Radiologic Technologist Practice Exam

The spatial resolution of a detector is primarily controlled by which factor?

1. Sampling frequency

2. Matrix size

3. Milliampere-seconds (mAs)

4. Analog-to-digital converter (ADC)

The correct answer is: Sampling frequency

The spatial resolution of a detector is primarily influenced by the sampling frequency. Sampling frequency refers to how often the analog signal is measured and converted into a digital format. A higher sampling frequency allows for more data points to be captured within a given spatial area, resulting in finer detail and improved clarity in the image produced. In imaging systems, this is crucial because better spatial resolution ensures that small structures or features within the imaged subject can be visualized clearly, which is essential for accurate diagnosis. If the sampling frequency is too low, it can lead to aliasing or loss of detail in the image, which compromises diagnostic quality. While matrix size can influence resolution, it is closely linked to the sampling frequency; a larger matrix size typically indicates a higher number of pixels, but without an adequate sampling frequency, the additional pixels may not accurately represent the finer details of an image. Consequently, though matrix size has its role in resolution, the core factor that directly controls how well those details are captured is indeed the sampling frequency. Milliampere-seconds (mAs) primarily affects image contrast and radiation dose rather than resolution. The analog-to-digital converter (ADC) is vital for converting the image data from analog to digital but does not control the resolution