Viewer systems and related methods with multi-piece registration

A method of registering medical images for viewing, comprising:

• electronically providing a database of candidate registrations of a plurality of different medical images for respective patients, wherein a pair of the different medical images of a single patient of the plurality of different medical images has multiple candidate registrations in the database of candidate registrations, and wherein multiple image regions of a first medical image of the pair of the different medical images are each related to an image region in a second medical image of the pair of different medical images through at least one candidate registration in the database of candidate registrations;
• electronically providing a viewer comprising a first window with a first viewing window user interface and a second window with a second viewing window user interface;
• displaying a viewport of the first medical image in the first window;
• displaying a viewport of the second medical image in the second window;
• accepting user input of a user to select one of the first window or the second window to be an active window for user navigation and which makes a non-selected other of the first window or the second window a non-active, follower window;
• obtaining candidate registrations from the database of candidate registrations that are related to the first medical image or the second medical image in the active window;
• and
• electronically automatically selecting a registration from the obtained candidate registrations based on proximity of the image region of the obtained candidate registrations to the viewport of the active window,
• wherein each image region is an area that is defined by a respective keypoint cluster, and
• wherein the electronically automatically selecting a registration from the obtained candidate registrations is based on a candidate registration quality measure.