Adaptive registration of varying contrast‐weighted images for improved tissue characterization (ARCTIC): Application to T 1 mapping

• Published in: Magnetic Resonance in Medicine
• Main Authors: Roujol, Sébastien, Foppa, Murilo, Weingärtner, Sebastian, Manning, Warren J., Nezafat, Reza
• Other Authors: NIH
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2014
• Subjects: Arctic
• Online Access: http://dx.doi.org/10.1002/mrm.25270; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fmrm.25270; https://onlinelibrary.wiley.com/doi/pdf/10.1002/mrm.25270

Purpose To propose and evaluate a novel nonrigid image registration approach for improved myocardial T 1 mapping. Methods Myocardial motion is estimated as global affine motion refined by a novel local nonrigid motion estimation algorithm. A variational framework is proposed, which simultaneously estimates motion field and intensity variations, and uses an additional regularization term to constrain the deformation field using automatic feature tracking. The method was evaluated in 29 patients by measuring the DICE similarity coefficient and the myocardial boundary error in short axis and four chamber data. Each image series was visually assessed as “no motion” or “with motion.” Overall T 1 map quality and motion artifacts were assessed in the 85 T 1 maps acquired in short axis view using a 4‐point scale (1‐nondiagnostic/severe motion artifact, 4‐excellent/no motion artifact). Results Increased DICE similarity coefficient (0.78 ± 0.14 to 0.87 ± 0.03, P < 0.001), reduced myocardial boundary error (1.29 ± 0.72 mm to 0.84 ± 0.20 mm, P < 0.001), improved overall T 1 map quality (2.86 ± 1.04 to 3.49 ± 0.77, P < 0.001), and reduced T 1 map motion artifacts (2.51 ± 0.84 to 3.61 ± 0.64, P < 0.001) were obtained after motion correction of “with motion” data (∼56% of data). Conclusions The proposed nonrigid registration approach reduces the respiratory‐induced motion that occurs during breath‐hold T 1 mapping, and significantly improves T 1 map quality. Magn Reson Med 73:1469–1482, 2015. © 2014 Wiley Periodicals, Inc.