Concentric ring artifacts in a reconstructed SPECT image may be caused by:

Concentric ring artifacts in a reconstructed SPECT image are primarily associated with inadequate uniformity. This uniformity is critical as it ensures that the imaging system captures consistent and accurate data across the field of view. When there is a discrepancy in the uniformity, it can lead to variations in the reconstructed image, resulting in artifacts that manifest as concentric rings.

Inadequate uniformity may arise from several factors, such as malfunctioning detector elements, variations in detector sensitivity, or differences in the attenuation of gamma rays. These inconsistencies can distort the data used to reconstruct the image, causing the circular patterns characteristic of concentric ring artifacts.

The importance of maintaining uniformity in the imaging process highlights the role of proper quality control measures, such as routine calibration and testing of the SPECT system. Each of these actions contributes to ensuring that the data collected is as consistent as possible, thus minimizing the appearance of such artifacts in the final images.