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https://www.readbyqxmd.com/read/29331056/exploring-the-advantages-of-multiband-fmri-with-simultaneous-eeg-to-investigate-coupling-between-gamma-frequency-neural-activity-and-the-bold-response-in-humans
#1
Makoto Uji, Ross Wilson, Susan T Francis, Karen J Mullinger, Stephen D Mayhew
We established an optimal combination of EEG recording during sparse multiband (MB) fMRI that preserves high-resolution, whole-brain fMRI coverage while enabling broad-band EEG recordings which are uncorrupted by MRI gradient artefacts (GAs). We first determined the safety of simultaneous EEG recording during MB fMRI. Application of MB factor = 4 produced <1°C peak heating of electrode/hardware during 20 min of GE-EPI data acquisition. However, higher SAR sequences require specific safety testing, with greater heating observed using PCASL with MB factor = 4...
January 13, 2018: Human Brain Mapping
https://www.readbyqxmd.com/read/29328049/pet-attenuation-correction-for-rigid-mr-tx-rx-coils-from-sup-176-sup-lu-background-activity
#2
Christoph W Lerche, Theodoros Kaltsas, Liliana Caldeira, Juergen J Scheins, Elena Rota Kops, Lutz Tellmann, Uwe Pietrzyk, Hans Herzog, Nadim Jon Shah
One challenge for PET-MR hybrid imaging is the correction for attenuation of the 511 keV annihilation radiation by the required RF transmit and/or RF receive coils. Although there are strategies for building PET transparent Tx/Rx coils, such optimised coils still cause signicant attenuation of the annihilation radiation leading to artefacts and biases in the reconstructed activity concentrations. We present a straightforward method to measure the attenuation of Tx/Rx coils in simultaneous MR-PET imaging based on the natural <sup>176</sup>Lu background contained in the scintillator of the PET detector without the requirement of an external CT scanner or PET scanner with transmission source...
January 12, 2018: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29325902/which-data-should-be-tracked-in-forward-dynamic-optimisation-to-best-predict-muscle-forces-in-a-pathological-co-contraction-case
#3
Colombe Bélaise, Benjamin Michaud, Fabien Dal Maso, Katja Mombaur, Mickaël Begon
The choice of the cost-function for predicting muscle forces during a movement remains a challenge, especially in patients with neuromuscular disorders. Forward dynamics-based optimisations mainly track joint kinematics or torques, combined with a least-excitation criterion. Tracking marker trajectories and/or electromyography (EMG) has rarely been proposed. Our objective was to determine the best tracking objective-function to accurately predict the upper-limb muscle forces. A musculoskeletal model was created and EMG was simulated to obtain a reference movement - a shoulder abduction...
January 4, 2018: Journal of Biomechanics
https://www.readbyqxmd.com/read/29322834/a-tertiary-centre-experience-of-thoracic-ct-and-cardiac-mri-scanning-in-the-presence-of-a-reveal-linq-insertable-cardiac-monitoring-system-a-case-series-review-of-artefact-patient-safety-and-data-preservation
#4
Benedict M Wiles, Caroline A Illingworth, Michael Lg Couzins, Paul R Roberts, Stephen P Harden
OBJECTIVE: At our tertiary cardiothoracic centre cardiac MRI and thoracic CT scans are performed in patients with implanted LINQ devices. The degree of foreign body artefact associated with the LINQ device, and its clinical importance, has not previously been assessed. A case series review was therefore performed with a simultaneous review of patient safety and data loss events, secondary to the MRI environment. METHODS: A local database search identified LINQ device patients who underwent thoracic CT or cardiac MRI scans between March 2014 and December 2016...
January 11, 2018: British Journal of Radiology
https://www.readbyqxmd.com/read/29318430/an-eight-year-prospective-controlled-study-about-the-safety-and-diagnostic-value-of-cardiac-and-non-cardiac-1-5-t-mri-in-patients-with-a-conventional-pacemaker-or-a-conventional-implantable-cardioverter-defibrillator
#5
Pierpaolo Lupo, Riccardo Cappato, Giovanni Di Leo, Francesco Secchi, Giacomo D E Papini, Sara Foresti, Hussam Ali, Guido M G De Ambroggi, Antonio Sorgente, Gianluca Epicoco, Paola M Cannaò, Francesco Sardanelli
OBJECTIVES: To investigate safety and diagnostic value of 1.5-T MRI in carriers of conventional pacemaker (cPM) or conventional implantable defibrillator (cICD). METHODS: We prospectively compared cPM/cICD-carriers undergoing MRI (study group, SG), excluding those device-dependent or implanted <6 weeks before enrolment or prior to 01/01/2000, with cPM/cICD-carriers undergoing chest x-ray, CT or follow-up (reference group, RG). RESULTS: 142 MRI (55 cardiac) were performed in 120 patients with cPM (n=71) or cICD (n=71)...
January 9, 2018: European Radiology
https://www.readbyqxmd.com/read/29310502/post-mortem-computed-tomography-technical-principles-and-recommended-parameter-settings-for-high-resolution-imaging
#6
Dominic Gascho, Michael J Thali, Tilo Niemann
Post-mortem computed tomography (PMCT) has become a standard procedure in many forensic institutes worldwide. However, the standard scan protocols offered by vendors are optimised for clinical radiology and its main considerations regarding computed tomography (CT), namely, radiation exposure and motion artefacts. Thus, these protocols aim at low-dose imaging and fast imaging techniques. However, these considerations are negligible in post-mortem imaging, which allows for significantly increased image quality...
January 1, 2018: Medicine, Science, and the Law
https://www.readbyqxmd.com/read/29310226/application-of-esi-hrms-for-molybdenum-speciation-in-natural-waters-an-investigation-of-molybdate-halide-reactions
#7
Duc Huy Dang, R Douglas Evans
High resolution electrospray ionization mass spectrometry (ESI-HRMS) was used to study the speciation of molybdate in interaction with halides (Cl, F, Br). Desolvation during electrospray ionization induced alteration of aqueous species but method optimization successfully suppressed artefact compounds. At low Mo concentrations, chloro(oxo)molybdate and fluoro(oxo)molybdate species were found and in natural samples, MoO3Cl was detected for the first time, to the best of our knowledge. Apparent equilibrium constants for Cl substitution on molybdate were calculated for a range of pH values from 4...
March 1, 2018: Talanta
https://www.readbyqxmd.com/read/29305164/recent-progress-in-asl
#8
REVIEW
Luis Hernandez-Garcia, Anish Lahiri, Jonas Schollenberger
This article aims to provide the reader with an overview of recent developments in Arterial Spin Labeling (ASL) MRI techniques. A great deal of progress has been made in recent years in terms of the SNR and acquisition speed. New strategies have been introduced to improve labeling efficiency, reduce artefacts, and estimate other relevant physiological parameters besides perfusion. As a result, ASL techniques has become a reliable workhorse for researchers as well as clinicians. After a brief overview of the technique's fundamentals, this article will review new trends and variants in ASL including vascular territory mapping and velocity selective ASL, as well as arterial blood volume imaging techniques...
January 2, 2018: NeuroImage
https://www.readbyqxmd.com/read/29303355/nitroimidazoles-as-hypoxic-cell-radiosensitizers-and-hypoxia-probes-misonidazole-myths-and-mistakes
#9
Peter Wardman
Nitroimidazoles have been extensively explored as hypoxic cell radiosensitizers but have had limited clinical success, with efficacy restricted by toxicity. However, they have proven clinically useful as probes for tumour hypoxia. Both applications, and probably much of the dose-limiting toxicities, reflect the dominant chemical property of electron affinity or ease of reduction, associated with the nitro substituent in an aromatic structure. This single dominant property affords unusual, indeed extraordinary flexibility in drug or probe design, suggesting further development is possible in spite of earlier limitations, in particular building on the benefit of hindsight and an appreciation of errors made in earlier studies...
January 5, 2018: British Journal of Radiology
https://www.readbyqxmd.com/read/29303294/-ultrasound-examination-of-the-chest-in-the-hands-of-the-clinical-physician
#10
Vratislav Sedlák, Vladimír Koblížek, Rastislav Šimek
Implementation of ultrasound into clinical medicine is current trend in many subspecialties of internal medicine. Remarkable development and use of this technology is currently present in intensive care and respiratory medicine. This review summarizes current knowledge and nomenclature of artefacts and findings in clinical chest ultrasound. It describes ultrasound-based approach in a differential diagnostic algorithm of acute severe dyspnoea. Chest ultrasound should be a standard knowledge of chest physician...
2018: Vnitr̆ní Lékar̆ství
https://www.readbyqxmd.com/read/29298688/enhanced-response-rate-to-pegylated-liposomal-doxorubicin-in-high-grade-serous-ovarian-carcinomas-harbouring-brca1-and-brca2-aberrations
#11
Robert L Hollis, Alison M Meynert, Michael Churchman, Tzyvia Rye, Melanie Mackean, Fiona Nussey, Mark J Arends, Andrew H Sims, Colin A Semple, C Simon Herrington, Charlie Gourley
BACKGROUND: Approximately 10-15% of ovarian carcinomas (OC) are attributed to inherited susceptibility, the majority of which are due to mutations in BRCA1 or BRCA2 (BRCA1/2). These patients display superior clinical outcome, including enhanced sensitivity to platinum-based chemotherapy. Here, we seek to investigate whether BRCA1/2 status influences the response rate to single-agent pegylated liposomal doxorubicin (PLD) in high grade serous (HGS) OC. METHODS: One hundred and forty-eight patients treated with single-agent PLD were identified retrospectively from the Edinburgh Ovarian Cancer Database...
January 3, 2018: BMC Cancer
https://www.readbyqxmd.com/read/29291083/still-slow-but-even-steadier-an-update-on-the-evolution-of-turtle-cranial-disparity-interpolating-shapes-along-branches
#12
Christian Foth, Eduardo Ascarrunz, Walter G Joyce
In a previous study, we estimated the cranial disparity of turtles (Testudinata) through time using geometric morphometric data from both terminal taxa and hypothetical ancestors to compensate for temporal gaps in the fossil record. While this method yielded reasonable results for the Mesozoic and the early Cenozoic, we found a large drop in cranial disparity for the Miocene, for which we found no correlation with known environmental changes or extinction events. Instead, we speculated that the Miocene dip was a result of poor sampling of fossils or ancestors in this time bin...
November 2017: Royal Society Open Science
https://www.readbyqxmd.com/read/29290405/ct-ventilation-imaging-derived-from-breath-hold-ct-exhibits-good-regional-accuracy-with-galligas-pet
#13
Enid M Eslick, John Kipritidis, Denis Gradinscak, Mark J Stevens, Dale L Bailey, Benjamin Harris, Jeremy T Booth, Paul J Keall
BACKGROUND AND PURPOSE: CT ventilation imaging (CTVI) derived from four dimensional CT (4DCT) has shown only moderate spatial accuracy in humans due to 4DCT image artefacts. Here we assess the accuracy of an improved CTVI using high quality exhale/inhale breath-hold CT (BHCT). MATERIALS AND METHODS: Eighteen lung cancer patients underwent exhale/inhale BHCT, 4DCT and Galligas PET ventilation scans in a single imaging session. For each BHCT and 4DCT scan, we performed deformable image registration (DIR) between the inhale and exhale phase images to quantify ventilation using three published metrics: (i) breathing induced lung density change, CTVIDIR-HU (ii) breathing induced volume change CTVIDIR-Jac and (iii) the regional air-tissue product, CTVIHU Spatial accuracy was reported as the voxel-wise Spearman correlation r between CTVI and Galligas PET...
December 28, 2017: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/29289335/cognitive-consequences-of-the-left-right-asymmetry-of-atrophy-in-semantic-dementia
#14
Anna M Woollams, Karalyn Patterson
Semantic dementia (SD) is a condition in which atrophy to the anterior temporal lobes (ATL) produces a selective deterioration of conceptual knowledge. As this atrophy is always bilateral but usually asymmetrical, differences in performance of the two SD subgroups-with left > right (L > R) versus right > left (R > L) atrophy-constitute a major source of evidence regarding the roles of the left and right sides of this region. We explored this issue using large scale case-series methodology, with a pool of 216 observations of neuropsychological data from 72 patients with SD...
December 5, 2017: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
https://www.readbyqxmd.com/read/29282805/when-structure-leads-to-sex-untangling-signals-in-population-genetic-data-sets
#15
Julian Catchen
A robust signal of population structure often provides the first glimpse into the evolutionary history of a species and its populations. In this issue of Molecular Ecology, new work from Louis Bernatchez's group (Benestan et al., ) starts with an investigation of apparent structure in two marine species and concludes with an identification of sex-linked genes, and in the process provides a model for robust analysis. Structure is the genetic signal left by natural selection as well as by neutral processes like migration and gene flow...
December 2017: Molecular Ecology
https://www.readbyqxmd.com/read/29280465/prostate-specific-membrane-antigen-positron-emission-tomography-computed-tomography-for-prostate-cancer-distribution-of-disease-and-implications-for-radiation-therapy-planning
#16
Sandeep K Gupta, Tahne Watson, Jim Denham, Thomas P Shakespeare, Natalie Rutherford, Nicholas McLeod, Kevin Picton, Paul Ainsworth, Tony Bonaventura, Jarad M Martin
PURPOSE: To explore the prostate-specific membrane antigen (PSMA)-avid distribution of prostate cancer (PC) on positron emission tomography (PET), both at the time of initial diagnosis and at the time of relapse after definitive local treatment. METHODS AND MATERIALS: A total of 179 PSMA PET scans in patients with nil or ≤3 lesions on conventional imaging were retrospectively categorized into 3 subgroups: group A, high-risk PC with no prior definitive therapy (n=34); group B, prior prostatectomy (n=75); and group C, prior radiation therapy (n=70)...
November 1, 2017: International Journal of Radiation Oncology, Biology, Physics
https://www.readbyqxmd.com/read/29280283/pet-ct-to-detect-adverse-reactions-to-metal-debris-in-patients-with-metal-on-metal-hip-arthroplasty-an-exploratory-prospective-study
#17
Erik Aro, Marko Seppänen, Keijo T Mäkelä, Pauliina Luoto, Anne Roivainen, Hannu T Aro
Metal-on-metal (MoM) bearings in total hip arthroplasties and hip resurfacing arthroplasties have recently shown a new type of complication: adverse reactions to metal debris (ARMD). ARMD is characterized by local severe inflammation and tissue necrosis leading to implant failures. The gluteal muscle region is important for the patient outcome after revision surgery. This prospective positron emission tomography/computed tomography (PET/CT) study was undertaken to evaluate the characteristics of 2-deoxy-2-[18 F]fluoro-d-glucose ([18 F]FDG) and [68 Ga]Gallium citrate ([68 Ga]Citrate) PET/CT in ARMD patients...
December 27, 2017: Clinical Physiology and Functional Imaging
https://www.readbyqxmd.com/read/29280211/radial-magnetic-resonance-imaging-mri-using-a-rotating-radiofrequency-rf-coil-at-9-4%C3%A2-t
#18
Mingyan Li, Ewald Weber, Jin Jin, Thimo Hugger, Yasvir Tesiram, Peter Ullmann, Simon Stark, Miguel Fuentes, Sven Junge, Feng Liu, Stuart Crozier
The rotating radiofrequency coil (RRFC) has been developed recently as an alternative approach to multi-channel phased-array coils. The single-element RRFC avoids inter-channel coupling and allows a larger coil element with better B1 field penetration when compared with an array counterpart. However, dedicated image reconstruction algorithms require accurate estimation of temporally varying coil sensitivities to remove artefacts caused by coil rotation. Various methods have been developed to estimate unknown sensitivity profiles from a few experimentally measured sensitivity maps, but these methods become problematic when the RRFC is used as a transceiver coil...
December 27, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/29279982/mapping-of-non-numerical-domains-on-space-a-systematic-review-and-meta-analysis
#19
REVIEW
Anne Macnamara, Hannah A D Keage, Tobias Loetscher
The spatial numerical association of response code (SNARC) effect is characterized by low numbers mapped to the left side of space and high numbers mapped to the right side of space. In addition to numbers, SNARC-like effects have been found in non-numerical magnitude domains such as time, size, letters, luminance, and more, whereby the smaller/earlier and larger/later magnitudes are typically mapped to the left and right of space, respectively. The purpose of this systematic and meta-analytic review was to identify and summarise all empirical papers that have investigated horizontal (left-right) SNARC-like mappings using non-numerical stimuli...
December 26, 2017: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
https://www.readbyqxmd.com/read/29278773/an-evaluation-of-the-efficacy-reliability-and-sensitivity-of-motion-correction-strategies-for-resting-state-functional-mri
#20
Linden Parkes, Ben Fulcher, Murat Yu Cel, Alex Fornitod
Estimates of functional connectivity derived from resting-state functional magnetic resonance imaging (rs-fMRI) are sensitive to artefacts caused by in-scanner head motion. This susceptibility has motivated the development of numerous denoising methods designed to mitigate motion-related artefacts. Here, we compare popular retrospective rs-fMRI denoising methods, such as regression of head motion parameters and mean white matter (WM) and cerebrospinal fluid (CSF) (with and without expansion terms), aCompCor, volume censoring (e...
December 23, 2017: NeuroImage
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