Which exposure factor is most likely to increase image density without altering subject contrast?

Increasing kilovoltage is the most effective way to enhance image density without significantly affecting subject contrast. When kilovoltage is increased, the energy of the X-ray photons is also increased, allowing for more photons to penetrate the subject and reach the image receptor. This results in a darker image, or greater density.

Importantly, while increasing kilovoltage increases the overall exposure and can lead to increased density, it does so without altering the inherent contrast between different tissues. High kilovoltage results in a wider penetration of X-rays, which allows for a more uniform exposure across tissues with various densities, thus maintaining the contrast of different structures.

Other factors may impact density but could also affect contrast. For example, while increasing tube current would increase the number of photons produced, it could alter the levels of contrast if the exposure is not optimally balanced. Lengthening exposure time can increase density but may also introduce the risk of motion blur, potentially altering perceived image quality. Decreasing the field of view (FOV) concentrates exposure on a smaller area, which might not consistently enhance density uniformly and can affect contrast based on what is in the smaller view.

Therefore, increasing kilovoltage stands out as the option that enhances density while preserving subject contrast effectively