What impact does increasing the focal spot size have on spatial resolution?

Increasing the focal spot size decreases spatial resolution. Spatial resolution refers to the ability to distinguish small details in an image, often described as the sharpness or clarity of the image. A smaller focal spot size produces a finer beam of radiation, which allows for better detail and sharper images. This is because a smaller beam can more precisely delineate the edges of structures being imaged.

When the focal spot size is larger, the x-ray beam becomes less focused, leading to a blurring effect. This blurring results in a loss of detail in the image, making it harder to differentiate between closely situated structures. Thus, for optimal spatial resolution, it is preferable to utilize a smaller focal spot size to achieve clearer and more distinct images.