keyword
MENU ▼
Read by QxMD icon Read
search

Mri techniques

keyword
https://www.readbyqxmd.com/read/28102958/sliding-window-prior-data-assisted-compressed-sensing-for-mri-tracking-of-lung-tumors
#1
Eugene Yip, Jihyun Yun, Keith Wachowicz, Zsolt Gabos, Satyapal Rathee, B G Fallone
PURPOSE: Hybrid magnetic resonance imaging and radiation therapy devices are capable of imaging in real-time to track intrafractional lung tumor motion during radiotherapy. Highly accelerated magnetic resonance (MR) imaging methods can potentially reduce system delay time and/or improves imaging spatial resolution, and provide flexibility in imaging parameters. Prior Data Assisted Compressed Sensing (PDACS) has previously been proposed as an acceleration method that combines the advantages of 2D compressed sensing and the KEYHOLE view-sharing technique...
January 2017: Medical Physics
https://www.readbyqxmd.com/read/28102196/whole-brain-3d-mapping-of-human-neural-transplant-innervation
#2
Jonas Doerr, Martin Karl Schwarz, Dirk Wiedermann, Anke Leinhaas, Alina Jakobs, Florian Schloen, Inna Schwarz, Michael Diedenhofen, Nils Christian Braun, Philipp Koch, Daniel A Peterson, Ulrich Kubitscheck, Mathias Hoehn, Oliver Brüstle
While transplantation represents a key tool for assessing in vivo functionality of neural stem cells and their suitability for neural repair, little is known about the integration of grafted neurons into the host brain circuitry. Rabies virus-based retrograde tracing has developed into a powerful approach for visualizing synaptically connected neurons. Here, we combine this technique with light sheet fluorescence microscopy (LSFM) to visualize transplanted cells and connected host neurons in whole-mouse brain preparations...
January 19, 2017: Nature Communications
https://www.readbyqxmd.com/read/28100426/ferumoxytol-mra-for-transcatheter-aortic-valve-replacement-planning-with-renal-insufficiency
#3
Kimberly Kallianos, Travis S Henry, Yerem Yeghiazarians, Jeffrey Zimmet, Kendrick A Shunk, Elaine E Tseng, Vaikom Mahadevan, Michael D Hope
BACKGROUND: Computed tomography angiography (CTA) is the test of choice for pre-procedure imaging of transcatheter aortic valve replacement (TAVR) candidates. The iodinated contrast required, however, increases the risk of renal dysfunction in patients with pre-existing renal failure. Ferumoxytol is a magnetic resonance imaging (MRI) contrast agent that can be used with renal failure. Its long vascular resonance time allows gated MRA sequences that approach CTA in image quality. We present respiratory and cardiac gated MRA enabled by ferumoxytol that can be post-processed in an analogous fashion to CTA...
December 30, 2016: International Journal of Cardiology
https://www.readbyqxmd.com/read/28097371/high-resolution-diffusion-weighted-imaging-for-solitary-orbital-tumors-3d-turbo-field-echo-with-diffusion-sensitized-driven-equilibrium-dsde-tfe-preparation-technique
#4
Akio Hiwatashi, Osamu Togao, Koji Yamashita, Kazufumi Kikuchi, Hiroshi Yoshikawa, Makoto Obara, Hiroshi Honda
PURPOSE: To differentiate cystic from solid solitary intraorbital tumors using 3D turbo field echo with diffusion-sensitized driven-equilibrium preparation without contrast material. MATERIALS AND METHODS: This retrospective study was approved by our institutional review boards, and written informed consent was waived. A total of 26 patients with intraorbital tumors were studied. Motion probing gradients were conducted at one direction with b‑values of 0 and 500 s/mm(2)...
January 17, 2017: Clinical Neuroradiology
https://www.readbyqxmd.com/read/28096729/advanced-mri-for-pediatric-brain-tumors-with-emphasis-on-clinical-benefits
#5
REVIEW
Hyun Woo Goo, Young-Shin Ra
Conventional anatomic brain MRI is often limited in evaluating pediatric brain tumors, the most common solid tumors and a leading cause of death in children. Advanced brain MRI techniques have great potential to improve diagnostic performance in children with brain tumors and overcome diagnostic pitfalls resulting from diverse tumor pathologies as well as nonspecific or overlapped imaging findings. Advanced MRI techniques used for evaluating pediatric brain tumors include diffusion-weighted imaging, diffusion tensor imaging, functional MRI, perfusion imaging, spectroscopy, susceptibility-weighted imaging, and chemical exchange saturation transfer imaging...
January 2017: Korean Journal of Radiology: Official Journal of the Korean Radiological Society
https://www.readbyqxmd.com/read/28096130/early-life-nutrition-and-neurodevelopment-use-of-the-piglet-as-a-translational-model
#6
REVIEW
Austin T Mudd, Ryan N Dilger
Optimal nutrition early in life is critical to ensure proper structural and functional development of infant organ systems. Although pediatric nutrition historically has emphasized research on the relation between nutrition, growth rates, and gastrointestinal maturation, efforts increasingly have focused on how nutrition influences neurodevelopment. The provision of human milk is considered the gold standard in pediatric nutrition; thus, there is interest in understanding how functional nutrients and bioactive components in milk may modulate developmental processes...
January 2017: Advances in Nutrition
https://www.readbyqxmd.com/read/28096104/recent-developments-in-the-surgical-management-of-paediatric-epilepsy
#7
REVIEW
Vijay M Ravindra, Matthew T Sweney, Robert J Bollo
Among the 1% of children affected by epilepsy, failure of pharmacological therapy and early age of seizure onset can lead to worse long-term cognitive outcomes, mental health disorders and impaired functional status. Surgical management often improves functional and cognitive outcomes in children with medically refractory epilepsy, especially when seizure remission is achieved. However, surgery remains underused in children with drug-resistant epilepsy, creating a large treatment gap. Several recent innovations have led to considerable improvement in surgical technique, including the recent development of minimally invasive diagnostic and therapeutic techniques such as stereotactic EEG, transcranial magnetic stimulation, MRI-guided laser ablation, as well as novel paradigms of neurostimulation...
January 17, 2017: Archives of Disease in Childhood
https://www.readbyqxmd.com/read/28095302/internal-evaluation-of-impregnation-treatment-of-waterlogged-wood-relation-between-concentration-of-internal-materials-and-relaxation-time-using-magnetic-resonance-imaging
#8
Yuki Kanazawa, Tetsuya Yamada, Aki Kido, Koji Fujimoto, Kyoko Takakura, Hiroaki Hayashi, Yasutaka Fushimi, Satoshi Kozawa, Koji Koizumi, Makiko Okuni, Naomi Ueda, Kaori Togashi
The purpose of this study is to clarify the degree of impregnation resulting from treatment of internal waterlogged wood samples using MRI. On a 1.5T MR scanner, T1 and T2 measurements were performed using inversion recovery and spin-echo sequences, respectively. The samples were cut waterlogged pieces of wood treated with various impregnation techniques which were divided into different concentrations of trehalose (C12H22O11) and polyethylene glycol (PEG; HO-(C2H4O)n-H) solutions. Then these samples underwent impregnation treatment every two weeks...
January 14, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28092785/integrated-ssfp-for-functional-brain-mapping-at-7t-with-reduced-susceptibility-artifact
#9
Kaibao Sun, Rong Xue, Peng Zhang, Zhentao Zuo, Zhongwei Chen, Bo Wang, Thomas Martin, Yi Wang, Lin Chen, Sheng He, Danny J J Wang
Balanced steady-state free precession (bSSFP) offers an alternative and potentially important tool to the standard gradient-echo echo-planar imaging (GE-EPI) for functional MRI (fMRI). Both passband and transition band based bSSFP have been proposed for fMRI. The applications of these methods, however, are limited by banding artifacts due to the sensitivity of bSSFP signal to off-resonance effects. In this article, a unique case of the SSFP-FID sequence, termed integrated-SSFP or iSSFP, was proposed to overcome the obstacle by compressing the SSFP profile into the width of a single voxel...
December 30, 2016: Journal of Magnetic Resonance
https://www.readbyqxmd.com/read/28092739/an-emg-driven-biomechanical-model-of-the-canine-cervical-spine
#10
M Alizadeh, G G Knapik, J S Dufour, C Zindl, M J Allen, J Bertran, N Fitzpatrick, W S Marras
Due to the frequency of cervical spine injuries in canines, the purpose of this effort was to develop an EMG-driven dynamic model of the canine cervical spine to assess a biomechanical understanding that enables one to investigate the risk of neck disorders. A canine subject was recruited in this investigation in order to collect subject specific data. Reflective markers and a motion capture system were used for kinematic measurement; surface electrodes were used to record electromyography signals, and with the aid of force plate kinetics were recorded...
December 26, 2016: Journal of Electromyography and Kinesiology
https://www.readbyqxmd.com/read/28092543/a-robust-wrap-reduction-algorithm-for-fringe-projection-profilometry-and-applications-in-magnetic-resonance-imaging
#11
Miguel Arevalillo-Herraez, Maximo Cobos, Miguel Garcia Pineda
In this paper, we present an effective algorithm to reduce the number of wraps in a two-dimensional (2-D) phase signal provided as input. The technique is based on an accurate estimate of the fundamental frequency of a 2-D complex signal with the phase given by the input, and the removal of a dependent additive term from the phase map. Unlike existing methods based on the Discrete Fourier Transform (DFT), the frequency is computed by using noise-robust estimates that are not restricted to integer values. Then, to deal with the problem of a non-integer shift in the frequency domain, an equivalent operation is carried out on the original phase signal...
January 10, 2017: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
https://www.readbyqxmd.com/read/28092411/measurement-of-arterial-transit-time-and-renal-blood-flow-using-pseudocontinuous-asl-mri-with-multiple-post-labeling-delays-feasibility-reproducibility-and-variation
#12
Dong Won Kim, Woo Hyun Shim, Seong Kuk Yoon, Jong Yeong Oh, Jeong Kon Kim, Hoesu Jung, Tsuyoshi Matsuda, Dongeun Kim
PURPOSE: To evaluate the feasibility, reproducibility, and variation of renal perfusion and arterial transit time (ATT) using pseudocontinuous arterial spin labeling magnetic resonance imaging (PCASL MRI) in healthy volunteers. MATERIALS AND METHODS: PCASL MRI at 3T was performed in 25 healthy volunteers on two different occasions. The ATT and ATT-corrected renal blood flow (ATT-cRBF) were calculated at four different post-labeling delay points (0.5, 1.0, 1.5, and 2...
January 16, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28092409/quantification-of-brown-and-white-adipose-tissue-based-on-gaussian-mixture-model-using-water-fat-and-t2-mri-in-adolescents
#13
Steve C N Hui, Jacky K L Ko, Teng Zhang, Lin Shi, David K W Yeung, Defeng Wang, Queenie Chan, Winnie C W Chu
PURPOSE: To develop a technique for the separation and quantification of brown adipose tissue (BAT) and white adipose tissue (WAT) using fat fraction and T2* intensity based on the Gaussian mixture model (GMM). MATERIALS AND METHODS: Chemical-shift water-fat and T2* images were acquired at the neck, supraclavicular, interscapular, and paravertebral regions in 24 volunteers (Obese: n = 12, female/male = 6/6, body mass index [BMI] = 31.3 ± 2.3 kg/m(2) , age = 16...
January 16, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28090794/novel-sluggish-speed-signs-on-ultrasound-is-indicative-of-hemangiomas
#14
Taisuke Furuta, Shoji Shimose, Yuko Nakashima, Tadahiko Kubo, Mitsuo Ochi
Background Hemangiomas are sometimes difficult to diagnose with current techniques. Sluggish speed signs (SSS) are a phenomenon that: (i) cannot be depicted as Doppler flow on Doppler ultrasound; (ii) can be observed as fluid movements on Doppler ultrasound; and (iii) cannot be depicted as waveforms on pulse Doppler mode. We hypothesized that SSS could be diagnostic indicators for hemangiomas. Purpose To evaluate whether ultrasound findings, in particular those relating to SSS, are a reliable tool for detecting hemangiomas compared to magnetic resonance imaging (MRI) and the gold standard for hemangioma diagnosis: pathological examination by biopsy or after surgical resection...
January 1, 2017: Acta Radiologica
https://www.readbyqxmd.com/read/28090600/learning-based-3t-brain-mri-segmentation-with-guidance-from-7t-mri-labeling
#15
Renping Yu, Minghui Deng, Pew-Thian Yap, Zhihui Wei, Li Wang, Dinggang Shen
Brain magnetic resonance image segmentation is one of the most important tasks in medical image analysis and has considerable importance to the effective use of medical imagery in clinical and surgical setting. In particular, the tissue segmentation of white matter (WM), gray matter (GM), and cerebrospinal fluid (CSF) is crucial for brain measurement and disease diagnosis. A variety of studies have shown that the learning-based techniques are efficient and effective in brain tissue segmentation. However, the learning-based segmentation methods depend largely on the availability of good training labels...
October 2016: Machine Learning in Medical Imaging
https://www.readbyqxmd.com/read/28090589/spiral-perfusion-imaging-with-consecutive-echoes-spice%C3%A2-for-the-simultaneous-mapping-of-dsc-and-dce-mri-parameters-in-brain-tumor-patients-theory-and-initial-feasibility
#16
Eric S Paulson, Douglas E Prah, Kathleen M Schmainda
Dynamic contrast-enhanced (DCE) and dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) are the perfusion imaging techniques most frequently used to probe the angiogenic character of brain neoplasms. With these methods, T1- and T2/T2*-weighted imaging sequences are used to image the distribution of gadolinium (Gd)-based contrast agents. However, it is well known that Gd exhibits combined T1, T2, and T2* shortening effects in tissue, and therefore, the results of both DCE- and DSC-MRI can be confounded by these opposing effects...
December 2016: Tomography: a Journal for Imaging Research
https://www.readbyqxmd.com/read/28090448/quantitative-techniques-for-musculoskeletal-mri-at-7-tesla
#17
REVIEW
Neal K Bangerter, Meredith D Taylor, Grayson J Tarbox, Antony J Palmer, Daniel J Park
Whole-body 7 Tesla MRI scanners have been approved solely for research since they appeared on the market over 10 years ago, but may soon be approved for selected clinical neurological and musculoskeletal applications in both the EU and the United States. There has been considerable research work on musculoskeletal applications at 7 Tesla over the past decade, including techniques for ultra-high resolution morphological imaging, 3D T2 and T2* mapping, ultra-short TE applications, diffusion tensor imaging of cartilage, and several techniques for assessing proteoglycan content in cartilage...
December 2016: Quantitative Imaging in Medicine and Surgery
https://www.readbyqxmd.com/read/28090447/quantitative-sodium-magnetic-resonance-imaging-of-cartilage-muscle-and-tendon
#18
REVIEW
Neal K Bangerter, Grayson J Tarbox, Meredith D Taylor, Joshua D Kaggie
Sodium magnetic resonance imaging (MRI), or imaging of the 23Na nucleus, has been under exploration for several decades, and holds promise for potentially revealing additional biochemical information about the health of tissues that cannot currently be obtained from conventional hydrogen (or proton) MRI. This additional information could serve as an important complement to conventional MRI for many applications. However, despite these exciting possibilities, sodium MRI is not yet used routinely in clinical practice, and will likely remain strictly in the domain of exploratory research for the coming decade...
December 2016: Quantitative Imaging in Medicine and Surgery
https://www.readbyqxmd.com/read/28090446/quantitative-imaging-methods-in-osteoporosis
#19
REVIEW
Ling Oei, Fjorda Koromani, Fernando Rivadeneira, M Carola Zillikens, Edwin H G Oei
Osteoporosis is characterized by a decreased bone mass and quality resulting in an increased fracture risk. Quantitative imaging methods are critical in the diagnosis and follow-up of treatment effects in osteoporosis. Prior radiographic vertebral fractures and bone mineral density (BMD) as a quantitative parameter derived from dual-energy X-ray absorptiometry (DXA) are among the strongest known predictors of future osteoporotic fractures. Therefore, current clinical decision making relies heavily on accurate assessment of these imaging features...
December 2016: Quantitative Imaging in Medicine and Surgery
https://www.readbyqxmd.com/read/28090441/principal-component-analysis-t1%C3%AF-voxel-based-relaxometry-of-the-articular-cartilage-a-comparison-of-biochemical-patterns-in-osteoarthritis-and-anterior-cruciate-ligament-subjects
#20
Valentina Pedoia, Colin Russell, Allison Randolph, Xiaojuan Li, Sharmila Majumdar
BACKGROUND: Quantitative MR, including T1ρ mapping, has been extensively used to probe early biochemical changes in knee articular cartilage of subjects with osteoarthritis (OA) and others at risk for cartilage degeneration, such as those with anterior cruciate ligament (ACL) injury and reconstruction. However, limited studies have been performed aimed to assess the spatial location and patterns of T1ρ. In this study we used a novel voxel-based relaxometry (VBR) technique coupled with principal component analysis (PCA) to extract relevant features so as to describe regional patterns and to investigate their similarities and differences in T1ρ maps in subjects with OA and subjects six months after ACL reconstruction (ACLR)...
December 2016: Quantitative Imaging in Medicine and Surgery
keyword
keyword
60150
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"