Motion
Think about the times you've taken a picture with your camera and it turned out blurry. Now think about what you did, or would have done if you would have retaken the picture. Read page 43 of your textbook. What you need to know is summarized below.
There are 2 types of motion:
- Voluntary motion is any motion that can be controlled by the patient. This includes voluntary movement of body parts and breathing.
- Involuntary motion is any motion that cannot be controlled by the patient. This includes such things as tremors, your heartbeat, and peristalsis (movement of your intestines).
There are ways to deal with both types of motion:
- Proper patient instruction - reminding the patient not to move and to hold their breaths for certain exams can go a long way towards controlling motion.
- Immobilization - if the patient is unable to cooperate, there are immobilization devices out there that can be used to help.
- High mA and low timer settings - (100 mA @ 1.0 sec = 100 mAs) and (1000 mA @ 0.1 sec = 100 mAs). Both of these technique settings will produce the exact same number of x-rays, meaning they will be equivalent in radiographic density. The second exposure, however, has a much shorter exposure time. The result will be MUCH less chance of motion. As we go through Anatomy and Positioning, you will see certain exams, such as the chest x-ray, using this concept.