Final answer:
Increasing NSA/NEX in medical imaging primarily improves signal-to-noise ratio, which can make details more visible despite the intrinsic spatial resolution limits of a method like SPECT. Higher magnetic fields used in MRI require smaller antennas for efficient broadcasting of higher frequency radio waves.
Step-by-step explanation:
Increasing the Number of Signal Averages (NSA) or Number of Excitations (NEX) in medical imaging typically enhances image quality by reducing noise, which can inadvertently improve the spatial resolution and detail in the resulting images. However, the direct impact on spatial resolution is minimal; instead, it's the reduction in noise that allows finer details to become more visible and discernible. In medical imaging techniques such as MRI, a higher NSA/NEX means that more signal data is being acquired, which leads to a better signal-to-noise ratio (SNR). This is essential for creating clearer images and can be particularly important in techniques like single-photon-emission computed tomography (SPECT), where spatial resolution is limited.
By improving SNR, structures within the image may be better resolved, notwithstanding the innate spatial resolution limits of the imaging technology. Furthermore, in MRI, the use of higher magnetic fields with corresponding higher frequency radio waves generally necessitates smaller antennas for the most efficient signal broadcast and reception.