Which of the following is a reconstruction method that assigns values in the projection to all points along the line of acquisition?

The method that assigns values in the projection to all points along the line of acquisition is Back Projection.

In the context of image reconstruction in PET and other tomographic imaging modalities, Back Projection works by mapping the measured projection data back into the image space. Essentially, it involves taking the projections collected from various angles and reintegrating them into the image. Each projection contributes to all the points along the corresponding line of detection, initially creating a blurred image that represents the distribution of the radioactivity within the scanned object.

This approach serves as a fundamental technique that allows for the generation of an image, where the values from the projections are simply redistributed along the angles at which they were acquired. Though Back Projection can result in a relatively poor quality image due to blurring, it is an essential step towards more sophisticated techniques like Filtered Back Projection and Iterative Reconstruction, which aim to refine the images further and improve resolution and contrast.