orig = dicomread('knee1.dcm');
moving = dicomread('knee2.dcm');
[optimizer,metric] = imregconfig('multimodal');
optimizer.MaximumIterations = 150;
optimizer.InitialRadius = 0.002;
[Registered, ~, tform] = imregister2(moving, orig, 'affine', optimizer, metric);
figure, imshowpair(Registered, orig)
Registered2 = imwarp(moving, tform, 'OutputView', imref2d(size(orig)));
figure, imshowpair(Registered2, orig)