115 research outputs found
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A comparison of semi-automated volumetric vs linear measurement of small vestibular schwannomas.
OBJECTIVE: Accurate and precise measurement of vestibular schwannoma (VS) size is key to clinical management decisions. Linear measurements are used in routine clinical practice but are prone to measurement error. This study aims to compare a semi-automated volume segmentation tool against standard linear method for measuring small VS. This study also examines whether oblique tumour orientation can contribute to linear measurement error. STUDY DESIGN: Experimental comparison of observer agreement using two measurement techniques. SETTING: Tertiary skull base unit. PARTICIPANTS: Twenty-four patients with unilateral sporadic small (< 15 mm maximum intracranial dimension) VS imaged with 1 mm-thickness T1-weighted Gadolinium enhanced MRI. MAIN OUTCOME MEASURES: (1) Intra and inter-observer intraclass correlation coefficients (ICC), repeatability coefficients (RC), and relative smallest detectable difference (%SDD). (2) Mean change in maximum linear dimension following reformatting to correct for oblique orientation of VS. RESULTS: Intra-observer ICC was higher for semi-automated volumetric when compared with linear measurements, 0.998 (95% CI 0.994-0.999) vs 0.936 (95% CI 0.856-0.972), p < 0.0001. Inter-observer ICC was also higher for volumetric vs linear measurements, 0.989 (95% CI 0.975-0.995) vs 0.946 (95% CI 0.880-0.976), p = 0.0045. The intra-observer %SDD was similar for volumetric and linear measurements, 9.9% vs 11.8%. However, the inter-observer %SDD was greater for volumetric than linear measurements, 20.1% vs 10.6%. Following oblique reformatting to correct tumour angulation, the mean increase in size was 1.14 mm (p = 0.04). CONCLUSION: Semi-automated volumetric measurements are more repeatable than linear measurements when measuring small VS and should be considered for use in clinical practice. Oblique orientation of VS may contribute to linear measurement error
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Intraoperative Monitoring of the Cochlear Nerve during Neurofibromatosis Type-2 Vestibular Schwannoma Surgery and Description of a "Test Intracochlear Electrode".
Objectives  A decision on whether to insert a cochlear implant can be made in neurofibromatosis 2 (NF2) if there is objective evidence of cochlear nerve (CN) function post vestibular schwannoma (VS) excision. We aimed to develop intraoperative CN monitoring to help in this decision. Design  We describe the intraoperative monitoring of a patient with NF2 and our stimulating and recording set up. A novel test electrode is used to stimulate the CN electrically. Setting  This study was set at a tertiary referral center for skull base pathology. Main outcome measure  Preserved auditory brainstem responses leading to cochlear implantation. Results  Electrical auditory brainstem response (EABR) waveforms will be displayed from different stages of the operation. A cochlear implant was inserted at the same sitting based on the EABR. Conclusion  Electrically evoked CN monitoring can provide objective evidence of CN function after VS excision and aid in the decision-making process of hearing rehabilitation in patients who will be rendered deaf
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A systematic review on prevention and management of wound infections from cochlear implantation.
OBJECTIVE OF REVIEW: Surgical site infections are a recognised complication of cochlear implant (CI) surgery with significant morbidity. Our aim was to search for the optimum prevention and management strategy to deal with this issue. TYPE OF REVIEW: Systematic review. SEARCH STRATEGY: A systematic literature search was undertaken from the databases of Embase, CINAHL, MEDLINE® , Web of Science, Scopus and Cochrane Library according to the predefined inclusion and exclusion criteria. EVALUATION METHOD: All relevant titles, abstracts and full-text articles were reviewed by two authors who resolved any differences by discussion and consultation with senior authors. RESULTS: Fourteen articles were included in our review. The overall quality of evidence was low with the vast majority of the studies being retrospective case series and expert opinions. No randomised controlled trials were noted. We found consistent reports that intraoperative prophylactic antibiotics should be given to all patients undergoing CI and that the vast majority of CI wound infections had grown Staphylococcal spp. or Pseudomonas spp. CONCLUSION: Our review has not identified any reliable or reproducible strategies to prevent and deal with wound infections after CI. We strongly encourage further research within this field and would suggest that a consensus of opinions from a multidisciplinary panel of experts may be a pragmatic way forward as an effective guide
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The Conditional Probability of Vestibular Schwannoma Growth at Different Time Points After Initial Stability on an Observational Protocol.
OBJECTIVE: The natural history of vestibular schwannomas (VS) is well documented in the literature, with tumour growth being paramount to decision making for both surveillance and treatment of these patients. Most previous studies refer to the risk of VS growth over a given period of time; however, this is not useful for counselling patients at different stages of their follow-up, as the risk of tumour growth is likely to be less following each subsequent year that a tumour does not grow. Accordingly, we investigated the conditional probability of VS growth at particular time-points, given a patient has not grown thus far. This Bayesian method of risk stratification allows for more tailored and accurate approximations of the risk of growth versus nongrowth of VS. METHODS: Retrospective analysis of a prospectively collected database in a tertiary referral skull base unit, containing all patients diagnosed between 2005 and 2014 with sporadic unilateral VS and a minimum of 5-year surveillance. RESULTS: A total of 341 patients met the inclusion criteria. The mean age at diagnosis was 67 years, the sizes of the VS at diagnosis were intracanalicular in 49%, small in 39%, medium in 11%, and large in 1%. Over the entire 5-year surveillance period, a total of 139 tumours were seen to grow (41%) and 202 did not grow (59%). At 1 year, the probability of growth given that the tumour had not grown to date was seen to be 21%, at 2 years 12%, at 3 years 9%, at 4 years 3%, and at 5 years 2%. The conditional probability of growth of extracanalicular VS was significantly higher in the first year when compared with intracanalicular VS (29% versus 13%, p = 0.01), but there was no such difference in years 2, 3, 4 or 5 (p = 0.60, 0.69, 0.36, 0.39, respectively). CONCLUSION: This is the first study in the literature concerned specifically with the conditional probability of VS growth. The data presented here can be used to better inform VS patients of their risk of growth at particular time points in their disease-the longer VS have been observed to be stable, the lower the risk of subsequent growth in a given year. Further, an extracanalicular vestibular schwannoma is more likely to grow in the first year compared with an intracanalicular vestibular schwannoma. Our data also adds support to surveillance protocols with increasingly infrequent MRI scans, as after 4 years of not growing, the risk of growth in year 5 falls to <2%
The Jet and Circumnuclear Environment of 3C 293
We present the new HST near-infrared polarimetry, broad and narrow-band
imaging, and MERLIN 4.5GHz Multi-Frequency Synthesis radio imaging of 3C 293, a
unique radio galaxy whose host is an obvious merger remnant, in an
exceptionally under-dense region of space. We have discovered near-infrared,
optical, and ultra-violet synchrotron emission from the jet. In the optical,
the jet is mostly obscured by a dust lane, but three knots are clear in our HST
NICMOS images at 1.6 and 2.0 microns, clearly aligning with features in the
radio. The outer jet knot is highly polarized (~15%) at 2 microns, confirming
the synchrotron emission mechanism. The radio-IR spectral index steepens
significantly with distance from the nucleus, as in 3C 273 and in contrast to M
87. The inner knot is visible (with hindsight) on the WFPC2 and STIS images
obtained for the earlier 3CR HST snapshot surveys. There is no [Fe II] emission
seen associated with the jet, constraining the role of shock-induced ionisation
by the jet. Overall there is a strong implication that the NIR jet emission is
indeed synchrotron.
From our NIR images, the core of the galaxy is clearly identifiable with the
main feature in the western extension of the radio ``jet'' image, although no
unresolved AGN component is identifiable even at K-band, consistent with an
FRII-like nucleus obscured by an optically thick torus. The galaxy appears to
have a single nucleus, with any multiple nuclei falling within the central
</~100 pc.Comment: ApJ accepted. 31 pages, 12 figures reproduced here at low resolution.
High resolution version available from
http://www.stsci.edu/~floyd/BIBLIOTECA/3c293
Longitudinal evaluation of quality of life in 288 patients with Neurofibromatosis 2
Advances in molecular biology have resulted in novel therapy for neurofibromatosis 2-related (NF2) tumours, highlighting the need for robust outcome measures. The disease-focused NF2 impact on quality of life (NFTI-QOL) patient questionnaire was assessed as an outcome measure for treatment in a multi-centre study. NFTI-QOL was related to clinician-rated severity (ClinSev) and genetic severity (GenSev) over repeated visits. Data were evaluated for 288 NF2 patients (n = 464 visits) attending the English national NF2 clinics from 2010 to 2012. The male-to-female ratio was equal and the mean age was 42.2 (SD 17.8) years. The analysis included NFTI-QOL eight-item score, ClinSev graded as mild, moderate, or severe, and GenSev as a rank order of the number of NF2 mutations (graded as mild, moderate, severe). The mean (SD) 8.7 (5.4) score for NFTI-QOL for either a first visit or all visits 9.2 (5.4) was similar to the published norm of 9.4 (5.5), with no significant relationships with age or gender. NFTI-QOL internal reliability was good, with a Cronbach’s alpha score of 0.85 and test re-test reliability r = 0.84. NFTI related to ClinSev (r = 0.41, p < 0.001; r = 0.46 for all visits), but weakly to GenSev (r = 0.16, p < 0.05; r = 0.15 for all visits). ClinSev related to GenSev (r = 0.41, p < 0.001; r = 0.42 for all visits). NFTI-QOL showed a good reliability and ability to detect significant longitudinal changes in the QOL of individuals. The moderate relationships of NFTI-QOL with clinician- and genetic-rated severity suggest that NFTI-QOL taps into NF2 patient experiences that are not encompassed by ClinSev rating or genotype
Pitch Comparisons between Electrical Stimulation of a Cochlear Implant and Acoustic Stimuli Presented to a Normal-hearing Contralateral Ear
Four cochlear implant users, having normal hearing in the unimplanted ear, compared the pitches of electrical and acoustic stimuli presented to the two ears. Comparisons were between 1,031-pps pulse trains and pure tones or between 12 and 25-pps electric pulse trains and bandpass-filtered acoustic pulse trains of the same rate. Three methods—pitch adjustment, constant stimuli, and interleaved adaptive procedures—were used. For all methods, we showed that the results can be strongly influenced by non-sensory biases arising from the range of acoustic stimuli presented, and proposed a series of checks that should be made to alert the experimenter to those biases. We then showed that the results of comparisons that survived these checks do not deviate consistently from the predictions of a widely-used cochlear frequency-to-place formula or of a computational cochlear model. We also demonstrate that substantial range effects occur with other widely used experimental methods, even for normal-hearing listeners
The state of play of blockchain technology in the financial services sector: A systematic literature review
The modern trends of digitalization have completely transformed and reshaped business practices, whole businesses, and even a number of industries. Blockchain technology is believed to be the latest advancement in industries such as the financial sector, where trust is of prime significance. Blockchain technology is a decentralized and coded security system which provides the capability for new digital services and platforms to be created through this emerging technology. This research presents a systematic review of scholarly articles on blockchain technology in the financial sector. We commenced by considering 227 articles and subsequently filtered this list down to 87 articles. From this, we present a classification framework that has three dimensions: blockchain-enabled financial benefits, challenges, and functionality. This research identifies implications for future research and practice within the blockchain paradigm
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Student pharmacists' experiences of teamwork in a quality improvement course
Student pharmacists need to work in teams in the educational and practice settings, but there is limited information on their teamwork experiences in the published literature. The study objective was to assess second-year (P2) student pharmacists' teamwork experiences in an experiential quality improvement (QI) course. A retrospective pre-post survey was conducted with P2 students to assess teamwork experience attitudes. Students reported their agreement with 17 statements about teamwork, first after the project was planned and again after the project was complete. A Kuder-Richardson 20 score was calculated to assess internal consistency. Differences between pre- and post- groups for each teamwork item were assessed using McNemar's test. An alpha level of 0.05 was used, and a Bonferroni correction was applied for multiple comparisons. Sixty P2 students (50%) responded to the survey. After the project was complete, the majority indicated agreement with good teamwork qualities and disagreement with poor teamwork qualities for most items. More than 60% of respondents indicated they would like to do collaborative work again while 20% of respondents indicated imbalances in member contributions caused conflict within the team. The majority of student pharmacists in this investigation had positive experiences working in teams, but new important findings from this study indicate that further work is needed to prevent imbalances in team-member contributions and to encourage students to work on future collaborative projects in some cases.12 month embargo; published online: 23 November 2018This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
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