| 1. |
- Michelin, Gaël, et al.
(författare)
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Spatio-temporal registration of 3D microscopy image sequences of arabidopsis floral meristems
- 2016
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Ingår i: Biomedical Imaging, IEEE International Symposium on. - 9781479923519 - 9781479923496
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The shoot apical meristem (SAM) is at the origin of all the plant above-ground organs (including stems, leaves and flowers) and is a biological object of interest for the understanding of plant morphogenesis. The quantification of tissue growth at a cellular level requires the analysis of 3D microscopic image sequences of developing meristems. To address inter-individual variability, it is also required to compare individuals. This obviously implies the ability to process inter-individual registration, i.e. to compute spatial and temporal correspondences between sequences from different meristems. In the present work, we propose a spatial registration method dedicated to microscopy floral meristem (FM) images, and the identification, for a given still image of a meristem, of its best corresponding time-point in a sequence of an other individual (temporal registration).
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| 2. |
- Refahi, Yassin, et al.
(författare)
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A multiscale analysis of early flower development in Arabidopsis provides an integrated view of molecular regulation and growth control
- 2021
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Ingår i: Developmental Cell. - : Elsevier BV. - 1534-5807. ; 56:4, s. 8-556
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Tidskriftsartikel (refereegranskat)abstract
- We have analyzed the link between the gene regulation and growth during the early stages of flower development in Arabidopsis. Starting from time-lapse images, we generated a 4D atlas of early flower development, including cell lineage, cellular growth rates, and the expression patterns of regulatory genes. This information was introduced in MorphoNet, a web-based platform. Using computational models, we found that the literature-based molecular network only explained a minority of the gene expression patterns. This was substantially improved by adding regulatory hypotheses for individual genes. Correlating growth with the combinatorial expression of multiple regulators led to a set of hypotheses for the action of individual genes in morphogenesis. This identified the central factor LEAFY as a potential regulator of heterogeneous growth, which was supported by quantifying growth patterns in a leafy mutant. By providing an integrated view, this atlas should represent a fundamental step toward mechanistic models of flower development. Refahi and Zardilis et al. present a 4D atlas of early flower development. They combine growth and gene expression to construct a molecular network model that correctly predicts a large majority of 28 gene expression patterns. This model suggests hypotheses for the combined action of regulatory genes in morphogenesis.
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| 3. |
- West, Jay B., et al.
(författare)
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Comparison and evaluation of retrospective intermodality image registration techniques
- 1997
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Ingår i: SPIE - The International Society for Optical Engineering. - : SPIE - International Society for Optical Engineering. ; , s. 332-347
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Konferensbidrag (refereegranskat)abstract
- All retrospective image registration methods have attached to them some intrinsic estimate of registration error. However, this estimate of accuracy may not always be a good indicator of the distance between actual and estimated positions of targets within the cranial cavity. This paper describes a project whose principal goal is to use a prospective method based on fiducial markers as a ’gold standard’ to perform an objective, blinded evaluation of the accuracy of several retrospective image-to-image registration techniques. Image volumes of three modalities – CT, MR, and PET – were taken of patients undergoing neurosurgery at Vanderbilt University Medical Center. These volumes had all traces of the fiducial markers removed, and were provided to project collaborators outside Vanderbilt, who then performed retrospective registrations on the volumes, calculating transformations from CT to MR and/or from PET to MR, and communicated their transformations to Vanderbilt where the accuracy of each registration was evaluated. In this evaluation the accuracy is measured at multiple ’regions of interest,’ i.e. areas in the brain which would commonly be areas of neurological interest. A region is defined in the MR image and its centroid C is determined. Then the prospective registration is used to obtain the corresponding point C’ in CT or PET. To this point the retrospective registration is then applied, producing C’ in MR. Statistics are gathered on the target registration error (TRE), which is the disparity between the original point C and its corresponding point C’. A second goal of the project is to evaluate the importance of correcting geometrical distortion in MR images, by comparing the retrospective TRE in the rectified images, i.e., those which have had the distortion correction applied, with that of the same images before rectification. This paper presents preliminary results of this study along with a brief description of each registration technique and an estimate of both preparation and execution time needed to perform the registration.
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