Final answer:
In the context of imaging, if collimation borders can't be detected, the most likely consequence is an image that's too dark due to overexposure. Collimation helps to reduce unnecessary exposure and improve image quality by limiting the radiation received by the detector.
Step-by-step explanation:
If the collimation borders cannot be detected, the exposure indicator number would likely indicate that the image is too light or too dark, which could misrepresent dose exposure. When selecting among the provided outcomes, the consequence in this specific scenario would most closely align with the image being too dark, which means there's excessive exposure. Without proper collimation, the detector receives radiation from a larger area than intended, which could increase the exposure to the detector and thus lead to a darker image. The other options, such as the image being distorted or lacking spatial resolution, are possible results of other types of errors in imaging techniques. For example, chromatic aberration may cause distortion, and poor spatial resolution is characteristic of certain imaging modalities, like SPECT, which has a spatial resolution around 1 cm.