How can spatial resolution be improved?

Increasing the source-to-image distance (SID) improves spatial resolution by reducing the penumbra effect. This effect occurs at the edges of the radiographic image due to the divergence of the X-ray beam; as the distance between the X-ray source and the image receptor increases, the beam spreads less and thus sharpens the edges of the structures being imaged. This results in clearer, more defined images, helping radiologists better discern fine details.

Higher SID also influences magnification; as the distance increases, objects appear smaller on the film, allowing for greater accuracy in measuring and interpreting the images. Therefore, increasing the SID is a reliable method to enhance spatial resolution in radiographic imaging.

In contrast, reducing kVp can lead to increased contrast but does not directly improve spatial resolution. Utilizing a larger focal spot would create a broader penumbra, negatively impacting sharpness. Decreasing patient thickness may reduce the amount of scatter and improve overall image quality, but it does not specifically address the factors that would enhance spatial resolution.