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Zacà D, Hasson U, Minati L, Jovicich J. Method for retrospective estimation of natural head movement during structural MRI. J Magn Reson Imaging 2018; 48:927-937. [PMID: 29393987 DOI: 10.1002/jmri.25959] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 01/16/2018] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Head motion during brain structural MRI scans biases brain morphometry measurements but quantitative retrospective methods estimating head motion from structural MRI have not been evaluated. PURPOSE To verify the hypothesis that two metrics retrospectively computed from MR images: 1) average edge strength (AES, reduced with image blurring) and 2) entropy (ENT, increased with blurring and ringing artifacts) could be sensitive to in-scanner head motion during acquisition of T1 -weighted MR images. STUDY TYPE Retrospective. POPULATION/SUBJECTS/PHANTOM/SPECIMEN/ANIMAL MODEL In all, 83 healthy control (HC) and 120 Parkinson's disease (PD) patients. FIELD STRENGTH/SEQUENCE 3D magnetization-prepared rapid gradient-echo (MPRAGE) images at 3T. ASSESSMENT We 1) compared AES and ENT distribution between HC and PD; 2) evaluated the correlation between tremor score (TS) and AES (or ENT) in PD; and 3) investigated cortical regions showing an association between AES (or ENT) and local and network-level covariance measures of cortical thickness (CT), gray to white matter contrast (GWC) and gray matter density maps (GMx). STATISTICAL TESTS 1) Student's t-test. 2) Spearman's rank correlation. 3) General linear model and partial least square analysis. RESULTS AES, but not ENT, differentiated HC and PD (P = 0.02, HC median AES = 39.8, interquartile range = 9.8, PD median AES = 37.6, interquartile range = 8.1). In PD, AES correlated negatively with TS (ρ = -0.21, P = 0.02) and showed a significant relationship (|Z| >3, P < 0.001) with structural covariance of CT and GWC in 54 out of 68 cortical regions. DATA CONCLUSION In clinical populations prone to head motion, AES can provide a reliable retrospective index of motion during structural scans, identifying brain areas whose morphometric measures covary with motion. LEVEL OF EVIDENCE 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;48:927-937.
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Affiliation(s)
- Domenico Zacà
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Rovereto, Italy
| | - Uri Hasson
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Rovereto, Italy
| | - Ludovico Minati
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Rovereto, Italy
| | - Jorge Jovicich
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Rovereto, Italy
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Ahmad R, Hu HH, Krishnamurthy R, Krishnamurthy R. Reducing sedation for pediatric body MRI using accelerated and abbreviated imaging protocols. Pediatr Radiol 2018; 48:37-49. [PMID: 29292482 DOI: 10.1007/s00247-017-3987-6] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 06/13/2017] [Accepted: 09/12/2017] [Indexed: 12/01/2022]
Abstract
Magnetic resonance imaging (MRI) is an established diagnostic imaging tool for investigating pediatric disease. MRI allows assessment of structure, function, and morphology in cardiovascular imaging, as well as tissue characterization in body imaging, without the use of ionizing radiation. For MRI in children, sedation and general anesthesia (GA) are often utilized to suppress patient motion, which can otherwise compromise image quality and diagnostic efficacy. However, evidence is emerging that use of sedation and GA in children might have long-term neurocognitive side effects, in addition to the short-term procedure-related risks. These concerns make risk-benefit assessment of sedation and GA more challenging. Therefore, reducing or eliminating the need for sedation and GA is an important goal of imaging innovation and research in pediatric MRI. In this review, the authors focus on technical and clinical approaches to reducing and eliminating the use of sedation in the pediatric population based on image acquisition acceleration and imaging protocols abbreviation. This paper covers important physiological and technical considerations for pediatric body MR imaging and discusses MRI techniques that offer the potential of recovering diagnostic-quality images from accelerated scans. In this review, the authors also introduce the concept of reporting elements for important indications for pediatric body MRI and use this as a basis for abbreviating the MR protocols. By employing appropriate accelerated and abbreviated approaches based on an understanding of the imaging needs and reporting elements for a given clinical indication, it is possible to reduce sedation and GA for pediatric chest, cardiovascular and abdominal MRI.
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Affiliation(s)
- Rizwan Ahmad
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
| | - Houchun Harry Hu
- Department of Radiology, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205, USA
| | - Ramkumar Krishnamurthy
- Department of Radiology, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205, USA
| | - Rajesh Krishnamurthy
- Department of Radiology, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205, USA.
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Nunes RG, Ferrazzi G, Price AN, Hutter J, Gaspar AS, Rutherford MA, Hajnal JV. Inner-volume echo volumar imaging (IVEVI) for robust fetal brain imaging. Magn Reson Med 2017; 80:279-285. [PMID: 29115686 DOI: 10.1002/mrm.26998] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 10/17/2017] [Accepted: 10/18/2017] [Indexed: 11/08/2022]
Abstract
PURPOSE Fetal functional MRI studies using conventional 2-dimensional single-shot echo-planar imaging sequences may require discarding a large data fraction as a result of fetal and maternal motion. Increasing the temporal resolution using echo volumar imaging (EVI) could provide an effective alternative strategy. Echo volumar imaging was combined with inner volume (IV) imaging (IVEVI) to locally excite the fetal brain and acquire full 3-dimensional images, fast enough to freeze most fetal head motion. METHODS IVEVI was implemented by modifying a standard multi-echo echo-planar imaging sequence. A spin echo with orthogonal excitation and refocusing ensured localized excitation. To introduce T2* weighting and to save time, the k-space center was shifted relative to the spin echo. Both single and multi-shot variants were tested. Acoustic noise was controlled by adjusting the amplitude and switching frequency of the readout gradient. Image-based shimming was used to minimize B0 inhomogeneities within the fetal brain. RESULTS The sequence was first validated in an adult. Eight fetuses were scanned using single-shot IVEVI at a 3.5 × 3.5 × 5.0 mm3 resolution with a readout duration of 383 ms. Multishot IVEVI showed reduced geometric distortions along the second phase-encode direction. CONCLUSIONS Fetal EVI remains challenging. Although effective echo times comparable to the T2* values of fetal cortical gray matter at 3 T could be achieved, controlling acoustic noise required longer readouts, leading to substantial distortions in single-shot images. Although multishot variants enabled us to reduce susceptibility-induced geometric distortions, sensitivity to motion was increased. Future studies should therefore focus on improvements to multishot variants. Magn Reson Med 80:279-285, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Rita G Nunes
- Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal.,Institute for Systems and Robotics and Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal.,Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom
| | - Giulio Ferrazzi
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom.,Centre for the Developing Brain, King's College London, London, United Kingdom
| | - Anthony N Price
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom.,Centre for the Developing Brain, King's College London, London, United Kingdom
| | - Jana Hutter
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom.,Centre for the Developing Brain, King's College London, London, United Kingdom
| | - Andreia S Gaspar
- Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal.,Institute for Systems and Robotics and Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal.,Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom
| | - Mary A Rutherford
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom.,Centre for the Developing Brain, King's College London, London, United Kingdom
| | - Joseph V Hajnal
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom.,Centre for the Developing Brain, King's College London, London, United Kingdom
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Alansary A, Rajchl M, McDonagh SG, Murgasova M, Damodaram M, Lloyd DFA, Davidson A, Rutherford M, Hajnal JV, Rueckert D, Kainz B. PVR: Patch-to-Volume Reconstruction for Large Area Motion Correction of Fetal MRI. IEEE TRANSACTIONS ON MEDICAL IMAGING 2017; 36:2031-2044. [PMID: 28880160 PMCID: PMC6051489 DOI: 10.1109/tmi.2017.2737081] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 06/07/2017] [Accepted: 08/01/2017] [Indexed: 05/23/2023]
Abstract
In this paper, we present a novel method for the correction of motion artifacts that are present in fetal magnetic resonance imaging (MRI) scans of the whole uterus. Contrary to current slice-to-volume registration (SVR) methods, requiring an inflexible anatomical enclosure of a single investigated organ, the proposed patch-to-volume reconstruction (PVR) approach is able to reconstruct a large field of view of non-rigidly deforming structures. It relaxes rigid motion assumptions by introducing a specific amount of redundant information that is exploited with parallelized patchwise optimization, super-resolution, and automatic outlier rejection. We further describe and provide an efficient parallel implementation of PVR allowing its execution within reasonable time on commercially available graphics processing units, enabling its use in the clinical practice. We evaluate PVR's computational overhead compared with standard methods and observe improved reconstruction accuracy in the presence of affine motion artifacts compared with conventional SVR in synthetic experiments. Furthermore, we have evaluated our method qualitatively and quantitatively on real fetal MRI data subject to maternal breathing and sudden fetal movements. We evaluate peak-signal-to-noise ratio, structural similarity index, and cross correlation with respect to the originally acquired data and provide a method for visual inspection of reconstruction uncertainty. We further evaluate the distance error for selected anatomical landmarks in the fetal head, as well as calculating the mean and maximum displacements resulting from automatic non-rigid registration to a motion-free ground truth image. These experiments demonstrate a successful application of PVR motion compensation to the whole fetal body, uterus, and placenta.
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55
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Antonov NK, Ruzal-Shapiro CB, Morel KD, Millar WS, Kashyap S, Lauren CT, Garzon MC. Feed and Wrap MRI Technique in Infants. Clin Pediatr (Phila) 2017; 56:1095-1103. [PMID: 27872353 DOI: 10.1177/0009922816677806] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The feed and wrap technique refers to the use of feeding and swaddling to induce natural sleep in infants. It can be used prior to an magnetic resonance imaging (MRI) scan, avoiding sedation or anesthesia. We performed a retrospective review of feed and wrap MRI scans in infants 3 months or younger over a 2-year period at our center (279 scans) to evaluate the efficacy of this technique. Of scan results reviewed, 79% addressed the clinical question, 20% partially addressed the clinical question, and 1% were technically inadequate. History of preterm birth (odds ratio [OR] = 2.368; P = .032) and spine MRI (OR = 2.821; P = .001) were associated with a less-successful scan outcome. The feed and wrap technique can be used successfully in infants undergoing MRI; however, it may be less successful in preterm infants and those requiring spinal MRI. A standardized technique performed by experienced personnel may avoid anesthesia and sedation in infants who require MRI.
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56
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Jakab A, Tuura R, Kellenberger C, Scheer I. In utero diffusion tensor imaging of the fetal brain: A reproducibility study. NEUROIMAGE-CLINICAL 2017; 15:601-612. [PMID: 28652972 PMCID: PMC5477067 DOI: 10.1016/j.nicl.2017.06.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 01/25/2017] [Accepted: 06/08/2017] [Indexed: 02/06/2023]
Abstract
Our purpose was to evaluate the within-subject reproducibility of in utero diffusion tensor imaging (DTI) metrics and the visibility of major white matter structures. Images for 30 fetuses (20-33. postmenstrual weeks, normal neurodevelopment: 6 cases, cerebral pathology: 24 cases) were acquired on 1.5 T or 3.0 T MRI. DTI with 15 diffusion-weighting directions was repeated three times for each case, TR/TE: 2200/63 ms, voxel size: 1 ∗ 1 mm, slice thickness: 3-5 mm, b-factor: 700 s/mm2. Reproducibility was evaluated from structure detectability, variability of DTI measures using the coefficient of variation (CV), image correlation and structural similarity across repeated scans for six selected structures. The effect of age, scanner type, presence of pathology was determined using Wilcoxon rank sum test. White matter structures were detectable in the following percentage of fetuses in at least two of the three repeated scans: corpus callosum genu 76%, splenium 64%, internal capsule, posterior limb 60%, brainstem fibers 40% and temporooccipital association pathways 60%. The mean CV of DTI metrics ranged between 3% and 14.6% and we measured higher reproducibility in fetuses with normal brain development. Head motion was negatively correlated with reproducibility, this effect was partially ameliorated by motion-correction algorithm using image registration. Structures on 3.0 T had higher variability both with- and without motion correction. Fetal DTI is reproducible for projection and commissural bundles during mid-gestation, however, in 16-30% of the cases, data were corrupted by artifacts, resulting in impaired detection of white matter structures. To achieve robust results for the quantitative analysis of diffusivity and anisotropy values, fetal-specific image processing is recommended and repeated DTI is needed to ensure the detectability of fiber pathways.
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Key Words
- AD, axial diffusivity
- CCA, corpus callosum agenesis
- CV, coefficient of variation
- Connectome
- DTI, diffusion tensor imaging
- Diffusion tensor imaging
- FA, fractional anisotropy
- Fetal brain connectivity
- Fetal diffusion MRI
- GW, gestational week
- MD, mean diffusivity
- Prenatal development
- RD, radial diffusivity
- ROI, region of interest
- SSIM, structural similarity index
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Affiliation(s)
- András Jakab
- Center for MR-Research, University Children's Hospital, Zürich, Switzerland; Computational Imaging Research Lab (CIR), Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria.
| | - Ruth Tuura
- Center for MR-Research, University Children's Hospital, Zürich, Switzerland
| | | | - Ianina Scheer
- Department of Diagnostic Imaging, University Children's Hospital, Zürich, Switzerland
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Miao H, Mistelbauer G, Karimov A, Alansary A, Davidson A, Lloyd DFA, Damodaram M, Story L, Hutter J, Hajnal JV, Rutherford M, Preim B, Kainz B, Groller ME. Placenta Maps: In Utero Placental Health Assessment of the Human Fetus. IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS 2017; 23:1612-1623. [PMID: 28252405 DOI: 10.1109/tvcg.2017.2674938] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The human placenta is essential for the supply of the fetus. To monitor the fetal development, imaging data is acquired using (US). Although it is currently the gold-standard in fetal imaging, it might not capture certain abnormalities of the placenta. (MRI) is a safe alternative for the in utero examination while acquiring the fetus data in higher detail. Nevertheless, there is currently no established procedure for assessing the condition of the placenta and consequently the fetal health. Due to maternal respiration and inherent movements of the fetus during examination, a quantitative assessment of the placenta requires fetal motion compensation, precise placenta segmentation and a standardized visualization, which are challenging tasks. Utilizing advanced motion compensation and automatic segmentation methods to extract the highly versatile shape of the placenta, we introduce a novel visualization technique that presents the fetal and maternal side of the placenta in a standardized way. Our approach enables physicians to explore the placenta even in utero. This establishes the basis for a comparative assessment of multiple placentas to analyze possible pathologic arrangements and to support the research and understanding of this vital organ. Additionally, we propose a three-dimensional structure-aware surface slicing technique in order to explore relevant regions inside the placenta. Finally, to survey the applicability of our approach, we consulted clinical experts in prenatal diagnostics and imaging. We received mainly positive feedback, especially the applicability of our technique for research purposes was appreciated.
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Affiliation(s)
- Haichao Miao
- Institute of Computer Graphics and Algorithms, TU Wien, Vienna, Austria
| | - Gabriel Mistelbauer
- Department of Simulation and Graphics, Otto-von-Guericke University, Magdeburg, Germany
| | - Alexey Karimov
- Institute of Computer Graphics and Algorithms, TU Wien, Vienna, Austria
| | - Amir Alansary
- Department of Computing, Imperial College, London, United Kingdom
| | | | | | | | - Lisa Story
- King's College London, London, United Kingdom
| | - Jana Hutter
- King's College London, London, United Kingdom
| | | | | | - Bernhard Preim
- Department of Simulation and Graphics, Otto-von-Guericke University, Magdeburg, Germany
| | - Bernhard Kainz
- Department of Computing, Imperial College, London, United Kingdom
| | - M Eduard Groller
- Institute of Computer Graphics and Algorithms, TU Wien, Vienna, Austria
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Abstract
PURPOSE To provide consensus-based, suggested imaging protocols to facilitate the accurate and timely diagnosis of a neonate with symptoms concerning for stroke. METHODS The Writing Group, an international collaboration of pediatric neurologists and neuroradiologists with expertise in perinatal and childhood stroke, participated in a series of pediatric stroke neuroimaging symposia. These discussions, in conjunction with extensive literature review, led to a consensus for imaging protocols to guide practitioners in the diagnosis of neonatal stroke subtypes as defined by the National Institute of Neurological Disorders and Stroke Common Data Elements. The epidemiology, clinical presentation, and associated risk factors for arterial ischemic stroke, cerebral sinovenous thrombosis, and hemorrhagic stroke are reviewed, with a focused discussion regarding the role of neuroimaging for each subtype. RESULTS In a neonate with suspected stroke, magnetic resonance imaging is the preferred modality, given the lack of X-irradiation, superior anatomic resolution, and sensitivity for acute ischemia. Core recommended sequences include diffusion-weighted imaging and apparent diffusion coefficient mapping to diagnose acute ischemia, gradient-recalled echo or susceptibility-weighted imaging to detect intracranial blood and its breakdown products, and T1- and T2-weighted imaging to assess for myelination, extra-axial blood, and edema. Magnetic resonance angiography of the brain may be useful to detect vascular abnormalities, with venography if venous sinus thrombosis is suspected. The application of more novel sequences, as well as the utility of follow up-imaging, is also discussed.
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Benkarim OM, Sanroma G, Zimmer VA, Muñoz-Moreno E, Hahner N, Eixarch E, Camara O, González Ballester MA, Piella G. Toward the automatic quantification of in utero brain development in 3D structural MRI: A review. Hum Brain Mapp 2017; 38:2772-2787. [PMID: 28195417 DOI: 10.1002/hbm.23536] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 01/13/2017] [Accepted: 01/25/2017] [Indexed: 11/08/2022] Open
Abstract
Investigating the human brain in utero is important for researchers and clinicians seeking to understand early neurodevelopmental processes. With the advent of fast magnetic resonance imaging (MRI) techniques and the development of motion correction algorithms to obtain high-quality 3D images of the fetal brain, it is now possible to gain more insight into the ongoing maturational processes in the brain. In this article, we present a review of the major building blocks of the pipeline toward performing quantitative analysis of in vivo MRI of the developing brain and its potential applications in clinical settings. The review focuses on T1- and T2-weighted modalities, and covers state of the art methodologies involved in each step of the pipeline, in particular, 3D volume reconstruction, spatio-temporal modeling of the developing brain, segmentation, quantification techniques, and clinical applications. Hum Brain Mapp 38:2772-2787, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
| | | | | | - Emma Muñoz-Moreno
- Fetal i+D Fetal Medicine Research Center, BCNatal - Barcelona Center for Maternal-Fetal and Neonatal Medicine (Hospital Clínic and Hospital Sant Joan de Deu), IDIBAPS, University of Barcelona, Spain.,Experimental 7T MRI Unit, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Nadine Hahner
- Fetal i+D Fetal Medicine Research Center, BCNatal - Barcelona Center for Maternal-Fetal and Neonatal Medicine (Hospital Clínic and Hospital Sant Joan de Deu), IDIBAPS, University of Barcelona, Spain
| | - Elisenda Eixarch
- Fetal i+D Fetal Medicine Research Center, BCNatal - Barcelona Center for Maternal-Fetal and Neonatal Medicine (Hospital Clínic and Hospital Sant Joan de Deu), IDIBAPS, University of Barcelona, Spain
| | - Oscar Camara
- DTIC, Universitat Pompeu Fabra, Barcelona, Spain
| | | | - Gemma Piella
- DTIC, Universitat Pompeu Fabra, Barcelona, Spain
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Turk EA, Luo J, Gagoski B, Pascau J, Bibbo C, Robinson JN, Grant PE, Adalsteinsson E, Golland P, Malpica N. Spatiotemporal alignment of in utero BOLD-MRI series. J Magn Reson Imaging 2017; 46:403-412. [PMID: 28152240 DOI: 10.1002/jmri.25585] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 11/22/2016] [Indexed: 11/12/2022] Open
Abstract
PURPOSE To present a method for spatiotemporal alignment of in-utero magnetic resonance imaging (MRI) time series acquired during maternal hyperoxia for enabling improved quantitative tracking of blood oxygen level-dependent (BOLD) signal changes that characterize oxygen transport through the placenta to fetal organs. MATERIALS AND METHODS The proposed pipeline for spatiotemporal alignment of images acquired with a single-shot gradient echo echo-planar imaging includes 1) signal nonuniformity correction, 2) intravolume motion correction based on nonrigid registration, 3) correction of motion and nonrigid deformations across volumes, and 4) detection of the outlier volumes to be discarded from subsequent analysis. BOLD MRI time series collected from 10 pregnant women during 3T scans were analyzed using this pipeline. To assess pipeline performance, signal fluctuations between consecutive timepoints were examined. In addition, volume overlap and distance between manual region of interest (ROI) delineations in a subset of frames and the delineations obtained through propagation of the ROIs from the reference frame were used to quantify alignment accuracy. A previously demonstrated rigid registration approach was used for comparison. RESULTS The proposed pipeline improved anatomical alignment of placenta and fetal organs over the state-of-the-art rigid motion correction methods. In particular, unexpected temporal signal fluctuations during the first normoxia period were significantly decreased (P < 0.01) and volume overlap and distance between region boundaries measures were significantly improved (P < 0.01). CONCLUSION The proposed approach to align MRI time series enables more accurate quantitative studies of placental function by improving spatiotemporal alignment across placenta and fetal organs. LEVEL OF EVIDENCE 1 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:403-412.
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Affiliation(s)
- Esra Abaci Turk
- Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States.,Madrid-MIT M+Vision Consortium in RLE, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Jie Luo
- Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States.,Madrid-MIT M+Vision Consortium in RLE, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Borjan Gagoski
- Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States.,Department of Radiology, Harvard Medical School, Boston Children's Hospital, Boston, MA, United States
| | - Javier Pascau
- Madrid-MIT M+Vision Consortium in RLE, Massachusetts Institute of Technology, Cambridge, MA, United States.,Instituto de Investigación Sanitaria Gregorio Marañón, CIBERSAM, Madrid, Spain.,Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Madrid, Spain
| | - Carolina Bibbo
- Maternal and Fetal Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Julian N Robinson
- Maternal and Fetal Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - P Ellen Grant
- Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Elfar Adalsteinsson
- Madrid-MIT M+Vision Consortium in RLE, Massachusetts Institute of Technology, Cambridge, MA, United States.,Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States.,Harvard-MIT Health Sciences and Technology, Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Polina Golland
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States.,Computer Science and Artificial Intelligence Laboratory (CSAIL), Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Norberto Malpica
- Madrid-MIT M+Vision Consortium in RLE, Massachusetts Institute of Technology, Cambridge, MA, United States.,Medical Image Analysis and Biometry Laboratory, Universidad Rey Juan Carlos, Madrid, Spain
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Devi CN, Chandrasekharan A, V.K. S, Alex ZC. Automatic segmentation of infant brain MR images: With special reference to myelinated white matter. Biocybern Biomed Eng 2017. [DOI: 10.1016/j.bbe.2016.11.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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62
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Marami B, Scherrer B, Afacan O, Erem B, Warfield SK, Gholipour A. Motion-Robust Diffusion-Weighted Brain MRI Reconstruction Through Slice-Level Registration-Based Motion Tracking. IEEE TRANSACTIONS ON MEDICAL IMAGING 2016; 35:2258-2269. [PMID: 27834639 PMCID: PMC5108524 DOI: 10.1109/tmi.2016.2555244] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This work proposes a novel approach for motion-robust diffusion-weighted (DW) brain MRI reconstruction through tracking temporal head motion using slice-to-volume registration. The slice-level motion is estimated through a filtering approach that allows tracking the head motion during the scan and correcting for out-of-plane inconsistency in the acquired images. Diffusion-sensitized image slices are registered to a base volume sequentially over time in the acquisition order where an outlier-robust Kalman filter, coupled with slice-to-volume registration, estimates head motion parameters. Diffusion gradient directions are corrected for the aligned DWI slices based on the computed rotation parameters and the diffusion tensors are directly estimated from the corrected data at each voxel using weighted linear least squares. The method was evaluated in DWI scans of adult volunteers who deliberately moved during scans as well as clinical DWI of 28 neonates and children with different types of motion. Experimental results showed marked improvements in DWI reconstruction using the proposed method compared to the state-of-the-art DWI analysis based on volume-to-volume registration. This approach can be readily used to retrieve information from motion-corrupted DW imaging data.
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Affiliation(s)
- Bahram Marami
- Department of Radiology, Boston Children's Hospital, and Harvard Medical School, Boston, MA 02115 USA
| | - Benoit Scherrer
- Department of Radiology, Boston Children's Hospital, and Harvard Medical School, Boston, MA 02115 USA
| | - Onur Afacan
- Department of Radiology, Boston Children's Hospital, and Harvard Medical School, Boston, MA 02115 USA
| | - Burak Erem
- Department of Radiology, Boston Children's Hospital, and Harvard Medical School, Boston, MA 02115 USA
| | - Simon K. Warfield
- Department of Radiology, Boston Children's Hospital, and Harvard Medical School, Boston, MA 02115 USA
| | - Ali Gholipour
- Department of Radiology, Boston Children's Hospital, and Harvard Medical School, Boston, MA 02115 USA
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Lloyd DFA, van Amerom JFP, Pushparajah K, Simpson JM, Zidere V, Miller O, Sharland G, Allsop J, Fox M, Lohezic M, Murgasova M, Malamateniou C, Hajnal JV, Rutherford M, Razavi R. An exploration of the potential utility of fetal cardiovascular MRI as an adjunct to fetal echocardiography. Prenat Diagn 2016; 36:916-925. [PMID: 27521762 PMCID: PMC5082528 DOI: 10.1002/pd.4912] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 08/01/2016] [Accepted: 08/09/2016] [Indexed: 11/11/2022]
Abstract
OBJECTIVES Fetal cardiovascular magnetic resonance imaging (MRI) offers a potential alternative to echocardiography, although in practice, its use has been limited. We sought to explore the need for additional imaging in a tertiary fetal cardiology unit and the usefulness of standard MRI sequences. METHODS Cases where the diagnosis was not fully resolved using echocardiography were referred for MRI. Following a three-plane localiser, fetal movement was assessed with a balanced steady-state free precession (bSSFP) cine. Single-shot fast spin echo and bSSFP sequences were used for diagnostic imaging. RESULTS Twenty-two fetal cardiac MRIs were performed over 12 months, at mean gestation of 32 weeks (26-38 weeks). The majority of referrals were for suspected vascular abnormalities (17/22), particularly involving the aortic arch (n = 10) and pulmonary vessels (n = 4). Single-shot fast spin echo sequences produced 'black-blood' images, useful for examining the extracardiac vasculature in these cases. BSSFP sequences were more useful for intracardiac structures. Real-time SSFP allowed for dynamic assessment of structures such as cardiac masses, with enhancement patterns also allowing for tissue characterisation in these cases. CONCLUSIONS Fetal vascular abnormalities such as coarctation can be difficult to diagnose by using ultrasound. Fetal MRI may have an adjunctive role in the evaluation of the extracardiac vascular anatomy and tissue characterisation. © 2016 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd.
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Affiliation(s)
- David F A Lloyd
- Evelina Children's Hospital, London, UK. .,Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK.
| | - Joshua F P van Amerom
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK
| | - Kuberan Pushparajah
- Evelina Children's Hospital, London, UK.,Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK
| | | | | | | | | | - Joanna Allsop
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK
| | - Matthew Fox
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK
| | - Maelene Lohezic
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK
| | - Maria Murgasova
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK
| | - Christina Malamateniou
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK
| | - Jo V Hajnal
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK
| | - Mary Rutherford
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK
| | - Reza Razavi
- Evelina Children's Hospital, London, UK.,Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK
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64
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Jaimes C, Gee MS. Strategies to minimize sedation in pediatric body magnetic resonance imaging. Pediatr Radiol 2016; 46:916-27. [PMID: 27229508 DOI: 10.1007/s00247-016-3613-z] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 01/11/2016] [Accepted: 02/05/2016] [Indexed: 12/13/2022]
Abstract
The high soft-tissue contrast of MRI and the absence of ionizing radiation make it a valuable tool for assessment of body pathology in children. Infants and young children are often unable to cooperate with awake MRI so sedation or general anesthesia might be required. However, given recent data on the costs and potential risks of anesthesia in young children, there is a need to try to decrease or avoid sedation in this population when possible. Child life specialists in radiology frequently use behavioral techniques and audiovisual support devices, and they practice with children and families using mock scanners to improve child compliance with MRI. Optimization of the MR scanner environment is also important to create a child-friendly space. If the child can remain inside the MRI scanner, a variety of emerging techniques can reduce the effect of involuntary motion. Using sequences with short acquisition times such as single-shot fast spin echo and volumetric gradient echo can decrease artifacts and improve image quality. Breath-holding, respiratory triggering and signal averaging all reduce respiratory motion. Emerging techniques such as radial and multislice k-space acquisition, navigator motion correction, as well as parallel imaging and compressed sensing reconstruction methods can further accelerate acquisition and decrease motion. Collaboration among radiologists, anesthesiologists, technologists, child life specialists and families is crucial for successful performance of MRI in young children.
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Affiliation(s)
- Camilo Jaimes
- Division of Pediatric Imaging, Department of Radiology, Massachusetts General Hospital, 55 Fruit St., Ellison 237, Boston, MA, 02114, USA.,Department of Radiology, Harvard Medical School, Boston, MA, USA
| | - Michael S Gee
- Division of Pediatric Imaging, Department of Radiology, Massachusetts General Hospital, 55 Fruit St., Ellison 237, Boston, MA, 02114, USA. .,Department of Radiology, Harvard Medical School, Boston, MA, USA.
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65
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You W, Evangelou IE, Zun Z, Andescavage N, Limperopoulos C. Robust preprocessing for stimulus-based functional MRI of the moving fetus. J Med Imaging (Bellingham) 2016; 3:026001. [PMID: 27081665 DOI: 10.1117/1.jmi.3.2.026001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 03/03/2016] [Indexed: 11/14/2022] Open
Abstract
Fetal motion manifests as signal degradation and image artifact in the acquired time series of blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) studies. We present a robust preprocessing pipeline to specifically address fetal and placental motion-induced artifacts in stimulus-based fMRI with slowly cycled block design in the living fetus. In the proposed pipeline, motion correction is optimized to the experimental paradigm, and it is performed separately in each phase as well as in each region of interest (ROI), recognizing that each phase and organ experiences different types of motion. To obtain the averaged BOLD signals for each ROI, both misaligned volumes and noisy voxels are automatically detected and excluded, and the missing data are then imputed by statistical estimation based on local polynomial smoothing. Our experimental results demonstrate that the proposed pipeline was effective in mitigating the motion-induced artifacts in stimulus-based fMRI data of the fetal brain and placenta.
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Affiliation(s)
- Wonsang You
- Children's National Medical Center , Department of Diagnostic Imaging and Radiology, 111 Michigan Avenue N.W., Washington, DC 20852, United States
| | - Iordanis E Evangelou
- Children's National Medical Center, Department of Diagnostic Imaging and Radiology, 111 Michigan Avenue N.W., Washington, DC 20852, United States; George Washington University, School of Medicine and Health Sciences, Department of Radiology, 2300 Eye Street N.W., Washington, DC 20037, United States
| | - Zungho Zun
- Children's National Medical Center , Department of Diagnostic Imaging and Radiology, 111 Michigan Avenue N.W., Washington, DC 20852, United States
| | - Nickie Andescavage
- Children's National Medical Center, Department of Fetal and Transitional Medicine, 111 Michigan Avenue N.W., Washington, DC 20852, United States; Children's National Medical Center, Department of Neonatology, 111 Michigan Avenue N.W., Washington, DC 20852, United States; George Washington University, School of Medicine and Health Sciences, Department of Pediatrics, 2300 Eye Street N.W., Washington, DC 20037, United States
| | - Catherine Limperopoulos
- Children's National Medical Center, Department of Diagnostic Imaging and Radiology, 111 Michigan Avenue N.W., Washington, DC 20852, United States; George Washington University, School of Medicine and Health Sciences, Department of Radiology, 2300 Eye Street N.W., Washington, DC 20037, United States; Children's National Medical Center, Department of Fetal and Transitional Medicine, 111 Michigan Avenue N.W., Washington, DC 20852, United States; George Washington University, School of Medicine and Health Sciences, Department of Pediatrics, 2300 Eye Street N.W., Washington, DC 20037, United States
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66
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Brix L, Ringgaard S, Sandager P, Petersen OB, Sørensen TS, Lundorf E, Stausbøl-Grøn B. Overcoming foetal motion using interactive real-time magnetic resonance imaging. Clin Physiol Funct Imaging 2016; 37:717-722. [PMID: 27005484 DOI: 10.1111/cpf.12364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 02/24/2016] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Foetal MRI has become an established image modality in the prenatal diagnosis of CNS anomalies, but image quality can be severely affected by foetal movements. The objective was to overcome these inherent motion problems by applying interactive real-time MRI and to evaluate the diagnostic usefulness of the applied real-time MRI sequence in relation to standard protocols. METHODS Ten healthy foetuses (gestation week 21·3 ± 0·5) were scanned using a system, which allowed visual feedback and interactive slice positioning in real time. The data were compared to a control group of 14 healthy foetuses (gestation week 21·0 ± 0·8) who had previously been scanned using standard MRI. Comparisons were carried out by two radiologists with regard to cerebral anthropometric sizes, presence of important brain structures, degree of movement, clinical image value, image quality and ability to obtain correct slice planes. RESULTS Two out of eight anthropometric sizes were statistically different between the two groups. Representation of cerebral structures was found in 70-100% in the real-time group. No statistically differences were found in clinical image value and image quality. The mean ability to obtain optimal slice planes was higher in the real-time group, but it was not significant. CONCLUSION Imaging of the foetal brain using the proposed interactive real-time MRI system is a promising alternative to traditional foetal MRI for anthropometrics or as a supplement for the representation of foetal brain structures in cases in which foetal motion causes challenges in relation to obtaining optimal slice planes using conventional MRI techniques.
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Affiliation(s)
- Lau Brix
- Department of Procurement & Clinical Engineering, Region Midt, Aarhus N, Denmark.,MR Research Centre, Aarhus University Hospital, Aarhus N, Denmark
| | | | - Puk Sandager
- Department of Obstetrics and Gynecology, Aarhus University Hospital, Aarhus N, Denmark.,Department of Clinical Medicine, Aarhus University, Aarhus N, Denmark
| | - Olav Bjørn Petersen
- Department of Obstetrics and Gynecology, Aarhus University Hospital, Aarhus N, Denmark.,Department of Clinical Medicine, Aarhus University, Aarhus N, Denmark
| | - Thomas Sangild Sørensen
- Department of Clinical Medicine, Aarhus University, Aarhus N, Denmark.,Department of Computer Science, Aarhus University, Aarhus N, Denmark
| | - Erik Lundorf
- MR Research Centre, Aarhus University Hospital, Aarhus N, Denmark
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67
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Jakab A, Pogledic I, Schwartz E, Gruber G, Mitter C, Brugger PC, Langs G, Schöpf V, Kasprian G, Prayer D. Fetal Cerebral Magnetic Resonance Imaging Beyond Morphology. Semin Ultrasound CT MR 2015; 36:465-75. [DOI: 10.1053/j.sult.2015.06.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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68
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Babayeva M, Kober T, Knowles B, Herbst M, Meuli R, Zaitsev M, Krueger G. Accuracy and Precision of Head Motion Information in Multi-Channel Free Induction Decay Navigators for Magnetic Resonance Imaging. IEEE TRANSACTIONS ON MEDICAL IMAGING 2015; 34:1879-1889. [PMID: 25781624 DOI: 10.1109/tmi.2015.2413211] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Free induction decay (FID) navigators were found to qualitatively detect rigid-body head movements, yet it is unknown to what extent they can provide quantitative motion estimates. Here, we acquired FID navigators at different sampling rates and simultaneously measured head movements using a highly accurate optical motion tracking system. This strategy allowed us to estimate the accuracy and precision of FID navigators for quantification of rigid-body head movements. Five subjects were scanned with a 32-channel head coil array on a clinical 3T MR scanner during several resting and guided head movement periods. For each subject we trained a linear regression model based on FID navigator and optical motion tracking signals. FID-based motion model accuracy and precision was evaluated using cross-validation. FID-based prediction of rigid-body head motion was found to be with a mean translational and rotational error of 0.14±0.21 mm and 0.08±0.13°, respectively. Robust model training with sub-millimeter and sub-degree accuracy could be achieved using 100 data points with motion magnitudes of ±2 mm and ±1° for translation and rotation. The obtained linear models appeared to be subject-specific as inter-subject application of a "universal" FID-based motion model resulted in poor prediction accuracy. The results show that substantial rigid-body motion information is encoded in FID navigator signal time courses. Although, the applied method currently requires the simultaneous acquisition of FID signals and optical tracking data, the findings suggest that multi-channel FID navigators have a potential to complement existing tracking technologies for accurate rigid-body motion detection and correction in MRI.
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69
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Ibrahim T, Few K, Greenwood R, Smith C, Malcolm P, Johnson G, Lally P, Thayyil S, Clarke P. 'Feed and wrap' or sedate and immobilise for neonatal brain MRI? Arch Dis Child Fetal Neonatal Ed 2015; 100:F465-6. [PMID: 26126844 DOI: 10.1136/archdischild-2015-308847] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/08/2015] [Indexed: 11/04/2022]
Affiliation(s)
- Therese Ibrahim
- Neonatal Intensive Care Unit, Norfolk and Norwich University Hospitals NHS Foundation Trust, Norwich, UK
| | - Karen Few
- Neonatal Intensive Care Unit, Norfolk and Norwich University Hospitals NHS Foundation Trust, Norwich, UK
| | - Richard Greenwood
- Department of Radiology, Norfolk and Norwich University Hospitals NHS Foundation Trust, Norwich, UK
| | - Cheryl Smith
- Department of Radiology, Norfolk and Norwich University Hospitals NHS Foundation Trust, Norwich, UK
| | - Paul Malcolm
- Department of Radiology, Norfolk and Norwich University Hospitals NHS Foundation Trust, Norwich, UK
| | - Glyn Johnson
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - Pete Lally
- Department of Paediatrics, Centre for Perinatal Neurosciences, Imperial College, London, UK
| | - Sudhin Thayyil
- Department of Paediatrics, Centre for Perinatal Neurosciences, Imperial College, London, UK
| | - Paul Clarke
- Neonatal Intensive Care Unit, Norfolk and Norwich University Hospitals NHS Foundation Trust, Norwich, UK
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70
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Kainz B, Steinberger M, Wein W, Kuklisova-Murgasova M, Malamateniou C, Keraudren K, Torsney-Weir T, Rutherford M, Aljabar P, Hajnal JV, Rueckert D. Fast Volume Reconstruction From Motion Corrupted Stacks of 2D Slices. IEEE TRANSACTIONS ON MEDICAL IMAGING 2015; 34:1901-13. [PMID: 25807565 PMCID: PMC7115883 DOI: 10.1109/tmi.2015.2415453] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Capturing an enclosing volume of moving subjects and organs using fast individual image slice acquisition has shown promise in dealing with motion artefacts. Motion between slice acquisitions results in spatial inconsistencies that can be resolved by slice-to-volume reconstruction (SVR) methods to provide high quality 3D image data. Existing algorithms are, however, typically very slow, specialised to specific applications and rely on approximations, which impedes their potential clinical use. In this paper, we present a fast multi-GPU accelerated framework for slice-to-volume reconstruction. It is based on optimised 2D/3D registration, super-resolution with automatic outlier rejection and an additional (optional) intensity bias correction. We introduce a novel and fully automatic procedure for selecting the image stack with least motion to serve as an initial registration target. We evaluate the proposed method using artificial motion corrupted phantom data as well as clinical data, including tracked freehand ultrasound of the liver and fetal Magnetic Resonance Imaging. We achieve speed-up factors greater than 30 compared to a single CPU system and greater than 10 compared to currently available state-of-the-art multi-core CPU methods. We ensure high reconstruction accuracy by exact computation of the point-spread function for every input data point, which has not previously been possible due to computational limitations. Our framework and its implementation is scalable for available computational infrastructures and tests show a speed-up factor of 1.70 for each additional GPU. This paves the way for the online application of image based reconstruction methods during clinical examinations. The source code for the proposed approach is publicly available.
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Affiliation(s)
| | - Markus Steinberger
- Institute for Computer Graphics and Vision at Graz University of Technology, Inffeldgasse 16, 8010 Graz, Austria
| | - Wolfgang Wein
- ImFusion GmbH and the Chair for Computer Aided Medical Procedures & Augmented Reality at TU Munich, Agnes-Pockels-Bogen 1, 80992 Munich, Germany
| | - Maria Kuklisova-Murgasova
- Department of Perinatal Imaging and Health within the Division of Imaging Sciences and Biomedical Engineering at King's College London, Strand, London WC2R 2LS, UK
| | - Christina Malamateniou
- Department of Perinatal Imaging and Health within the Division of Imaging Sciences and Biomedical Engineering at King's College London, Strand, London WC2R 2LS, UK
| | - Kevin Keraudren
- Department of Computing, Imperial College London, 180 Queen's Gate, London SW7 2AZ, UK
| | - Thomas Torsney-Weir
- Visualization and Data Analysis group within the Faculty of Computer Science at the University of Vienna, Waehringer Strae 29, 1090 Vienna, Austria
| | - Mary Rutherford
- Department of Perinatal Imaging and Health within the Division of Imaging Sciences and Biomedical Engineering at King's College London, Strand, London WC2R 2LS, UK
| | - Paul Aljabar
- Department of Perinatal Imaging and Health within the Division of Imaging Sciences and Biomedical Engineering at King's College London, Strand, London WC2R 2LS, UK
| | - Joseph V. Hajnal
- Department of Perinatal Imaging and Health within the Division of Imaging Sciences and Biomedical Engineering at King's College London, Strand, London WC2R 2LS, UK
| | - Daniel Rueckert
- Department of Computing, Imperial College London, 180 Queen's Gate, London SW7 2AZ, UK
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71
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Neonatal brain MRI segmentation: A review. Comput Biol Med 2015; 64:163-78. [DOI: 10.1016/j.compbiomed.2015.06.016] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Revised: 06/06/2015] [Accepted: 06/18/2015] [Indexed: 11/20/2022]
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72
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Story L, Rutherford M. Advances and applications in fetal magnetic resonance imaging. ACTA ACUST UNITED AC 2015. [DOI: 10.1111/tog.12203] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Lisa Story
- London Deanery; Darent Valley Hospital; Darenth Wood Road Dartford Kent DA2 8DA UK
| | - Mary Rutherford
- King's College London; Perinatal Imaging Unit; St Thomas's Hospital; Westminster Bridge Road London SE1 7EH UK
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73
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Tourbier S, Bresson X, Hagmann P, Thiran JP, Meuli R, Cuadra MB. An efficient total variation algorithm for super-resolution in fetal brain MRI with adaptive regularization. Neuroimage 2015; 118:584-97. [PMID: 26072252 DOI: 10.1016/j.neuroimage.2015.06.018] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 05/08/2015] [Accepted: 06/04/2015] [Indexed: 11/18/2022] Open
Abstract
Although fetal anatomy can be adequately viewed in new multi-slice MR images, many critical limitations remain for quantitative data analysis. To this end, several research groups have recently developed advanced image processing methods, often denoted by super-resolution (SR) techniques, to reconstruct from a set of clinical low-resolution (LR) images, a high-resolution (HR) motion-free volume. It is usually modeled as an inverse problem where the regularization term plays a central role in the reconstruction quality. Literature has been quite attracted by Total Variation energies because of their ability in edge preserving but only standard explicit steepest gradient techniques have been applied for optimization. In a preliminary work, it has been shown that novel fast convex optimization techniques could be successfully applied to design an efficient Total Variation optimization algorithm for the super-resolution problem. In this work, two major contributions are presented. Firstly, we will briefly review the Bayesian and Variational dual formulations of current state-of-the-art methods dedicated to fetal MRI reconstruction. Secondly, we present an extensive quantitative evaluation of our SR algorithm previously introduced on both simulated fetal and real clinical data (with both normal and pathological subjects). Specifically, we study the robustness of regularization terms in front of residual registration errors and we also present a novel strategy for automatically select the weight of the regularization as regards the data fidelity term. Our results show that our TV implementation is highly robust in front of motion artifacts and that it offers the best trade-off between speed and accuracy for fetal MRI recovery as in comparison with state-of-the art methods.
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Affiliation(s)
- Sébastien Tourbier
- Centre d'Imagerie BioMédicale (CIBM), Switzerland; Radiology department, Lausanne University Hospital Center (CHUV), University of Lausanne (UNIL), Switzerland.
| | - Xavier Bresson
- Signal Processing Laboratory (LTS2), Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland
| | - Patric Hagmann
- Radiology department, Lausanne University Hospital Center (CHUV), University of Lausanne (UNIL), Switzerland
| | - Jean-Philippe Thiran
- Signal Processing Laboratory (LTS5), Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland; Radiology department, Lausanne University Hospital Center (CHUV), University of Lausanne (UNIL), Switzerland
| | - Reto Meuli
- Radiology department, Lausanne University Hospital Center (CHUV), University of Lausanne (UNIL), Switzerland
| | - Meritxell Bach Cuadra
- Centre d'Imagerie BioMédicale (CIBM), Switzerland; Radiology department, Lausanne University Hospital Center (CHUV), University of Lausanne (UNIL), Switzerland; Signal Processing Laboratory (LTS5), Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland
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74
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Gholipour A, Estroff JA, Barnewolt CE, Robertson RL, Grant PE, Gagoski B, Warfield SK, Afacan O, Connolly SA, Neil JJ, Wolfberg A, Mulkern RV. Fetal MRI: A Technical Update with Educational Aspirations. CONCEPTS IN MAGNETIC RESONANCE. PART A, BRIDGING EDUCATION AND RESEARCH 2014; 43:237-266. [PMID: 26225129 PMCID: PMC4515352 DOI: 10.1002/cmr.a.21321] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Fetal magnetic resonance imaging (MRI) examinations have become well-established procedures at many institutions and can serve as useful adjuncts to ultrasound (US) exams when diagnostic doubts remain after US. Due to fetal motion, however, fetal MRI exams are challenging and require the MR scanner to be used in a somewhat different mode than that employed for more routine clinical studies. Herein we review the techniques most commonly used, and those that are available, for fetal MRI with an emphasis on the physics of the techniques and how to deploy them to improve success rates for fetal MRI exams. By far the most common technique employed is single-shot T2-weighted imaging due to its excellent tissue contrast and relative immunity to fetal motion. Despite the significant challenges involved, however, many of the other techniques commonly employed in conventional neuro- and body MRI such as T1 and T2*-weighted imaging, diffusion and perfusion weighted imaging, as well as spectroscopic methods remain of interest for fetal MR applications. An effort to understand the strengths and limitations of these basic methods within the context of fetal MRI is made in order to optimize their use and facilitate implementation of technical improvements for the further development of fetal MR imaging, both in acquisition and post-processing strategies.
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Affiliation(s)
- Ali Gholipour
- Department of Radiology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Judith A Estroff
- Department of Radiology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Carol E Barnewolt
- Department of Radiology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Richard L Robertson
- Department of Radiology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - P Ellen Grant
- Department of Radiology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Borjan Gagoski
- Department of Radiology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Simon K Warfield
- Department of Radiology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Onur Afacan
- Department of Radiology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Susan A Connolly
- Department of Radiology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Jeffrey J Neil
- Department of Radiology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Adam Wolfberg
- Boston Maternal Fetal Medicine, Boston, Massachusetts, USA
| | - Robert V Mulkern
- Department of Radiology, Boston Children's Hospital, Boston, Massachusetts, USA
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75
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New imaging strategies using a motion-resistant liver sequence in uncooperative patients. BIOMED RESEARCH INTERNATIONAL 2014; 2014:142658. [PMID: 25243115 PMCID: PMC4163429 DOI: 10.1155/2014/142658] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 08/17/2014] [Indexed: 12/14/2022]
Abstract
MR imaging has unique benefits for evaluating the liver because of its high-resolution capability and ability to permit detailed assessment of anatomic lesions. In uncooperative patients, motion artifacts can impair the image quality and lead to the loss of diagnostic information. In this setting, the recent advances in motion-resistant liver MR techniques, including faster imaging protocols (e.g., dual-echo magnetization-prepared rapid-acquisition gradient echo (MP-RAGE), view-sharing technique), the data under-sampling (e.g., gradient recalled echo (GRE) with controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA), single-shot echo-train spin-echo (SS-ETSE)), and motion-artifact minimization method (e.g., radial GRE with/without k-space-weighted image contrast (KWIC)), can provide consistent, artifact-free images with adequate image quality and can lead to promising diagnostic performance. Understanding of the different motion-resistant options allows radiologists to adopt the most appropriate technique for their clinical practice and thereby significantly improve patient care.
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76
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Frick N, Fazelnia C, Kanzian K, Hitzl W, Fischer T, Forstner R, Bogner G. The Reliability of Fetal MRI in the Assessment of Brain Malformations. Fetal Diagn Ther 2014; 37:93-101. [DOI: 10.1159/000363652] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Accepted: 05/10/2014] [Indexed: 11/19/2022]
Abstract
Objectives: To assess the inter- and intraobserver reliability of different fetal MRI measurements in cases of fetal brain malformations and to examine the concordance between ultrasonography (US) and MRI findings. Methods: Fetal brain MRIs and US findings of 56 pregnant women were retrieved from the institutional database. Standardized fetal brain MRI measurements were performed by 4 observers, and the inter- and intraobserver reliability was determined. Additionally, US and MRI findings were retrospectively compared. Results: The interobserver intraclass correlation coefficient (ICC) was above 0.9 for the cerebellum and posterior horn of the lateral ventricle. The measurements regarding the third ventricle (0.50), the fourth ventricle (0.58), and the corpus callosum (0.63) showed poor reliability. Overall, the intraobserver reliability was greater than the interobserver reliability. US and MRI findings were discordant in 29% of the cases with MRI rendering an extended diagnosis in 18%, a change of diagnosis in 3.6%, and excluding pathological findings suspected on US in 7.1%. Conclusions: Fetal MRI is a valuable complement to US in the investigation of fetal brain malformations. The reliability of most parameters was high, except for the measurements of the third and fourth ventricles and the corpus callosum.
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77
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Plunk MR, Chapman T. The fundamentals of fetal MR imaging: Part 1. Curr Probl Diagn Radiol 2014; 43:331-46. [PMID: 25060713 DOI: 10.1067/j.cpradiol.2014.05.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 05/22/2014] [Indexed: 11/22/2022]
Abstract
Congenital malformations detected in any fetal system using ultrasound may be further evaluated with magnetic resonance imaging (MRI) to improve counseling, to plan deliveries appropriately, and sometimes to enable fetal interventions. In this first half of a 2-part review, the history and safety factors regarding fetal MRI, as well as the practical aspects of image acquisition, are discussed. In addition, as central nervous system anomalies are most commonly and best evaluated using fetal MRI, challenging central nervous system anomalies, such as fetal ventriculomegaly, posterior anomalies, and neural tube defects, detected using prenatal ultrasound are also reviewed with a focus on the fundamental implications of these diagnoses.
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Affiliation(s)
- Matthew R Plunk
- Department of Radiology, University of Washington School of Medicine, Seattle, WA
| | - Teresa Chapman
- Department of Radiology, University of Washington School of Medicine, Seattle, WA; Department of Radiology, Seattle Children׳s Hospital, Seattle, WA.
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78
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Automated fetal brain segmentation from 2D MRI slices for motion correction. Neuroimage 2014; 101:633-43. [PMID: 25058899 DOI: 10.1016/j.neuroimage.2014.07.023] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 06/05/2014] [Accepted: 07/15/2014] [Indexed: 01/18/2023] Open
Abstract
Motion correction is a key element for imaging the fetal brain in-utero using Magnetic Resonance Imaging (MRI). Maternal breathing can introduce motion, but a larger effect is frequently due to fetal movement within the womb. Consequently, imaging is frequently performed slice-by-slice using single shot techniques, which are then combined into volumetric images using slice-to-volume reconstruction methods (SVR). For successful SVR, a key preprocessing step is to isolate fetal brain tissues from maternal anatomy before correcting for the motion of the fetal head. This has hitherto been a manual or semi-automatic procedure. We propose an automatic method to localize and segment the brain of the fetus when the image data is acquired as stacks of 2D slices with anatomy misaligned due to fetal motion. We combine this segmentation process with a robust motion correction method, enabling the segmentation to be refined as the reconstruction proceeds. The fetal brain localization process uses Maximally Stable Extremal Regions (MSER), which are classified using a Bag-of-Words model with Scale-Invariant Feature Transform (SIFT) features. The segmentation process is a patch-based propagation of the MSER regions selected during detection, combined with a Conditional Random Field (CRF). The gestational age (GA) is used to incorporate prior knowledge about the size and volume of the fetal brain into the detection and segmentation process. The method was tested in a ten-fold cross-validation experiment on 66 datasets of healthy fetuses whose GA ranged from 22 to 39 weeks. In 85% of the tested cases, our proposed method produced a motion corrected volume of a relevant quality for clinical diagnosis, thus removing the need for manually delineating the contours of the brain before motion correction. Our method automatically generated as a side-product a segmentation of the reconstructed fetal brain with a mean Dice score of 93%, which can be used for further processing.
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79
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Ferrazzi G, Kuklisova Murgasova M, Arichi T, Malamateniou C, Fox MJ, Makropoulos A, Allsop J, Rutherford M, Malik S, Aljabar P, Hajnal JV. Resting State fMRI in the moving fetus: a robust framework for motion, bias field and spin history correction. Neuroimage 2014; 101:555-68. [PMID: 25008959 DOI: 10.1016/j.neuroimage.2014.06.074] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 06/23/2014] [Accepted: 06/28/2014] [Indexed: 10/25/2022] Open
Abstract
There is growing interest in exploring fetal functional brain development, particularly with Resting State fMRI. However, during a typical fMRI acquisition, the womb moves due to maternal respiration and the fetus may perform large-scale and unpredictable movements. Conventional fMRI processing pipelines, which assume that brain movements are infrequent or at least small, are not suitable. Previous published studies have tackled this problem by adopting conventional methods and discarding as much as 40% or more of the acquired data. In this work, we developed and tested a processing framework for fetal Resting State fMRI, capable of correcting gross motion. The method comprises bias field and spin history corrections in the scanner frame of reference, combined with slice to volume registration and scattered data interpolation to place all data into a consistent anatomical space. The aim is to recover an ordered set of samples suitable for further analysis using standard tools such as Group Independent Component Analysis (Group ICA). We have tested the approach using simulations and in vivo data acquired at 1.5 T. After full motion correction, Group ICA performed on a population of 8 fetuses extracted 20 networks, 6 of which were identified as matching those previously observed in preterm babies.
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Affiliation(s)
- Giulio Ferrazzi
- Centre for the Developing Brain, Division of Imaging Sciences & Biomedical Engineering, King's College London, St Thomas' Hospital, Westminster Bridge Rd, London SE1 7EH, UK.
| | - Maria Kuklisova Murgasova
- Centre for the Developing Brain, Division of Imaging Sciences & Biomedical Engineering, King's College London, St Thomas' Hospital, Westminster Bridge Rd, London SE1 7EH, UK
| | - Tomoki Arichi
- Centre for the Developing Brain, Division of Imaging Sciences & Biomedical Engineering, King's College London, St Thomas' Hospital, Westminster Bridge Rd, London SE1 7EH, UK; Department of Biomedical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Christina Malamateniou
- Centre for the Developing Brain, Division of Imaging Sciences & Biomedical Engineering, King's College London, St Thomas' Hospital, Westminster Bridge Rd, London SE1 7EH, UK
| | - Matthew J Fox
- Centre for the Developing Brain, Division of Imaging Sciences & Biomedical Engineering, King's College London, St Thomas' Hospital, Westminster Bridge Rd, London SE1 7EH, UK
| | - Antonios Makropoulos
- Centre for the Developing Brain, Division of Imaging Sciences & Biomedical Engineering, King's College London, St Thomas' Hospital, Westminster Bridge Rd, London SE1 7EH, UK
| | - Joanna Allsop
- Centre for the Developing Brain, Division of Imaging Sciences & Biomedical Engineering, King's College London, St Thomas' Hospital, Westminster Bridge Rd, London SE1 7EH, UK
| | - Mary Rutherford
- Centre for the Developing Brain, Division of Imaging Sciences & Biomedical Engineering, King's College London, St Thomas' Hospital, Westminster Bridge Rd, London SE1 7EH, UK
| | - Shaihan Malik
- Centre for the Developing Brain, Division of Imaging Sciences & Biomedical Engineering, King's College London, St Thomas' Hospital, Westminster Bridge Rd, London SE1 7EH, UK
| | - Paul Aljabar
- Centre for the Developing Brain, Division of Imaging Sciences & Biomedical Engineering, King's College London, St Thomas' Hospital, Westminster Bridge Rd, London SE1 7EH, UK
| | - Joseph V Hajnal
- Centre for the Developing Brain, Division of Imaging Sciences & Biomedical Engineering, King's College London, St Thomas' Hospital, Westminster Bridge Rd, London SE1 7EH, UK
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80
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Plaisier A, Pieterman K, Lequin MH, Govaert P, Heemskerk AM, Reiss IKM, Krestin GP, Leemans A, Dudink J. Choice of diffusion tensor estimation approach affects fiber tractography of the fornix in preterm brain. AJNR Am J Neuroradiol 2014; 35:1219-25. [PMID: 24407271 DOI: 10.3174/ajnr.a3830] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Neonatal DTI enables quantitative assessment of microstructural brain properties. Although its use is increasing, it is not widely known that vast differences in tractography results can occur, depending on the diffusion tensor estimation methodology used. Current clinical work appears to be insufficiently focused on data quality and processing of neonatal DTI. To raise awareness about this important processing step, we investigated tractography reconstructions of the fornix with the use of several estimation techniques. We hypothesized that the method of tensor estimation significantly affects DTI tractography results. MATERIALS AND METHODS Twenty-eight DTI scans of infants born <29 weeks of gestation, acquired at 30-week postmenstrual age and without intracranial injury observed, were prospectively collected. Four diffusion tensor estimation methods were applied: 1) linear least squares; 2) weighted linear least squares; 3) nonlinear least squares, and 4) robust estimation of tensors by outlier rejection. Quality of DTI data and tractography results were evaluated for each method. RESULTS With nonlinear least squares and robust estimation of tensors by outlier rejection, significantly lower mean fractional anisotropy values were obtained than with linear least squares and weighted linear least squares. Visualized quality of tract reconstruction was significantly higher by use of robust estimation of tensors by outlier rejection and correlated with quality of DTI data. CONCLUSIONS Quality assessment and choice of processing methodology have considerable impact on neonatal DTI analysis. Dedicated acquisition, quality assessment, and advanced processing of neonatal DTI data must be ensured before performing clinical analyses, such as associating microstructural brain properties with patient outcome.
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Affiliation(s)
- A Plaisier
- From the Division of Neonatology, Department of Pediatrics (A.P., K.P., P.G., A.M.H., J.D.), Erasmus Medical Center-Sophia, Rotterdam, The NetherlandsDepartments of Radiology (A.P., M.H.L., A.M.H., G.P.K., J.D.)
| | - K Pieterman
- From the Division of Neonatology, Department of Pediatrics (A.P., K.P., P.G., A.M.H., J.D.), Erasmus Medical Center-Sophia, Rotterdam, The Netherlands
| | - M H Lequin
- Departments of Radiology (A.P., M.H.L., A.M.H., G.P.K., J.D.)
| | - P Govaert
- From the Division of Neonatology, Department of Pediatrics (A.P., K.P., P.G., A.M.H., J.D.), Erasmus Medical Center-Sophia, Rotterdam, The NetherlandsDepartment of Pediatrics (P.G.), Koningin Paola Children's Hospital, Antwerp, Belgium
| | - A M Heemskerk
- From the Division of Neonatology, Department of Pediatrics (A.P., K.P., P.G., A.M.H., J.D.), Erasmus Medical Center-Sophia, Rotterdam, The NetherlandsDepartments of Radiology (A.P., M.H.L., A.M.H., G.P.K., J.D.)
| | - I K M Reiss
- Neonatology (I.K.M.R.), Erasmus Medical Center, Rotterdam, The Netherlands
| | - G P Krestin
- Departments of Radiology (A.P., M.H.L., A.M.H., G.P.K., J.D.)
| | - A Leemans
- Image Sciences Institute (A.L.), University Medical Center Utrecht, Utrecht, The Netherlands
| | - J Dudink
- From the Division of Neonatology, Department of Pediatrics (A.P., K.P., P.G., A.M.H., J.D.), Erasmus Medical Center-Sophia, Rotterdam, The NetherlandsDepartments of Radiology (A.P., M.H.L., A.M.H., G.P.K., J.D.)
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