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Automated image registration of gated cardiac single‐photon emission computed tomography and magnetic resonance imaging
Author(s) -
Aladl Usaf E.,
Hurwitz Gilbert A.,
Dey Damini,
Levin David,
Drangova Maria,
Slomka Piotr J.
Publication year - 2004
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.20003
Subject(s) - magnetic resonance imaging , segmentation , artificial intelligence , single photon emission computed tomography , thresholding , image registration , nuclear medicine , computer science , preprocessor , emission computed tomography , mutual information , computer vision , medicine , positron emission tomography , radiology , image (mathematics)
Purpose To develop an automatic registration method for electrocardiogram‐gated myocardial perfusion single‐photon emission computed tomography (SPECT) and cardiac cine‐magnetic resonance imaging (MRI). Materials and Methods Paired myocardial perfusion SPECT (MPS) and MRI from 20 patients were considered. MR images were presegmented by heart localization based on detection of cardiac motion and optimal thresholding. A registration algorithm based on mutual information was subsequently applied to all time frames or a selected subset from both modalities. Results A preprocessing step significantly improved the accuracy of the registration when compared to automatic registration performed without preprocessing. Errors in translation parameters ( T x , T y , T z ) averaged (1.0 ± 1.5, 1.1 ± 1.3, 0.9 ± 0.9) pixels with MRI segmentation and (4.6 ± 3.2, 3.4 ± 2.6, 3.0 ± 3.4) pixels without MRI segmentation. Errors in rotation parameters (R x , R y , R z ) averaged (5.4 ± 2.9, 3.4 ± 2.7, 4.5 ± 3.6) degrees with MRI segmentation and (9.3 ± 6.1, 4.8 ± 4.3, 14.6 ± 12.6) degrees without MRI segmentation. Error was calculated as the absolute difference between the expert manual and the automatic registration transformation. Conclusion Automatic registration of gated MPS and cine MRI is possible with the use of a mutual information‐based technique when MR images are presegmented. Cardiac motion can be used to isolate the left ventricle (LV) on the MR images automatically, and subsequently the segmented MR images can be coregistered with gated MPS. J. Magn. Reson. Imaging 2004;19:283–290. © 2004 Wiley‐Liss, Inc.