Effect of SID on patient dose
Changing the distance of the X-ray tube to the patient affects the dose applied
to the patient.
For example doubling the distance reduces the dose by a factor of 4. The new
dose can be calculated by a formula:
new mAs = known mAs × ( new distance
2
/ old distance
2
)
The distance of the X-ray tube to the patient cannot be less than 30 cm.
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| DR 100s | Introduction
0411D EN 20220627 1040
