Which statement about the effect of the filter cut-off frequency is true?

The statement that the lower the cutoff frequency, the smoother the image, is true because the cutoff frequency in image processing, such as in nuclear medicine and other imaging modalities, regulates how much detail and noise is retained in an image. A lower cutoff frequency allows fewer high-frequency components (which often correspond to noise and fine details) to pass through the filter, effectively smoothing the image. This results in a more uniform appearance with less graininess or visual clutter, which can be particularly useful when assessing structures where detail is less important compared to overall clarity.

In contrast, higher cutoff frequencies permit more high-frequency information to remain, which can enhance detail but may also increase image noise. Thus, lower cutoff frequencies contribute to a smoother visual representation of the underlying anatomy or pathology. Understanding this relationship is crucial for radiologists and nuclear medicine professionals when interpreting images or making adjustments for optimal image quality.