Final answer:
The missing information from CT scan images of the abdomen can be retrieved using retrospective reconstruction. Prospective reconstruction and multiplanar reformation are other techniques used in CT imaging, but they do not retrieve missing information.
Step-by-step explanation:
When conducting a CT scan of the abdomen, if the images do not include the entire abdomen, the missing information can be retrieved through retrospective reconstruction. Retrospective reconstruction allows the radiologist to review the original raw data acquired during the scan and generate additional image slices or reformatted images to include the missing information. This is done by adjusting parameters such as slice thickness and reconstruction algorithm.
Prospective reconstruction, on the other hand, refers to the process of generating images in real-time as the CT scan is being performed. Multiplanar reformation is a technique that allows the radiologist to view and analyze the CT data in different planes (e.g., sagittal, coronal) to better visualize specific structures or lesions. However, it does not retrieve the missing information from the original scan.