You can tell that both sets of images are CT scans because they are obviously SLICES (not projections, like an X-ray), and the cortical bone is very white. If you look at image sequence A, you can see a lot of internal detail in every bone, such as where the medullary cavity is. This is a bone window, a particular brightness and contrast setting that shows bone best. The soft tissues look washed out. In image sequence B, you can still see the bones, but most of them look completely white and you can no longer see much internal detail. However you can see the muscles and fat of the soft tissues much better, so these images are being displayed with a soft tissue window.

You have finished the upper extremity images, and can go on the the next topic.