What can result from having a CT reconstruction that is lower than the PET reconstruction field of view?

When the CT reconstruction field of view is smaller than that of the PET reconstruction, it can lead to the presence of streak artifacts as well as potentially falsely low uptake in the identified regions. This occurs because the mismatch in the fields of view results in poor alignment and reconstruction of the data. As a consequence, the incomplete coverage from the CT scan fails to properly account for the full range of emitted positrons during the PET scan. This can create null or diminished signal areas in the PET images where the corresponding CT data does not support adequate attenuation correction.

Streak artifacts, often resulting from inadequate data sampling or mismatch in data acquisition, can confuse interpretation, leading to misleading assessments of radiopharmaceutical distribution. Additionally, because the reconstruction misrepresents the underlying anatomy or pathology, the quantification of radiopharmaceutical uptake can be negatively impacted, resulting in incorrect estimates of metabolic activity within tissues, specifically in regions where the CT and PET data do not align properly.

In this context, the other options do not correctly capture the primary implications of having a CT reconstruction that is smaller than the PET field of view. For instance, while noise may occur in the imaging process, it is not the direct result of this specific mismatch; similarly, falsely high radiopharmaceutical