from sternum to spine, forelimbs pulled forward
- VD/DV: Sternum and spine aligned, symmetrical position
- Inspiration: Have patient take deep breath during exposure
- Collimation: Include rib margins
Abdominal Radiography#
- Include entire abdomen from diaphragm to pelvis end
- Lateral view: limbs pulled forward and back
- VD view: symmetrical position
Technical Parameters#
| Region | kVp Range | mAs Range | Focal Distance |
|---|---|---|---|
| Thorax (cat) | 50-60 | 2-4 | 100 cm |
| Thorax (dog) | 60-80 | 3-6 | 100 cm |
| Abdomen (cat) | 55-65 | 4-8 | 100 cm |
| Abdomen (dog) | 65-85 | 6-12 | 100 cm |
| Extremity | 45-60 | 2-6 | 100 cm |
Technical Settings by Anatomical Region
Technique Selection
Digital radiography has wide exposure latitude, but correct kVp-mAs combination should be used for optimal images.
Radiation Safety#
ALARA Principle
As Low As Reasonably Achievable - Keep radiation exposure at the lowest possible level.
Protective Equipment
Use lead apron, thyroid shield, protective gloves. Never perform manual restraint without entering the X-ray beam path.
Distance and Time
Stay at least 2 meters from the source. Minimize exposure time.
Dosimeter Use
Track your monthly radiation dose. Legal limits: 20 mSv/year (occupational).
Image Quality Optimization#
- Contrast: Controlled by kVp (lower kVp = higher contrast)
- Density: Controlled by mAs (higher mAs = darker image)
- Sharpness: Related to immobility and focal spot size
- Artifact control: Check collar, microchip position
Common Errors#
| Error | Cause | Solution |
|---|---|---|
| Motion blur | Patient movement | Sedation, short exposure time |
| Low contrast | High kVp | Decrease kVp value |
| Too light image | Low mAs | Increase mAs value |
| Clipped anatomy | Wrong collimation | Include entire region |
Professional Tip
Before every exposure, check position, technical settings, and protective equipment. Repeat exposures expose both patient and staff to unnecessary radiation.
