What is defined as the detector's ability to respond to different exposure levels?

The correct answer is dynamic range, which refers to the detector's ability to respond to a variety of exposure levels. In mammography and other forms of imaging, dynamic range indicates how well the imaging system can capture and differentiate between a wide spectrum of signal intensities. A detector with a broad dynamic range can produce high-quality images even when the amount of radiation exposure varies significantly. This capability is essential for accurately portraying areas of interest that may have differing densities or compositions, such as in breast tissue where both fatty and dense regions are present.

A system with limited dynamic range might lead to images that either overexpose or underexpose certain areas, obscuring critical details necessary for evaluation. Therefore, a high dynamic range is crucial for ensuring that subtle differences in tissue characteristics are captured and represented in the final image, ultimately aiding in accurate diagnoses.