bluuebunny/crossref_metadata_2025_split huggingface dataset:
Patient‐specific estimation of spatially variant image noise for a pinhole cardiacSPECTcamera
Authors: Cuddy‐Walsh Sarah G. , Wells R. Glenn 
Published: March 2018

PurposeNew single photon emission computed tomography (SPECT) cameras using fixed pinhole collimation are increasingly popular. Pinhole collimators are known to have variable sensitivity with distance and angle from the pinhole aperture. It follows that pinholeSPECTsystems will also have spatially variant sensitivity and hence spatially variant image noise. The objective of this study was to develop and validate a rapid method for analytically estimating a map of the noise magnitude in a reconstructed image using data from a single clinical acquisition.MethodsThe projected voxel (PV) noise estimation method uses a modified forward projector with attenuation effects to estimate the number of photons detected from each voxel in the field‐of‐view. We approximate the noise for each voxel as the standard deviation of a Poisson distribution with a mean equal to the number of detected photons. An empirical formula is used to address scaling discrepancies caused by image reconstruction. Calibration coefficients are determined for thePVmethod by comparing it with noise measured from a nonparametrically bootstrapped set of images of a spherical uniformly filled Tc‐99m water phantom. Validation studies comparePVnoise estimates with bootstrapped measured noise for 31 patient images (5 min, 340 MBq,99mTc‐tetrofosmin rest study).ResultsBland–Altman analysis showsR2correlations ≥70% between thePV‐estimated and ‐measured image noise. For the 31 patient cardiac images, thePVnoise estimate has an average bias of 0.1% compared to bootstrapped noise and have a coefficient of variation (CV) ≤ 17%. The bootstrap approach to noise measurement requires 5 h of computation for each image, whereas thePVnoise estimate requires only 64 s. In cardiac images, image noise due to attenuation and camera sensitivity varies on average from 4% at the apex to 9% in the basal posterior region of the heart. The standard deviation between 15 healthy patient study images (including physiological variability in the population) ranges from 6% to 16.5% over the length of the heart.ConclusionsThePVmethod provides a rapid estimate for spatially variant patient‐specific image noise magnitude in a pinhole‐collimated dedicated cardiacSPECTcamera with a bias of −0.3% and better than 83% precision.
System for image‐guided resection of nonpalpable breast lesions: Proof of concept
Authors: Arsenali Bruno , de Jong Hugo W. A. M. , Viergever Max A. , Gilhuijs Kenneth G. A. 
Published: March 2018

PurposeIn breast‐conserving surgery (BCS), the cancer is sometimes incompletely excised, leading to reduced patient survival. To pursue complete excisions, radioactive seed localization (RSL) may be used to insert an iodine‐125 seed into the tumor. The seed is used as a marker for the location of the tumor during surgery. RSL does not, however, show the extent of the tumor. Based on RSL, we pursue to visualize the seed location together with the extent from diagnostic images.MethodsA system with two gamma‐camera heads and two parallel‐hole collimators was recently proposed to triangulate the location of an iodine‐125 seed during BCS. In the present study, this system was extended with a range camera to visualize a sphere centered on the seed in relation to the breast. This sphere contains the entire tumor and thus defines the target volume for BCS. Physical experiments with acrylic block phantoms (thickness ranging from 3.5 to 6.5 cm) were performed to assess the absolute bias and the precision with which this sphere can be visualized.ResultsWhen a 6.5 cm thick phantom was used, along the horizontal plane, the target volume was visualized with an absolute bias and a precision of 2.1 and 0.8 mm, respectively. Along the vertical axis (i.e., z‐axis), these values were 4.2 and 2.8 mm, respectively.ConclusionsThe proposed system visualizes the target volume with an absolute bias that may be acceptable for BCS.
A re‐examination of the BIS/BAS scales: Evidence for BIS and BAS as unidimensional scales
Authors: Maack Danielle J. , Ebesutani Chad 
Published: March 2018

AbstractObjectivesCarver and White's behavioral inhibition system and behavioral activation system (BIS/BAS) scales are the most widely used to assess constructs of the revised reinforcement sensitivity theory. This study provides a re‐examination of the latent structure of the original BIS/BAS scales.MethodsThe interpretability of the three purported BAS subfactors relative to a “general behavioral activation” factor was assessed using Schmid–Leiman and standard confirmatory factor analysis. Regarding the BIS scale, comparisons were made between (a) Carver and White's unidimensional BIS model, (b) Johnson, Turner, and Iwata's 2‐factor BIS model, (c) Heym, Ferguson, and Lawrence's alternative 2‐factor BIS model, and (d) a modified Heym et al. model (unidimensional) controlling for method effects of reverse‐scored items.ResultsResults revealed the majority of variance of individual BAS items was accounted for by a common, general BAS dimension. Additionally, for the BIS scale, results of the χ2 difference statistical test supporting the 1‐factor model, as well as the noted theoretical and psychometric difficulties in interpreting a multifactor BIS scale, provide converging support that BIS items actually represent a single, unidimensional factor.ConclusionsThe collective results suggested that the BIS and BAS scales should be conceptualized as separate unidimensional measures, which is consistent with theory behind the original development.
Predicting Average Molecular Weights and Branching Level for Self‐Condensing Vinyl Copolymerization in a CSTR
Authors: Buren Bradley D. , Zhao Yutian R. , Puskas Judit E. , McAuley Kimberley B. 
Published: March 2018

AbstractA continuous stirred‐tank reactor (CSTR) model is developed to produce arborescent polyisobutylene via carbocationic copolymerization of isobutylene and inimer using multidimensional method of moments. The model is used to predict dynamic changes in average branching level (Bkin) and number‐average and weight‐average molecular weights (). Simulations of this self‐condensing vinyl copolymerization (SCVCP) show a tendency toward higher polydispersity and higher Bkin compared to batch reactor simulations conducted using the same recipes and residence times. At high inimer feed concentration and/or long residence time, the model predicts that a CSTR does not reach steady‐state operation due to increasing toward infinity. There is a narrow operating range in which inimer feed concentrations can be adjusted to achieve a desired steady‐state . If SCVCP is to be conducted in a CSTR, it will be important to ensure that residence times and inimer feed concentrations are selected within the stable operating window.
Assessment of MR‐based and quantitative susceptibility mapping for the quantification of liver iron concentration in a mouse model at 7T
Authors: Simchick Gregory , Liu Zhi , Nagy Tamas , Xiong May , Zhao Qun 
Published: March 2018

PurposeTo assess the feasibility of quantifying liver iron concentration (LIC) using
and quantitative susceptibility mapping (QSM) at a high field strength of 7 Tesla (T).MethodsFive different concentrations of Fe‐dextran were injected into 12 mice to produce various degrees of liver iron overload. After mice were sacrificed, blood and liver samples were harvested. Ferritin enzyme‐linked immunosorbent assay (ELISA) and inductively coupled plasma mass spectrometry were performed to quantify serum ferritin concentration and LIC. Multiecho gradient echo MRI was conducted to estimate
and the magnetic susceptibility of each liver sample through complex nonlinear least squares fitting and a morphology enabled dipole inversion method, respectively.ResultsAverage estimates of serum ferritin concentration, LIC,
, and susceptibility all show good linear correlations with injected Fe‐dextran concentration; however, the standard deviations in the estimates of
and susceptibility increase with injected Fe‐dextran concentration. Both
and susceptibility measurements also show good linear correlations with LIC (R2 = 0.78 and R2 = 0.91, respectively), and a susceptibility‐to‐LIC conversion factor of 0.829 ppm/(mg/g wet) is derived.ConclusionThe feasibility of quantifying LIC using MR‐based
and QSM at a high field strength of 7T is demonstrated. Susceptibility quantification, which is an intrinsic property of tissues and benefits from being field‐strength independent, is more robust than
quantification in this ex vivo study. A susceptibility‐to‐LIC conversion factor is presented that agrees relatively well with previously published QSM derived results obtained at 1.5T and 3T.
Single‐shot spiral imaging at 7 T
Authors: Engel Maria , Kasper Lars , Barmet Christoph , Schmid Thomas , Vionnet Laetitia , Wilm Bertram , Pruessmann Klaas P. 
Published: March 2018

PurposeThe purpose of this work is to explore the feasibility and performance of single‐shot spiral MRI at 7 T, using an expanded signal model for reconstruction.MethodsGradient‐echo brain imaging is performed on a 7 T system using high‐resolution single‐shot spiral readouts and half‐shot spirals that perform dual‐image acquisition after a single excitation. Image reconstruction is based on an expanded signal model including the encoding effects of coil sensitivity, static off‐resonance, and magnetic field dynamics. The latter are recorded concurrently with image acquisition, using NMR field probes. The resulting image resolution is assessed by point spread function analysis.ResultsSingle‐shot spiral imaging is achieved at a nominal resolution of 0.8 mm, using spiral‐out readouts of 53‐ms duration. High depiction fidelity is achieved without conspicuous blurring or distortion. Effective resolutions are assessed as 0.8, 0.94, and 0.98 mm in CSF, gray matter and white matter, respectively. High image quality is also achieved with half‐shot acquisition yielding image pairs at 1.5‐mm resolution.ConclusionUse of an expanded signal model enables single‐shot spiral imaging at 7 T with unprecedented image quality. Single‐shot and half‐shot spiral readouts deploy the sensitivity benefit of high field for rapid high‐resolution imaging, particularly for functional MRI and arterial spin labeling.
Technique development of 3D dynamic CS‐EPSI for hyperpolarized 13C pyruvate MR molecular imaging of human prostate cancer
Authors: Chen Hsin‐Yu , Larson Peder E.Z. , Gordon Jeremy W. , Bok Robert A. , Ferrone Marcus , van Criekinge Mark , Carvajal Lucas , Cao Peng , Pauly John M. , Kerr Adam B. , Park Ilwoo , Slater James B. , Nelson Sarah J. , Munster Pamela N. , Aggarwal Rahul , Kurhanewicz John , Vigneron Daniel B. 
Published: March 2018

PurposeThe purpose of this study was to develop a new 3D dynamic carbon‐13 compressed sensing echoplanar spectroscopic imaging (EPSI) MR sequence and test it in phantoms, animal models, and then in prostate cancer patients to image the metabolic conversion of hyperpolarized [1‐13C]pyruvate to [1‐13C]lactate with whole gland coverage at high spatial and temporal resolution.MethodsA 3D dynamic compressed sensing (CS)‐EPSI sequence with spectral–spatial excitation was designed to meet the required spatial coverage, time and spatial resolution, and RF limitations of the 3T MR scanner for its clinical translation for prostate cancer patient imaging. After phantom testing, animal studies were performed in rats and transgenic mice with prostate cancers. For patient studies, a GE SPINlab polarizer (GE Healthcare, Waukesha, WI) was used to produce hyperpolarized sterile GMP [1‐13C]pyruvate. 3D dynamic 13C CS‐EPSI data were acquired starting 5 s after injection throughout the gland with a spatial resolution of 0.5 cm3, 18 time frames, 2‐s temporal resolution, and 36 s total acquisition time.ResultsThrough preclinical testing, the 3D CS‐EPSI sequence developed in this project was shown to provide the desired spectral, temporal, and spatial 5D HP 13C MR data. In human studies, the 3D dynamic HP CS‐EPSI approach provided first‐ever simultaneously volumetric and dynamic images of the LDH‐catalyzed conversion of [1‐13C]pyruvate to [1‐13C]lactate in a biopsy‐proven prostate cancer patient with full gland coverage.ConclusionThe results demonstrate the feasibility to characterize prostate cancer metabolism in animals, and now patients using this new 3D dynamic HP MR technique to measure kPL, the kinetic rate constant of [1‐13C]pyruvate to [1‐13C]lactate conversion.
Impact of a fatigue management in work programme on meeting work demands of individuals with rheumatic diseases: A pilot study
Authors: McCormack Róisín C. , O’Shea Finbar , Doran Michele , Connolly Deirdre 
Published: March 2018

AbstractIntroductionWork disability and job loss are serious consequences of rheumatic diseases (RDs), and fatigue is a symptom of RDs commonly reported to have an impact on work performance. A FAtigue ManagEment in Work (FAME‐W) programme was developed to facilitate the self‐management of fatigue in work. The present pilot study explored if FAME‐W could facilitate individuals with RDs to manage fatigue in work and improve their ability to meet work demands.MethodsTwenty‐seven individuals with a variety of rheumatic diagnoses completed a 4‐week, 2‐h occupational therapy‐led self‐management programme. Each week focused on fatigue‐related topics, including fatigue and activity management, pain management and joint protection, mental well‐being, effective communication with employers and work colleagues, and employment legislation. Individual workplace ergonomic assessments were also offered. Study measures (work function, fatigue, pain, mood and self‐efficacy) were completed prior to starting FAME‐W, immediately post‐intervention and 12 weeks post‐intervention.ResultsParticipants (56% male) had a mean age of 43 years. No significant improvements were observed immediately post‐programme. However, at the 12‐week follow‐up, significant improvements were reported in meeting work demands (scheduling [p = 0.046], output [p = 0.002], physical [p = 0.003], mental [p = 0.016]), fatigue [p = 0.001], pain [p = 0.01], anxiety [p = 0.001], depression [p < 0.001], self‐efficacy [p < 0.001] and Arthritis Impact Measurement Scales 2‐Short Form (physical: p = 0.005; symptoms: p = 0.010; affect: p = 0.010; social: p = 0.001).ConclusionsSignificant improvements were reported in participants’ ability to meet various demands of their work 3 months post‐FAME‐W. These findings suggest that FAME‐W has the potential to assist individuals with RDs to meet the demands of their work, although further research is required to test the effectiveness of this intervention.
Patients with spondyloarthritis are equally satisfied with follow‐up by physiotherapist and rheumatologist
Authors: Holøyen Pauline Kjelsvik , Stensdotter Ann‐Katrin 
Published: March 2018

AbstractObjectiveInternational guidelines recommend that patients with spondyloarthritis (SpA) have lifelong physiotherapy, as physical activity and exercise are essential for optimizing health throughout the course of the disease. The aim of the present study was to investigate if a physiotherapy‐led outpatient clinic specializing in SpA could provide satisfactory follow‐up as an alternative to standard visits with a rheumatologist (RT). We hypothesized that satisfaction would be similar in patients followed by a physiotherapist (PT) or an RT.MethodsA total of 68 patients were randomized to follow‐up every fourth month by a PT or RT, for three visits in total. Patient satisfaction was evaluated using the Leeds Satisfaction Questionnaire (LSQ). Function, mobility and disease activity were rated using the Bath Ankylosing Spondylitis Functional Index (BASFI), Mobility Index (BASMI) and Ankylosing Spondylitis Disease Activity Score (ASDAS).ResultsPatients were equally satisfied with PT and RT follow‐up at the first (p = 0.062) and last (p = 0.710) visit. At the second visit, the RT group was seen by a nurse, and was more satisfied than the PT group (p = 0.015). Function deteriorated in both the PT (p = 0.014) and RT (p = 0.007) groups. Mobility increased in the PT group (p = 0.020). Disease activity was not affected.ConclusionsPatients seem to be equally satisfied with either of the follow‐up regimes. The PT‐led follow‐up did not seem to affect the patients' course of disease negatively. The results indicate that it would be safe to implement a PT‐led clinic for patients with SpA in specialist health services, but longer‐term follow‐up is necessary to support the findings of this study.
Fish Community Responses to Submerged Aquatic Vegetation in Maumee Bay, Western Lake Erie
Authors: Miller Jacob W. , Kocovsky Patrick M. , Wiegmann Daniel , Miner Jeffrey G. 
Published: March 2018

Abstract
Submerged aquatic vegetation (SAV) in clearwater systems simultaneously provides habitat for invertebrate prey and acts as refugia for small fishes. Many fishes in Lake Erie rely on shallow, heavily vegetated bays as spawning grounds and the loss or absence of which is known to reduce recruitment in other systems. The Maumee River and Maumee Bay, which once had abundant macrophyte beds, have experienced a decline of SAV and an increase in suspended solids (turbidity) over the last century due to numerous causes. To compare fish communities in open-water (turbid) and in SAV (clearer water) habitats in this region, which is designated by the U.S. Environmental Protection Agency as an Area of Concern, and to indicate community changes that could occur with expansion of SAV habitat, we sampled a 300-ha sector of northern Maumee Bay that contained both habitats. Using towed neuston nets through patches of each habitat, we determined that areas of SAV contained more species and a different species complex (based on the Jaccard index and the wetland fish index), than did the open-water habitat (averaging 8.6 versus 5 species per net trawl). The SAV habitat was dominated by centrarchids, namely Largemouth Bass Micropterus salmoides, Bluegill Lepomis macrochirus, and Black Crappie Pomoxis nigromaculatus. Open-water habitat was dominated by Spottail Shiner Notropis hudsonius, Gizzard Shad Dorosoma cepedianum, and White Perch Morone americana, an invasive species. These results indicate that restoration efforts aimed at decreasing turbidity and increasing the distribution of SAV could cause substantive shifts in the fish community and address important metrics for assessing the beneficial use impairments in this Area of Concern.
Boundary settings for the seismic dynamic response analysis of rock masses using the numerical manifold method
Authors: Yang Yongtao , Guo Hongwei , Fu Xiaodong , Zheng Hong 
Published: March 2018

SummaryAiming to accurately simulate seismic dynamic response of rock masses using the numerical manifold method (NMM), boundary settings must be treated carefully. In this paper, 4 issues in boundary settings are investigated to improve the performance of NMM: (1) Nonreflecting boundaries including the viscous boundary and viscoelastic boundary are considered; (2) A free‐field boundary is incorporated into NMM to accurately simulate external source wave motion; (3) A seismic input boundary is considered, and the force input method is introduced; and (4) A static‐dynamic unified boundary is incorporated for the convenience of transforming displacement boundary into other types of boundaries, such as nonreflecting boundaries and seismic input boundary. Several benchmark problems are solved to validate the improved NMM. Simulation results agree well with analytical ones, indicating that the improved NMM is able to simulate seismic dynamic response of rock masses reliably and correctly.
Development of a new patient‐reported outcome (PRO) measure on the Impact of Nighttime Urination (INTU) in patients with nocturia—Psychometric validation
Authors: Bennett Jason B. , Gillard Kristin Khalaf , Banderas Benjamin , Abrams Steven , Cheng Linda , Fein Seymour 
Published: March 2018

AimsTo psychometrically evaluate the Impact of Nighttime Urination (INTU) questionnaire, a new patient‐reported outcome measure developed to assess the impact of nocturia on health and functioning in a multicenter, behavioral modification (fluid restriction) study.MethodsParticipants aged 50‐95 years with at least two voiding episodes/night for ≥6 months completed voiding diaries and the INTU on 3 consecutive days during weeks 1 and 2 (same day recall) and completed the Pittsburgh Sleep Quality Index (PSQI) and Nocturia Quality of Life Questionnaire (N‐QOL) at baseline and days 8 and 15. Psychometric evaluations of the INTU were conducted.ResultsRasch analysis showed the INTU to be a unidimensional construct, with most items located on the severe end of the symptom severity continuum. In addition to an Overall Impact Score (10 items), exploratory factor analysis affirmed by confirmatory factor analysis identified two domains: Daytime (six items) and Nighttime (four items) Impact Scores (comparative fit index = 0.968; root mean square error of approximation = 0.08). Concurrent validity met prespecified hypotheses, indicating similarity of concepts with the PSQI (correlation [r] = 0.627) and N‐QOL (r = −0.784) total scores. The INTU differentiated among patients with different nocturic episode frequencies (P < 0.05 for all three summary scores). Statistically significant decreases were observed in mean Overall and Nighttime Impact Scores at week 2 versus week 1 in responders, indicating that the instrument can detect changes in response to symptom improvements.ConclusionsThe INTU questionnaire demonstrated robust measurement properties and is a suitable tool for assessing the patient‐reported impact of nocturia on health and functioning.
The history of the Society of Urodynamics, Female Pelvic Medicine, and Urogenital Reconstruction
Authors: Weissbart Steven J. , Zimmern Philippe E. , Nitti Victor W. , Lemack Gary E. , Kobashi Kathleen C. , Vasavada Sandip P. , Wein Alan J. 
Published: March 2018

AimsTo review the history of the Society of Urodynamics, Female Pelvic Medicine and Urogenital Reconstruction (SUFU).MethodsWe reviewed Society meeting minutes, contacted all living former Society presidents, searched the William P. Didusch Center for Urology History records, and asked Society members to share their important Society experiences in order to gather important historical information about the Society.ResultsThe Society initially formed as the Urodynamics Society in 1969 in the backdrop of a growing passion for scientific research in the country after World War II ended. Since then, Society meetings have provided a pivotal forum for the advancement of science in lower urinary tract dysfunction. Meetings occurred annually until 2004, when the meeting schedule increased to biannual. The journal, Neurourology and Urodynamics, became the official journal of the Society in 2005. SUFU has authored important guidelines on urodynamics (2012), non‐neurogenic overactive bladder (2012), and stress urinary incontinence (2017) and has shared important collaborations with other societies, including the American Urological Association (AUA), the International Continence Society (ICS), and the International Society of Pelvic Neuromodulation (ISPiN). SUFU has also been instrumental in trainee education and helped to establish formal fellowship training in the field in addition to holding a yearly educational meeting for urology residents. The Society has been led by 21 presidents throughout its history.ConclusionThroughout the Society's near half‐century long existence, the Society has fostered research, published guidelines, and educated trainees in order to improve the care of individuals suffering from lower urinary tract dysfunction.