Question

When the collimated field must extend past the edge of the body, allowing primary radiation to strike the tabletop, as in a lateral lumbar spine radiograph, what may be done to prevent excessive radiographic density owing to undercutting?

Use lead rubber to absorb tabletop primary radiation

Answer 1

To prevent excessive radiographic density during a lateral lumbar spine radiograph, lead rubber is used to absorb primary radiation that would strike the tabletop. Additionally, fast films and increasing distance from the radiation source also help reduce exposure.

Step-by-step explanation:

When conducting a lateral lumbar spine radiograph where the collimated field extends past the edge of the body, it's crucial to control radiographic density due to undercutting. To prevent excessive radiographic density in these cases, the use of lead rubber or similar shielding materials can absorb the primary radiation that would otherwise strike the tabletop. This is a common radiologic practice that aligns with the principle of ALARA (As Low As Reasonably Achievable), aiming to minimize radiation exposure while achieving the necessary diagnostic quality.

Apart from using lead shielding, it's also essential to consider the principles of time, distance, and shielding to limit radiation exposure. Practices such as using fast films, which reduce the time needed to obtain images, and increasing the distance between the radiation source and the technician can contribute to lower doses of radiation received by both the patient and the medical staff.