36,652 research outputs found
Letter, from Martin Block to Carson Robison
No full text1 page, this letter is a written out telegram from Block to Robison in response to his Feb. 3, 1949 telegram
Undersampled radial MRI with multiple coils. Iterative image reconstruction using a total variation constraint
No full textThe reconstruction of artifact-free images from radially encoded MRI acquisitions poses a difficult task for undersampled data sets, that is for a much lower number of spokes in k-space than data samples per spoke. Here, we developed an iterative reconstruction method for undersampled radial MRI which (i) is based on a nonlinear optimization, (ii) allows for the incorporation of prior knowledge with use of penalty functions, and (iii) deals with data from multiple coils. The procedure arises as a two-step mechanism which first estimates the coil profiles and then renders a final image that complies with the actual observations. Prior knowledge is introduced by penalizing edges in coil profiles and by a total variation constraint for the final image. The latter condition leads to an effective suppression of undersampling (streaking) artifacts and further adds a certain degree of denoising. Apart from simulations, experimental results for a radial spin-echo MRI sequence are presented for phantoms and human brain in vivo at 2.9 T using 24,48, and 96 spokes with 256 data samples. In comparison to conventional reconstructions (regridding) the proposed method yielded visually improved image quality in all cases
Model-based iterative reconstruction for radial fast spin-echo MRI.
No full textIn radial fast spin-echo magnetic resonance imaging (MRI), a set of overlapping spokes with an inconsistent T2 weighting is acquired, which results in an averaged image contrast when employing conventional image reconstruction techniques. This work demonstrates that the problem may be overcome with the use of a dedicated reconstruction method that further allows for T2 quantification by extracting the embedded relaxation information. Thus, the proposed reconstruction method directly yields a spin-density and relaxivity map from only a single radial data set. The method is based on an inverse formulation of the problem and involves a modeling of the received MRI signal. Because the solution is found by numerical optimization, the approach exploits all data acquired. Further, it handles multicoil data and optionally allows for the incorporation of additional prior knowledge. Simulations and experimental results for a phantom and human brain in vivo demonstrate that the method yields spin-density and relaxivity maps that are neither affected by the typical artifacts from TE mixing, nor by streaking artifacts from the incomplete k-space coverage at individual echo times
Suppression of MRI Truncation Artifacts Using Total Variation Constrained Data Extrapolation
No full textThe finite sampling of k-space in MRI causes spurious image artifacts, known as Gibbs ringing, which result from signal truncation at the border of k-space. The effect is especially visible for acquisitions at low resolution and commonly reduced by filtering at the expense of image blurring. The present work demonstrates that the simple assumption of a piecewise-constant object can be exploited to extrapolate the data in k-space beyond the measured part. The method allows for a significant reduction of truncation artifacts without compromising resolution. The assumption translates into a total variation minimization problem, which can be solved with a nonlinear optimization algorithm. In the presence of substantial noise, a modified approach offers edge-preserving denoising by allowing for slight deviations from the measured data in addition to supplementing data. The effectiveness of these methods is demonstrated with simulations as well as experimental data for a phantom and human brain in vivo
Aus Berlin: Neues vom Kojoten ein Gespräch zwischen Martin Glaser und René Block über dessen geplanten Vortrag in Darmstadt = From Berlin: news from the coyote : a conversation between Martin Glaser and René Block on the latter's planned lecture in Darmstadt
No full textFast mesh-based motion estimation employing an embedded block model
No full textA fast algorithm for mesh-based motion estimation employing uniform triangular patches is proposed. The technique utilises an embedded block model to estimate the motion of the mesh grid points. Without the need for time-consuming, evaluation, the algorithm reduces the number of search iterations according to the inherent motion. A block-wise coding approach is taken for the motion information, permitting any picture degradation caused by the fast algorithm to be successfully compensated by the residue coding. Simulations on three classes of test sequence show that the proposed algorithm results in a better PSNR-rate performance than the hexagonal matching algorithm. Moreover, a reduction of up to 91% in mesh iterations is obtained
Questions and request submitted to Hon. Antonio R. Martin, Vice-Consul of Spain by Temporary Council of Block Chairmen of Heart Mountain Relocation Project, January 13, 1943
No full textQuestions submitted to Antonio R. Martin by Temporary Council of Block Chairmen at Heart Mountain incarceration camp. Questions cover international laws, rights at incarceration camp, facilities and services, and repatriation.The Japanese American Archival Collection documents the people, places, and daily life of Japanese Americans, primarily those who lived in the once thriving community of pre-war Florin in the Sacramento region, as well as the conditions in American incarceration camps during World War II. The approximately 7,000 original items include personal and official letters, photographs, diaries, arts and crafts, newsletters, textiles, camps artifacts, yearbooks and other publications
Data from: Low-dose sugammadex reverses moderate rocuronium-induced neuromuscular block in horses
No full textPlease cite as:
Manuel Martin-Flores, Daniel Sakai, Joaquin Araos, Luis Campoy. (2024) Data from: Low-dose sugammadex reverses moderate rocuronium-induced neuromuscular block in horses. [dataset] Cornell University eCommons Repository. https://doi.org/10.7298/dmq3-yh66These files contain data supporting all results reported in M Martin-Flores et al, EVJ-OA-23-200.R1 - Low-dose sugammadex reverses moderate rocuronium-induced neuromuscular block in horses.
Fourteen adult horses undergoing different procedures were anesthetized with detomidine and isoflurane. All horses received NMB with rocuronium 0.3 mg/kg IV. Neuromuscular function was measured with acceleromyographic train-of-four (TOF) ratio. Recovery occurred spontaneously in five horses weighing [median (range)] 548 (413 – 594) kg and was enhanced with sugammadex 200 mg (total dose) in nine horses [433 (362 – 515)] kg. Recovery time from moderate NMB to a TOF ratio 1.0, and total duration of NMB were compared between groups.
The dose of sugammadex was 0.46 (0.39 – 0.55) mg/kg. The recovery period lasted 21 (17 – 39) minutes for spontaneous and 4 (3 – 7) minutes for sugammadex. Total duration of NMB was 58 (41 – 70) minutes for spontaneous and 36 (21 – 43) for sugammadex (both p ≤ 0.003). There were no instances of recurarization
Waitin\u27 for the train to come in, waitin\u27 for my gal to come [first line of chorus]
No full textPerformers: Johnnie Johnston, Jo StaffordPiano, Voice and Chord
Jack Alive / Martin Dead : The Location of the "Author" in Jack London\u27s Martin Eden
No full textThis essay is an attempt to read Martin Eden, Jack Londonʼs autobiographical novel, in terms of the inextricable relationship between the author and the protagonist. Critics have often taken the unbalanced plot and the lack of ironic distance between narrator and character in Martin Eden as the technical weakness of London, but this paper argues that the achievement of this novel owes a great deal to the attachment of London to Martin. The unbalanced structure is a necessary product of the severe struggle of the author to kill his romantic alter ego. // Martin, who aspires to win Ruth Morse, tries to cross class boundaries by making a career of a writer. Even after realizing the emptiness of Ruth, who turns out to be nothing but a typical figure of the bourgeoisie, he somehow persists in loving her. The notion underlying here is that, for Martin, love, career and art are fundamentally inseparable. He objects to the aestheteʼs view of Brissenden on account of his separation of art from career. Martinʼs identity and life consist only in the triunity of love/career/art; the alternative is the repudiation of life. Thus, the unnatural delay of his disappointment in love can be regarded as Londonʼs strategy to set the suicide of Martin as the necessary consequence of the story. // By finishing the story and killing Martin, London finally detaches himself from Martin, reconstructs his self, and, unlike Martin, survives as a professional writer. In this sense, Martin Eden is a story about “writerʼs self-reconstruction.
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