Fig. 2From: Evaluation of lung perfusion by using lung perfusion SPECT and lung CT with breathing synchronization softwareAlgorism of the breathing synchronization software. The scaled and co-registered SPECT image was generated from the original SPECT image and planar images using the breathing synchronization software. Abbreviations: CT = computed tomography; NMI = normalized mutual information; and SPECT = single-photon emission computed tomographyBack to article page