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Image registration for triggered and non‐triggered DTI of the human kidney: Reduced variability of diffusion parameter estimation
Author(s) -
Seif Maryam,
Lu Huanxiang,
Boesch Chris,
Reyes Mauricio,
Vermathen Peter
Publication year - 2015
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.24671
Subject(s) - fractional anisotropy , diffusion mri , image registration , coronal plane , nuclear medicine , effective diffusion coefficient , medicine , magnetic resonance imaging , nuclear magnetic resonance , computer science , artificial intelligence , physics , radiology , image (mathematics)
Background To investigate if non‐rigid image‐registration reduces motion artifacts in triggered and non‐triggered diffusion tensor imaging (DTI) of native kidneys. A secondary aim was to determine, if improvements through registration allow for omitting respiratory‐triggering. Methods Twenty volunteers underwent coronal DTI of the kidneys with nine b‐values (10–700 s/mm 2 ) at 3 Tesla. Image‐registration was performed using a multimodal nonrigid registration algorithm. Data processing yielded the apparent diffusion coefficient (ADC), the contribution of perfusion (F P ), and the fractional anisotropy (FA). For comparison of the data stability, the root mean square error (RMSE) of the fitting and the standard deviations within the regions of interest (SD ROI ) were evaluated. Results RMSEs decreased significantly after registration for triggered and also for non‐triggered scans ( P < 0.05). SD ROI for ADC, FA, and F P were significantly lower after registration in both medulla and cortex of triggered scans ( P < 0.01). Similarly the SD ROI of FA and F P decreased significantly in non‐triggered scans after registration ( P < 0.05). RMSEs were significantly lower in triggered than in non‐triggered scans, both with and without registration ( P < 0.05). Conclusion Respiratory motion correction by registration of individual echo‐planar images leads to clearly reduced signal variations in renal DTI for both triggered and particularly non‐triggered scans. Secondarily, the results suggest that respiratory‐triggering still seems advantageous. J. Magn. Reson. Imaging 2015;41:1228–1235. © 2014 Wiley Periodicals, Inc.