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Barbieri M, Fantazzini P, Testa C, Bortolotti V, Baruffaldi F, Kogan F, Brizi L. Characterization of Structural Bone Properties through Portable Single-Sided NMR Devices: State of the Art and Future Perspectives. Int J Mol Sci 2021; 22:7318. [PMID: 34298936 PMCID: PMC8303251 DOI: 10.3390/ijms22147318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 06/30/2021] [Accepted: 07/02/2021] [Indexed: 11/18/2022] Open
Abstract
Nuclear Magnetic Resonance (NMR) is a well-suited methodology to study bone composition and structural properties. This is because the NMR parameters, such as the T2 relaxation time, are sensitive to the chemical and physical environment of the 1H nuclei. Although magnetic resonance imaging (MRI) allows bone structure assessment in vivo, its cost limits the suitability of conventional MRI for routine bone screening. With difficulty accessing clinically suitable exams, the diagnosis of bone diseases, such as osteoporosis, and the associated fracture risk estimation is based on the assessment of bone mineral density (BMD), obtained by the dual-energy X-ray absorptiometry (DXA). However, integrating the information about the structure of the bone with the bone mineral density has been shown to improve fracture risk estimation related to osteoporosis. Portable NMR, based on low-field single-sided NMR devices, is a promising and appealing approach to assess NMR properties of biological tissues with the aim of medical applications. Since these scanners detect the signal from a sensitive volume external to the magnet, they can be used to perform NMR measurement without the need to fit a sample inside a bore of a magnet, allowing, in principle, in vivo application. Techniques based on NMR single-sided devices have the potential to provide a high impact on the clinical routine because of low purchasing and running costs and low maintenance of such scanners. In this review, the development of new methodologies to investigate structural properties of trabecular bone exploiting single-sided NMR devices is reviewed, and current limitations and future perspectives are discussed.
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Affiliation(s)
- Marco Barbieri
- Department of Radiology, Stanford University, Stanford, CA 94395, USA;
- Department of Physics and Astronomy “Augusto Righi”, University of Bologna, 40127 Bologna, Italy; (P.F.); (C.T.)
| | - Paola Fantazzini
- Department of Physics and Astronomy “Augusto Righi”, University of Bologna, 40127 Bologna, Italy; (P.F.); (C.T.)
| | - Claudia Testa
- Department of Physics and Astronomy “Augusto Righi”, University of Bologna, 40127 Bologna, Italy; (P.F.); (C.T.)
- IRCCS Istituto delle Scienze Neurologiche Bologna, Functional and Molecular Neuroimaging Unit, 40139 Bologna, Italy
| | - Villiam Bortolotti
- Department of Civil, Chemical, Environmental, and Materials Engineering, University of Bologna, 40134 Bologna, Italy;
| | - Fabio Baruffaldi
- Medical Technology Laboratory, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy;
| | - Feliks Kogan
- Department of Radiology, Stanford University, Stanford, CA 94395, USA;
| | - Leonardo Brizi
- Department of Physics and Astronomy “Augusto Righi”, University of Bologna, 40127 Bologna, Italy; (P.F.); (C.T.)
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Barbieri M, Fantazzini P, Bortolotti V, Baruffaldi F, Festa A, Manners DN, Testa C, Brizi L. Single-sided NMR to estimate morphological parameters of the trabecular bone structure. Magn Reson Med 2020; 85:3353-3369. [PMID: 33349979 DOI: 10.1002/mrm.28648] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 11/24/2020] [Accepted: 11/24/2020] [Indexed: 11/06/2022]
Abstract
PURPOSE Single-sided 1 H-NMR is proposed for the estimation of morphological parameters of trabecular bone, and potentially the detection of pathophysiological alterations of bone structure. In this study, a new methodology was used to estimate such parameters without using an external reference signal, and to study intratrabecular and intertrabecular porosities, with a view to eventually scanning patients. METHODS Animal trabecular bone samples were analyzed by a single-sided device. The Carr-Purcell-Meiboom-Gill sequence of 1 H nuclei of fluids, including marrow, confined inside the bone, was analyzed by quasi-continuous T2 distributions and separated into two 1 H pools: short and long T2 components. The NMR parameters were estimated using models of trabecular bone structure, and compared with the corresponding micro-CT. RESULTS Without any further assumptions, the internal reference parameter (short T2 signal intensity fraction) enabled prediction of the micro-CT parameters BV/TV (volume of the trabeculae/total sample volume) and BS/TV (external surface of the trabeculae/total sample volume) with linear correlation coefficient >0.80. The assignment of the two pools to intratrabecular and intertrabecular components yielded an estimate of average intratrabecular porosity (33 ± 5)%. Using the proposed models, the NMR-estimated BV/TV and BS/TV were found to be linearly related to the corresponding micro-CT values with high correlation (>0.90 for BV/TV; >0.80 for BS/TV) and agreement coefficients. CONCLUSION Low-field, low-cost portable devices that rely on intrinsic magnetic field gradients and do not use ionizing radiation are viable tools for in vitro preclinical studies of pathophysiological structural alterations of trabecular bone.
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Affiliation(s)
- Marco Barbieri
- Physics and Astronomy Department, University of Bologna, Bologna, Italy.,Department of Radiology, Stanford University, Stanford, CA, USA
| | - Paola Fantazzini
- Physics and Astronomy Department, University of Bologna, Bologna, Italy
| | - Villiam Bortolotti
- Department of Civil, Chemical, Environmental, and Materials Engineering, University of Bologna, Bologna, Italy
| | | | - Anna Festa
- IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - David N Manners
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Claudia Testa
- Physics and Astronomy Department, University of Bologna, Bologna, Italy.,National Institute for Nuclear Physics Bologna, Bologna, Italy
| | - Leonardo Brizi
- Physics and Astronomy Department, University of Bologna, Bologna, Italy.,National Institute for Nuclear Physics Bologna, Bologna, Italy
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Talozzi L, Testa C, Evangelisti S, Cirignotta L, Bianchini C, Ratti S, Fantazzini P, Tonon C, Manners DN, Lodi R. Along-tract analysis of the arcuate fasciculus using the Laplacian operator to evaluate different tractography methods. Magn Reson Imaging 2018; 54:183-193. [PMID: 30165094 DOI: 10.1016/j.mri.2018.08.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 07/08/2018] [Accepted: 08/24/2018] [Indexed: 12/18/2022]
Abstract
PURPOSE We propose a new along-tract algorithm to compare different tractography algorithms in tract curvature mapping and along-tract analysis of the arcuate fasciculus (AF). In particular, we quantified along-tract diffusion parameters and AF spatial distribution evaluating hemispheric asymmetries in a group of healthy subjects. METHODS The AF was bilaterally reconstructed in a group of 29 healthy subjects using the probabilistic ball-and-sticks model, and both deterministic and probabilistic constrained spherical deconvolution. We chose cortical ROIs as tractography targets and the developed along-tract algorithm used the Laplacian operator to parameterize the volume of the tract, allowing along-tract analysis and tract curvature mapping independent of the tractography algorithm used. RESULTS The Laplacian parameterization successfully described the tract geometry underlying hemispheric asymmetries in the AF curvature. Using the probabilistic tractography methods, we found more tracts branching towards cortical terminations in the left hemisphere. This influenced the left AF curvature and its diffusion parameters, which were significantly different with respect to the right. In particular, we detected projections towards the middle temporal and inferior frontal gyri bilaterally, and towards the superior temporal and precentral gyri in the left hemisphere, with a significantly increased volume and connectivity. CONCLUSIONS The approach we propose is useful to evaluate brain asymmetries, assessing the volume, the diffusion properties and the quantitative spatial localization of the AF.
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Affiliation(s)
- Lia Talozzi
- Department of Biomedical and NeuroMotor Sciences, Functional MR Unit, University of Bologna, Bologna, Italia
| | - Claudia Testa
- Department of Biomedical and NeuroMotor Sciences, Functional MR Unit, University of Bologna, Bologna, Italia
| | - Stefania Evangelisti
- Department of Biomedical and NeuroMotor Sciences, Functional MR Unit, University of Bologna, Bologna, Italia
| | - Lorenzo Cirignotta
- Department of Biomedical and NeuroMotor Sciences, Functional MR Unit, University of Bologna, Bologna, Italia
| | - Claudio Bianchini
- Department of Biomedical and NeuroMotor Sciences, Functional MR Unit, University of Bologna, Bologna, Italia
| | - Stefano Ratti
- Department of Biomedical and NeuroMotor Sciences, Cellular Signalling Laboratory, University of Bologna, Bologna, Italia
| | - Paola Fantazzini
- Department of Physics and Astronomy, University of Bologna, Bologna, Italy, and Centro Enrico Fermi, Roma, Italia
| | - Caterina Tonon
- Department of Biomedical and NeuroMotor Sciences, Functional MR Unit, University of Bologna, Bologna, Italia; IRCCS Istituto delle Scienze Neurologiche di Bologna, Diagnostica Funzionale Neuroradiologica, Bologna, Italia.
| | - David Neil Manners
- Department of Biomedical and NeuroMotor Sciences, Functional MR Unit, University of Bologna, Bologna, Italia
| | - Raffaele Lodi
- Department of Biomedical and NeuroMotor Sciences, Functional MR Unit, University of Bologna, Bologna, Italia; IRCCS Istituto delle Scienze Neurologiche di Bologna, Diagnostica Funzionale Neuroradiologica, Bologna, Italia
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Camaiti M, Brizi L, Bortolotti V, Papacchini A, Salvini A, Fantazzini P. An Environmental Friendly Fluorinated Oligoamide for Producing Nonwetting Coatings with High Performance on Porous Surfaces. ACS Appl Mater Interfaces 2017; 9:37279-37288. [PMID: 28960056 DOI: 10.1021/acsami.7b09440] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The changes in the surface wettability of many materials are receiving increased attention in recent years. It is not too hard to fabricate resistant hydrophobic surfaces through products bearing both hydrophobic and reactive hydrophilic end groups. More challenging is obtaining resistant nonwetting surfaces through noncovalent reversible bonds. In this work, a fluorinated oligo(ethylenesuccinamide), soluble in solvent benign for operators and environment, has been synthesized. It contains two opposite functional groups (perfluoropolyether segments and amidic groups) (SC2-PFPE) that provide water repellency while hydrophilicity is retained. Its performance has been tested on porous calcarenite and investigated by magnetic resonance imaging, water capillary absorption, and vapor diffusivity tests. The results demonstrate that SC2-PFPE modifies the wettability of porous substrates in a drastic and durable way and reduces the vapor condensation inside the pore space due to the perfluoropolyether segments that act at the air/surface interface.
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Affiliation(s)
- Mara Camaiti
- Institute of Geosciences and Earth Resources, National Research Council , Via G. La Pira 4, 50121 Florence, Italy
- Centro Fermi-Museo Storico della Fisica e Centro Studi e Ricerche "Enrico Fermi" , P.za del Viminale 1, 00184 Rome, Italy
| | - Leonardo Brizi
- Centro Fermi-Museo Storico della Fisica e Centro Studi e Ricerche "Enrico Fermi" , P.za del Viminale 1, 00184 Rome, Italy
- Department of Physics and Astronomy, University of Bologna , Viale Berti Pichat 6/2, 40127 Bologna, Italy
| | - Villiam Bortolotti
- Department DICAM, University of Bologna , Via Terracini 28, 40131 Bologna, Italy
| | - Alessandra Papacchini
- Department of Chemistry "Ugo Schiff", University of Florence , Via della Lastruccia 3-13, 50019 Sesto Fiorentino (Florence), Italy
| | - Antonella Salvini
- Department of Chemistry "Ugo Schiff", University of Florence , Via della Lastruccia 3-13, 50019 Sesto Fiorentino (Florence), Italy
| | - Paola Fantazzini
- Centro Fermi-Museo Storico della Fisica e Centro Studi e Ricerche "Enrico Fermi" , P.za del Viminale 1, 00184 Rome, Italy
- Department of Physics and Astronomy, University of Bologna , Viale Berti Pichat 6/2, 40127 Bologna, Italy
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Bortolotti V, Brizi L, Fantazzini P, Landi G, Zama F. Filtering techniques for efficient inversion of two-dimensional Nuclear Magnetic Resonance data. ACTA ACUST UNITED AC 2017. [DOI: 10.1088/1742-6596/904/1/012005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Brizi L, Barbieri M, Baruffaldi F, Bortolotti V, Fersini C, Liu H, Nogueira d'Eurydice M, Obruchkov S, Zong F, Galvosas P, Fantazzini P. Bone volume-to-total volume ratio measured in trabecular bone by single-sided NMR devices. Magn Reson Med 2017; 79:501-510. [PMID: 28394083 DOI: 10.1002/mrm.26697] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 03/10/2017] [Accepted: 03/11/2017] [Indexed: 12/15/2022]
Abstract
PURPOSE Reduced bone strength is associated with a loss of bone mass, usually evaluated by dual-energy X-ray absorptiometry, although it is known that the bone microstructure also affects the bone strength. Here, a method is proposed to measure (in laboratory) the bone volume-to-total volume ratio by single-sided NMR scanners, which is related to the microstructure of the trabecular bone. METHODS Three single-sided scanners were used on animal bone samples. These low-field, mobile, low-cost devices are able to detect the NMR signal, regardless of the sample sizes, without the use of ionizing radiations, with the further advantage of signal localization offered by their intrinsic magnetic field gradients. RESULTS The performance of the different single-sided scanners have been discussed. The results have been compared with bone volume-to-total volume ratio by micro CT and MRI, obtaining consistent values. CONCLUSIONS Our results demonstrate the feasibility of the method for laboratory analyses, which are useful for measurements like porosity on bone specimens. This can be considered as the first step to develop an NMR method based on the use of a mobile single-sided device, for the diagnosis of osteoporosis, through the acquisition of the signal from the appendicular skeleton, allowing for low-cost, wide screening campaigns. Magn Reson Med 79:501-510, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Leonardo Brizi
- Department of Physics and Astronomy, University of Bologna, Bologna, Italy.,Centro Fermi - Museo Storico della Fisica e Centro Studi e Ricerche "Enrico Fermi", Roma, Italy
| | - Marco Barbieri
- Department of Physics and Astronomy, University of Bologna, Bologna, Italy
| | | | | | | | - Huabing Liu
- MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Marcel Nogueira d'Eurydice
- MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Sergei Obruchkov
- MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Fangrong Zong
- MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Petrik Galvosas
- MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Paola Fantazzini
- Department of Physics and Astronomy, University of Bologna, Bologna, Italy.,Centro Fermi - Museo Storico della Fisica e Centro Studi e Ricerche "Enrico Fermi", Roma, Italy
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Prada F, Caroselli E, Mengoli S, Brizi L, Fantazzini P, Capaccioni B, Pasquini L, Fabricius KE, Dubinsky Z, Falini G, Goffredo S. Ocean warming and acidification synergistically increase coral mortality. Sci Rep 2017; 7:40842. [PMID: 28102293 PMCID: PMC5244398 DOI: 10.1038/srep40842] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 11/25/2016] [Indexed: 11/14/2022] Open
Abstract
Organisms that accumulate calcium carbonate structures are particularly vulnerable to ocean warming (OW) and ocean acidification (OA), potentially reducing the socioeconomic benefits of ecosystems reliant on these taxa. Since rising atmospheric CO2 is responsible for global warming and increasing ocean acidity, to correctly predict how OW and OA will affect marine organisms, their possible interactive effects must be assessed. Here we investigate, in the field, the combined temperature (range: 16–26 °C) and acidification (range: pHTS 8.1–7.4) effects on mortality and growth of Mediterranean coral species transplanted, in different seasonal periods, along a natural pH gradient generated by a CO2 vent. We show a synergistic adverse effect on mortality rates (up to 60%), for solitary and colonial, symbiotic and asymbiotic corals, suggesting that high seawater temperatures may have increased
their metabolic rates which, in conjunction with decreasing pH, could have led to rapid deterioration of cellular processes and performance. The net calcification rate of the symbiotic species was not affected by decreasing pH, regardless of temperature, while in the two asymbiotic species it was negatively affected by increasing acidification and temperature, suggesting that symbiotic corals may be more tolerant to increasing warming and acidifying conditions compared to asymbiotic ones.
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Affiliation(s)
- F Prada
- Marine Science Group, Department of Biological, Geological and Environmental Sciences, University of Bologna, Via Selmi 3, I-40126 Bologna, Italy
| | - E Caroselli
- Marine Science Group, Department of Biological, Geological and Environmental Sciences, University of Bologna, Via Selmi 3, I-40126 Bologna, Italy
| | - S Mengoli
- Department of Management, University of Bologna, Via Capo di Lucca 34, I-40126 Bologna, Italy
| | - L Brizi
- Department of Physics and Astronomy, University of Bologna, Viale Berti Pichat 6/2, I-40127 Bologna, Italy.,Museo Storico e Centro Studi e Ricerche Enrico Fermi, Piazza del Viminale 1, I-00184 Roma, Italy
| | - P Fantazzini
- Department of Physics and Astronomy, University of Bologna, Viale Berti Pichat 6/2, I-40127 Bologna, Italy.,Museo Storico e Centro Studi e Ricerche Enrico Fermi, Piazza del Viminale 1, I-00184 Roma, Italy
| | - B Capaccioni
- Department of Biological, Geological and Environmental Sciences, University of Bologna, Piazza di Porta S. Donato 1, I-40127 Bologna, Italy
| | - L Pasquini
- Department of Physics and Astronomy, University of Bologna, Viale Berti Pichat 6/2, I-40127 Bologna, Italy
| | - K E Fabricius
- Australian Institute of Marine Science, PMB 3, Townsville 4810, Queensland, Australia
| | - Z Dubinsky
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, 52900 Ramat-Gan, Israel
| | - G Falini
- Department of Chemistry "G. Ciamician", University of Bologna, Via Selmi 2, I-40126 Bologna, Italy
| | - S Goffredo
- Marine Science Group, Department of Biological, Geological and Environmental Sciences, University of Bologna, Via Selmi 3, I-40126 Bologna, Italy
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Fantazzini P, Mengoli S, Pasquini L, Bortolotti V, Brizi L, Mariani M, Di Giosia M, Fermani S, Capaccioni B, Caroselli E, Prada F, Zaccanti F, Levy O, Dubinsky Z, Kaandorp JA, Konglerd P, Hammel JU, Dauphin Y, Cuif JP, Weaver JC, Fabricius KE, Wagermaier W, Fratzl P, Falini G, Goffredo S. Gains and losses of coral skeletal porosity changes with ocean acidification acclimation. Nat Commun 2015; 6:7785. [PMID: 26183259 PMCID: PMC4518299 DOI: 10.1038/ncomms8785] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 06/10/2015] [Indexed: 11/09/2022] Open
Abstract
Ocean acidification is predicted to impact ecosystems reliant on calcifying organisms, potentially reducing the socioeconomic benefits these habitats provide. Here we investigate the acclimation potential of stony corals living along a pH gradient caused by a Mediterranean CO2 vent that serves as a natural long-term experimental setting. We show that in response to reduced skeletal mineralization at lower pH, corals increase their skeletal macroporosity (features >10 μm) in order to maintain constant linear extension rate, an important criterion for reproductive output. At the nanoscale, the coral skeleton's structural features are not altered. However, higher skeletal porosity, and reduced bulk density and stiffness may contribute to reduce population density and increase damage susceptibility under low pH conditions. Based on these observations, the almost universally employed measure of coral biomineralization, the rate of linear extension, might not be a reliable metric for assessing coral health and resilience in a warming and acidifying ocean.
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Affiliation(s)
- Paola Fantazzini
- 1] Department of Physics and Astronomy, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy [2] Centro Enrico Fermi, Piazza del Viminale 1, 00184 Rome, Italy
| | - Stefano Mengoli
- Department of Management, University of Bologna, Via Capo di Lucca 34, 40126 Bologna, Italy
| | - Luca Pasquini
- Department of Physics and Astronomy, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy
| | - Villiam Bortolotti
- Department of Civil, Chemical, Environmental, and Materials Engineering, University of Bologna, Via Terracini 28, 40131 Bologna, Italy
| | - Leonardo Brizi
- 1] Department of Physics and Astronomy, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy [2] Centro Enrico Fermi, Piazza del Viminale 1, 00184 Rome, Italy
| | - Manuel Mariani
- 1] Department of Physics and Astronomy, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy [2] Centro Enrico Fermi, Piazza del Viminale 1, 00184 Rome, Italy
| | - Matteo Di Giosia
- Department of Chemistry 'G. Ciamician', University of Bologna, Via F. Selmi 2, 40126 Bologna, Italy
| | - Simona Fermani
- Department of Chemistry 'G. Ciamician', University of Bologna, Via F. Selmi 2, 40126 Bologna, Italy
| | - Bruno Capaccioni
- Department of Biological, Geological and Environmental Sciences, Section of Geology, University of Bologna, Piazza di Porta S. Donato 1, 40126 Bologna, Italy
| | - Erik Caroselli
- Marine Science Group, Department of Biological, Geological and Environmental Sciences, Section of Biology, University of Bologna, Via F. Selmi 3, 40126 Bologna, Italy
| | - Fiorella Prada
- Marine Science Group, Department of Biological, Geological and Environmental Sciences, Section of Biology, University of Bologna, Via F. Selmi 3, 40126 Bologna, Italy
| | - Francesco Zaccanti
- Marine Science Group, Department of Biological, Geological and Environmental Sciences, Section of Biology, University of Bologna, Via F. Selmi 3, 40126 Bologna, Italy
| | - Oren Levy
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - Zvy Dubinsky
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - Jaap A Kaandorp
- Section Computational Science, Faculty of Science, University of Amsterdam, Science Park 904, room C3.147, 1090 GE Amsterdam, The Netherlands
| | - Pirom Konglerd
- Section Computational Science, Faculty of Science, University of Amsterdam, Science Park 904, room C3.147, 1090 GE Amsterdam, The Netherlands
| | - Jörg U Hammel
- Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Outstation at DESY, Building 25c Notkestr. 85, D-22607 Hamburg, Germany
| | - Yannicke Dauphin
- Micropaléontologie, UFR TEB Université P. &M. Curie, 75252 Paris, France
| | - Jean-Pierre Cuif
- Micropaléontologie, UFR TEB Université P. &M. Curie, 75252 Paris, France
| | - James C Weaver
- Wyss Institute for Biologically Inspired Engineering at Harvard University, 60 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - Katharina E Fabricius
- Australian Institute of Marine Science, PMB 3, Townsville, 4810 Queensland, Australia
| | - Wolfgang Wagermaier
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany
| | - Peter Fratzl
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany
| | - Giuseppe Falini
- Department of Chemistry 'G. Ciamician', University of Bologna, Via F. Selmi 2, 40126 Bologna, Italy
| | - Stefano Goffredo
- Marine Science Group, Department of Biological, Geological and Environmental Sciences, Section of Biology, University of Bologna, Via F. Selmi 3, 40126 Bologna, Italy
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Pasquini L, Molinari A, Fantazzini P, Dauphen Y, Cuif JP, Levy O, Dubinsky Z, Caroselli E, Prada F, Goffredo S, Di Giosia M, Reggi M, Falini G. Isotropic microscale mechanical properties of coral skeletons. J R Soc Interface 2015; 12. [PMID: 25977958 DOI: 10.1098/rsif.2015.0168] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Scleractinian corals are a major source of biogenic calcium carbonate, yet the relationship between their skeletal microstructure and mechanical properties has been scarcely studied. In this work, the skeletons of two coral species:solitary Balanophyllia europaea and colonial Stylophora pistillata, were investigated by nanoindentation. The hardness HIT and Young's modulus E(IT) were determined from the analysis of several load-depth data on two perpendicular sections of the skeletons: longitudinal (parallel to the main growth axis) and transverse. Within the experimental and statistical uncertainty,the average values of the mechanical parameters are independent on the section's orientation. The hydration state of the skeletons did not affect the mechanical properties. The measured values, EIT in the 76-77 GPa range, and H(IT) in the 4.9–5.1 GPa range, are close to the ones expected for polycrystalline pure aragonite. Notably, a small difference in H(IT) is observed between the species. Different from corals, single-crystal aragonite and the nacreous layer of the seashell Atrina rigida exhibit clearly orientation-dependent mechanical properties. The homogeneous and isotropic mechanical behaviour of the coral skeletons at the microscale is correlated with the microstructure,observed by electron microscopy and atomic force microscopy, and with the X-ray diffraction patterns of the longitudinal and transverse sections.
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Camaiti M, Bortolotti V, Fantazzini P. Stone porosity, wettability changes and other features detected by MRI and NMR relaxometry: a more than 15-year study. Magn Reson Chem 2015; 53:34-47. [PMID: 25322710 DOI: 10.1002/mrc.4163] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 09/15/2014] [Accepted: 09/18/2014] [Indexed: 06/04/2023]
Abstract
Scientists applying magnetic resonance techniques to cultural heritage are now a quite vast and international community, even if these applications are not yet well known outside this community. Not only laboratory experiments but also measurements in the field are now possible, with the use of portable nuclear magnetic resonance (NMR) instruments that enable non-invasive and non-destructive studies on items of any size, of high artistic and historical value as well as diagnosis of their conservation state. The situation was completely different in the second half of the 1990s when our group started working on applications of NMR to cultural heritage, by combining the knowledge of NMR for fluids in porous media at the University of Bologna, with the skilfulness of the chemists for cultural heritage of CNR and University of Florence, and Safeguarding Cultural Heritage Department of Aosta. Since then, our interest has been mainly devoted to develop methods to study the structure of pore space and their changes as a result of the decay, as well as to evaluate performance of the protective and conservative treatments of porous materials like stone, ceramic, cements and wood. In this paper, we will review the pathway that led us from the first tentative experiments, in the second half of the 1990s to the current work on these topics.
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Affiliation(s)
- Mara Camaiti
- Institute for Geosciences and Earth Resources-CNR Section of Florence, Via La Pira, 4, 50121, Florence, Italy; Centro Enrico Fermi, Piazza del Viminale 1, 00184, Rome, Italy
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Bortolotti V, Brizi L, Brown RJS, Fantazzini P, Mariani M. Nano and sub-nano multiscale porosity formation and other features revealed by 1H NMR relaxometry during cement hydration. Langmuir 2014; 30:10871-10877. [PMID: 25152010 DOI: 10.1021/la501677k] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Cement hydration occurs when water is added to cement powder, leading to the formation of crystalline products like Portlandite and the quasi-amorphous, poorly crystalline, calcium silicate hydrate (C-S-H) gel. Despite its importance in determining the final properties of the cement, many models exist for the nano and sub-nano level organization of this "liquid stone." (1)H NMR relaxometry in White Portland Cement paste during hydration allowed us to monitor the formation and evolution of the multiscale porosity of the cement, with the formation of structures at nano and sub-nano levels of C-S-H gel (calcium silicate interlayer water, water in small and large gel pores) along with three low-mobility (1)H pools, identified as (1)H nuclei in C-S-H layers, likely belonging to OH groups, with (1)H nuclei in Portlandite, and in crystal water of Ettringite. By assuming these assignments, our data allowed us to compute the distances of pairs of (1)H nuclei in Portlandite and in crystal water ((1.9 ± 0.2) Å and (1.6 ± 0.1) Å, respectively), consistent with the known values of these distances. The picture of the porous structure at nano and sub-nano levels emerging from our results is consistent with the Jennings colloidal model for C-S-H gel. Moreover, the constant values observed during hydration of parameters extracted from our data analysis strongly support that model, being compatible with the picture of C-S-H gel developing in comparable-sized clumps of the same composition, but not easily interpretable by models proposing quasi continuous sheets of C-S-H layers.
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Affiliation(s)
- Villiam Bortolotti
- DICAM and ‡Department of Physics and Astronomy, University of Bologna , 40100 Bologna, Italy
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Goffredo S, Prada F, Caroselli E, Capaccioni B, Zaccanti F, Pasquini L, Fantazzini P, Fermani S, Reggi M, Levy O, Fabricius KE, Dubinsky Z, Falini G. Biomineralization control related to population density under ocean acidification. Nat Clim Chang 2014; 4:593-597. [PMID: 25071869 PMCID: PMC4110709 DOI: 10.1038/nclimate2241] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Anthropogenic CO2 is a major driver of current environmental change in most ecosystems1, and the related ocean acidification (OA) is threatening marine biota2. With increasing pCO2, calcification rates of several species decrease3, although cases of up-regulation are observed4. Here, we show that biological control over mineralization relates to species abundance along a natural pH gradient. As pCO2 increased, the mineralogy of a scleractinian coral (Balanophyllia europaea) and a mollusc (Vermetus triqueter) did not change. In contrast, two calcifying algae (Padina pavonica and Acetabularia acetabulum) reduced and changed mineralization with increasing pCO2, from aragonite to the less soluble calcium sulphates and whewellite, respectively. As pCO2 increased, the coral and mollusc abundance was severely reduced, with both species disappearing at pH < 7.8. Conversely, the two calcifying and a non-calcifying algae (Lobophora variegata) showed less severe or no reductions with increasing pCO2, and were all found at the lowest pH site. The mineralization response to decreasing pH suggests a link with the degree of control over the biomineralization process by the organism, as only species with lower control managed to thrive in the lowest pH.
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Affiliation(s)
- Stefano Goffredo
- Marine Science Group, Department of Biological, Geological and Environmental Sciences, Section of Biology, Alma Mater Studiorum – University of Bologna, Via F. Selmi 3, 40126 Bologna, Italy
- Corresponding authors: Stefano Goffredo – , Tel. +39 051 2094244, Fax +39 051 2094286.; Giuseppe Falini – , Tel. +39 051 2099484
| | - Fiorella Prada
- Marine Science Group, Department of Biological, Geological and Environmental Sciences, Section of Biology, Alma Mater Studiorum – University of Bologna, Via F. Selmi 3, 40126 Bologna, Italy
| | - Erik Caroselli
- Marine Science Group, Department of Biological, Geological and Environmental Sciences, Section of Biology, Alma Mater Studiorum – University of Bologna, Via F. Selmi 3, 40126 Bologna, Italy
| | - Bruno Capaccioni
- Department of Biological, Geological and Environmental Sciences, Section of Geology, Alma Mater Studiorum – University of Bologna, Piazza di Porta S. Donato 1, 40127 Bologna, Italy
| | - Francesco Zaccanti
- Marine Science Group, Department of Biological, Geological and Environmental Sciences, Section of Biology, Alma Mater Studiorum – University of Bologna, Via F. Selmi 3, 40126 Bologna, Italy
| | - Luca Pasquini
- Department of Physics and Astronomy, Alma Mater Studiorum – University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy
| | - Paola Fantazzini
- Department of Physics and Astronomy, Alma Mater Studiorum – University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy
- Centro Enrico Fermi, Piazza del Viminale 1, 00184 Rome, Italy
| | - Simona Fermani
- Department of Chemistry “G. Ciamician”, Alma Mater Studiorum – University of Bologna, Via F. Selmi 2, 40126 Bologna, Italy
| | - Michela Reggi
- Department of Chemistry “G. Ciamician”, Alma Mater Studiorum – University of Bologna, Via F. Selmi 2, 40126 Bologna, Italy
| | - Oren Levy
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, 52900 Ramat-Gan, Israel
| | | | - Zvy Dubinsky
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, 52900 Ramat-Gan, Israel
| | - Giuseppe Falini
- Department of Chemistry “G. Ciamician”, Alma Mater Studiorum – University of Bologna, Via F. Selmi 2, 40126 Bologna, Italy
- Corresponding authors: Stefano Goffredo – , Tel. +39 051 2094244, Fax +39 051 2094286.; Giuseppe Falini – , Tel. +39 051 2099484
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Fantazzini P, Mengoli S, Evangelisti S, Pasquini L, Mariani M, Brizi L, Goffredo S, Caroselli E, Prada F, Falini G, Levy O, Dubinsky Z. A time-domain nuclear magnetic resonance study of Mediterranean scleractinian corals reveals skeletal-porosity sensitivity to environmental changes. Environ Sci Technol 2013; 47:12679-12686. [PMID: 24144399 DOI: 10.1021/es402521b] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Mediterranean corals are a natural model for studying global warming, as the Mediterranean basin is expected to be one of the most affected regions and the increase in temperature is one of the greatest threats for coral survival. We have analyzed for the first time with time-domain nuclear magnetic resonance (TD-NMR) the porosity and pore-space structure, important aspects of coral skeletons, of two scleractinian corals, Balanophyllia europaea (zooxanthellate) and Leptopsammia pruvoti (nonzooxanthellate), taken from three different sites on the western Italian coast along a temperature gradient. Comparisons have been made with mercury intrusion porosimetry and scanning electron microscopy images. TD-NMR parameters are sensitive to changes in the pore structure of the two coral species. A parameter, related to the porosity, is larger for L. pruvoti than for B. europaea, confirming previous non-NMR results. Another parameter representing the fraction of the pore volume with pore sizes of less than 10-20 μm is inversely related, with a high degree of statistical significance, to the mass of the specimen and, for B. europaea, to the temperature of the growing site. This effect in the zooxanthellate species, which could reduce its resistance to mechanical stresses, may depend on an inhibition of the photosynthetic process at elevated temperatures and could have particular consequences in determining the effects of global warming on these species.
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Affiliation(s)
- Paola Fantazzini
- Department of Physics and Astronomy, University of Bologna , Viale Berti Pichat 6/2, 40127 Bologna, Italy
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Bortolotti V, Fantazzini P, Gombia M, Greco D, Rinaldin G, Sykora S. PERFIDI filters to suppress and/or quantify relaxation time components in multi-component systems: an example for fat-water systems. J Magn Reson 2010; 206:219-226. [PMID: 20702125 DOI: 10.1016/j.jmr.2010.07.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Revised: 07/08/2010] [Accepted: 07/15/2010] [Indexed: 05/29/2023]
Abstract
Parametrically Enabled Relaxation FIlters with Double and multiple Inversion (PERFIDI) is an experimental NMR/MRI technique devised to analyze samples/voxels characterized by multi-exponential longitudinal relaxation. It is based on a linear combination of NMR sequences with suitable preambles composed of inversion pulses. Given any standard NMR/MRI sequence, it permits one to modify it in a way which will attenuate, in a predictable manner and before data acquisition, signals arising from components with different r rates (r=1/T1). Consequently, it is possible to define relatively simple protocols to suppress and/or to quantify signals of different components. This article describes a simple way to construct low-pass, high-pass and band-pass PERFIDI filters. Experimental data are presented in which the method has been used to separate fat and water proton signals. We also present a novel protocol for very fast determination of the ratio between the fat signal and the total signal which avoids any time-consuming magnetization recovery multi-array data acquisition. The method has been validated also for MRI, producing well T1-contrasted images.
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Affiliation(s)
- V Bortolotti
- Department DICAM, University of Bologna, Viale Risorgimento 2, 40136 Bologna, Italy
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Gombia M, Bortolotti V, De Carlo B, Mongiorgi R, Zanna S, Fantazzini P. Nanopore Structure Buildup during Endodontic Cement Hydration Studied by Time-Domain Nuclear Magnetic Resonance of Lower and Higher Mobility 1H. J Phys Chem B 2010; 114:1767-74. [DOI: 10.1021/jp907248r] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mirko Gombia
- Department of Physics, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy; DICAM, University of Bologna, Via Terracini 28, 40131 Bologna, Italy; and Dipartimento di Scienze della Terra e Geologico−Ambientali, University of Bologna, Piazza di Porta S. Donato 1, 40127 Bologna, Italy
| | - Villiam Bortolotti
- Department of Physics, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy; DICAM, University of Bologna, Via Terracini 28, 40131 Bologna, Italy; and Dipartimento di Scienze della Terra e Geologico−Ambientali, University of Bologna, Piazza di Porta S. Donato 1, 40127 Bologna, Italy
| | - Boris De Carlo
- Department of Physics, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy; DICAM, University of Bologna, Via Terracini 28, 40131 Bologna, Italy; and Dipartimento di Scienze della Terra e Geologico−Ambientali, University of Bologna, Piazza di Porta S. Donato 1, 40127 Bologna, Italy
| | - Romano Mongiorgi
- Department of Physics, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy; DICAM, University of Bologna, Via Terracini 28, 40131 Bologna, Italy; and Dipartimento di Scienze della Terra e Geologico−Ambientali, University of Bologna, Piazza di Porta S. Donato 1, 40127 Bologna, Italy
| | - Silvano Zanna
- Department of Physics, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy; DICAM, University of Bologna, Via Terracini 28, 40131 Bologna, Italy; and Dipartimento di Scienze della Terra e Geologico−Ambientali, University of Bologna, Piazza di Porta S. Donato 1, 40127 Bologna, Italy
| | - Paola Fantazzini
- Department of Physics, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy; DICAM, University of Bologna, Via Terracini 28, 40131 Bologna, Italy; and Dipartimento di Scienze della Terra e Geologico−Ambientali, University of Bologna, Piazza di Porta S. Donato 1, 40127 Bologna, Italy
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Palombarini M, Gombia M, Fantazzini P, Giardino R, Giavaresi G, Parrilli A, Vittur F, Guillot G. Inhomogeneity of rat vertebrae trabecular architecture by high-field 3D mu-magnetic resonance imaging and variable threshold image segmentation. J Magn Reson Imaging 2009; 30:825-33. [PMID: 19787728 DOI: 10.1002/jmri.21902] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To analyze the 3D microarchitecture of rat lumbar vertebrae by micro-magnetic resonance imaging (micro-MRI). MATERIALS AND METHODS micro-MR images (20 x 20 x 20 microm(3) apparent voxel size) were acquired with a three-dimensional spin-echo pulse sequence on four lumbar vertebrae of two rats. Apparent microarchitectural parameters like trabecular bone fraction (BV/TV), specific bone surface (BS/TV), mean intercept length (MIL), and Euler number per unit volume (Euler density, E(V)) were calculated using a novel semiquantitative variable threshold segmentation technique. The threshold value T was obtained as a point of minimum or maximum of the function E(V) = E(V)(T). RESULTS Quantitative 3D analysis of micro-MRI images revealed a higher connectivity in the peripheral regions (E(V) = -570 +/- 70 mm(-3)) than in the central regions (E(V) = -130 +/- 50 mm(-3)) of the analyzed rat lumbar vertebrae. Smaller intertrabecular cavities and larger bone volume fractions were observed in peripheral regions as compared to central ones (MIL = 0.18 +/- 0.01 mm and 0.26 +/- 0.01 mm; BV/TV = 34 +/- 3% and 29 +/- 3%, respectively). The quantitative 3D study of MIL showed a structural anisotropy of the trabeculae along the longitudinal axis seen on the images. The inhomogeneity of the bone architecture was validated by micro-computed tomography (micro-CT) images at the same spatial resolution. CONCLUSION 3D high-field micro-MRI is a suitable technique for the assessment of bone quality in experimental animal models.
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Gombia M, Bortolotti V, Brown RJS, Camaiti M, Cavallero L, Fantazzini P. Water Vapor Absorption in Porous Media Polluted by Calcium Nitrate Studied by Time Domain Nuclear Magnetic Resonance. J Phys Chem B 2009; 113:10580-6. [DOI: 10.1021/jp902781f] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mirko Gombia
- Department of Physics, University of Bologna, Viale B. Pichat 6/2, 40127 Bologna, Italy, Department DICMA, University of Bologna, Via Terracini 28, 40131 Bologna, Italy, 953 West Bonita Avenue, Claremont, California 91711-4193, and Istituto ICVBC-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Florence, Italy
| | - Villiam Bortolotti
- Department of Physics, University of Bologna, Viale B. Pichat 6/2, 40127 Bologna, Italy, Department DICMA, University of Bologna, Via Terracini 28, 40131 Bologna, Italy, 953 West Bonita Avenue, Claremont, California 91711-4193, and Istituto ICVBC-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Florence, Italy
| | - Robert J. S. Brown
- Department of Physics, University of Bologna, Viale B. Pichat 6/2, 40127 Bologna, Italy, Department DICMA, University of Bologna, Via Terracini 28, 40131 Bologna, Italy, 953 West Bonita Avenue, Claremont, California 91711-4193, and Istituto ICVBC-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Florence, Italy
| | - Mara Camaiti
- Department of Physics, University of Bologna, Viale B. Pichat 6/2, 40127 Bologna, Italy, Department DICMA, University of Bologna, Via Terracini 28, 40131 Bologna, Italy, 953 West Bonita Avenue, Claremont, California 91711-4193, and Istituto ICVBC-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Florence, Italy
| | - Luisa Cavallero
- Department of Physics, University of Bologna, Viale B. Pichat 6/2, 40127 Bologna, Italy, Department DICMA, University of Bologna, Via Terracini 28, 40131 Bologna, Italy, 953 West Bonita Avenue, Claremont, California 91711-4193, and Istituto ICVBC-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Florence, Italy
| | - Paola Fantazzini
- Department of Physics, University of Bologna, Viale B. Pichat 6/2, 40127 Bologna, Italy, Department DICMA, University of Bologna, Via Terracini 28, 40131 Bologna, Italy, 953 West Bonita Avenue, Claremont, California 91711-4193, and Istituto ICVBC-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Florence, Italy
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Fantazzini P, Gombia M, Schembri P, Simoncini N, Virgili R. Use of Magnetic Resonance Imaging for monitoring Parma dry-cured ham processing. Meat Sci 2009; 82:219-27. [PMID: 20416754 DOI: 10.1016/j.meatsci.2009.01.014] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Revised: 11/11/2008] [Accepted: 01/09/2009] [Indexed: 11/29/2022]
Abstract
Protocols were developed to apply Magnetic Resonance Imaging (MRI) to the dry-curing of Italian Parma ham. NMR relaxation analyses were performed on dry-cured hams at different processing stages to evaluate the ranges of variation of (1)H relaxation times T(1) and T(2) in representative ham muscle tissues, due to dehydration and salt uptake. MRI maps of the same ham sections were acquired, allowing T(1) and T(2) average values to be computed in selected Regions of Interest (ROI) inside muscle Semimembranosus, Semitendinosus and Biceps femoris. Chloride and moisture were determined by conventional chemical methods on the same ROIs, and MRI T(1) and T(1)/T(2) ratio were selected in a model (R(2)=0.90, P<0.05) fitting the salt content of the analysed muscle cores. Short Time Inversion Recovery (STIR) sequences were also applied to green and cured hams, but on fresh samples only, a bright image, displaying a clear separation between lean and fat tissue, was obtained.
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Affiliation(s)
- P Fantazzini
- Department of Physics, University of Bologna, Viale C. Berti Pichat 6/2, I-40127 Bologna, Italy
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Brai M, Casieri C, De Luca F, Fantazzini P, Gombia M, Terenzi C. Validity of NMR pore-size analysis of cultural heritage ancient building materials containing magnetic impurities. Solid State Nucl Magn Reson 2007; 32:129-135. [PMID: 18023331 DOI: 10.1016/j.ssnmr.2007.10.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2007] [Revised: 10/10/2007] [Accepted: 10/11/2007] [Indexed: 05/25/2023]
Abstract
NMR relaxation time distributions, obtained with laboratory and portable devices, are utilized to characterize the pore-size distributions of building materials coming from the Roman remains of the Greek-Roman Theatre of Taormina. To validate the interpretation of relaxation data in terms of pore-size distribution, comparison of results from standard and in situ NMR experiments with results of the mercury intrusion porosimetry (MIP) has been made. Although the pore-size distributions can be obtained by NMR in terms of either longitudinal (T(1)) or transverse (T(2)) relaxation times distributions, the shorter duration of the T(2) measurement makes it, in principle, preferable, although the determination of T(2) distributions is not necessarily an easy alternative to finding T(1) distributions. Among other things, the T(1) distribution is almost independent of the inhomogeneity of the magnetic field, while the T(2) distribution is strongly influenced by it. This paper was aimed at answering two questions: what are the validity limits to interpret NMR data in terms of pore-size distributions and whether the portable device can successfully be applied as a non-destructive and non-invasive tool for in situ NMR analysis of building materials, particularly those of Cultural Heritage interest.
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Affiliation(s)
- M Brai
- Dipartimento di Fisica e Tecnologie Relative, Università di Palermo, V.le delle Scienze Pad.18, I-90128 Palermo, Italy
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Brai M, Camaiti M, Casieri C, De Luca F, Fantazzini P. Nuclear magnetic resonance for cultural heritage. Magn Reson Imaging 2007; 25:461-5. [PMID: 17466764 DOI: 10.1016/j.mri.2006.11.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2006] [Accepted: 11/30/2006] [Indexed: 11/17/2022]
Abstract
Nuclear magnetic resonance (NMR) portable devices are now being used for nondestructive in situ analysis of water content, pore space structure and protective treatment performance in porous media in the field of cultural heritage. It is a standard procedure to invert T(1) and T(2) relaxation data of fully water-saturated samples to get "pore size" distributions, but the use of T(2) requires great caution. It is well known that dephasing effects due to water molecule diffusion in a magnetic field gradient can affect transverse relaxation data, even if the smallest experimentally available half echo time tau is used in Carr-Purcell-Meiboom-Gill experiments. When a portable single-sided NMR apparatus is used, large field gradients due to the instrument, at the scale of the sample, are thought to be the dominant dephasing cause. In this paper, T(1) and T(2) (at different tau values) distributions were measured in natural (Lecce stone) and artificial (brick samples coming from the Greek-Roman Theatre of Taormina) porous media of interest for cultural heritage by a standard laboratory instrument and a portable device. While T(1) distributions do not show any appreciable effect from inhomogeneous fields, T(2) distributions can show strong effects, and a procedure is presented based on the dependence of 1/T(2) on tau to separate pore-scale gradient effects from sample-scale gradient effects. Unexpectedly, the gradient at the pore scale can be, in some cases, strong enough to make negligible the effects of gradients at the sample scale of the single-sided device.
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Affiliation(s)
- Maria Brai
- Dipartimento di Fisica e Tecnologie Relative, Università di Palermo, V.le delle Scienze Pad. 18, I-90128 Palermo, Italy
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Gombia M, Bortolotti V, Fantazzini P, Camaiti M, Schillaci T, Brai M, Lo Casto A, Sorrentino F. Water capillary absorption in porous media in different wettability conditions studied by quantitative MRI and X-ray CT. Magn Reson Imaging 2007. [DOI: 10.1016/j.mri.2007.01.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Kuethe DO, Scholz MD, Fantazzini P. Imaging inert fluorinated gases in cracks: perhaps in David's ankles. Magn Reson Imaging 2007; 25:505-8. [PMID: 17466774 DOI: 10.1016/j.mri.2006.11.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2006] [Accepted: 11/30/2006] [Indexed: 11/24/2022]
Abstract
Inspired by the challenge of determining the nature of cracks on the ankles of Michelangelo's statue David, we discovered that one can image SF(6) gas in cracks in marble samples with alacrity. The imaging method produces images of gas with a signal-to-noise ratio (SNR) of 100-250, which is very high for magnetic resonance imaging (MRI) in general, let alone for an image of a gas at thermal equilibrium polarization. To put this unusual SNR in better perspective, we imaged SF(6) in a crack in a marble sample and imaged the lung tissue of a live rat (a more familiar variety of sample to many MRI scientists) using the same pulse sequence, the same size coils and the same MRI system. In both cases, we try to image subvoxel thin sheets of material that should appear bright against a darker background. By choosing imaging parameters appropriate for the different relaxation properties of SF(6) gas versus lung tissue and by choosing voxel sizes appropriate for the different goals of detecting subvoxel cracks on marble versus resolving subvoxel thin sheets of tissue, the SNR for voxels full of material was 220 and 14 for marble and lung, respectively. A major factor is that we chose large voxels to optimize SNR for detecting small cracks and we chose small voxels for resolving lung features at the expense of SNR. Imaging physics will cooperate to provide detection of small cracks on marble, but David's size poses a challenge for magnet designers. For the modest goal of imaging cracks in the left ankle, we desire a magnet with an approximately 32-cm gap and a flux density of approximately 0.36 T that weighs <500 kg.
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Sykora S, Bortollotti V, Fantazzini P. PERFIDI: parametrically enabled relaxation filters with double and multiple inversion. Magn Reson Imaging 2007; 25:529-32. [PMID: 17466780 DOI: 10.1016/j.mri.2006.12.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Accepted: 12/01/2006] [Indexed: 10/23/2022]
Abstract
We present a novel approach to the nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) analysis of complex samples with nontrivial distribution of longitudinal relaxation rate R(1). Parametrically enabled relaxation filters with double and multiple inversion (PERFIDI) aim to separate signals arising from components with different R(1) values prior to actual data acquisition. Given any standard NMR/MRI pulse sequence, which, by itself, is insensitive to differences in R(1) values, it can be combined with a PERFIDI preamble, which functions as a preliminary R(1) filter and confers on the original technique sensitivity to the dimension R(1). This article states the principles of the approach, including the way to account for instrumental imperfections, and shows how PERFIDI with specific filter profile functions can be built. Using terms borrowed from electronics, these filters are classified as low-pass, high-pass and band-pass types. Also included are an experimental verification example and a discussion of potential applications of PERFIDI in various NMR areas.
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Affiliation(s)
- Stanislav Sykora
- Extra Byte, Via Raffaello Sanzio 22C, Castano Primo I-20022, Italy
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Fantazzini P, Garavaglia C, Gomez S, Toffanin R, Vittur F. Chondrocyte-alginate bioconstructs: An nuclear magnetic resonance relaxation study. J Biomed Mater Res A 2007; 83:345-53. [PMID: 17450576 DOI: 10.1002/jbm.a.31239] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Proton nuclear magnetic resonance (NMR) relaxometry can give informations about hydrogel scaffold properties. As these properties can be modified with culture time and conditions according to scaffold biodegradability and new tissue biosynthesis, the aim of this research was to test the efficiency of this noninvasive NMR technique in the follow-up of 3D cultures for tissue engineering. The distributions of proton relaxation times T1 and T2 have been measured on cylindrical gel samples of different types of alginate, in the presence or absence of hyaluronate, in gels or bioconstructs with encapsulated chondrocytes cultured for 30 days in normal or reduced weight conditions. It was found that T2 increases with the mannuronate/guluronate ratio in alginate samples and with the presence of hyaluronate. The distributions of both T1 and T2 result wider for bioconstructs cultured in normal gravity than for those cultured in reduced weight conditions. Neither cell growing nor collagen production but only GAG neosynthesis have been demonstrated in our experimental conditions. In conclusion, T2 is sensitive to the gel properties (possibly to the rigidity of macromolecular components). The homogeneity of bioconstructs can be monitored by the distribution of T1 and T2. We propose that nonspatially resolved NMR relaxometry can efficiently be used in monitoring tissue development in a biodegradable scaffold for tissue engineering.
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Affiliation(s)
- Paola Fantazzini
- Department of Physics, University of Bologna, Viale Berti Pichat 6/2, I-40127 Bologna, Italy
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Bortolotti V, Camaiti M, Casieri C, De Luca F, Fantazzini P, Terenzi C. Water absorption kinetics in different wettability conditions studied at pore and sample scales in porous media by NMR with portable single-sided and laboratory imaging devices. J Magn Reson 2006; 181:287-95. [PMID: 16782372 DOI: 10.1016/j.jmr.2006.05.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2006] [Revised: 05/23/2006] [Accepted: 05/30/2006] [Indexed: 05/10/2023]
Abstract
NMR relaxation time distributions of water (1)H obtained by a portable single-sided surface device have been compared with MRI internal images obtained with a laboratory imaging apparatus on the same biocalcarenite (Lecce Stone) samples during capillary water uptake. The aim of this work was to check the ability of NMR methods to quantitatively follow the absorption phenomenon under different wettability conditions of the internal pore surfaces. Stone wettability changes were obtained by capillary absorption of a chloroform solution of Paraloid PB72, a hydrophobic acrylic resin frequently used to protect monuments and buildings, through one face of each sample. Both relaxation and imaging data have been found in good quantitative agreement each other and with masses of water determined by weighing the samples. In particular the Washburn model of water capillary rise applied to the imaging data allowed us to quantify the sorptivity in both treated and untreated samples. Combining relaxation and imaging data, a synergetic improvement of our understanding of the water absorption kinetics at both pore and sample scales is obtained. Since relaxation data have been taken over the course of time without interrupting the absorption process, simply by keeping the portable device on the surface opposite to the absorption, the results show that the single-sided NMR technique is a powerful tool for in situ evaluation of water-repellent treatments frequently used for consolidation and/or protection of stone artifacts.
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Affiliation(s)
- V Bortolotti
- Dipartimento DICMA, Università di Bologna, Viale Risorgimento 2, I-40126 Bologna, Italy
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Marcos M, Cano P, Fantazzini P, Garavaglia C, Gomez S, Garrido L. NMR relaxometry and imaging of water absorbed in biodegradable polymer scaffolds. Magn Reson Imaging 2006; 24:89-95. [PMID: 16410183 DOI: 10.1016/j.mri.2005.10.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2005] [Revised: 10/16/2005] [Accepted: 10/16/2005] [Indexed: 11/20/2022]
Abstract
Porous substrates made of poly(3-hydroxybutyrate-3-hydroxyvalerate) (PHBHV) were prepared by a particulate leaching method. After removing the salt by extraction in water, proton nuclear magnetic resonance (NMR) relaxometry and imaging were performed on sets of PHBHV substrates immersed in phosphate-buffered solution during 3 months at different time points. Polarized optical microscopy studies were performed on thin sections, 25 and 5 mum, of the PHBHV samples. The results of NMR relaxometry showed two (1)H nuclei populations, well distinguishable on the free induction decay (FID), due to the different decay time constants, a factor of 10(2) apart. Thus, it was possible to separate the two populations, giving separate distributions of T(1) relaxation times. One population could be associated with water protons in the pores and the other to macromolecular protons. The distributions of T(1) and T(2) of the water proton shifted to lower values with increasing immersion time to a constant value after 30 days. The results obtained by NMR imaging showed an initial increase in the apparent porosity, reaching a plateau after 25 days of immersion. This increase is attributed mainly to the absorption of water in the microporosity as supported by the results of the relaxometry measurements and shown by scanning electron microscopy. The average porosity measured by NMR imaging at the plateau, 78+/-3%, is slightly higher than that determined by optical microscopy, 73+/-9%, which may be due to the fact that the latter method did not resolve the microporosity. Overall, the results suggest that at early stages after immersing the scaffolds in the aqueous medium, first 30 days approximately, NMR imaging could underestimate the porosity of the substrate.
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Affiliation(s)
- Marta Marcos
- Department of Physical Chemistry, Institute of Polymer Science and Technology, CSIC, E-28006 Madrid, Spain
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Fantazzini P, Brown RJS. Initially linear echo-spacing dependence of 1/T2 measurements in many porous media with pore-scale inhomogeneous fields. J Magn Reson 2005; 177:228-35. [PMID: 16150621 DOI: 10.1016/j.jmr.2005.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2005] [Revised: 07/24/2005] [Accepted: 08/01/2005] [Indexed: 05/04/2023]
Abstract
For a liquid sample with unrestricted diffusion in a constant magnetic field gradient g, the increase R in R2=1/T2 for CPMG measurements is 1/3(taugammag)2D, where gamma is magnetogyric ratio, tau is the half the echo spacing TE, and D is the diffusion constant. For measurements on samples of porous media with pore fluids and without externally applied gradients there may still be significant pore-scale local inhomogeneous fields due to susceptibility differences, whose contributions to R2 depend on tau. Here, diffusion is not unrestricted nor is the field gradient constant. One class of approaches to this problem is to use an "effective gradient" or some kind of average gradient. Then, R2 is often plotted against tau2, with the effective gradient determined from the slope of some of the early points. In many cases, a replot of R2 against tau instead of tau2 shows a substantial straight-line interval, often including the earliest available points. In earlier work [G.C. Borgia, R.J.S. Brown, P. Fantazzini, Phys. Rev. E 51 (1995) 2104; R.J.S. Brown, P. Fantazzini, Phys. Rev. B 47 (1993) 14823] these features were noted, and attention was called to the fact that very large changes in field and gradient are likely for a small part of the pore fluid over distances very much smaller than pore dimensions. A truncated Cauchy-Lorentz (C-L) distribution of local fields in the pore space was used to explain observations, giving reduced effects of diffusion because of the averaging properties of the C-L distribution, the truncation being at approximately +/-1/2chiB0, where chi is the susceptibility difference. It was also noted that, when there is a narrow range of pore size a, over a range of about 40 of the parameter xi=1/3chinua2/D, where nu is the frequency, R2 does not depend much on pore size a nor on diffusion constant D. Examples are shown where plots of R2 vs tau show better linear fits to the data for small tau values than do plots vs tau2. The present work shows that, if both grain-scale and sample-scale gradients are present for samples with narrow ranges of T2, it may be possible to identify the separate effects with the linear and quadratic coefficients in a second-order polynomial fit to the early data points. Of course, many porous media have wide pore size and T2 distributions and hence wide ranges of xi. For some of these wide distributions we have plotted R2 vs tau for signal percentiles, normalized to total signal for shortest tau, again showing initially linear tau-dependence even when available data do not cover the longest and/or shortest T2 values for alltau values. For the examples presented, both the intercepts and the initial slopes of the plots of R2 vs tau increase systematically with signal percentile, starting at smallest R2.
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Affiliation(s)
- Paola Fantazzini
- University of Bologna, Department of Physics, Viale Berti Pichat 6/2, 40127 Bologna, Italy.
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Fantazzini P, Bortolotti V, Garavaglia C, Gombia M, Riccardi S, Schembri P, Virgili R, Soresi Bordini C. Magnetic resonance imaging and relaxation analysis to predict noninvasively and nondestructively salt-to-moisture ratios in dry-cured meat. Magn Reson Imaging 2005; 23:359-61. [PMID: 15833647 DOI: 10.1016/j.mri.2004.11.064] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2004] [Accepted: 11/15/2004] [Indexed: 11/25/2022]
Abstract
The current systems are unable to control and predict the cured meat composition nondestructively and in a reasonable time for production needs. In this work, T1 and T2 maps were obtained, with a monoexponential model, on internal sections of Longissimus dorsi muscle at increasing salting times. The maps allow one to visualize the salting process nondestructively and noninvasively. The method goes beyond the simple qualitative visualization, because, for each section of the sample and in any region of the section, it is possible to obtain quantitative information on the progress of salting and to predict salt-to-moisture ratios. In addition, detailed relaxation measurements were performed on samples cored after imaging in order to define better the relaxation properties of the dry-cured meat.
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Affiliation(s)
- Paola Fantazzini
- Department of Physics, University of Bologna, 40127 Bologna, Italy.
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Maccotta A, Fantazzini P, Garavaglia C, Donato ID, Perzia P, Brai M, Morreale F. Preliminary1H NMR Study on Archaeological Waterlogged Wood. ACTA ACUST UNITED AC 2005; 95:117-24. [PMID: 16485652 DOI: 10.1002/adic.200590013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Magnetic Resonance Relaxation (MRR) and Magnetic Resonance Imaging (MRI) are powerful tools to obtain detailed information on the pore space structure that one is unlikely to obtain in other ways. These techniques are particularly suitable for Cultural Heritage materials, because they use water 1H nuclei as a probe. Interaction with water is one of the main causes of deterioration of materials. Porous structure in wood, for example, favours the penetration of water, which can carry polluting substances and promote mould growth. A particular case is waterlogged wood from underwater discoveries and moist sites; in fact, these finds are very fragile because of chemical, physical and biological decay from the long contact with the water. When wood artefacts are brought to the surface and directly dried in air, there is the collapse of the cellular structures, and wood loses its original form and dimensions and cannot be used for study and museum exhibits. In this work we have undertaken the study of some wood finds coming from Ercolano's harbour by MRR and MRI under different conditions, and we have obtained a characterization of pore space in wood and images of the spatial distribution of the confined water in the wood.
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Affiliation(s)
- Antonella Maccotta
- Dipartimento di Chimica, Università di Siena, Via A. Moro, 53100 Siena, Italy
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Abstract
The magnetic resonance in porous media (MRPM) community is now a vast community of scientists from all over the world who recognize magnetic resonance as an instrument of choice for the characterization of pore space and of the distribution, diffusion and flow of fluids inside a vast range of different materials. The MRPM conferences are the occasions in which this community gets together, compares notes and grows. The scene was different in 1990, when this series of conferences was promoted at Bologna. I will go briefly over the history of these events, showing the role played by the University of Bologna and in particular by the intuition, ingenuity and passion of Giulio Cesare Borgia. The MRPM work at Bologna began in the mid-1980s. New correlations were found among parameters from NMR relaxation measurements and oil field parameters such as porosity, permeability to fluid flow, irreducible water saturation, residual oil saturation and pore-system surface-to-volume ratio, and fast algorithms were developed to give the different NMR parameters. Interest in valid interpretation of data led to extensive work also on the inversion of multiexponential relaxation data and the effects of inhomogeneous fields from susceptibility differences on distributions of relaxation times. In the last few years, extensive developments were made of combined magnetic resonance imaging and relaxation measurements in different fields.
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Affiliation(s)
- Paola Fantazzini
- Dipartimento di Fisica, Università di Bologna, 40127 Bologna, Italy.
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Fantazzini P, Gore JC, Korb JP. The seventh international conference on magnetic resonance applications to porous media. Magn Reson Imaging 2005; 23:121-3. [PMID: 15833601 DOI: 10.1016/j.mri.2004.11.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2004] [Accepted: 11/10/2004] [Indexed: 11/18/2022]
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Fantazzini P, Garavaglia C, Palombarini M, Brown RJS, Giavaresi G, Giardino R. Analysis of 1H-NMR relaxation time distributions in L1 to L6 rat lumbar vertebrae. Magn Reson Imaging 2004; 22:689-95. [PMID: 15172063 DOI: 10.1016/j.mri.2004.01.064] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2003] [Accepted: 01/29/2004] [Indexed: 11/16/2022]
Abstract
A better knowledge of the NMR relaxation behavior of bone tissue can improve the definition of imaging protocols to detect bone diseases like osteoporosis. The six rat lumbar vertebrae, from L1 to L6, were analyzed by means of both transverse (T(2)) and longitudinal (T(1)) relaxation of (1)H nuclei at 20 MHz and 30 degrees C. Distributions of relaxation times, computed using the multiexponential inversion software uniform penalty inversion, extend over decades for both T(2) and T(1) relaxation. In all samples, the free induction decay (FID) from an inversion-recovery (IR) T(1) measurement shows an approximately Gaussian (solid-like) component, exp[-1/2(t/T(GC))2], with T(GC) approximately 12 micros (GC for Gaussian component) and a liquid-like component (LLC) with initially simple-exponential decay. Averaging and smoothing procedures are adopted to obtain the ratio alpha between GC and LLC signals and to get separate T(1) distributions for GC and LLC. Distributions of T(1) for LLC show peaks centered at 300-500 ms and shoulders going down to 10 ms, whereas distributions of T(1) for GC are single broad peaks centered at roughly 100 ms. The T(2) distributions by Carr-Purcell-Meiboom-Gill at 600 micros echo spacing are very broad and extend from 1 ms to hundreds of ms. This long echo spacing does not allow one to see a peak in the region of hundreds of micros, which is better seen by single spin-echo T(2) measurements. Results of the relaxation analysis were then compared with densitometric data. From the study, a clear picture of the intratrabecular and intertrabecular (1)H signals emerges. In particular, the GC is presumed to be due to (1)H in collagen, LLC due to all the fluids in the bone including water and fat, and the very short T(2) peak due to the intratrabecular water. Overall, indications of some trends in composition and in pore-space distributions going from L1 to L6 appeared. Published results on rat vertebrae obtained by fitting the curves by discrete two-component models for both T(2) and T(1) are consistent with our results and can be better interpreted in light of the shown distributions of relaxation times.
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Affiliation(s)
- P Fantazzini
- Dipartimento di Fisica, Università di Bologna, Bologna, Italy.
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Abstract
Despite significant differences between bone tissues and other porous media such as oilfield rocks, there are common features as well as differences in the response of NMR relaxation measurements to the internal structures of the materials. Internal surfaces contribute to both transverse (T2) and longitudinal (T1) relaxation of pore fluids, and in both cases the effects depend on, among other things, local surface-to-volume ratio (S/V). In both cases variations in local S/V can lead to distributions of relaxation times, sometimes over decades. As in rocks, it is useful to take bone data under different conditions of cleaning, saturation, and desaturation. T1 and T2 distributions are computed using UPEN. In trabecular bone it is easy to see differences in dimensions of intertrabecular spaces in samples that have been de-fatted and saturated with water, with longer T1 and T2 for larger pores. Both T1 and T2 distributions for these water-saturated samples are bimodal, separating or partly separating inter- and intratrabecular water. The T1 peak times have a ratio of from 10 to 30, depending on pore size, but for the smaller separations the distributions may not have deep minima. The T2 peak times have ratios of over 1000, with intratrabecular water represented by large peaks at a fraction of a ms, which we can observe only by single spin echoes. CPMG data show peaks at about a second, tapering down to small amplitudes by a ms. In all samples the free induction decay (FID) from an inversion-recovery (IR) T1 measurement shows an approximately Gaussian (solid-like) component, exp[-1/2 (T/TGC), with TGC approximately 11.7+/-0.7 micros (GC for "Gaussian Component"), and a liquid-like component (LLC) with initially simple-exponential decay at the rate-average time T(2-FID) for the first 100 micros. Averaging and smoothing procedures are adopted to derive T(2-FID) as a function of IR time and to get T1 distributions for both the GC and the LLC. It appears that contact with the GC, which is presumed to be 1H on collagen, leads to the T2 reduction of at least part of the LLC, which is presumed to be water. Progressive drying of the cleaned and water-saturated samples confirms that the long T1 and T2 components were in the large intertrabecular spaces, since the corresponding peaks are lost. Further drying leads to further shortening of T2 for the remaining water but eventually leads to lengthening of T1 for both the collagen and the water. After the intertrabecular water is lost by drying, T1 is the same for GC and LLC. T(2-FID) is found to be roughly 320/alpha micros, where alpha is the ratio of the extrapolated GC to LLC, appearing to indicate a time tau of about 320 micros for 1H transverse magnetization in GC to exchange with that of LLC. This holds for all samples and under all conditions investigated. The role of the collagen in relaxation is confirmed by treatment to remove the mineral component, observing that the GC remains and has the same TGC and has the same effect on the relaxation times of the associated water. Measurements on cortical bone show the same collagen-related effects but do not have the long T1 and T2 components.
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Affiliation(s)
- Paola Fantazzini
- Univ. of Bologna, Dept. of Physics, Viale Berti Pichat 6/2, 40127 Bologna, Italy.
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Borgia GC, Bortolotti V, Fantazzini P, Gombia M, Zaniboni M. Improved pore space structure characterization by fusion of relaxation tomography maps. Magn Reson Imaging 2003; 21:393-4. [PMID: 12850742 DOI: 10.1016/s0730-725x(03)00147-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Quantitative Relaxation Tomography in porous media furnishes maps of internal sections where each pixel represents T1 or T2 of water 1H in the corresponding voxel, so that quantitative information on the pore space structure can be obtained. The porosity can be determined at different length scales by correcting pixel by pixel the signal intensity for T2 decay. Moreover, on the basis of the distribution of T1, the microporosity fraction can be computed, as well as several voxel-average porosities. Since T1 and T2 encode different pieces of information, fusion image techniques can improve the characterization of the pore space, showing simultaneously, on the same image, maps of the two parameters. Examples are given of application to a water-saturated travertine core and to a pig femur. Different kinds of look-up tables were tried by varying two of the three dimensions of the HSV color space in such a way as to optimize both the T1 and T2 contrasts simultaneously.
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Affiliation(s)
- G C Borgia
- University of Bologna, Dept. of ICMA, Viale Risorgimento 2, 40136 Bologna, Italy
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Appolonia L, Borgia GC, Bortolotti V, Brown RJ, Fantazzini P, Rezzaro G. Effects of hydrophobic treatments of stone on pore water studied by continuous distribution analysis of NMR relaxation times. Magn Reson Imaging 2001; 19:509-12. [PMID: 11445343 DOI: 10.1016/s0730-725x(01)00280-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The effects of protective hydrophobic products applied to porous media such as stone or mortar vary greatly with the product, the porous medium, and the mode of application. Nuclear Magnetic Resonance (NMR) measurements on fluids in the pore spaces of both treated and untreated samples can give information on the contact of the fluid with the internal surfaces, which is affected by all the above factors. Continuous distributions of relaxation times T(1) and T(2) of water in the pores of both synthetic and natural porous media were obtained before and after hydrophobic treatment. The synthetic porous media are ceramic filter materials characterized by narrow distributions of pore dimensions and show that the treatment does not produce large changes in the relaxation times of the water. For three travertine samples most of a long relaxation time component, presumably from the largest pores, remains after treatment, while the amplitude of an intermediate component is greatly reduced. For three pudding-stone samples, treatment leads to a substantial loss from the long component and an even greater loss from the intermediate component.
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Affiliation(s)
- L Appolonia
- Safeguarding Cultural Heritage Department, Piazza Narbonne 3, 11100, Aosta, Italy
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Abstract
One of the most critical structural parameters in elastomeric materials is the density of cross-linking between the polymeric chains. This chemical feature greatly affects chain motions and is determinant in controlling mechanical properties of the final product. NMR techniques are widely and efficiently applied to investigation of such materials. In this study we have measured both transverse and longitudinal 1H relaxation times of a series of polybutadiene rubber samples with increasing crosslink density induced by chemical treatment. This approach allowed the observation of T(1) and T(2) decrease with the increase of crosslink density in the samples examined. The data obtained have been analyzed and compared to theoretical models.
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Affiliation(s)
- G C Borgia
- University of Bologna, Department ICMA, Viale Risorgimento 2, 40136, Bologna, Italy
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Abstract
The multiexponential inversion program UPEN by the authors [J. Magn. Reson. 1998; 132: 65-77; Ibid. 2000;147:273-85] employs negative feedback to a regularization penalty to implement variable smoothing when both sharp and broad features appear on a single distribution of relaxation times. This allows a good fit to relaxation data that correspond to a sum of decaying exponentials plus random noise, but it usually does not give a good fit to data that are distorted by systematic errors from instrument problems, which can cause erroneous "resolution" or erroneous non-resolution of peaks. UPEN provides a series of diagnostic parameters to help identify such data problems that can lead to interpretation errors, and, in particular, to warn when a close call on the resolution or non-resolution of nearby peaks might be questionable. Examples are given from a series of T(2) data sets from desiccated bone samples, with examples where the presence of two peaks is required by good data, examples where the presence of two peaks is negated by good data, and examples where the resolution or non-resolution of peaks cannot be trusted because of instrumental distortions revealed by UPEN diagnostic parameters. It is suggested that processing relaxation data with UPEN in nearly real time could permit retaking data while a sample is still available if the diagnostic parameters show instrumental problems.
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Affiliation(s)
- G C Borgia
- University of Bologna, Dept. of ICMA, Viale Risorgimento 2, 40136, Bologna, Italy
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Fantazzini P, Garavaglia C, Guglielmi G. From porous media to trabecular bone relaxation analysis: spatial variation of marrow 1H relaxation time distributions detected in vitro by quasi-continuous distribution analysis. Magn Reson Imaging 2001; 19:477-80. [PMID: 11445334 DOI: 10.1016/s0730-725x(01)00271-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Quasi-continuous distributions of T(1) and T(2) of 1H nuclei were analyzed in vitro at 20MHz on some twenty fresh bone samples of pig femur. Large numbers of data points allowed a detailed investigation. Relaxation data were inverted by UPEN (Uniform PENalty inversion). In all samples the widths of the distributions, covering more than two decades, are not even close to being compatible with single exponential components. Moreover, the T(1) and T(2) distributions show enough character to distinguish the samples. We observe a spatial variation of these characteristics and in particular a second peak centered at 500-600 ms appearing in some proximal femur samples. The quasi-continuous distribution allows one to correlate the water content of the sample with parts of the distributions in specific time ranges. The signal fraction with T(1) values longer than a cutoff time of about 170 ms is in very good agreement with the water content of the samples and is significantly larger in the group of samples cored from proximal femur. Also T(2) distributions differentiate the samples, and the signal fraction with T(2) shorter than about 30 ms is significantly larger in the group of distal femur samples.
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Affiliation(s)
- P Fantazzini
- Physics Department, University of Bologna, Viale Berti Pichat 6/2, 40127, Bologna, Italy.
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Abstract
MR-Relaxation (MRR) of 1H nuclei and MR-Cryoporometry (MRC) are combined to assess their feasibility and their potential in the study of bone microstructure. In principle, both techniques are able to give information on the structure of the pore space confining the fluids. Cow femur samples were carefully cored and cleaned in order to remove the natural fluids inside. For MRR analysis quasi-continuous distributions of T(1) and T(2) were obtained on samples fully saturated with water. Cyclohexane was used as a saturating fluid for MRC analysis. All T(1) and T(2) quasi-continuous distributions of water confined in bone samples are more than three decades wide, showing sufficient details to differentiate the samples. Pore size distributions obtained by MRC also differentiate the samples showing different characteristics of the pore space structure in the range of the highest sensitivity of the method (typically 3 to 100 nm, mesopore range). In particular, in samples where MRR shows a large fraction of signal with relaxation times below 10(2) ms, MRC indicates a large fraction of pore volume with pore sizes in the mesopore range.
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Affiliation(s)
- P Fantazzini
- Physics Department, University of Bologna, Viale Berti Pichat 6/2, Bologna, Italy.
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43
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Borgia GC, Bortolotti V, Camaiti M, Cerri F, Fantazzini P, Piacenti F. Performance evolution of hydrophobic treatments for stone conservation investigated by MRI. Magn Reson Imaging 2001; 19:513-6. [PMID: 11445344 DOI: 10.1016/s0730-725x(01)00281-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
1H-MRI has been applied to the evaluation of the performances of a hydrophobic polymer (Paraloid B72), widely used for the conservation of monumental buildings and other stone artifacts. By this technique it has been possible to visualize the water diffusion in a treated rock material (Pietra di Lecce, a highly porous Italian biocalcarenite) and then indirectly the spatial distribution of the polymer in the rock. The effects of wetting-drying cycles on the hydrophobic efficacy of the acrylic polymer in the inner layers of the rock were also studied. A notable decrease in the water-repellence inside the stone was detected and attributed to a loss of adhesion of the polymer to the substrate, promoted by the action of water.
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Affiliation(s)
- G C Borgia
- Dept. ICMA, University of Bologna, Viale Risorgimento 2, 40136, Bologna, Italy
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44
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Abstract
Longitudinal and transverse NMR relaxation of 1H nuclei were studied in vitro on fresh animal femur samples. A large number of data points were taken, starting at 100 micros for T(1) by inversion-recovery, at 200 micros for T(2) by single-echo sequences, and at 600 micros for T(2) by CPMG echo-trains. Quasi-continuous distributions of relaxation times were computed, giving wide distributions for all samples. Bulk marrow removed from the medullary cavity showed T(2) distributions from about 20 ms to 600 ms and T(1) distributions from about 40 ms to 2 s. The 1H nuclei in trabecular bone samples, where marrow is confined, may show long tails for T(2) at relaxation times down to 250 micros, the origin of which is still not known. These tails are absent in bulk marrow from the medullary cavity. The differences observed in T(1) distributions among trabecular bone samples are in accordance with the different marrow compositions. Discrete exponential fits were computed also, and in most cases four discrete exponential components were required to fit the experimental data adequately. However, the discrete components do not seem to correspond to any physically distinguishable separate compartments.
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Affiliation(s)
- P Fantazzini
- Physics Department, University of Bologna, Viale Berti Pichat 6/2, Bologna, Italy.
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45
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Borgia GC, Brown RJ, Fantazzini P. Uniform-penalty inversion of multiexponential decay data. II. Data spacing, T(2) data, systemic data errors, and diagnostics. J Magn Reson 2000; 147:273-285. [PMID: 11097819 DOI: 10.1006/jmre.2000.2197] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The basic method of UPEN (uniform penalty inversion of multiexponential decay data) is given in an earlier publication (Borgia et al., J. Magn. Reson. 132, 65-77 (1998)), which also discusses the effects of noise, constraints, and smoothing on the resolution or apparent resolution of features of a computed distribution of relaxation times. UPEN applies negative feedback to a regularization penalty, allowing stronger smoothing for a broad feature than for a sharp line. This avoids unnecessarily broadening the sharp line and/or breaking the wide peak or tail into several peaks that the relaxation data do not demand to be separate. The experimental and artificial data presented earlier were T(1) data, and all had fixed data spacings, uniform in log-time. However, for T(2) data, usually spaced uniformly in linear time, or for data spaced in any manner, we have found that the data spacing does not enter explicitly into the computation. The present work shows the extension of UPEN to T(2) data, including the averaging of data in windows and the use of the corresponding weighting factors in the computation. Measures are implemented to control portions of computed distributions extending beyond the data range. The input smoothing parameters in UPEN are normally fixed, rather than data dependent. A major problem arises, especially at high signal-to-noise ratios, when UPEN is applied to data sets with systematic errors due to instrumental nonidealities or adjustment problems. For instance, a relaxation curve for a wide line can be narrowed by an artificial downward bending of the relaxation curve. Diagnostic parameters are generated to help identify data problems, and the diagnostics are applied in several examples, with particular attention to the meaningful resolution of two closely spaced peaks in a distribution of relaxation times. Where feasible, processing with UPEN in nearly real time should help identify data problems while further instrument adjustments can still be made. The need for the nonnegative constraint is greatly reduced in UPEN, and preliminary processing without this constraint helps identify data sets for which application of the nonnegative constraint is too expensive in terms of error of fit for the data set to represent sums of decaying positive exponentials plus random noise.
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Affiliation(s)
- G C Borgia
- Department of ICMA, University of Bologna, Viale Risorgimento 2, 40136 Bologna, Italy
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46
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Borgia GC, Bortolotti V, Brown RJ, Fantazzini P. A method for approximating fractional power average relaxation times without inversion of multiexponential relaxation data. Magn Reson Imaging 1998; 16:625-7. [PMID: 9803924 DOI: 10.1016/s0730-725x(98)00039-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A method is presented for approximating fractional power averages of relaxation times for data equispaced in log time, without the need to invert multiexponential relaxation data. This form of average permits giving emphasis to short or long times depending on the choice of the p value, thus giving the possibility of representing different specific properties of porous media. This method has been tested on a large number of nuclear magnetic resonance (NMR) relaxation measurements in porous samples. This new algorithm appears to be robust with respect to both measurement and computation, and its major advantage is that it does not depend on a particular inversion method. Moreover, it permits a very fast computation.
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Affiliation(s)
- G C Borgia
- Department of Chemical Mining and Environmental Engineering, University of Bologna, Italy
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47
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Abstract
When multiexponential relaxation data are inverted to give quasi-continuous distributions of relaxation times, the computed distribution is usually smoothed by means of an applied penalty function equal to a coefficient, C, times the integrated square of amplitude, slope, or curvature. When the distribution has a sharp peak and either a broad peak or long tail, smoothing with a fixed coefficient, C, widens the sharp peak and/or breaks up the broad peak or tail into two or more separate peaks. An iterative feedback procedure is used to generate a separate C value for each computed point in such a way as to give roughly equal contributions to the penalty function from each computed point. This permits adequate smoothing of broad features without oversmoothing sharp peaks. Examples are given for artificial data, for nuclear magnetic resonance in fluids in porous media, and for nuclear magnetic resonance in biological tissues.
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Affiliation(s)
- G C Borgia
- Department of Chemical Mining and Environmental Engineering, University of Bologna, Italy
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48
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Borgia GC, Brown RJ, Fantazzini P. Estimates of permeability and irreducible water saturation by means of a new robust computation of fractional power average relaxation times. Magn Reson Imaging 1998; 16:613-5. [PMID: 9803921 DOI: 10.1016/s0730-725x(98)00042-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In a suite of water-saturated sandstones, we have recently demonstrated that irreducible water saturation can be well estimated using relaxation time only, in the form of any of several "averages" giving more emphasis to short times than does the geometric mean time. The best estimate of permeability came from fits giving more emphasis to slightly longer times. In this paper we present estimates of irreducible water saturation and permeability using approximations (here called Robusta approximation) to the fractional power average relaxation time (Tp)1/p. The advantage of this approximation is that it does not involve previous computation of exponential components; therefore, it does not depend on the choice of the inversion method, and it permits a very fast computation. The Robusta approximation gives some of the best correlations using p = -0.55 for irreducible water saturation and p = +0.18 for permeability.
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Affiliation(s)
- G C Borgia
- Department of Chemical Mining and Environmental Engineering, University of Bologna, Italy
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49
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Abstract
NMR relaxation data and those from many other physical measurements are sums of exponentially decaying components, combined with some unavoidable measurement noise. When decay data are inverted in order to give quasi-continuous distributions of relaxation times, some smoothing of the distributions is normally implemented to avoid excess variation. When the same distribution has a sharp peak and a much broader peak or a "tail," as for many porous media saturated with liquids, an inversion program using a fixed smoothing coefficient may broaden the sharp peak and/or break the wide peak or tail into several separate peaks, even if the coefficient is adaptively chosen in accord with the noise level of the data. We deal with this problem by using variable smoothing, determined by iterative feedback in such a way that the smoothing penalty is roughly constant. This uniform-penalty (UP) smoothing can give sharp lines, not broadened more than is consistent with the noise, and in the same distribution it can show a tail decades long without breaking it up into several peaks. The noise level must be known approximately, but it can be determined more than adequately by a preliminary inversion. The same iterative procedure is used to implement constraints such as non-negative (NN) or monotonic-from-peak (MT). The significance of an additional resolved peak may be tested by finding the cost of using MT to force a unimodal solution. A bimodal constraint can be applied. Decay data representing sharp lines in contact with broad features can require substantial computing time and some controls to stabilize the iterative sequence. However, UP can be made to function smoothly for a very wide variety of decay curves, which can be processed without adjustment of parameters, including the dimensionless smoothing parameters. Extensive testing has been done with artificial data. Examples are shown for artificial data, biological tissues, ceramic technology, and sandstones. Expressions are given relating noise level to line width and for significance of increase or decrease in error of fit.
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Affiliation(s)
- G C Borgia
- Department of ICMA, University of Bologna, Italy
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50
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Fantazzini P, Sarra A. 1H spin-lattice relaxation parameters in the length of human intestine resected for cancer. MAGMA 1996; 4:157-61. [PMID: 9220404 DOI: 10.1007/bf01772003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
1H spin-lattice relaxation curves were acquired for samples of intestinal adenocarcinoma (B) and of uninvolved tissue at the upper (A) and lower (C) resection margin of lengths of intestine taken at surgery from 20 patients. Each sample showed a wide distribution of relaxation times with the order of 90% of the signal in a single peak at long times. Several different single-parameter relaxation times computed from discrete-exponential analysis showed that most of the relaxation times for C and B are in the upper two-thirds of the range of times for A. The mean time for the tumor is about 10% longer (with p < 0.01) than for the upper resection margin. The difference between the tumor and the lower resection margin is not significant. Distribution width parameters associated with A and C were significantly larger than those associated with the tumors. Two-exponential fits indicate that the fast-relaxing component represents a smaller signal fraction for the tumor B than for A or C.
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Affiliation(s)
- P Fantazzini
- Dipartimento di Fisica, Università di Bologna, Italy
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