Example images of one patient with lung lesions. Example of coronal and sagittal images of one patient with lung lesions, illustrating the effects of various rigid and non-rigid registration strategies using CT or PET as input data. The four lower rows show the test scan registered onto the retest scan (reference, shown on the top row). VOIretest is shown in red, indicted by blue arrows. All images are resliced to the same position of VOIretest and all images are shown using the same colour scales.