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Kline-Fath BM, Calvo-Garcia MA. Prenatal Imaging of Congenital Malformations of the Brain. Semin Ultrasound CT MR 2011; 32:167-88. [DOI: 10.1053/j.sult.2011.02.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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102
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Habas PA, Scott JA, Roosta A, Rajagopalan V, Kim K, Rousseau F, Barkovich AJ, Glenn OA, Studholme C. Early folding patterns and asymmetries of the normal human brain detected from in utero MRI. Cereb Cortex 2011; 22:13-25. [PMID: 21571694 DOI: 10.1093/cercor/bhr053] [Citation(s) in RCA: 158] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Early cortical folding and the emergence of structural brain asymmetries have been previously analyzed by neuropathology as well as qualitative analysis of magnetic resonance imaging (MRI) of fetuses and preterm neonates. In this study, we present a dedicated image analysis framework and its application for the detection of folding patterns during the critical period for the formation of many primary sulci (20-28 gestational weeks). Using structural information from in utero MRI, we perform morphometric analysis of cortical plate surface development and modeling of early folding in the normal fetal brain. First, we identify regions of the fetal brain surface that undergo significant folding changes during this developmental period and provide precise temporal staging of these changes for each region of interest. Then, we highlight the emergence of interhemispheric structural asymmetries that may be related to future functional specialization of cortical areas. Our findings complement previous descriptions of early sulcogenesis based on neuropathology and qualitative evaluation of 2D in utero MRI by accurate spatial and temporal mapping of the emergence of individual sulci as well as structural brain asymmetries. The study provides the missing starting point for their developmental trajectories and extends our understanding of normal cortical folding.
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Affiliation(s)
- Piotr A Habas
- Biomedical Image Computing Group, University of California San Francisco, San Francisco, CA 94143, USA.
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103
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Oubel E, Koob M, Studholme C, Dietemann JL, Rousseau F. Reconstruction of scattered data in fetal diffusion MRI. Med Image Anal 2011; 16:28-37. [PMID: 21636311 DOI: 10.1016/j.media.2011.04.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 02/14/2011] [Accepted: 04/17/2011] [Indexed: 11/29/2022]
Abstract
In this paper we present a method for reconstructing diffusion-weighted MRI data on regular grids from scattered data. The proposed method has the advantage that no specific diffusion model needs to be assumed. Previous work assume the tensor model, but this is not suitable under certain conditions like intravoxel orientational heterogeneity (IVOH). Data reconstruction is particularly important when studying the fetal brain in utero, since registration methods applied for movement and distortion correction produce scattered data in spatial and diffusion domains. We propose the use of a groupwise registration method, and a dual spatio-angular interpolation by using radial basis functions (RBF). Leave-one-out experiments performed on adult data showed a high accuracy of the method. The application to fetal data showed an improvement in the quality of the sequences according to objective criteria based on fractional anisotropy (FA) maps, and differences in the tractography results.
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104
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Scott JA, Habas PA, Kim K, Rajagopalan V, Hamzelou KS, Corbett-Detig JM, Barkovich AJ, Glenn OA, Studholme C. Growth trajectories of the human fetal brain tissues estimated from 3D reconstructed in utero MRI. Int J Dev Neurosci 2011; 29:529-36. [PMID: 21530634 DOI: 10.1016/j.ijdevneu.2011.04.001] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2010] [Revised: 03/16/2011] [Accepted: 04/07/2011] [Indexed: 12/20/2022] Open
Abstract
In the latter half of gestation (20-40 gestational weeks), human brain growth accelerates in conjunction with cortical folding and the deceleration of ventricular zone progenitor cell proliferation. These processes are reflected in changes in the volume of respective fetal tissue zones. Thus far, growth trajectories of the fetal tissue zones have been extracted primarily from 2D measurements on histological sections and magnetic resonance imaging (MRI). In this study, the volumes of major fetal zones-cortical plate (CP), subplate and intermediate zone (SP+IZ), germinal matrix (GMAT), deep gray nuclei (DG), and ventricles (VENT)--are calculated from automatic segmentation of motion-corrected, 3D reconstructed MRI. We analyzed 48 T2-weighted MRI scans from 39 normally developing fetuses in utero between 20.57 and 31.14 gestational weeks (GW). The supratentorial volume (STV) increased linearly at a rate of 15.22% per week. The SP+IZ (14.75% per week) and DG (15.56% per week) volumes increased at similar rates. The CP increased at a greater relative rate (18.00% per week), while the VENT (9.18% per week) changed more slowly. Therefore, CP increased as a fraction of STV and the VENT fraction declined. The total GMAT volume slightly increased then decreased after 25 GW. We did not detect volumetric sexual dimorphisms or total hemispheric volume asymmetries, which may emerge later in gestation. Further application of the automated fetal brain segmentation to later gestational ages will bridge the gap between volumetric studies of premature brain development and normal brain development in utero.
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Affiliation(s)
- Julia A Scott
- Biomedical Image Computing Group, Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA.
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105
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Lodygensky GA, Vasung L, Sizonenko SV, Hüppi PS. Neuroimaging of cortical development and brain connectivity in human newborns and animal models. J Anat 2011; 217:418-28. [PMID: 20979587 DOI: 10.1111/j.1469-7580.2010.01280.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Significant human brain growth occurs during the third trimester, with a doubling of whole brain volume and a fourfold increase of cortical gray matter volume. This is also the time period during which cortical folding and gyrification take place. Conditions such as intrauterine growth restriction, prematurity and cerebral white matter injury have been shown to affect brain growth including specific structures such as the hippocampus, with subsequent potentially permanent functional consequences. The use of 3D magnetic resonance imaging (MRI) and dedicated postprocessing tools to measure brain tissue volumes (cerebral cortical gray matter, white matter), surface and sulcation index can elucidate phenotypes associated with early behavior development. The use of diffusion tensor imaging can further help in assessing microstructural changes within the cerebral white matter and the establishment of brain connectivity. Finally, the use of functional MRI and resting-state functional MRI connectivity allows exploration of the impact of adverse conditions on functional brain connectivity in vivo. Results from studies using these methods have for the first time illustrated the structural impact of antenatal conditions and neonatal intensive care on the functional brain deficits observed after premature birth. In order to study the pathophysiology of these adverse conditions, MRI has also been used in conjunction with histology in animal models of injury in the immature brain. Understanding the histological substrate of brain injury seen on MRI provides new insights into the immature brain, mechanisms of injury and their imaging phenotype.
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106
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Hayat TTA, Nihat A, Martinez-Biarge M, McGuinness A, Allsop JM, Hajnal JV, Rutherford MA. Optimization and initial experience of a multisection balanced steady-state free precession cine sequence for the assessment of fetal behavior in utero. AJNR Am J Neuroradiol 2011; 32:331-8. [PMID: 21087938 PMCID: PMC7965695 DOI: 10.3174/ajnr.a2295] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Accepted: 07/15/2010] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The assessment of motor function is an essential component of neurologic examinations, which imaging studies have extended to the fetus. US assessment is hampered by a limited FOV, whereas MR imaging has the potential to be an alternative. Our objectives were to optimize a cine MR imaging sequence for capturing fetal movements and to perform a pilot analysis of the relationship between the frequency of movements and uterine spatial constrictions in healthy fetuses. MATERIALS AND METHODS Initially, a bSSFP cine sequence was selected for optimization, and various compromises were explored in all acquisition parameters to achieve an effective balance between anatomic coverage of the fetus and the temporal resolution of cine data, with the aim of maximizing both. Subsequently, cross-sectional qualitative and quantitative analyses of fetal movements were performed prospectively by using a cohort of 37 healthy fetuses (median GA, 29 weeks; range, 20-37 weeks) with the optimized cine protocol. Two smaller subgroups were selected for representative sampling of overall behavior patterns by using cine data of longer duration and for volumetric quantification of free intrauterine space. RESULTS The optimized cine sequence, with TR/TE of 3.21/1.59 ms, coupled with parallel imaging and partial-Fourier imaging, resulted in a section-acquisition time of 0.303 seconds. Anatomic coverage was enhanced by using a combination of thick sagittal sections (30-40 mm) and multisection acquisitions to display movements in all fetal limbs, head, and trunk simultaneously. All expected motor patterns were observed throughout this gestational period, and a significant decreasing trend in overall movement frequency with age was demonstrated (r = -0.514, P = .0011). Also a significant negative correlation was found between overall movement frequency and the total intrauterine free space (r = -0.703, P = .0001). Furthermore, a significant decrease in the frequency of leg movements was shown in fetuses older then 30 weeks' GA compared with those younger than that (P = .015). CONCLUSIONS Cine MR imaging is effective for observing fetal movements from midgestation with near full-body coverage. Also, reductions in free space with increasing GA appear to be a factor in the gradual reductions in overall levels of fetal activity as well as in restrictions in movement within specific regions of the fetal anatomy.
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Affiliation(s)
- T T A Hayat
- Perinatal Imaging Group, MRC Clinical Sciences Centre, Hammersmith Hospital, London, United Kingdom.
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107
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Habas PA, Kim K, Rousseau F, Glenn OA, Barkovich AJ, Studholme C. Atlas-based segmentation of developing tissues in the human brain with quantitative validation in young fetuses. Hum Brain Mapp 2011; 31:1348-58. [PMID: 20108226 DOI: 10.1002/hbm.20935] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Imaging of the human fetus using magnetic resonance (MR) is an essential tool for quantitative studies of normal as well as abnormal brain development in utero. However, because of fundamental differences in tissue types, tissue properties and tissue distribution between the fetal and adult brain, automated tissue segmentation techniques developed for adult brain anatomy are unsuitable for this data. In this paper, we describe methodology for automatic atlas-based segmentation of individual tissue types in motion-corrected 3D volumes reconstructed from clinical MR scans of the fetal brain. To generate anatomically correct automatic segmentations, we create a set of accurate manual delineations and build an in utero 3D statistical atlas of tissue distribution incorporating developing gray and white matter as well as transient tissue types such as the germinal matrix. The probabilistic atlas is associated with an unbiased average shape and intensity template for registration of new subject images to the space of the atlas. Quantitative whole brain 3D validation of tissue labeling performed on a set of 14 fetal MR scans (20.57-22.86 weeks gestational age) demonstrates that this atlas-based EM segmentation approach achieves consistently high DSC performance for the main tissue types in the fetal brain. This work indicates that reliable measures of brain development can be automatically derived from clinical MR imaging and opens up possibility of further 3D volumetric and morphometric studies with multiple fetal subjects.
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Affiliation(s)
- Piotr A Habas
- Biomedical Image Computing Group, Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California 94143, USA.
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108
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Zhang Z, Liu S, Lin X, Teng G, Yu T, Fang F, Zang F. Development of fetal brain of 20 weeks gestational age: assessment with post-mortem Magnetic Resonance Imaging. Eur J Radiol 2010; 80:e432-9. [PMID: 21146341 DOI: 10.1016/j.ejrad.2010.11.024] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 11/06/2010] [Accepted: 11/12/2010] [Indexed: 11/27/2022]
Abstract
BACKGROUND The 20th week gestational age (GA) is at mid-gestation and corresponds to the age at which the termination of pregnancy in several countries and the first Magnetic Resonance Imaging (MRI) can be performed, and at which the premature babies may survive. However, at present, very little is known about the exact anatomical character at this GA. OBJECTIVE To delineate the developing fetal brain of 20 weeks GA and obtain the three dimensional visualization model. MATERIALS AND METHODS 20 fetal specimens were scanned by 3.0 T and 7.0 T post-mortem MRI, and the three dimensional visualization model was obtained with Amira 4.1. RESULTS Most of the sulci or their anlage, except the postcentral sulcus and intraparietal sulcus, were present. The laminar organization, described as layers with different signal intensities, was most clearly distinguished at the parieto-occipital lobe and peripheral regions of the hippocampus. The basal nuclei could be clearly visualized, and the brain stem and cerebellum had formed their common shape. On the visualization model, the shape and relative relationship of the structures could be appropriately delineated. The ranges of normal values of the brain structures were obtained, but no sexual dimorphisms or cerebral asymmetries were found. CONCLUSIONS The developing fetal brain of 20 weeks GA can be clearly delineated on 3.0 T and 7.0 T post-mortem MRIs, and the three dimensional visualization model supplies great help in precise cognition of the immature brain. These results may have positive influences on the evaluation of the fetal brain in the uterus.
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Affiliation(s)
- Zhonghe Zhang
- Research Center for Sectional and Imaging Anatomy, Shandong University School of Medicine, 44 Wen-hua Xi Road, 250012 Jinan, Shandong, China
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109
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110
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Corbett-Detig J, Habas PA, Scott JA, Kim K, Rajagopalan V, McQuillen PS, Barkovich AJ, Glenn OA, Studholme C. 3D global and regional patterns of human fetal subplate growth determined in utero. Brain Struct Funct 2010; 215:255-63. [PMID: 21046152 PMCID: PMC3041913 DOI: 10.1007/s00429-010-0286-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Accepted: 10/06/2010] [Indexed: 12/13/2022]
Abstract
The waiting period of subplate evolution is a critical phase for the proper formation of neural connections in the brain. During this time, which corresponds to 15 to 24 postconceptual weeks (PCW) in the human fetus, thalamocortical and cortico-cortical afferents wait in and are in part guided by molecules embedded in the extracellular matrix of the subplate. Recent advances in fetal MRI techniques now allow us to study the developing brain anatomy in 3D from in utero imaging. We describe a reliable segmentation protocol to delineate the boundaries of the subplate from T2-W MRI. The reliability of the protocol was evaluated in terms of intra-rater reproducibility on a subset of the subjects. We also present the first 3D quantitative analyses of temporal changes in subplate volume, thickness, and contrast from 18 to 24 PCW. Our analysis shows that firstly, global subplate volume increases in proportion with the supratentorial volume; the subplate remained approximately one-third of supratentorial volume. Secondly, we found both global and regional growth in subplate thickness and a linear increase in the median and maximum subplate thickness through the waiting period. Furthermore, we found that posterior regions--specifically the occipital pole, ventral occipito-temporal region, and planum temporale--of the developing brain underwent the most statistically significant increases in subplate thickness. During this period, the thickest region was the developing somatosensory/motor cortex. The subplate growth patterns reported here may be used as a baseline for comparison to abnormal fetal brain development.
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Affiliation(s)
- J Corbett-Detig
- Biomedical Image Computing Group, Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94143-0628, USA.
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111
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Habas PA, Kim K, Corbett-Detig JM, Rousseau F, Glenn OA, Barkovich AJ, Studholme C. A spatiotemporal atlas of MR intensity, tissue probability and shape of the fetal brain with application to segmentation. Neuroimage 2010; 53:460-70. [PMID: 20600970 DOI: 10.1016/j.neuroimage.2010.06.054] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2010] [Revised: 06/18/2010] [Accepted: 06/21/2010] [Indexed: 11/27/2022] Open
Abstract
Modeling and analysis of MR images of the developing human brain is a challenge due to rapid changes in brain morphology and morphometry. We present an approach to the construction of a spatiotemporal atlas of the fetal brain with temporal models of MR intensity, tissue probability and shape changes. This spatiotemporal model is created from a set of reconstructed MR images of fetal subjects with different gestational ages. Groupwise registration of manual segmentations and voxelwise nonlinear modeling allow us to capture the appearance, disappearance and spatial variation of brain structures over time. Applying this model to atlas-based segmentation, we generate age-specific MR templates and tissue probability maps and use them to initialize automatic tissue delineation in new MR images. The choice of model parameters and the final performance are evaluated using clinical MR scans of young fetuses with gestational ages ranging from 20.57 to 24.71 weeks. Experimental results indicate that quadratic temporal models can correctly capture growth-related changes in the fetal brain anatomy and provide improvement in accuracy of atlas-based tissue segmentation.
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Affiliation(s)
- Piotr A Habas
- Biomedical Image Computing Group, University of California San Francisco, San Francisco, CA 94143, USA.
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112
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Zhang Z, Liu S, Lin X, Sun B, Yu T, Geng H. Development of fetal cerebral cortex: assessment of the folding conditions with post-mortem magnetic resonance imaging. Int J Dev Neurosci 2010; 28:537-43. [PMID: 20457247 DOI: 10.1016/j.ijdevneu.2010.05.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Revised: 03/14/2010] [Accepted: 05/03/2010] [Indexed: 11/19/2022] Open
Abstract
Quantitative data of fetal cortical folding and its developmental changes supply important information in the estimation of fetal age and assessment of brain maturation, so the increasing tendencies of cortical growth and its folding conditions at the beginning of the second and third trimesters with post-mortem Magnetic Resonance Imaging (MRI) were analyzed. 131 fetal specimens of 14-40 weeks gestational age (GA) were selected and scanned with 3.0 T MR. Then the length of folded cortical margin (LFCM) and length of unfolded cortical margin (LUCM) were measured by Photoshop and ZoomMagic software. Degrees of cortical folding (DCF) were calculated by means of (LFCM-LUCM)/LFCM. Growth curves were obtained between the 3 above values and GA, and significant differences in age stages, hemispheres and genders were analyzed. The relationship between LFCM in centimeters, DCF and GA in weeks was described by two exponential growth curves [LFCM=5.325 exp(0.079GA); DCF=11.890 exp(0.043GA)]. The curves increased rapidly after 26 weeks GA, which could be recognized as a cut-off point of fetal cortical and sulcal development. LUCM and GA were described by a logarithmic growth curve which slowed down after 26 weeks GA [LUCM=30.580 Ln(GA)-72.490]. Significant differences of the 3 values before and after 26 weeks GA (p<0.01), but not any in hemispheres and genders were noticed. These results, which may be valuable in assessing normal brain development and can serve as a model in clinical settings, indicate that the cerebral volume first increases and is then followed by increases of the surface area.
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Affiliation(s)
- Zhonghe Zhang
- Research Center for Sectional and Imaging Anatomy, Shandong University School of Medicine, Jinan, Shandong, China
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113
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Kochunov P, Castro C, Davis D, Dudley D, Brewer J, Zhang Y, Kroenke CD, Purdy D, Fox PT, Simerly C, Schatten G. Mapping primary gyrogenesis during fetal development in primate brains: high-resolution in utero structural MRI of fetal brain development in pregnant baboons. Front Neurosci 2010; 4:20. [PMID: 20631812 PMCID: PMC2896074 DOI: 10.3389/fnins.2010.00020] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Accepted: 03/29/2010] [Indexed: 12/18/2022] Open
Abstract
The global and regional changes in the fetal cerebral cortex in primates were mapped during primary gyrification (PG; weeks 17-25 of 26 weeks total gestation). Studying pregnant baboons using high-resolution MRI in utero, measurements included cerebral volume, cortical surface area, gyrification index and length and depth of 10 primary cortical sulci. Seven normally developing fetuses were imaged in two animals longitudinally and sequentially. We compared these results to those on PG that from the ferret studies and analyzed them in the context of our recent studies of phylogenetics of cerebral gyrification. We observed that in both primates and non-primates, the cerebrum undergoes a very rapid transformation into the gyrencephalic state, subsequently accompanied by an accelerated growth in brain volume and cortical surface area. However, PG trends in baboons exhibited some critical differences from those observed in ferrets. For example, in baboons, the growth along the long (length) axis of cortical sulci was unrelated to the growth along the short (depth) axis and far outpaced it. Additionally, the correlation between the rate of growth along the short sulcal axis and heritability of sulcal depth was negative and approached significance (r = -0.60; p < 0.10), while the same trend for long axis was positive and not significant (p = 0.3; p = 0.40). These findings, in an animal that shares a highly orchestrated pattern of PG with humans, suggest that ontogenic processes that influence changes in sulcal length and depth are diverse and possibly driven by different factors in primates than in non-primates.
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Affiliation(s)
- Peter Kochunov
- Research Imaging Institute, The University of Texas Health Science Center at San AntonioSan Antonio, TX, USA
- Southwest National Primate Research CenterSan Antonio, TX, USA
| | - Carlos Castro
- Division of Developmental and Regenerative Medicine, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of MedicinePittsburgh, PA, USA
- Pittsburgh Development Center, Magee-Womens Research Institute and FoundationPittsburgh, PA, USA
| | - Duff Davis
- Research Imaging Institute, The University of Texas Health Science Center at San AntonioSan Antonio, TX, USA
- Southwest National Primate Research CenterSan Antonio, TX, USA
| | - Donald Dudley
- Department of Obstetrics and Gynecology, The University of Texas Health Science Center at San AntonioSan Antonio, TX, USA
| | - Jordan Brewer
- Research Imaging Institute, The University of Texas Health Science Center at San AntonioSan Antonio, TX, USA
| | - Yi Zhang
- Research Imaging Institute, The University of Texas Health Science Center at San AntonioSan Antonio, TX, USA
| | - Christopher D. Kroenke
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science UniversityBeaverton, OR, USA
| | | | - Peter T. Fox
- Research Imaging Institute, The University of Texas Health Science Center at San AntonioSan Antonio, TX, USA
| | - Calvin Simerly
- Division of Developmental and Regenerative Medicine, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of MedicinePittsburgh, PA, USA
- Pittsburgh Development Center, Magee-Womens Research Institute and FoundationPittsburgh, PA, USA
| | - Gerald Schatten
- Division of Developmental and Regenerative Medicine, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of MedicinePittsburgh, PA, USA
- Pittsburgh Development Center, Magee-Womens Research Institute and FoundationPittsburgh, PA, USA
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114
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Sawada K, Sun XZ, Fukunishi K, Kashima M, Saito S, Sakata-Haga H, Sukamoto T, Aoki I, Fukui Y. Ontogenetic pattern of gyrification in fetuses of cynomolgus monkeys. Neuroscience 2010; 167:735-40. [DOI: 10.1016/j.neuroscience.2010.02.045] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Revised: 02/15/2010] [Accepted: 02/18/2010] [Indexed: 11/29/2022]
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115
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Abstract
Fetal MRI is clinically performed to evaluate the brain in cases where an abnormality is detected by prenatal sonography. These most commonly include ventriculomegaly, abnormalities of the corpus callosum, and abnormalities of the posterior fossa. Fetal MRI is also increasingly performed to evaluate fetuses who have normal brain findings on prenatal sonogram but who are at increased risk for neurodevelopmental abnormalities, such as complicated monochorionic twin pregnancies. This paper will briefly discuss the common clinical conditions imaged by fetal MRI as well as recent advances in fetal MRI research.
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116
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Jiang S, Xue H, Counsell S, Anjari M, Allsop J, Rutherford M, Rueckert D, Hajnal JV. Diffusion tensor imaging (DTI) of the brain in moving subjects: application to in-utero fetal and ex-utero studies. Magn Reson Med 2009; 62:645-55. [PMID: 19526505 DOI: 10.1002/mrm.22032] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We present a methodology to achieve 3D high-resolution diffusion tensor image reconstruction of the brain in moving subjects. The source data is diffusion-sensitized single-shot echo-planar images. After continuous scanning to acquire a repeated series of parallel slices with 15 diffusion directions, image registration is used to realign the images to correct for subject motion. Once aligned, the diffusion images are treated as irregularly-sampled data where each voxel is associated with an appropriately rotated diffusion direction. This data is used to estimate the diffusion tensor on a regular grid. The method has been tested on data acquired at 1.5T from adults who deliberately moved and from eight fetuses imaged in utero. Maps of apparent diffusion coefficient (ADC) were reliably produced in all cases and promising performance was achieved for fractional anisotropy maps. Results from normal fetal brains were found to be consistent with published data from premature infants of similar gestational age.
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Affiliation(s)
- Shuzhou Jiang
- Imaging Science Department, MRC Clinical Sciences Centre, Imperial College Hammersmith Hospital Campus, London, UK
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117
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Takahashi E, Dai G, Wang R, Ohki K, Rosen GD, Galaburda AM, Grant PE, Wedeen VJ. Development of cerebral fiber pathways in cats revealed by diffusion spectrum imaging. Neuroimage 2009; 49:1231-40. [PMID: 19747553 DOI: 10.1016/j.neuroimage.2009.09.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 08/23/2009] [Accepted: 09/01/2009] [Indexed: 12/18/2022] Open
Abstract
Examination of the three-dimensional axonal pathways in the developing brain is key to understanding the formation of cerebral connectivity. By tracing fiber pathways throughout the entire brain, diffusion tractography provides information that cannot be achieved by conventional anatomical MR imaging or histology. However, standard diffusion tractography (based on diffusion tensor imaging, or DTI) tends to terminate in brain areas with low water diffusivity, indexed by low diffusion fractional anisotropy (FA), which can be caused by crossing fibers as well as fibers with less myelin. For this reason, DTI tractography is not effective for delineating the structural changes that occur in the developing brain, where the process of myelination is incomplete, and where crossing fibers exist in greater numbers than in the adult brain. Unlike DTI, diffusion spectrum imaging (DSI) can define multiple directions of water diffusivity; as such, diffusion tractography based on DSI provides marked flexibility for delineation of fiber tracts in areas where the fiber architecture is complex and multidirectional, even in areas of low FA. In this study, we showed that FA values were lower in the white matter of newborn (postnatal day 0; P0) cat brains than in the white matter of infant (P35) and juvenile (P100) cat brains. These results correlated well with histological myelin stains of the white matter: the newborn kitten brain has much less myelin than that found in cat brains at later stages of development. Using DSI tractography, we successfully identified structural changes in thalamo-cortical and cortico-cortical association tracts in cat brains from one stage of development to another. In newborns, the main body of the thalamo-cortical tract was smooth, and fibers branching from it were almost straight, while the main body became more complex and branching fibers became curved reflecting gyrification in the older cats. Cortico-cortical tracts in the temporal lobe were smooth in newborns, and they formed a sharper angle in the later stages of development. The cingulum bundle and superior longitudinal fasciculus became more visible with time. Within the first month after birth, structural changes occurred in these tracts that coincided with the formation of the gyri. These results show that DSI tractography has the potential for mapping morphological changes in low FA areas associated with growth and development. The technique may also be applicable to the study of other forms of brain plasticity, including future studies in vivo.
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Affiliation(s)
- Emi Takahashi
- Department of Radiology, Harvard Medical School, Charlestown, MA, USA.
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Abstract
Fetal magnetic resonance imaging (MRI) may add important diagnostic information to prenatal sonography and has the power to confirm or change decisions at critical points in clinical care. Recent studies have shown MRI to be a critical clinical adjunct in the evaluation of the developing central nervous system (CNS), especially at early gestational ages, and MRI has been used in three significant ways: (1) for the quantification of brain growth and structural abnormalities using biometry, (2) for the qualitative evaluation of CNS microstructure, and (3) for the qualitative assessment of dynamic fetal movements in utero.
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119
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Abstract
Recent technological advances in fetal magnetic resonance imaging (MRI) and increased reliability of MRI in depicting abnormalities and lesions, especially in the central nervous system, are increasingly bringing up challenging issues with regard to accurate diagnosis. There are also pitfalls not only attributable to image acquisition but also in clinical interpretation. The misinterpretation of findings because of insufficient knowledge about fetal brain development as visualized by MRI may also be regarded as an important limitation of fetal MRI. We provide an overview of the most common pitfalls experienced in fetal MRI in routine practice, demonstrate how to identify some of the factors that lead to imaging misinterpretation, and suggest ways to tackle these problems, with an emphasis on MR techniques and image calibration.
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Affiliation(s)
- Ali Al-Mukhtar
- Department of Radiology, Division of General and Pediatric Radiology, Medical University of Vienna, Vienna, Austria.
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120
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Abstract
The development of the cerebral cortex, white matter microstructure, and the basal ganglia can be well characterized using structural magnetic resonance imaging (MRI). In this review, we analyzed structural in vitro MRI studies of transient cellular cerebral zones that are sites of neurogenetic events (proliferation, migration, cell aggregation, growth of axonal pathways, myelinization, and synaptogenesis). During early fetal life, from 9-13 postconceptional weeks, a thick, densely packed cellular ventricular/subventricular zone and ganglionic eminence indicate intensive proliferation of neuroepithelial stem cells. During the mid and late fetal phase, other cellular zones also became discernable: (1) the intermediate zone as a migratory and axonal growth zone; (2) the subplate zone as a synaptic, extracellular matrix-rich "waiting" compartment; and (3) the cell-dense cortical plate with postmigratory neurons. The preterm phase is characterized by the growth of cortical, thalamic, and striatal pathways; formation of white matter segments; and stratification within the subplate. Thalamocortical fibers cause lamination in the cortical plate, which leads to the formation of a substrate of sensory input. Preterm cerebral immaturity is characterized by considerable extracellular space at sites of axonal growth and a delineable subplate. The intensity of axonal growth, together with a high, gradient-dependent requirement for axonal guidance, forms a substrate for selective vulnerability of specific segments of cerebral white matter in the preterm brain. In summary, the combination of in vitro MRI, histologic analysis, and in vivo MRI is a promising new approach for studying the etiology and treatment of developmental disorders.
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Affiliation(s)
- Ivica Kostovic
- Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia.
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121
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Abstract
The fetal brain is a dynamic structure, which can now be imaged using magnetic resonance imaging (MRI). This article will review techniques of fetal MRI as well as several key aspects of brain development and their appearance on MRI. An understanding of normal fetal brain development is essential to correctly identifying developmental abnormalities.
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Affiliation(s)
- Orit A Glenn
- Department of Radiology, Neuroradiology Section, University of California, San Francisco, CA 94143, USA.
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122
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Joó JG, Rigó J. [Significance of magnetic resonance studies in prenatal diagnosis of malformations of the fetal central nervous system]. Orv Hetil 2009; 150:1275-80. [PMID: 19531461 DOI: 10.1556/oh.2009.28626] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
MRI investigation, as an imaging technique, has been gaining more and more importance in prenatal diagnostics. It has become essential due to its advantages in diagnosing the malformations of the central nervous system. Similarly to ultrasonography, its reliability is greatly dependent on the knowledge of the person performing the investigation. In addition to the knowledge of the exact anatomy of central nervous system, the researcher should have a multidisciplinary approach. In the case of malformations where repeated investigations are needed to provide a diagnosis in early pregnancy (e.g. neural tube defects), ultrasonography is more effective than MRI. In case of intrauterine infections and malformations of the posterior fossa, however, the two imaging techniques are excellent supplements to each other. MRI also plays an important role in making the prognosis for fetal ventriculomegaly, as well as in the short term diagnosis of ischaemias affecting the fetal nervous system. Difficulties in evaluating ultrasonographic images (owing to maternal obesity, oligohydramnion) render MRI an important technique in making the final diagnosis. Currently, the drawbacks of MRI include reduced accessibility, poor cost-effectiveness and shortage of skilled experts in this technique.
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Affiliation(s)
- József Gábor Joó
- Semmelweis Egyetem, Altalános Orvostudományi Kar, I. Szülészeti és Nogyógyászati Klinika, Budapest.
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123
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Abstract
MRI is being increasingly used to assess for fetal abnormalities. Although significant progress in the field of fetal MRI has occurred during the past 20 years, continued technical advances will likely contribute to significant growth of the field. Moreover, with continued hardware and software improvements, additional MRI sequences will likely become available. Prenatal MRI complements ultrasound because of larger field-of-view, superior soft tissue contrast, easier and more precise volumetric measurement, and greater accuracy in the demonstration of intracranial and spinal abnormalities. While ultrasound remains the primary modality for fetal imaging, these advantages of MRI make it a valuable adjunct to fetal surgery. Because fetal MRI involves many disciplines, the future of fetal MR will best be achieved through collaborative efforts.
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Affiliation(s)
- Orit A Glenn
- Department of Radiology, University of California, San Francisco, CA 94143, USA.
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124
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Sawada K, Sun XZ, Fukunishi K, Kashima M, Sakata-Haga H, Tokado H, Aoki I, Fukui Y. Developments of sulcal pattern and subcortical structures of the forebrain in cynomolgus monkey fetuses: 7-tesla magnetic resonance imaging provides high reproducibility of gross structural changes. Brain Struct Funct 2009; 213:469-80. [DOI: 10.1007/s00429-009-0204-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Accepted: 01/20/2009] [Indexed: 10/21/2022]
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125
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Kalpouzos G, Chételat G, Baron JC, Landeau B, Mevel K, Godeau C, Barré L, Constans JM, Viader F, Eustache F, Desgranges B. Voxel-based mapping of brain gray matter volume and glucose metabolism profiles in normal aging. Neurobiol Aging 2009; 30:112-24. [PMID: 17630048 DOI: 10.1016/j.neurobiolaging.2007.05.019] [Citation(s) in RCA: 264] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2006] [Revised: 05/04/2007] [Accepted: 05/21/2007] [Indexed: 11/26/2022]
Abstract
With age, the brain undergoes both structural and functional alterations, probably resulting in reported cognitive declines. Relatively few investigations have sought to identify those areas that remain intact with aging, or undergo the least deterioration, which might underlie cognitive preservations. Our aim here was to establish a comprehensive profile of both structural and functional changes in the aging brain, using up-to-date voxel-based methodology (i.e. optimized voxel-based morphometry (VBM) procedure; resting-state (18)FDG-PET with correction for partial volume effects (PVE)) in 45 optimally healthy subjects aged 20-83 years. Negative and positive correlations between age and both gray matter (GM) volume and (18)FDG uptake were assessed. The frontal cortex manifested the greatest deterioration, both structurally and functionally, whereas the anterior hippocampus, the thalamus and (functionally) the posterior cingulate cortex were the least affected. Our results support the developmental theory which postulates that the first regions to emerge phylogenetically and ontogenetically are the most resistant to age effects, and the last ones the most vulnerable. Furthermore, the lesser affected anterior hippocampal region, together with the lesser functional alteration of the posterior cingulate cortex, appear to mark the parting of the ways between normal aging and Alzheimer's disease, which is characterized by early and prominent deterioration of both structures.
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Affiliation(s)
- Grégoria Kalpouzos
- Inserm-EPHE-Université de Caen/Basse-Normandie, Unité de Recherche E0218, GIP Cyceron, Caen, France
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126
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Habas PA, Kim K, Rousseau F, Glenn OA, Barkovich AJ, Studholme C. Atlas-based segmentation of the germinal matrix from in utero clinical MRI of the fetal brain. ACTA ACUST UNITED AC 2008; 11:351-8. [PMID: 18979766 DOI: 10.1007/978-3-540-85988-8_42] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Abstract
Recently developed techniques for reconstruction of high-resolution 3D images from fetal MR scans allows us to study the morphometry of developing brain tissues in utero. However, existing adult brain analysis methods cannot be directly applied as the anatomy of the fetal brain is significantly different in terms of geometry and tissue morphology. We describe an approach to atlas-based segmentation of the fetal brain with particular focus on the delineation of the germinal matrix, a transient structure related to brain growth. We segment 3D images reconstructed from in utero clinical MR scans and measure volumes of different brain tissue classes for a group of fetal subjects at gestational age 20.5-22.5 weeks. We also include a partial validation of the approach using manual tracing of the germinal matrix at different gestational ages.
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Affiliation(s)
- Piotr A Habas
- Biomedical Image Computing Group, University of California, San Francisco, San Francisco, CA 94143, USA.
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127
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128
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Refining clinical phenotypes in septo-optic dysplasia based on MRI findings. Eur J Pediatr 2008; 167:1269-76. [PMID: 18231810 DOI: 10.1007/s00431-007-0666-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2007] [Accepted: 12/19/2007] [Indexed: 10/22/2022]
Abstract
Septo-optic dysplasia (SOD) is a heterogeneous brain midline anomaly associated with ophthalmological, endocrinological, and/or neurodevelopmental symptoms. The clinical phenotype correlates with abnormal brain magnetic resonance imaging (MRI) findings. However, variations of the septum pellucidum (SP) appearance and their clinical impact have not been studied in depth. Sixty-eight patients with optic nerve hypoplasia (ONH) were investigated for the presence of associated SP anomalies and correlations between clinical findings and their MRI abnormalities established. Thirty patients had either complete (n = 22) or partial (n = 8) absence of the SP. Pituitary hormone deficiencies were present in 64% or 25% of the cases, respectively. Neurological symptoms did not occur in patients with SP remnants or unilateral ONH. Hippocampus abnormalities (43%) that have not been described before in SOD and falx abnormalities (17%) correlated significantly with neurological symptoms and developmental delay (p < 0.05 and p < 0.01, respectively). Maternal age at birth was low (21.2 years) and drug abuse during pregnancy was reported in 27% of the patients. Twelve patients with pituitary anomaly and ONH but normal SP showed similar clinical and MRI features, and were classified as SOD-like. The remaining 26 patients were not assigned to SOD. We conclude that unilateral ONH and SP remnants are associated with a milder SOD phenotype. Hippocampus abnormalities and falx abnormalities seem to constitute important features of severe clinical disease, irrespective of SP appearance. Our anamnestic data support the hypothesis of vascular disruption during embryogenesis.
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129
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130
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Techniques et indications de l’IRM du cerveau fœtal. IMAGERIE DE LA FEMME 2008. [DOI: 10.1016/s1776-9817(08)77192-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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131
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Kasprian G, Brugger PC, Weber M, Krssák M, Krampl E, Herold C, Prayer D. In utero tractography of fetal white matter development. Neuroimage 2008; 43:213-24. [PMID: 18694838 DOI: 10.1016/j.neuroimage.2008.07.026] [Citation(s) in RCA: 150] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2007] [Revised: 07/02/2008] [Accepted: 07/06/2008] [Indexed: 11/26/2022] Open
Abstract
Diffusion tensor imaging (DTI) and tractography are noninvasive tools that enable the study of three-dimensional diffusion characteristics and their molecular, cellular, and microstructural correlates in the human brain. To date, these techniques have mainly been limited to postnatal MR studies of premature infants and newborns. The primary aim of this cross-sectional study was to assess the potential of in utero DTI and tractography to visualize the main projection and commissural pathways in 40 living, non-sedated human fetuses between 18 and 37 gestational weeks (GW) of age, with no structural brain pathologies. During a mean time of 1 min and 49 s, an axial, single-shot, echo planar DT sequence, with 32 diffusion gradient encoding directions and a reconstructed voxel size of 1.44 mm/1.45 mm/4.5 mm, was acquired. Most (90%) of the fetuses were imaged in the cephalic presentation. In 40% of examined fetuses, DTI measurements were robust enough to successfully calculate and visualize bilateral, craniocaudally oriented (mainly sensorimotor), and callosal trajectories in utero. Furthermore, fiber lengths, ADC, FA, and eigenvalues (lambda(1), lambda(2) and lambda(3)) were determined at different anatomically defined areas. FA values and the axial eigenvalue (lambda(1)) showed a characteristic distribution, with the highest values for the splenium, followed by the genu, the right, and the left posterior limb of the internal capsule. The right-sided sensorimotor trajectories were found to be significantly longer than on the left side (p=0.007), reflecting higher right-sided lambda(1) values (14 cases vs. 9 cases). Based on the good correlation of these initial in utero tractography results with prior documented postmortem and ex utero DTI data, this new imaging technique promises new insights into the normal and pathological development of the unborn child.
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Affiliation(s)
- Gregor Kasprian
- Department of Radiology, Medical University of Vienna, Vienna, Austria.
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132
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Huisman TAGM, Solopova A. MR fetography using heavily T2-weighted sequences: comparison of thin- and thick-slab acquisitions. Eur J Radiol 2008; 71:557-63. [PMID: 18619753 DOI: 10.1016/j.ejrad.2008.06.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2007] [Revised: 05/27/2008] [Accepted: 06/03/2008] [Indexed: 11/29/2022]
Abstract
PURPOSE To evaluate the use of MR-fetography sequences in identifying the major fetal structures and to compare thick- and thin-slab acquisitions for their diagnostic value. MATERIALS AND METHODS Twenty-one consecutive, pregnant women with suspected fetal pathology underwent fetal magnetic resonance imaging (MRI) using a 1.5 T MRI unit. Heavily T2-weighted, single-shot fast spin-echo (SSFSE) sequences with a long echo train (MR-fetography) were acquired in a thick- and thin-slab modus. Thick- and thin-slab acquisitions were reviewed by two experienced radiologists with regard to the overall image quality and landmark anatomical structures (spinal canal, spinal cord, posterior fossa, cerebellum, brainstem, basal cisterns, stomach, urinary bladder and umbilical cord according to a three-scale grading system (good, moderate and poor). Visibility scores were calculated and compared between both sequences. RESULTS Overall image quality was graded good in 76.2%, moderate in 19.0% and poor in 4.8% for thick-slab images and good in 81%, moderate in 14.3% and poor in 4.8% for thin-slab images. The visibility scores of the thick/thin-slab images for evaluation of the main fetal structures were as follows: for the spinal canal 2.8+/-0.4/2.9+/-0.54 (p>0.05), spinal cord 2.4+/-0.75/2.7+/-0.66 (p>0.05), posterior fossa components (cerebellum, brainstem and basal cisterns) 2.4+/-0.68/2.8+/-0.54; 2.4+/-0.67/2.7+/-0.66; 2.5+/-0.51/2.7+/-0.56 (p<0.05), stomach 2.8+/-0.44/2.9+/-0.48 (p>0.05), urinary bladder 2.8+/-0.51/2.8+/-0.54 (p>0.05) and umbilical cord 2.9+/-0.30/2.6+/-0.60 (p<0.05). CONCLUSION Heavily T2-weighted MR-fetography renders a quick overview of fetal contours, fetal position, amount of amniotic fluid and integrity and presence of several major fluid containing structures. Thick- and thin-slab acquisitions render complementary information. Thick-slab images display the entire fetus in one projection while thin-slab images provide more detailed anatomical information. The short imaging time usually allows measuring both thick- and thin-slab images. MR-fetography is as a helpful addition to conventional fetal MRI. MR-fetography should not be viewed as a single, stand alone sequence but as a supporting fast MR sequence in a well-designed multisequence fetal MRI protocol. Future studies evaluating larger patient groups are mandatory.
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Affiliation(s)
- Thierry A G M Huisman
- Department of Diagnostic Imaging, University Children's Hospital Zurich, Switzerland.
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133
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Rutherford M, Jiang S, Allsop J, Perkins L, Srinivasan L, Hayat T, Kumar S, Hajnal J. MR imaging methods for assessing fetal brain development. Dev Neurobiol 2008; 68:700-11. [PMID: 18383541 DOI: 10.1002/dneu.20614] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Fetal magnetic resonance imaging provides an ideal tool for investigating growth and development of the brain in vivo. Current imaging methods have been hampered by fetal motion but recent advances in image acquisition can produce high signal to noise, high resolution 3-dimensional datasets suitable for objective quantification by state of the art post acquisition computer programs. Continuing development of imaging techniques will allow a unique insight into the developing brain, more specifically process of cell migration, axonal pathway formation, and cortical maturation. Accurate quantification of these developmental processes in the normal fetus will allow us to identify subtle deviations from normal during the second and third trimester of pregnancy either in the compromised fetus or in infants born prematurely.
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Affiliation(s)
- Mary Rutherford
- Imaging Sciences Department, MRC Clinical Sciences Centre, Imperial College, London W12 OHS, UK.
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134
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Parazzini C, Righini A, Rustico M, Consonni D, Triulzi F. Prenatal magnetic resonance imaging: brain normal linear biometric values below 24 gestational weeks. Neuroradiology 2008; 50:877-83. [DOI: 10.1007/s00234-008-0421-7] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2008] [Accepted: 05/20/2008] [Indexed: 11/29/2022]
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135
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Affiliation(s)
- Catherine Garel
- Service de Radiologie Pédiatrique, Hôpital d'Enfants Armand-Trousseau, 26-28 Avenue du Dr Arnold Netter, 75571, Paris Cedex 12, France.
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136
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Garel C. Fetal MRI: what is the future? ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2008; 31:123-128. [PMID: 18254129 DOI: 10.1002/uog.5249] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
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137
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In-utero three dimension high resolution fetal brain diffusion tensor imaging. MEDICAL IMAGE COMPUTING AND COMPUTER-ASSISTED INTERVENTION : MICCAI ... INTERNATIONAL CONFERENCE ON MEDICAL IMAGE COMPUTING AND COMPUTER-ASSISTED INTERVENTION 2008. [PMID: 18051039 DOI: 10.1007/978-3-540-75757-3_3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
We present a methodology to achieve 3D high resolution in-utero fetal brain DTI that shows excellent ADC as well as promising FA maps. After continuous DTI scanning to acquire a repeated series of parallel slices with 15 diffusion directions, image registration is used to realign the images to correct for fetal motion. Once aligned, the diffusion images are treated as irregularly sampled data where each voxel is associated with an appropriately rotated diffusion direction, and used to estimate the diffusion tensor on a regular grid. The method has been tested successful on eight fetuses and has been validated on adults imaged at 1.5T.
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138
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Liu F, Garland M, Duan Y, Stark RI, Xu D, Dong Z, Bansal R, Peterson BS, Kangarlu A. Study of the development of fetal baboon brain using magnetic resonance imaging at 3 Tesla. Neuroimage 2007; 40:148-59. [PMID: 18155925 DOI: 10.1016/j.neuroimage.2007.11.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2007] [Revised: 10/30/2007] [Accepted: 11/13/2007] [Indexed: 11/16/2022] Open
Abstract
Direct observational data on the development of the brains of human and nonhuman primates is on remarkably scant, and most of our understanding of primate brain development is extrapolated from findings in rodent models. Magnetic resonance imaging (MRI) is a promising tool for the noninvasive, longitudinal study of the developing primate brain. We devised a protocol to scan pregnant baboons serially at 3 T for up to 3 h per session. Seven baboons were scanned 1-6 times, beginning as early as 56 days post-conceptional age, and as late as 185 days (term approximately 185 days). Successful scanning of the fetal baboon required careful animal preparation and anesthesia, in addition to optimization of the scanning protocol. We successfully acquired maps of relaxation times (T(1) and T(2)) and high-resolution anatomical images of the brains of fetal baboons at multiple time points during the course of gestation. These images demonstrated the convergence of gray and white matter contrast near term, and furthermore demonstrated that the loss of contrast at that age is a consequence of the continuous change in relaxation times during fetal brain development. These data furthermore demonstrate that maps of relaxation times have clear advantages over the relaxation time weighted images for the tracking of the changes in brain structure during fetal development. This protocol for in utero MRI of fetal baboon brains will help to advance the use of nonhuman primate models to study fetal brain development longitudinally.
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Affiliation(s)
- Feng Liu
- Department of Psychiatry, New York State Psychiatric Institute, Columbia University Medical Center, 1051 Riverside Drive, New York, NY 10032, USA.
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139
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Foetal growth determines cerebral ventricular volume in infants The Generation R Study. Neuroimage 2007; 39:1491-8. [PMID: 18089296 DOI: 10.1016/j.neuroimage.2007.11.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2007] [Revised: 10/22/2007] [Accepted: 11/07/2007] [Indexed: 11/20/2022] Open
Abstract
The cerebral ventricular system is a marker of brain development and a predictor of neurodevelopmental outcome. In premature or dysmature neonates, neuroanatomical structures including the ventricular system appear to be altered. The present study aims to provide information on the association between foetal growth and neonatal cerebral ventricular size in the normal population. Within the Generation R Study, a population-based cohort study, we used three-dimensional cranial ultrasound to determine lateral ventricular volume in 778 term infants aged 4-12 weeks. Foetal growth characteristics were repeatedly measured in early, mid- and late pregnancy and analysed in relation to ventricular volume divided by head circumference. Results revealed positive associations between foetal head circumference in late pregnancy and log-transformed ventricular volume (beta=0.077, 95% confidence interval (0.017; 0.136), equivalent to a 7.7% increase in ventricular volume per standard deviation of head circumference). Similarly, in a per week-longer gestational duration, ventricular volume in infancy was 6.0% larger. Multilevel modelling demonstrated that reduced growth of foetal head circumference and biparietal diameter during pregnancy were associated with decreased ventricular volume in infancy. In conclusion, foetal maturation is positively associated to cerebral ventricular size in term infants. Larger ventricular size in term infants needs to be distinguished from ventricular enlargement due to intraventricular haemorrhage or white matter damage in premature or dysmature infants. Moreover, the naturally occurring enlargement of ventricles during infancy should be considered in interpreting reports on increased ventricular volumes in several neuropsychiatric disorders.
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140
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Cannie M, De Keyzer F, Meersschaert J, Jani J, Lewi L, Deprest J, Dymarkowski S, Demaerel P. A diffusion-weighted template for gestational age-related apparent diffusion coefficient values in the developing fetal brain. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2007; 30:318-24. [PMID: 17688307 DOI: 10.1002/uog.4078] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
OBJECTIVE To determine the pattern of apparent diffusion coefficient (ADC) values in the normal fetal brain obtained with diffusion-weighted images (DWI) on magnetic resonance imaging (MRI) as a template for normal brain development throughout gestation. METHODS This was a prospective study of 46 fetuses without suspicion of brain pathology undergoing a total of 66 ultrasound examinations between 17 and 37 weeks of gestation. At T2-weighted MRI, four left and four right brain regions were delineated on transverse slices of the native DWI using a b-value of 0 s/mm2 (b0 images). We examined native b-value images and calculated ADC(avg), ADC(low) and ADC(high) in the basal ganglia, cerebellar hemisphere, frontal parenchyma and occipital parenchyma. Linear regression analysis was used to assess the relationship between gestational age and b0 values as well as the calculated ADC values. RESULTS Delineations were successful in all fetuses for all regions except for the cerebellar hemispheres in four fetuses. There was a negative correlation between gestational age and b0 values in all examined anatomical regions (P<0.002). For ADC(avg), there were no significant changes in the basal ganglia with increasing gestational age, a positive correlation in the frontal (P<0.0001) and occipital (P=0.03) parenchyma and a negative correlation in the cerebellar hemispheres (P=0.01). For ADC(low), there was a negative correlation between gestational age and the cerebellum (P=0.0002) and basal ganglia (P=0.047), but no correlation for the frontal or occipital parenchyma. For ADC(high), there was a positive correlation with gestational age for the frontal parenchyma (P=0.004), occipital parenchyma (P=0.02) and basal ganglia (P=0.03) but there was no correlation for the cerebellum. CONCLUSIONS DWI b0 values decreased in the left and right basal ganglia, cerebellar hemisphere, frontal parenchyma and occipital parenchyma between 17 and 37 weeks of gestation and ADC(avg) values increased in two out of four cerebral regions. It remains to be determined to what extent these observations differ in fetuses with suspicion of brain anomalies and whether such measurements will be useful and more predictive of outcome compared with standard MRI sequences.
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Affiliation(s)
- M Cannie
- Department of Radiology, University Hospitals Leuven, Leuven, Belgium
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141
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Prayer D, Brugger P, Kasprian G. The Pediatric Posterior Fossa: Fetal MRI. Neuroradiol J 2007; 20:403-9. [DOI: 10.1177/197140090702000403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2007] [Accepted: 07/23/2007] [Indexed: 11/17/2022] Open
Affiliation(s)
- D. Prayer
- Department of Neuroradiology, University Clinics of Radiodiagnostics, Vienna, Austria
| | - P.C. Brugger
- Center for Anatomy and Cell Biology, Vienna, Austria
| | - G. Kasprian
- Department of Conservative and Childhood Radiology, University Clinics of Radiodiagnostics Medical University; Vienna, Austria
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142
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Brown MA, Martin DR, Semelka RC. Future directions in MR imaging of the female pelvis. Magn Reson Imaging Clin N Am 2007; 14:431-7, v. [PMID: 17433975 DOI: 10.1016/j.mric.2007.01.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
New technology continues to change the field of MR imaging. This article describes select areas of technical development that are likely to have an increasing clinical impact on MR imaging of the female pelvis, including high-field imaging, parallel imaging, contrast agents, diffusion-weighted imaging and spectroscopy, and MR-guided intervention.
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Affiliation(s)
- Michèle A Brown
- Department of Radiology, University of California, San Diego Medical Center, 200 West Arbor Drive, San Diego, CA 92103-8756, USA.
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Prayer D, Brugger PC. Investigation of normal organ development with fetal MRI. Eur Radiol 2007; 17:2458-71. [PMID: 17342486 DOI: 10.1007/s00330-007-0604-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2006] [Revised: 12/15/2006] [Accepted: 01/22/2007] [Indexed: 01/28/2023]
Abstract
The understanding of the presentation of normal organ development on fetal MRI forms the basis for recognition of pathological states. During the second and third trimesters, maturational processes include changes in size, shape and signal intensities of organs. Visualization of these developmental processes requires tailored MR protocols. Further prerequisites for recognition of normal maturational states are unequivocal intrauterine orientation with respect to left and right body halves, fetal proportions, and knowledge about the MR presentation of extrafetal/intrauterine organs. Emphasis is laid on the demonstration of normal MR appearance of organs that are frequently involved in malformation syndromes. In addition, examples of time-dependent contrast enhancement of intrauterine structures are given.
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Affiliation(s)
- Daniela Prayer
- Department of Radiology, Medical University of Vienna, Waehringerguertel 18-20, 1090, Vienna, Austria.
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144
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Tumeh PC, Alavi A, Houseni M, Greenfield A, Chryssikos T, Newberg A, Torigian DA, Moonis G. Structural and Functional Imaging Correlates for Age-Related Changes in the Brain. Semin Nucl Med 2007; 37:69-87. [PMID: 17289456 DOI: 10.1053/j.semnuclmed.2006.10.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In recent years, investigators have made significant progress in documenting brain structure and function as it relates to aging by using positron emission tomography, conventional magnetic resonance (MR) imaging, advanced MR techniques, and functional MR imaging. This review summarizes the latest advances in understanding physiologic maturation and aging as detected by these neuroimaging modalities. We also present our experience with MR volumetric and positron emission tomography analysis in separate cohorts of healthy subjects in the pediatric and adult age groups respectively. Our results are consistent with previous studies and include the following: total brain volume was found to increase with age (up to 20 years of age). Whole brain metabolism and frontal lobe metabolism both decrease significantly with age (38% and 42%, respectively), whereas cerebellar metabolism does not show a significant decline with age. Defining normal alterations in brain function and structure allows early detection of disorders such as Alzheimer's and Parkinson's diseases, which are commonly associated with normal aging.
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Affiliation(s)
- Paul C Tumeh
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA
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145
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Cannie M, Jani J, Dymarkowski S, Deprest J. Fetal magnetic resonance imaging: luxury or necessity? ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2006; 27:471-6. [PMID: 16619388 DOI: 10.1002/uog.2776] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
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