TY - JOUR
T1 - Signed-distance function based non-rigid registration of image series with varying image intensity
AU - Škardová, Kateřina
AU - Oberhuber, Tomáš
AU - Tintěra, Jaroslav
AU - Chabiniok, Radomír
N1 - Publisher Copyright:
© 2021 American Institute of Mathematical Sciences. All rights reserved.
PY - 2021/3
Y1 - 2021/3
N2 - In this paper we propose a method for locally adjusted optical flow-based registration of multimodal images, which uses the segmentation of object of interest and its representation by the signed-distance function (OFdist method). We deal with non-rigid registration of the image series acquired by the Modiffied Look-Locker Inversion Recovery (MOLLI) magnetic resonance imaging sequence, which is used for a pixel-wise estimation of T1 relaxation time. The spatial registration of the images within the series is necessary to compensate the patient's imperfect breath-holding. The evolution of intensities and a large variation of image contrast within the MOLLI image series, together with the myocardium of left ventricle (the object of interest) typically not being the most distinct object in the scene, makes the registration challenging. The paper describes all components of the proposed OFdist method and their implementation. The method is then compared to the performance of a standard mutual information maximization-based registration method, applied either to the original image (MIM) or to the signed-distance function (MIMdist). Several experiments with synthetic and real MOLLI images are carried out. On synthetic image with a single object, MIM performed the best, while OFdist and MIMdist provided better results on synthetic images with more than one object and on real images. When applied to signed-distance function of two objects of interest, MIMdist provided a larger registration error, but more homogeneously distributed, compared to OFdist. For the real MOLLI image series with left ventricle pre-segmented using a level-set method, the proposed OFdist registration performed the best, as is demonstrated visually and by measuring the increase of mutual information in the object of interest and its neighborhood.
AB - In this paper we propose a method for locally adjusted optical flow-based registration of multimodal images, which uses the segmentation of object of interest and its representation by the signed-distance function (OFdist method). We deal with non-rigid registration of the image series acquired by the Modiffied Look-Locker Inversion Recovery (MOLLI) magnetic resonance imaging sequence, which is used for a pixel-wise estimation of T1 relaxation time. The spatial registration of the images within the series is necessary to compensate the patient's imperfect breath-holding. The evolution of intensities and a large variation of image contrast within the MOLLI image series, together with the myocardium of left ventricle (the object of interest) typically not being the most distinct object in the scene, makes the registration challenging. The paper describes all components of the proposed OFdist method and their implementation. The method is then compared to the performance of a standard mutual information maximization-based registration method, applied either to the original image (MIM) or to the signed-distance function (MIMdist). Several experiments with synthetic and real MOLLI images are carried out. On synthetic image with a single object, MIM performed the best, while OFdist and MIMdist provided better results on synthetic images with more than one object and on real images. When applied to signed-distance function of two objects of interest, MIMdist provided a larger registration error, but more homogeneously distributed, compared to OFdist. For the real MOLLI image series with left ventricle pre-segmented using a level-set method, the proposed OFdist registration performed the best, as is demonstrated visually and by measuring the increase of mutual information in the object of interest and its neighborhood.
KW - Distance function
KW - Image segmentation
KW - Locally adjusted image registration
KW - Optical flow
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U2 - 10.3934/dcdss.2020386
DO - 10.3934/dcdss.2020386
M3 - Article
AN - SCOPUS:85099694424
SN - 1937-1632
VL - 14
SP - 1145
EP - 1160
JO - Discrete and Continuous Dynamical Systems - Series S
JF - Discrete and Continuous Dynamical Systems - Series S
IS - 3
ER -