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MR image segmentation

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https://www.readbyqxmd.com/read/29136034/a-fast-stochastic-framework-for-automatic-mr-brain-images-segmentation
#1
Marwa Ismail, Ahmed Soliman, Mohammed Ghazal, Andrew E Switala, Georgy Gimel'farb, Gregory N Barnes, Ashraf Khalil, Ayman El-Baz
This paper introduces a new framework for the segmentation of different brain structures (white matter, gray matter, and cerebrospinal fluid) from 3D MR brain images at different life stages. The proposed segmentation framework is based on a shape prior built using a subset of co-aligned training images that is adapted during the segmentation process based on first- and second-order visual appearance characteristics of MR images. These characteristics are described using voxel-wise image intensities and their spatial interaction features...
2017: PloS One
https://www.readbyqxmd.com/read/29134190/locally-adaptive-magnetic-resonance-intensity-models-for-unsupervised-segmentation-of-multiple-sclerosis-lesions
#2
Alfiia Galimzianova, Žiga Lesjak, Daniel L Rubin, Boštjan Likar, Franjo Pernuš, Žiga Špiclin
Multiple sclerosis (MS) is a neurological disease characterized by focal lesions and morphological changes in the brain captured on magnetic resonance (MR) images. However, extraction of the corresponding imaging markers requires accurate segmentation of normal-appearing brain structures (NABS) and the lesions in MR images. On MR images of healthy brains, the NABS can be accurately captured by MR intensity mixture models, which, in combination with regularization techniques, such as in Markov random field (MRF) models, are known to give reliable NABS segmentation...
January 2018: Journal of Medical Imaging
https://www.readbyqxmd.com/read/29132939/automated-brain-tissue-and-myelin-volumetry-based-on-quantitative-mr-imaging-with-various-in-plane-resolutions
#3
Christina Andica, Akifumi Hagiwara, Masaaki Hori, Misaki Nakazawa, Masami Goto, Saori Koshino, Koji Kamagata, Kanako K Kumamaru, Shigeki Aoki
BACKGROUND AND PURPOSE: Segmented brain tissue volume and myelin volume can now be automatically calculated using the SyMRI, which is based on quantification of R1 and R2 relaxation rates and proton density. The aim of this study was to determine the validity of SyMRI brain tissue and myelin volumetry using various in-plane resolutions. METHODS: We scanned 10 healthy subjects on a 1.5 T MR scanner with in-plane resolutions of 0.8, 2.0, and 3.0mm. Two scans were performed for each resolution...
November 10, 2017: Journal of Neuroradiology. Journal de Neuroradiologie
https://www.readbyqxmd.com/read/29128992/mapping-of-hepatic-vasculature-in-potential-living-liver-donors-comparison-of-gadoxetic-acid-enhanced-mr-imaging-using-caipirinha-technique-with-ct-angiography
#4
Kartik Jhaveri, Lijun Guo, Luís Guimarães, Ravi Menezes, Ian McGilvray, Mark Cattral, David Grant
PURPOSE: To retrospectively evaluate gadoxetic acid-enhanced magnetic resonance angiography (MRA) using controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) technique for mapping hepatic vascular anatomy in potential living liver donors, with CT angiography (CTA) as reference standard. METHODS: 82 potential living liver donors who underwent MRA and CTA were enrolled in this HIPAA-compliant IRB-approved study. MRA and CTA images were evaluated by two reviewers in consensus with respect to (1) image quality scores for depiction of the hepatic vessels and (2) accuracy of MRA for determining the hepatic vascular variants with CTA as reference standard...
November 11, 2017: Abdominal Radiology
https://www.readbyqxmd.com/read/29127999/high-resolution-isotropic-three-dimensional-mr-imaging-of-the-extraforaminal-segments-of-the-cranial-nerves
#5
REVIEW
Jessica Wen, Naman S Desai, Dean Jeffery, Nafi Aygun, Ari Blitz
High-resolution isotropic 3-dimensional (D) MR imaging with and without contrast is now routinely used for imaging evaluation of cranial nerve anatomy and pathologic conditions. The anatomic details of the extraforaminal segments are well-visualized on these techniques. A wide range of pathologic entities may cause enhancement or displacement of the nerve, which is now visible to an extent not available on standard 2D imaging. This article highlights the anatomy of extraforaminal segments of the cranial nerves and uses select cases to illustrate the utility and power of these sequences, with a focus on constructive interference in steady-state...
February 2018: Magnetic Resonance Imaging Clinics of North America
https://www.readbyqxmd.com/read/29116626/unclassified-hepatocellular-adenoma-in-a-middle-aged-woman-with-glucose-intolerance
#6
Kumi Ozaki, Kenichi Harada, Toru Yamamoto, Hiroyuki Aoyagi, Yasuharu Kaizaki, Jun Yoshikawa
The patient was a 43-year-old woman with obesity (body mass index: 29.1) and glucose intolerance who was not taking oral contraceptives. An ultrasound showed a hypoechoic hepatic mass. Dynamic contrast-enhanced computed tomography revealed a lesion in segment 6 that showed homogeneous and slight-to-moderate enhancement in the arterial phase with persistent enhancement during the portal and equilibrium phases. On magnetic resonance (MR) imaging, the lesion demonstrated hyperintensity on T2- and diffusion-weighted images and hypointensity in the hepatobiliary phase of gadoxetic-acid-enhanced MR imaging...
November 7, 2017: Clinical Journal of Gastroenterology
https://www.readbyqxmd.com/read/29116052/quantitative-performance-evaluation-of-sup-124-sup-i-pet-mri-lesion-dosimetry-in-differentiated-thyroid-cancer
#7
Roel Wierts, Walter Jentzen, Harald H Quick, Hendrik J Wisselink, Ivo N A Pooters, Joachim E Wildberger, Ken Herrmann, Gerrit J Kemerink, Walter H Backes, Felix M Mottaghy
The aim was to investigate the quantitative performance of 124I PET/MRI for pre-therapy lesion dosimetry in differentiated thyroid cancer. Phantom measurements were performed on a PET/MRI system (Biograph mMR, Siemens Healthcare) using 124I and 18F. The PET calibration factor and the influence of radiofrequency coil attenuation were determined using a cylindrical phantom homogeneously filled with radioactivity. The calibration factor was 1.00 ± 0.02 for 18F and 0.88 ± 0.02 for 124I. Near the radiofrequency surface coil an underestimation of less than 5% in radioactivity concentration was observed...
November 8, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29103482/quantitative-evaluation-of-knee-cartilage-and-meniscus-destruction-in-patients-with-rheumatoid-arthritis-using-t1%C3%AF-and-t2-mapping
#8
Xiang Hong Meng, Zhi Wang, Li Guo, Xiu Chan Liu, Yu Wei Zhang, Ze Wei Zhang, Xin Long Ma
OBJECTIVE: To calculate T1ρ and T2 values of articular cartilage and menisci in knee joints of patients with RA, and compare the values between RA patients and healthy volunteers, to gain insight into the pathogenesis of cartilage and meniscus degradation in patients with RA. MATERIALS AND METHODS: Nine patients with RA and knee joints symptoms were enrolled in the study, twenty healthy volunteers without knee joint diseases were included as controls. Sagittal fat-saturated T1ρ and T2 mapping images were obtained on a 3T MR scanner (GE750, GE Healthcare, Waukesha, WI), using a dedicated 8-channel knee coil...
November 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/29103477/atherosclerotic-plaque-features-and-distribution-in-bilateral-carotid-arteries-of-asymptomatic-elderly-population-a-3d-multicontrast-mr-vessel-wall-imaging-study
#9
Ying Cai, Le He, Chun Yuan, Huijun Chen, Qiang Zhang, Rui Li, Cheng Li, Xihai Zhao
PURPOSE: This study sought to investigate the characteristics of morphology, compositions and distribution of carotid atherosclerotic plaques in asymptomatic elderly population using three dimensional (3D) multicontrast magnetic resonance vessel wall imaging. MATERIALS AND METHODS: 146 asymptomatic elderly subjects (≥60years) were recruited and underwent 3D multicontrast MR vessel wall imaging for bilateral carotid arteries on a 3.0T MR scanner. The presence of carotid atherosclerotic plaque was determined and the stenosis was measured...
November 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/29103469/improved-clinical-workflow-for-simultaneous-whole-body-pet-mri-using-high-resolution-caipirinha-accelerated-mr-based-attenuation-correction
#10
Martin T Freitag, Matthias Fenchel, Philipp Bäumer, Thorsten Heußer, Christopher M Rank, Marc Kachelrieß, Daniel Paech, Klaus Kopka, Sebastian Bickelhaupt, Antonia Dimitrakopoulou-Strauss, Klaus Maier-Hein, Ralf Floca, Mark E Ladd, Heinz-Peter Schlemmer, Florian Maier
PURPOSE: To explore the value and reproducibility of a novel magnetic resonance based attenuation correction (MRAC) using a CAIPIRINHA-accelerated T1-weighted Dixon 3D-VIBE sequence for whole-body PET/MRI compared to the clinical standard. METHODS: The PET raw data of 19 patients from clinical routine were reconstructed with standard MRAC (MRACstd) and the novel MRAC (MRACcaipi), a prototype CAIPIRINHA accelerated Dixon 3D-VIBE sequence, both acquired in 19 s/bed position...
November 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/29103086/a-novel-public-mr-image-dataset-of-multiple-sclerosis-patients-with-lesion-segmentations-based-on-multi-rater-consensus
#11
Žiga Lesjak, Alfiia Galimzianova, Aleš Koren, Matej Lukin, Franjo Pernuš, Boštjan Likar, Žiga Špiclin
Quantified volume and count of white-matter lesions based on magnetic resonance (MR) images are important biomarkers in several neurodegenerative diseases. For a routine extraction of these biomarkers an accurate and reliable automated lesion segmentation is required. To objectively and reliably determine a standard automated method, however, creation of standard validation datasets is of extremely high importance. Ideally, these datasets should be publicly available in conjunction with standardized evaluation methodology to enable objective validation of novel and existing methods...
November 4, 2017: Neuroinformatics
https://www.readbyqxmd.com/read/29101392/active-contours-driven-by-difference-of-gaussians
#12
Farhan Akram, Miguel Angel Garcia, Domenec Puig
In this paper, a novel edge-based active contour method is proposed based on the difference of Gaussians (DoG) to segment intensity inhomogeneous images. DoG is known as a feature enhancement tool, which can enhance the edges of an image. However, in the proposed energy functional it is used as an edge-indicator parameter, which acts like a balloon force during the level-set curve evolution process. In the proposed formulation, the internal energy term penalizes the deviation of the level-set function from a signed distance function and external energy term evolves the contour towards the boundaries of the objects...
November 3, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29100938/generative-diffeomorphic-modelling-of-large-mri-data-sets-for-probabilistic-template-construction
#13
Claudia Blaiotta, Patrick Freund, M Jorge Cardoso, John Ashburner
In this paper we present a hierarchical generative model of medical image data, which can capture simultaneously the variability of both signal intensity and anatomical shapes across large populations. Such a model has a direct application for learning average-shaped probabilistic tissue templates in a fully automated manner. While in principle the generality of the proposed Bayesian approach makes it suitable to address a wide range of medical image computing problems, our work focuses primarily on neuroimaging applications...
October 31, 2017: NeuroImage
https://www.readbyqxmd.com/read/29100254/volumetric-assessment-of-swallowing-muscles-a%C3%A2-comparison-of-ct-and-mri-segmentation
#14
Kim Barbara Sporns, Uta Hanning, Rene Schmidt, Paul Muhle, Rainer Wirth, Sebastian Zimmer, Rainer Dziewas, Sonja Suntrup-Krueger, Peter Bernhard Sporns, Walter Heindel, Wolfram Schwindt
Purpose Recent retrospective studies have proposed a high correlation between atrophy of swallowing muscles, age, severity of dysphagia and aspiration status based on computed tomography (CT). However, ionizing radiation poses an ethical barrier to research in prospective non-patient populations. Hence, there is a need to prove the efficacy of techniques that rely on noninvasive methods and produce high-resolution soft tissue images such as magnetic resonance imaging (MRI). The objective of this study was therefore to compare the segmentation results of swallowing muscles using CT and MRI...
November 3, 2017: RöFo: Fortschritte Auf Dem Gebiete der Röntgenstrahlen und der Nuklearmedizin
https://www.readbyqxmd.com/read/29097012/intensity-based-dual-model-method-for-generation-of-synthetic-ct-images-from-standard-t2-weighted-mr-images-generalized-technique-for-four-different-mr-scanners
#15
Lauri Koivula, Mika Kapanen, Tiina Seppälä, Juhani Collan, Jason A Dowling, Peter B Greer, Christian Gustafsson, Adalsteinn Gunnlaugsson, Lars E Olsson, Leonard Wee, Juha Korhonen
BACKGROUND AND PURPOSE: Recent studies have shown that it is possible to conduct entire radiotherapy treatment planning (RTP) workflow using only MR images. This study aims to develop a generalized intensity-based method to generate synthetic CT (sCT) images from standard T2-weighted (T2w) MR images of the pelvis. MATERIALS AND METHODS: This study developed a generalized dual model HU conversion method to convert standard T2w MR image intensity values to synthetic HU values, separately inside and outside of atlas-segmented bone volume contour...
October 30, 2017: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/29089416/voxel-based-analysis-of-recurrence-dynamics-in-intracranial-aneurysms-after-coiling
#16
Marielle Ernst, Anika Buchholz, Romain Bourcier, Hubert Desal, Pierre-Yves Le Floch, Markus Möhlenbruch, Martin Bendszus, Jens Fiehler
BACKGROUND: Understanding aneurysm growth is critical for the appropriate follow-up of patients after coil embolization and the need for retreatment. The purpose of the study was to stratify the growth dynamics of aneurysm recurrences after coiling by volumetric analysis and to determine predictive factors for aneurysm recurrences. METHODS: Source images of follow-up three-dimensional time of flight MR angiography (ToF-MRA) scans were compared with the first post-interventional ToF-MRA scan and analyzed for residual flow after co-registration using ANALYZE-software...
October 31, 2017: Journal of Neurointerventional Surgery
https://www.readbyqxmd.com/read/29082761/brain-mr-image-segmentation-using-nams-in-pseudo-color
#17
Hua Li, Chuanbo Chen, Shaohong Fang, Shengrong Zhao
Image segmentation plays a crucial role in various biomedical applications. In general, the segmentation of brain Magnetic Resonance (MR) images is mainly used to represent the image with several homogeneous regions instead of pixels for surgical analyzing and planning. This paper proposes a new approach for segmenting MR brain images by using pseudo-color based segmentation with Non-symmetry and Anti-packing Model with Squares (NAMS). First of all, the NAMS model is presented. The model can represent the image with sub-patterns to keep the image content and largely reduce the data redundancy...
October 28, 2017: Computer Assisted Surgery (Abingdon, England)
https://www.readbyqxmd.com/read/29080955/fusion-of-ct-coronary-angiography-and-whole-heart-dynamic-3d-cardiac-mr-perfusion-building-a-framework-for-comprehensive-cardiac-imaging
#18
Jochen von Spiczak, Robert Manka, Alexander Gotschy, Sabrina Oebel, Sebastian Kozerke, Sandra Hamada, Hatem Alkadhi
The purpose of this work was to develop a framework for 3D fusion of CT coronary angiography (CTCA) and whole-heart dynamic 3D cardiac magnetic resonance perfusion (3D-CMR-Perf) image data-correlating coronary artery stenoses to stress-induced myocardial perfusion deficits for the assessment of coronary artery disease (CAD). Twenty-three patients who underwent CTCA and 3D-CMR-Perf for various indications were included retrospectively. For CTCA, image quality and coronary diameter stenoses > 50% were documented...
October 28, 2017: International Journal of Cardiovascular Imaging
https://www.readbyqxmd.com/read/29076331/an-evaluation-of-the-benefits-of-simultaneous-acquisition-on-pet-mr-coregistration-in-head-neck-imaging
#19
Serena Monti, Carlo Cavaliere, Mario Covello, Emanuele Nicolai, Marco Salvatore, Marco Aiello
Coregistration of multimodal diagnostic images is crucial for qualitative and quantitative multiparametric analysis. While retrospective coregistration is computationally intense and could be inaccurate, hybrid PET/MR scanners allow acquiring implicitly coregistered images. Aim of this study is to assess the performance of state-of-the-art coregistration methods applied to PET and MR acquired as single modalities, comparing the results with the implicitly coregistration of a hybrid PET/MR, in complex anatomical regions such as head/neck (HN)...
2017: Journal of Healthcare Engineering
https://www.readbyqxmd.com/read/29072503/a-segmentation-of-brain-mri-images-utilizing-intensity-and-contextual-information-by-markov-random-field
#20
Mingsheng Chen, Qingguang Yan, Mingxin Qin
BACKGROUND AND OBJECTIVE: Image segmentation is a preliminary and fundamental step in computer aided magnetic resonance imaging (MRI) images analysis. But the performance of most current image segmentation methods is easily depreciated by noise in MRI images. A precise and anti-noise segmentation of MRI images is desired in modern medical image diagnosis. METHODS: This paper presents a segmentation of MRI images which combines fuzzy clustering and Markov random field (MRF)...
October 26, 2017: Computer Assisted Surgery (Abingdon, England)
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