What is the typical size of the detector in a narrow fan beam system?

In a narrow fan beam system, the typical size of the detector is about 4 cm. This measurement is significant because it relates directly to the overall design and function of the imaging system. A 4 cm detector is effectively sized to capture the output from the narrow fan beam, which is generally used in high-resolution bone density examinations. This size allows for optimal imaging of the target area while reducing the amount of scatter and maintaining the focus of the beam on the region of interest.

In contrast, smaller or larger detectors would either fail to adequately capture important details or may introduce issues such as increased noise or reduced sensitivity. The choice of a 4 cm detector reflects a balance between sensitivity and practicality for reliable bone density measurements, ensuring that the images produced are clear and diagnostically useful.