Fusion imaging: Combined visualization of 3D reconstructed coronary arterytree and 3D myocardial scintigraphic image in coronary artery disease

Background: In patients with coronary artery disease, coronary angiography is performed for assessment of epicardial coronary artery stenoses. In addi tion, myocardial scintigraphy is commonly used to evaluate regional myocard ial perfusion. These two-dimensional (2D) imaging modalities are typically reviewed through a subjective, visual observation by a physician. Even thou gh on the analysis of 2D display scintigraphic myocardial perfusion segment s are arbitrarily assigned to three major coronary artery systems, the stan dard myocardial distribution territories of the coronary tree correspond on ly in 50-60% of patients. On the other hand, the mental integration of both 2D images of coronary angiography and myocardial scintigraphy does not all ow an accurate assignment of particular myocardial perfusion regions to the corresponding vessels. To achieve an objective assignment of each vessel s egment of the coronary artery tree to the corresponding myocardial regions, we have developed a 3D 'fusion image' technique and applied it to patients with coronary artery disease. The morphological data (coronary angiography ) and perfusion data (myocardial scintigraphy) are displayed in a 3D format , and these two 3D data sets are merged into one 3D image. Results: Seventy -eight patients with coronary artery disease were studied with this new 3D fusion technique. Of 162 significant coronary lesions, 120 (74%) showed goo d coincidence with regional myocardial perfusion abnormality on 3D fusion i mage. No regional myocardial perfusion abnormality was found in 44 (26%) le sions. Furthermore, the 3D fusion image revealed 24 ischemic myocardial reg ions that could not be related to angiographically significant coronary art ery lesions. Conclusion: The results of this study demonstrate that our new ly developed 3D fusion technique is useful for an accurate assignment of co ronary vessel segments to the corresponding myocardial perfusion regions, a nd suggest that it may be helpful to improve the interpretative and decisio n-making process in the treatment of patients with coronary artery disease.