Image reconstruction for the ClearPET™ Neuro

Weber, Simone; Morel, C.; Simon, L.; Krieguer, M.; Rey, M.; Gundlich, Brigitte; Khodaverdi, Maryam

doi:10.1016/j.nima.2006.08.048

Cited by 21 publications

(13 citation statements)

References 17 publications

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“…, 2006). Careful estimation of the sensitivity matrix was thus required to minimize artefacts in the images, and the scanner geometry has necessarily to be considered in the reconstruction algorithms (Weber et al. , 2006).…”

Section: Methodsmentioning

confidence: 99%

“…PlanTIS has a geometry (see Figure 1c) that is quite different from that of a conventional scanner in which the rings (360°) are fully equipped with detectors (Mosset et al, 2006). Careful estimation of the sensitivity matrix was thus required to minimize artefacts in the images, and the scanner geometry has necessarily to be considered in the reconstruction algorithms (Weber et al, 2006). In addition, a normalization procedure was performed to correct for detector inhomogeneity.…”

Section: Plant Tomographic Imaging System (Plantis)mentioning

confidence: 99%

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Combined MRI–PET dissects dynamic changes in plant structures and functions

et al. 2009

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SUMMARYUnravelling the factors determining the allocation of carbon to various plant organs is one of the great challenges of modern plant biology. Studying allocation under close to natural conditions requires noninvasive methods, which are now becoming available for measuring plants on a par with those developed for humans. By combining magnetic resonance imaging (MRI) and positron emission tomography (PET), we investigated three contrasting root/shoot systems growing in sand or soil, with respect to their structures, transport routes and the translocation dynamics of recently fixed photoassimilates labelled with the shortlived radioactive carbon isotope 11 C. Storage organs of sugar beet (Beta vulgaris) and radish plants (Raphanus sativus) were assessed using MRI, providing images of the internal structures of the organs with high spatial resolution, and while species-specific transport sectoralities, properties of assimilate allocation and unloading characteristics were measured using PET. Growth and carbon allocation within complex root systems were monitored in maize plants (Zea mays), and the results may be used to identify factors affecting root growth in natural substrates or in competition with roots of other plants. MRI-PET co-registration opens the door for non-invasive analysis of plant structures and transport processes that may change in response to genomic, developmental or environmental challenges. It is our aim to make the methods applicable for quantitative analyses of plant traits in phenotyping as well as in understanding the dynamics of key processes that are essential to plant performance.

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Section: Methodsmentioning

confidence: 99%

Section: Plant Tomographic Imaging System (Plantis)mentioning

confidence: 99%

Combined MRI–PET dissects dynamic changes in plant structures and functions

et al. 2009

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“…Quantitative analysis of the distribution of 11 C-isotope in the root/soil volume was conducted by a PET setup dedicated for plant analysis (PLANTIS) based in the CLEARPET-system (Streun et al 2006) in a coincidence design. Reconstruction used the specifically designed algorithms (Weber et al 2006).…”

Section: Analysis Of Root Structure and Function In Soilmentioning

confidence: 99%

Temperature responses of roots: impact on growth, root system architecture and implications for phenotyping

Nagel

Kastenholz

Jahnke

et al. 2009

Functional Plant Biol.

218

176

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Abstract. Root phenotyping is a challenging task, mainly because of the hidden nature of this organ. Only recently, imaging technologies have become available that allow us to elucidate the dynamic establishment of root structure and function in the soil. In root tips, optical analysis of the relative elemental growth rates in root expansion zones of hydroponically-grown plants revealed that it is the maximum intensity of cellular growth processes rather than the length of the root growth zone that control the acclimation to dynamic changes in temperature. Acclimation of entire root systems was studied at high throughput in agar-filled Petri dishes. In the present study, optical analysis of root system architecture showed that low temperature induced smaller branching angles between primary and lateral roots, which caused a reduction in the volume that roots access at lower temperature. Simulation of temperature gradients similar to natural soil conditions led to differential responses in basal and apical parts of the root system, and significantly affected the entire root system. These results were supported by first data on the response of root structure and carbon transport to different root zone temperatures. These data were acquired by combined magnetic resonance imaging (MRI) and positron emission tomography (PET). They indicate acclimation of root structure and geometry to temperature and preferential accumulation of carbon near the root tip at low root zone temperatures. Overall, this study demonstrated the value of combining different phenotyping technologies that analyse processes at different spatial and temporal scales. Only such an integrated approach allows us to connect differences between genotypes obtained in artificial high throughput conditions with specific characteristics relevant for field performance. Thus, novel routes may be opened up for improved plant breeding as well as for mechanistic understanding of root structure and function.

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“…To this aim, the GATE Monte-Carlo package was used in combination with the software for tomographic image reconstruction (STIR, version 2) to simulate: (i) a novel highly uniform 18 F-fluorodeoxyglucose ( 18 F-FDG) plane source, based on a thin-layer chromatography (TLC) plate, to obtain reconstructed plane source images and (ii) a conventional 18 F-FDG line source, to obtain the point spread function (PSF) of line source reconstructed images, for comparison. In the past few years, ongoing work on STIR reconstruction for large commercial PET scanners has been carried out [3][4][5][6][7][8][9]. None of these, however, simulate the GE Discovery ST scanner that is used in this study.…”

Section: Introductionmentioning

confidence: 99%