In CBCT imaging, reducing the Field of View will generally have what effect on patient radiation dose?

In CBCT imaging, reducing the Field of View will generally have what effect on patient radiation dose?

• A. Increase dose
• B. Decrease dose
• C. No change
• D. Random dose fluctuations

Answer: (B)

Reducing the Field of View in CBCT confines the x‑ray beam to a smaller region, so fewer tissues are irradiated. Since patient dose is tied to the amount of tissue exposed and energy deposited, a smaller irradiated volume means less total radiation dose to the patient. The dose per voxel in the imaged area is typically similar, but because fewer voxels are irradiated, the overall dose drops. Scatter and out‑of‑field exposure also decrease with a smaller FOV, reinforcing the reduction. So, overall, decreasing the FOV lowers the patient dose.

Reducing the Field of View in CBCT confines the x‑ray beam to a smaller region, so fewer tissues are irradiated. Since patient dose is tied to the amount of tissue exposed and energy deposited, a smaller irradiated volume means less total radiation dose to the patient. The dose per voxel in the imaged area is typically similar, but because fewer voxels are irradiated, the overall dose drops. Scatter and out‑of‑field exposure also decrease with a smaller FOV, reinforcing the reduction. So, overall, decreasing the FOV lowers the patient dose.