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Baertsch T, Huang YY, Menozzi M. Head-mounted display versus computer monitor for visual attention screening: A comparative study. Heliyon 2023; 9:e16610. [PMID: 37484365 PMCID: PMC10360570 DOI: 10.1016/j.heliyon.2023.e16610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 05/21/2023] [Accepted: 05/22/2023] [Indexed: 07/25/2023] Open
Abstract
Visual attention is crucial to many tasks during working. When it is impaired, the risk of occupational accidents is increased. A potential accident prevention would be the tracking of employees' attentional states to construct break regimes. There is a promising visual attention test administered on a computer monitor (CM) that has several advantages over widely used continuous performance tests in detecting inattentiveness in occupational environments. However, as the setup with a CM is impractical for the use in particular working environments (e.g., lack of space or disturbing exposure to light), the test was implemented into a head-mounted display (HMD). This study aimed to investigate whether the HMD version of the test is a suitable alternative to the CM version. For this purpose, participants (N = 30; 20-29 y) performed both tests. The performance on the HMD was significantly lower than on the CM. Moreover, the performances were compared with normative data recorded with a CM in a previous study. These data significantly differ from the data recorded with the CM in the present study. This emphasizes the importance of a standardized test environment, which could be provided by an HMD. Conclusively, this study revealed that the new VR tool, based on a previous test designed to assess visual skills in a complex visual environment, exhibited good psychometric property regarding the reliability. In additional, no problems were revealed regarding the functionality and usability of the HMD.
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Affiliation(s)
- Tanja Baertsch
- Department of Health Sciences and Technology, ETH Zürich, Zurich, 8092, Switzerland
| | - Ying-Yin Huang
- Department of Industrial Engineering and Management, National Taipei University of Technology (Taipei Tech), Taipei, Taiwan
| | - Marino Menozzi
- Department of Health Sciences and Technology, ETH Zürich, Zurich, 8092, Switzerland
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Katsuyama Y, Kojima T, Shirasaka T, Kondo M, Kato T. Characteristics of the deep learning-based virtual monochromatic image with fast kilovolt-switching CT: a phantom study. Radiol Phys Technol 2023; 16:77-84. [PMID: 36583827 DOI: 10.1007/s12194-022-00695-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 12/19/2022] [Accepted: 12/23/2022] [Indexed: 12/31/2022]
Abstract
PURPOSE We assessed the physical properties of virtual monochromatic images (VMIs) obtained with different energy levels in various contrast settings and radiation doses using deep learning-based spectral computed tomography (DL-Spectral CT) and compared the results with those from single-energy CT (SECT) imaging. MATERIALS AND METHODS A Catphan® 600 phantom was scanned by DL-Spectral CT at various radiation doses. We reconstructed the VMIs obtained at 50, 70, and 100 keV. SECT (120 kVp) images were acquired at the same radiation doses. The standard deviations of the CT number and noise power spectrum (NPS) were calculated for noise characterization. We evaluated the spatial resolution by determining the 10% task-based transfer function (TTF) level, and we assessed the task-based detectability index (d'). RESULTS Regardless of the radiation dose, the noise was the lowest at 70 keV VMI. The NPS showed that the noise amplitude at all spatial frequencies was the lowest among other VMI and 120 kVp images. The spatial resolution was higher for 70 keV VMI compared to the other VMIs, except for high-contrast objects. The d' of 70 keV VMI was the highest among the VMI and 120 kVp images at all radiation doses and contrast settings. The d' of the 70 keV VMIs at the minimum dose was higher than that at the maximum dose in any other image. CONCLUSION The physical properties of the DL-Spectral CT VMIs varied with the energy level. The 70 keV VMI had the highest detectability by far among the VMI and 120-kVp images. DL-Spectral CT may be useful to reduce radiation doses.
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Affiliation(s)
- Yuna Katsuyama
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Fukuoka, Japan.
| | - Tsukasa Kojima
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Fukuoka, Japan.,Department of Health Sciences, Graduate school of Medical Sciences, Kyushu University, Fukuoka, Fukuoka, Japan
| | - Takashi Shirasaka
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Fukuoka, Japan
| | - Masatoshi Kondo
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Fukuoka, Japan
| | - Toyoyuki Kato
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Fukuoka, Japan
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Matambisso G, Brokhattingen N, Maculuve S, Cisteró P, Mbeve H, Escoda A, Miguel J, Buetas E, de Jong I, Cuna B, Melembe C, Ndimande N, Porras G, Chen H, Tetteh KKA, Drakeley C, Gamain B, Chitnis C, Chauhan V, Quintó L, Galatas B, Macete E, Mayor A. Gravidity and malaria trends interact to modify P. falciparum densities and detectability in pregnancy: a 3-year prospective multi-site observational study. BMC Med 2022; 20:396. [PMID: 36376866 PMCID: PMC9664815 DOI: 10.1186/s12916-022-02597-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 10/06/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Low-density Plasmodium falciparum infections prevail in low transmission settings, where immunity is expected to be minimal, suggesting an immune-independent effect on parasite densities. We aimed to describe parasite densities in pregnancy, and determine how gravidity and antibody-mediated immunity affect these, during a period of declining malaria transmission in southern Mozambique. METHODS We documented P. falciparum infections at first antenatal care visits (n = 6471) between November 2016 and October 2019 in Ilha Josina (high-to-moderate transmission area), Manhiça (low transmission area), and Magude (pre-elimination area). Two-way interactions in mixed-effects regression models were used to assess gravidity-dependent differences in quantitative PCR-determined P. falciparum positivity rates (PfPRqPCR) and densities, in the relative proportion of detectable infections (pDi) with current diagnostic tests (≥ 100 parasites/μL) and in antimalarial antibodies. RESULTS PfPRqPCR declined from 28 to 13% in Ilha Josina and from 5-7 to 2% in Magude and Manhiça. In primigravidae, pDi was highest in Ilha Josina at the first study year (p = 0.048), which declined with falling PfPRqPCR (relative change/year: 0.41, 95% CI [0.08; 0.73], p = 0.029), with no differences in antibody levels. Higher parasite densities in primigravidae from Ilha Josina during the first year were accompanied by a larger reduction of maternal hemoglobin levels (- 1.60, 95% CI [- 2.49; - 0.72; p < 0.001), than in Magude (- 0.76, 95% CI [- 1.51; - 0.01]; p = 0.047) and Manhiça (- 0.44, 95% CI [- 0.99; 0.10; p = 0.112). In contrast, multigravidae during the transmission peak in Ilha Josina carried the lowest pDi (p = 0.049). As PfPRqPCR declined, geometric mean of parasite densities increased (4.63, 95% CI [1.28; 16.82], p = 0.020), and antibody levels declined among secundigravidae from Ilha Josina. CONCLUSIONS The proportion of detectable and clinically relevant infections is the highest in primigravid women from high-to-moderate transmission settings and decreases with declining malaria. In contrast, the falling malaria trends are accompanied by increased parasite densities and reduced humoral immunity among secundigravidae. Factors other than acquired immunity thus emerge as potentially important for producing less detectable infections among primigravidae during marked declines in malaria transmission.
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Affiliation(s)
- Glória Matambisso
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | | | - Sónia Maculuve
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Pau Cisteró
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Henriques Mbeve
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Anna Escoda
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Judice Miguel
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Elena Buetas
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Ianthe de Jong
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Boaventura Cuna
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Cardoso Melembe
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Nelo Ndimande
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Gemma Porras
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Haily Chen
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Kevin K A Tetteh
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Chris Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Benoit Gamain
- Université de Paris, Biologie Intégrée du Globule Rouge, UMR_S1134, Inserm, 75015, Paris, France
| | - Chetan Chitnis
- Department of Parasites & Insect Vectors, Malaria Parasite Biology and Vaccines, Institut Pasteur, Paris, France
| | - Virander Chauhan
- Malaria Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | - Llorenç Quintó
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique.,ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Beatriz Galatas
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique.,ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Eusébio Macete
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique.,National Directare of Health, Ministry of Health, Maputo, Mozambique
| | - Alfredo Mayor
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique. .,ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain. .,Spanish Consortium for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain. .,Department of Physiologic Sciences, Faculty of Medicine, Universidade Eduardo Mondlane, Maputo, Mozambique.
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Awamoto E, Awamoto S, Mizoguchi N, Kato T. Detectability of category 3 or higher microcalcifications on digital mammograms: a comparative study between 5-MP color and monochrome liquid crystal display monitors. Radiol Phys Technol 2022. [PMID: 36076142 DOI: 10.1007/s12194-022-00679-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 08/25/2022] [Accepted: 08/27/2022] [Indexed: 10/14/2022]
Abstract
This study explored the detectability of category 3 or higher microcalcifications using 5-MP color and monochrome monitors. Contrast detail mammography phantom with polymethyl methacrylate (PMMA) images were observed in color and monochrome by five radiographers, and the image quality figures (IQF) were calculated based on the gold disc locations identified. Five radiographers and two radiologists observed 200 mammograms from 100 patients (including 36 with microcalcifications) and rated the microcalcifications. The results were analyzed using area under the curve (AUC) and jackknife resampling. A paired t test was used for statistical analysis (p < 0.05). The mean IQF of color and monochrome monitors were 10.73 and 10.49 (30 mm PMMA, p = 0.653) and 8.47 and 8.74 (50 mm PMMA, p = 0.774), respectively. The mean AUC of color and monochrome monitors were 0.917 and 0.936 (p = 0.335), respectively, with windowing and magnification. The detectability of microcalcifications was not significantly different between the monitors.
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Dickel L, Monsimet J, Lafage D, Devineau O. Characterization of habitat requirements of European fishing spiders. PeerJ 2022; 10:e12806. [PMID: 35178294 PMCID: PMC8815374 DOI: 10.7717/peerj.12806] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 12/27/2021] [Indexed: 01/10/2023] Open
Abstract
Wetlands are among the most threatened habitats in the world, and so are their species, which suffer habitat loss due to climate and land use changes. Freshwater species, and especially arthropods, receive comparatively little attention in conservation plans, and the goals to stop and reverse the destruction of wetlands published 25 years ago in a manifesto by the Union of Concerned Scientists have not been reached. In this study, we investigated the occurrence and habitat requirements at two spatial scales of two species of European fishing spiders Dolomedes, which rely heavily on declining wetland habitats in Sweden and southern Norway. We collected occurrence data for Dolomedes plantarius and Dolomedes fimbriatus, using a live-determination method. We modelled the placement of nursery webs to describe fine-scale habitat requirements related to vegetation and micro-climate. Using a machine learning approach, we described the habitat features for each species and for co-occurrence sites, thus providing insight into variables relevant for the presence and detectability of Dolomedes. Nursery placement is mostly dependent on proximity to water, presence of Carex sp. (Sedges) and crossing vegetation structures, and on humidity, while detection can be affected by weather conditions. Furthermore, co-occurrence sites were more similar to D. plantarius sites than to D. fimbriatus sites, whereby surrounding forest, water type and velocity, elevation and latitude were of importance for explaining which species of Dolomedes was present. Overall, habitat requirements were narrower for D. plantarius compared to D. fimbiratus.
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Affiliation(s)
- Lisa Dickel
- Department of Forestry and Wildlife Management, Inland Norway University of Applied Sciences, Campus Evenstad, Koppang, Norway,Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Sciences and Technology (NTNU), Trondheim, Norway
| | - Jérémy Monsimet
- Department of Forestry and Wildlife Management, Inland Norway University of Applied Sciences, Campus Evenstad, Koppang, Norway
| | - Denis Lafage
- Department of Environmental and Life Sciences/Biology, Karslstad University, Karlstad, Sweden,CNRS, ECOBIO (Ecosystèmes, Biodiversité, Évolution)-UMR 6553, University of Rennes, Rennes, France
| | - Olivier Devineau
- Department of Forestry and Wildlife Management, Inland Norway University of Applied Sciences, Campus Evenstad, Koppang, Norway
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Cui Z, Zhao W, Zhang Y, Zhao N, Shan G, Yu X, Ye X. Testing the efficacy of camera-trap sampling designs for monitoring giant pandas in a heterogeneous landscape. Environ Sci Pollut Res Int 2022; 29:14098-14110. [PMID: 34601689 DOI: 10.1007/s11356-021-16765-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 09/23/2021] [Indexed: 06/13/2023]
Abstract
The use of camera traps is prevalent in the ecological study of giant pandas (Ailuropoda melanoleuca). The reliability of camera-trap surveying results greatly depends on sampling designs that significantly influence the detection probability of the target species. Few studies have tested the efficacy of sampling designs on camera-trap surveys for monitoring giant pandas in a heterogeneous landscape. In this study, we conducted camera trapping of giant pandas based on two different sampling schemes in Changqing National Nature Reserve of China, and evaluated their outcomes based on three aspects: occupancy analysis, photographic rate, and activity pattern. The results demonstrated that both climate heterogeneity and distance to the nearest road had a strong positive influence on site occupancy, and slope and forest cover had a significant negative impact on site occupancy. Significant differences in the direction or magnitude of variables' influences indicated that there were apparently spatial-temporal dynamics of giant panda distribution between two sampling schemes. The low detection probabilities indicated that both sampling schemes were not robust to accurately monitor giant pandas in the whole study area. We recommended that more suitable sampling designs with local covariates be developed for camera-trap surveys monitoring giant pandas to account for temporal variability and small-scale variation in heterogeneous landscapes.
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Affiliation(s)
- Zhenxia Cui
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, People's Republic of China
- Research Center for UAV Remote Sensing, Shaanxi Normal University, Xi'an, 710119, People's Republic of China
| | - Wenai Zhao
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, People's Republic of China
- Research Center for UAV Remote Sensing, Shaanxi Normal University, Xi'an, 710119, People's Republic of China
| | - Yashuai Zhang
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, People's Republic of China
- Research Center for UAV Remote Sensing, Shaanxi Normal University, Xi'an, 710119, People's Republic of China
| | - Naxun Zhao
- Administration of Shaanxi Changqing National Nature Reserve, Hanzhong, 723000, People's Republic of China
| | - Guoyu Shan
- Administration of Shaanxi Changqing National Nature Reserve, Hanzhong, 723000, People's Republic of China
| | - Xiaoping Yu
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, People's Republic of China
- Research Center for UAV Remote Sensing, Shaanxi Normal University, Xi'an, 710119, People's Republic of China
| | - Xinping Ye
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, People's Republic of China.
- Research Center for UAV Remote Sensing, Shaanxi Normal University, Xi'an, 710119, People's Republic of China.
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Abstract
Dual-energy CT, the object is scanned at two different energies, makes it possible to identify the characteristics of materials that cannot be evaluated on conventional single-energy CT images. This imaging method can be used to perform material decomposition based on differences in the material-attenuation coefficients at different energies. Dual-energy analyses can be classified as image data-based- and raw data-based analysis. The beam-hardening effect is lower with raw data-based analysis, resulting in more accurate dual-energy analysis. On virtual monochromatic images, the iodine contrast increases as the energy level decreases; this improves visualization of contrast-enhanced lesions. Also, the application of material decomposition, such as iodine- and edema images, increases the detectability of lesions due to diseases encountered in daily clinical practice. In this review, the minimal essentials of dual-energy CT scanning are presented and its usefulness in daily clinical practice is discussed.
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Affiliation(s)
- Fuminari Tatsugami
- Department of Diagnostic Radiology, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan.
| | - Toru Higaki
- Department of Diagnostic Radiology, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Yuko Nakamura
- Department of Diagnostic Radiology, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Yukiko Honda
- Department of Diagnostic Radiology, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Kazuo Awai
- Department of Diagnostic Radiology, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
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Sghaier M, Chouzenoux E, Pesquet JC, Muller S. A Novel Task-Based reconstruction approach for digital breast tomosynthesis. Med Image Anal 2021; 77:102341. [PMID: 34998110 DOI: 10.1016/j.media.2021.102341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/16/2021] [Accepted: 12/20/2021] [Indexed: 10/19/2022]
Abstract
The reconstruction of a volumetric image from Digital Breast Tomosynthesis (DBT) measurements is an ill-posed inverse problem, for which existing iterative regularized approaches can provide a good solution. However, the clinical task is somehow omitted in the derivation of those techniques, although it plays a primary role in the radiologist diagnosis. In this work, we address this issue by introducing a novel variational formulation for DBT reconstruction, tailored for a specific clinical task, namely the detection of microcalcifications. Our method aims at simultaneously enhancing the detectability performance and enabling a high-quality restoration of the background breast tissues. Our contribution is threefold. First, we introduce an original task-based reconstruction framework through the proposition of a detectability function inspired from mathematical model observers. Second, we propose a novel total-variation regularizer where the gradient field accounts for the different morphological contents of the imaged breast. Third, we integrate the two developed measures into a cost function, minimized thanks to a new form of the Majorize Minimize Memory Gradient (3MG) algorithm. We conduct a numerical comparison of the convergence speed of the proposed method with those of standard convex optimization algorithms. Experimental results show the interest of our DBT reconstruction approach, qualitatively and quantitatively.
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Affiliation(s)
- Maissa Sghaier
- University of Paris-Saclay, CentraleSupélec, CVN, Inria, 09 Rue Joliot Curie, Gif-sur-Yvette 91190, France; GE Healthcare, 283 Rue de la Minière, Buc 78530, France.
| | - Emilie Chouzenoux
- University of Paris-Saclay, CentraleSupélec, CVN, Inria, 09 Rue Joliot Curie, Gif-sur-Yvette 91190, France.
| | - Jean-Christophe Pesquet
- University of Paris-Saclay, CentraleSupélec, CVN, Inria, 09 Rue Joliot Curie, Gif-sur-Yvette 91190, France.
| | - Serge Muller
- GE Healthcare, 283 Rue de la Minière, Buc 78530, France.
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González-López A. High frequency residues: A new set of signals for detectability studies of an X-ray imaging system. Phys Med 2021; 91:54-61. [PMID: 34710791 DOI: 10.1016/j.ejmp.2021.10.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 09/09/2021] [Accepted: 10/15/2021] [Indexed: 10/20/2022] Open
Abstract
A new set of signals for studying detectability of an X-ray imaging system is presented. The results obtained with these signals are intended to complement the NEQ results. The signals are generated from line spread profiles by progressively removing their lower frequency components and the resulting high frequency residues (HFRs) form the set of signals to be used in detectability studies. Detectability indexes for these HFRs are obtained using a non-prewhitening (NPW) observer and a series of edge images are used to obtain the HFRs, the covariance matrices required by the NPW model and the MTF and NPS used in NEQ calculations. The template used in the model is obtained by simulating the processes of blurring and sampling of the edge images. Comparison between detectability indexes for the HFRs and NEQ are carried out for different acquisition techniques using different beam qualities and doses. The relative sensitivity shown by detectability indexes using HFRs is higher than that of NEQ, especially at lower doses. Also, the different observers produce different results at high doses: while the ideal Bayesian observer used by NEQ distinguishes between beam qualities, the NPW used with the HFRs produces no differences between them. Delta functions used in HFR are the opposite of complex exponential functions in terms of their support in the spatial and frequency domains. Since NEQ can be interpreted as detectability of these complex exponential functions, detectability of HFRs is presented as a natural complement to NEQ in the performance assessment of an imaging system.
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Affiliation(s)
- Antonio González-López
- Servicio de Radiofísica y Protección Radiológica. Hospital Clínico Universitario Virgen de la Arrixaca, ctra. Madrid-Cartagena s/n, 30120 El Palmar (Murcia), Spain.
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Ichikawa H, Kawakami K, Onoguchi M, Shibutani T, Nagatake K, Hosoya T, Ito T, Kato T, Tsuchikame H, Shimada H. Automatic quantification package (Hone Graph) for phantom-based image quality assessment in bone SPECT: computerized automatic classification of detectability. Ann Nucl Med 2021; 35:937-46. [PMID: 34028702 DOI: 10.1007/s12149-021-01631-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 05/12/2021] [Indexed: 01/12/2023]
Abstract
OBJECTIVE We previously developed a custom-design thoracic bone scintigraphy-specific phantom ("SIM2 bone phantom") to assess image quality in bone single-photon emission computed tomography (SPECT). We aimed to develop an automatic assessment system for imaging technology in bone SPECT and demonstrate the validity of this system. METHODS Four spherical lesions of 13-, 17-, 22-, and 28-mm diameters in the vertebrae of SIM2 bone phantom simulating the thorax were filled with radioactivity (target-to-background ratio: 4). Dynamic SPECT acquisitions were performed for 15 min; reconstructions were performed using ordered subset expectation maximization at 3-15-min timepoints. Consequently, 216 lesions (54 SPECT images) were obtained: 120 and 96 lesions were used for software development and validation, respectively. The developed software used statistical parametric mapping to rigidly register and automatically calculate quantitative indexes (contrast-to-noise ratio, % coefficient of variance, % detectability equivalence volume, recovery coefficient, target-to-normal bone ratio, and full width at half maximum). A detectability score (DS) was used to define the four observation types (4, excellent; 3, adequate; 2, average; 1, poor) to score hot spherical lesions. The gold standard for DSs was independently classified by three experienced board-certified nuclear medicine technologists using the four observation types; thereafter, a consensus regarding the gold standard for DSs was reached. Using 120 lesions for development, decision tree analysis was performed to determine DS based on the quantitative indexes. We verified the validation of the quantitative indexes and their threshold values for automatic classification using 96 lesions for validation. RESULTS The trends in the automatically calculated quantitative indices were consistent. Decision tree analysis produced four terminal groups; two quantitative indexes (% detectability equivalence volume and contrast-to-noise ratio) were used to classify DS. The automatically classified DSs exhibited an almost perfect agreement with the gold standard. The percentage agreement and kappa coefficient were 91.7% and 0.93, respectively, in 96 lesions for validation. CONCLUSIONS The developed software automatically classified the detectability of hot lesions in the SIM2 bone phantom using the automatically calculated quantitative indexes, suggesting that this software could provide a means to automatically perform detectability analysis after data input that is excellent in reproducibility and accuracy.
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Kersting D, Jentzen W, Sraieb M, Costa PF, Conti M, Umutlu L, Antoch G, Nader M, Herrmann K, Fendler WP, Rischpler C, Weber M. Comparing lesion detection efficacy and image quality across different PET system generations to optimize the iodine-124 PET protocol for recurrent thyroid cancer. EJNMMI Phys 2021; 8:14. [PMID: 33587222 PMCID: PMC7884562 DOI: 10.1186/s40658-021-00361-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 01/28/2021] [Indexed: 12/13/2022] Open
Abstract
Background In recurrent differentiated thyroid cancer patients, detectability in 124I PET is limited for lesions with low radioiodine uptake. We assess the improvements in lesion detectability and image quality between three generations of PET scanners with different detector technologies. The results are used to suggest an optimized protocol. Methods Datasets of 10 patients with low increasing thyroglobulin or thyroglobulin antibody levels after total thyroidectomy and radioiodine therapies were included. PET data were acquired and reconstructed on a Biograph mCT PET/CT (whole-body, 4-min acquisition time per bed position; OSEM, OSEM-TOF, OSEM-TOF+PSF), a non-TOF Biograph mMR PET/MR (neck region, 4 min and 20 min; OSEM), and a new generation Biograph Vision PET/CT (whole-body, 4 min; OSEM, OSEM-TOF, OSEM-TOF+PSF). The 20-min image on the mMR was used as reference to calculate the detection efficacy in the neck region. Image quality was rated on a 5-point scale. Results All detected lesions were in the neck region. Detection efficacy was 8/9 (Vision OSEM-TOF and OSEM-TOF+PSF), 4/9 (Vision OSEM), 3/9 (mMR OSEM and mCT OSEM-TOF+PSF), and 2/9 (mCT OSEM and OSEM-TOF). Median image quality was 4 (Vision OSEM-TOF and OSEM-TOF+PSF), 3 (Vision OSEM, mCT OSEM-TOF+PSF, and mMR OSEM 20-min), 2 (mCT OSEM-TOF), 1.5 (mCT OSEM), and 1 (mMR OSEM 4 min). Conclusion At a clinical standard acquisition time of 4 min per bed position, the new generation Biograph Vision using a TOF-based image reconstruction demonstrated the highest detectability and image quality and should, if available, be preferably used for imaging of low-uptake lesions. A prolonged acquisition time for the mostly affected neck region can be useful. Supplementary Information The online version contains supplementary material available at 10.1186/s40658-021-00361-y.
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Affiliation(s)
- David Kersting
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Hufelandstrasse 55, 45147, Essen, Germany. .,West German Cancer Center (WTZ), Essen, Germany. .,German Cancer Consortium (DKTK), Essen and Dusseldorf, Germany.
| | - Walter Jentzen
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Hufelandstrasse 55, 45147, Essen, Germany.,West German Cancer Center (WTZ), Essen, Germany.,German Cancer Consortium (DKTK), Essen and Dusseldorf, Germany
| | - Miriam Sraieb
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Hufelandstrasse 55, 45147, Essen, Germany.,West German Cancer Center (WTZ), Essen, Germany.,German Cancer Consortium (DKTK), Essen and Dusseldorf, Germany
| | - Pedro Fragoso Costa
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Hufelandstrasse 55, 45147, Essen, Germany.,West German Cancer Center (WTZ), Essen, Germany.,German Cancer Consortium (DKTK), Essen and Dusseldorf, Germany
| | | | - Lale Umutlu
- West German Cancer Center (WTZ), Essen, Germany.,German Cancer Consortium (DKTK), Essen and Dusseldorf, Germany.,Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, 45147, Essen, Germany
| | - Gerald Antoch
- German Cancer Consortium (DKTK), Essen and Dusseldorf, Germany.,Medical Faculty, Department of Diagnostic and Interventional Radiology, University Dusseldorf, 40225, Dusseldorf, Germany
| | - Michael Nader
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Hufelandstrasse 55, 45147, Essen, Germany.,West German Cancer Center (WTZ), Essen, Germany.,German Cancer Consortium (DKTK), Essen and Dusseldorf, Germany
| | - Ken Herrmann
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Hufelandstrasse 55, 45147, Essen, Germany.,West German Cancer Center (WTZ), Essen, Germany.,German Cancer Consortium (DKTK), Essen and Dusseldorf, Germany
| | - Wolfgang Peter Fendler
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Hufelandstrasse 55, 45147, Essen, Germany.,West German Cancer Center (WTZ), Essen, Germany.,German Cancer Consortium (DKTK), Essen and Dusseldorf, Germany
| | - Christoph Rischpler
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Hufelandstrasse 55, 45147, Essen, Germany.,West German Cancer Center (WTZ), Essen, Germany.,German Cancer Consortium (DKTK), Essen and Dusseldorf, Germany
| | - Manuel Weber
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Hufelandstrasse 55, 45147, Essen, Germany.,West German Cancer Center (WTZ), Essen, Germany.,German Cancer Consortium (DKTK), Essen and Dusseldorf, Germany
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12
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Hailemeskel E, Tebeje SK, Behaksra SW, Shumie G, Shitaye G, Keffale M, Chali W, Gashaw A, Ashine T, Drakeley C, Bousema T, Gadisa E, Tadesse FG. The epidemiology and detectability of asymptomatic plasmodium vivax and plasmodium falciparum infections in low, moderate and high transmission settings in Ethiopia. Malar J 2021; 20:59. [PMID: 33482841 PMCID: PMC7821398 DOI: 10.1186/s12936-021-03587-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 01/05/2021] [Accepted: 01/07/2021] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND As countries move to malaria elimination, detecting and targeting asymptomatic malaria infections might be needed. Here, the epidemiology and detectability of asymptomatic Plasmodium falciparum and Plasmodium vivax infections were investigated in different transmission settings in Ethiopia. METHOD A total of 1093 dried blood spot (DBS) samples were collected from afebrile and apparently healthy individuals across ten study sites in Ethiopia from 2016 to 2020. Of these, 862 were from community and 231 from school based cross-sectional surveys. Malaria infection status was determined by microscopy or rapid diagnostics tests (RDT) and 18S rRNA-based nested PCR (nPCR). The annual parasite index (API) was used to classify endemicity as low (API > 0 and < 5), moderate (API ≥ 5 and < 100) and high transmission (API ≥ 100) and detectability of infections was assessed in these settings. RESULTS In community surveys, the overall prevalence of asymptomatic Plasmodium infections by microscopy/RDT, nPCR and all methods combined was 12.2% (105/860), 21.6% (183/846) and 24.1% (208/862), respectively. The proportion of nPCR positive infections that was detectable by microscopy/RDT was 48.7% (73/150) for P. falciparum and 4.6% (2/44) for P. vivax. Compared to low transmission settings, the likelihood of detecting infections by microscopy/RDT was increased in moderate (Adjusted odds ratio [AOR]: 3.4; 95% confidence interval [95% CI] 1.6-7.2, P = 0.002) and high endemic settings (AOR = 5.1; 95% CI 2.6-9.9, P < 0.001). After adjustment for site and correlation between observations from the same survey, the likelihood of detecting asymptomatic infections by microscopy/RDT (AOR per year increase = 0.95, 95% CI 0.9-1.0, P = 0.013) declined with age. CONCLUSIONS Conventional diagnostics missed nearly half of the asymptomatic Plasmodium reservoir detected by nPCR. The detectability of infections was particularly low in older age groups and low transmission settings. These findings highlight the need for sensitive diagnostic tools to detect the entire parasite reservoir and potential infection transmitters.
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Affiliation(s)
- Elifaged Hailemeskel
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
- Department of Biomedical Sciences, College of Natural and Computational Sciences, Addis Ababa University, PO Box 1176, Addis Ababa, Ethiopia
- Department of Biology, College of Natural and Computational Sciences, Wollo University, PO Box, 1145, Dessie, Ethiopia
- Department of Medical Microbiology, Radboud University Medical Center, 6525 GA, Nijmegen, The Netherlands
| | - Surafel K Tebeje
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
- Department of Medical Microbiology, Radboud University Medical Center, 6525 GA, Nijmegen, The Netherlands
| | - Sinknesh W Behaksra
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Girma Shumie
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Getasew Shitaye
- Department of Biomedical Sciences, School of Medical Sciences, Bahir Dar University, Bahir Dar, Ethiopia
| | - Migbaru Keffale
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Wakweya Chali
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Abrham Gashaw
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Temesgen Ashine
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, WC1E 7HT, London, UK
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, 6525 GA, Nijmegen, The Netherlands
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, WC1E 7HT, London, UK
| | - Endalamaw Gadisa
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Fitsum G Tadesse
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia.
- Department of Medical Microbiology, Radboud University Medical Center, 6525 GA, Nijmegen, The Netherlands.
- Institute of Biotechnology, Addis Ababa University, PO Box, 1176, Addis Ababa, Ethiopia.
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13
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Ouchi K, Sakuma T, Ojiri H. Coronary artery fistula in adults: Incidence and appearance on cardiac computed tomography and comparison of detectability and hemodynamic effects with those on transthoracic echocardiography. J Cardiol 2020; 76:593-600. [PMID: 32636129 DOI: 10.1016/j.jjcc.2020.06.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 05/19/2020] [Accepted: 06/10/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND The widespread use of cardiac computed tomography (CT) has increased the incidental discovery of fistulas of the coronary artery (CAF). This condition is rare and can affect hemodynamic parameters, but few reports focus on its hemodynamic effects. We investigated the frequency and types of CAF on CT and compared them with those of transthoracic echocardiography (TTE) to evaluate the detectability of CAF and its hemodynamic effects. MATERIALS AND METHODS We retrospectively evaluated cardiac CT images of 6789 adult patients who underwent imaging from January 1, 2013 through September 30, 2019 at our institution. We assessed the CT images for the presence of CAF and compared our findings with those obtained by TTE in control cases without CAF. RESULTS The prevalence of CAF determined with cardiac CT was 0.91%, with the left anterior descending artery (67.7%) as the most common site of origin and the main pulmonary artery (82.3%) as the most common origin of drainage. The incidence of aneurysm accompanying CAF was 48.4%. Color Doppler in TTE demonstrated abnormal flow that would suggest the presence of CAF of only 23.1%. Echocardiographic findings of hemodynamics did not differ significantly between patients with and without CAF nor between elderly and non-elderly patients with CAF. CONCLUSIONS Our study revealed differing prevalence and types of CAF from those reported using coronary angiography and little impact of CAF on hemodynamics. Color Doppler in TTE did not readily depict abnormal flow that might suggest the presence of a fistula, but cardiac CT allowed noninvasive and comprehensive assessment of CAF. Thus, we believe the acquisition of cardiac CT is necessary to establish the cause of continuous murmur that is not identified with TTE.
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Affiliation(s)
- Kotaro Ouchi
- Department of Radiology, The Jikei University School of Medicine, Tokyo, Japan.
| | - Toru Sakuma
- Department of Radiology, The Jikei University School of Medicine, Tokyo, Japan
| | - Hiroya Ojiri
- Department of Radiology, The Jikei University School of Medicine, Tokyo, Japan
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14
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Bechtold R, Tselepidakis N, Garlow B, Glaister S, Zhu W, Liu R, Szewc A, Tandon A, Buono Z, Pitingolo J, Madalo C, Ferrara I, Shale C, Benassi T, Belzberg M, Gorelick N, Hwang B, Molina CA, Coles G, Tyler B, Suk I, Huang J, Brem H, Manbachi A. Minimizing cotton retention in neurosurgical procedures: which imaging modality can help? Proc SPIE Int Soc Opt Eng 2020; 11317:1131704. [PMID: 35350430 PMCID: PMC8958457 DOI: 10.1117/12.2548847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Cotton balls are used in neurosurgical procedures to assist with hemostasis and improve vision within the operative field. Although the surgeon can reshape pieces of cotton for multiple intraoperative uses, this customizability and scale also places them at perpetual risk of being lost, as blood-soaked cotton balls are visually similar to raw brain tissue. Retained surgical cotton can induce potentially life-threatening immunologic responses, impair postoperative imaging, lead to a textiloma or misdiagnosis, and/or require reoperation. This study investigated three imaging modalities (optical, acoustic, and radiographic) to find the most effective method of identifying foreign bodies during neurosurgery. First, we examined the use of dyes to increase contrast between cotton and surrounding parenchyma (optical approach). Second, we explored the ability to distinguish surgical cotton on or below the tissue surface from brain parenchyma using ultrasound imaging (acoustic approach). Lastly, we analyzed the ability of radiography to differentiate between brain parenchyma and cotton. Our preliminary testing demonstrated that dark-colored cotton is significantly more identifiable than white cotton on the surface level. Additional testing revealed that cotton has noticeable different acoustic characteristics (eg, speed of sound, absorption) from neural tissue, allowing for enhanced contrast in applied ultrasound imaging. Radiography, however, did not present sufficient contrast, demanding further examination. These solutions have the potential to significantly reduce the possibility of intraoperative cotton retention both on and below the surface of the brain, while still providing surgeons with traditional cotton material properties without affecting the surgical workflow.
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Affiliation(s)
- Raphael Bechtold
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD
| | - Niki Tselepidakis
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD
| | - Benjamin Garlow
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD
| | - Sean Glaister
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD
| | - William Zhu
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD
| | - Renee Liu
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD
| | - Alexandra Szewc
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD
| | - Arushi Tandon
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD
| | - Zachary Buono
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD
| | - James Pitingolo
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD
| | - Cristina Madalo
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD
| | - Isabella Ferrara
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD
| | - Collin Shale
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD
| | - Thomas Benassi
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD
| | - Micah Belzberg
- Department of Plastic Surgery, Johns Hopkins University, Baltimore, MD
| | - Noah Gorelick
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD
| | - Brian Hwang
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD
| | - Camilo A Molina
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD
| | - George Coles
- Johns Hopkins Applied Physics Laboratory, Laurel, MD
| | - Betty Tyler
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD
| | - Ian Suk
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD
| | - Judy Huang
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD
| | - Henry Brem
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD
| | - Amir Manbachi
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD
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15
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Alonzo-Proulx O, Mainprize JG, Harvey JA, Yaffe MJ. Investigating the feasibility of stratified breast cancer screening using a masking risk predictor. Breast Cancer Res 2019; 21:91. [PMID: 31399056 PMCID: PMC6688203 DOI: 10.1186/s13058-019-1179-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 07/26/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Women with dense breasts face a double risk for breast cancer; they are at a higher risk for development of breast cancer than those with less dense breasts, and there is a greater chance that mammography will miss detection of a cancer in dense breasts due to the masking effect of surrounding fibroglandular tissue. These women may be candidates for supplemental screening. In this study, a masking risk model that was previously developed is tested on a cohort of cancer-free women to assess potential efficiency of stratification. METHODS Three masking risk models based on (1) BI-RADS density, (2) volumetric breast density (VBD), and (3) a combination of VBD and detectability were applied to stratify the mammograms of 1897 cancer-free women. The fraction of cancer-free women whose mammograms were deemed by the algorithm to be masked and who would be considered for supplemental imaging was computed as was the corresponding fraction in a screened population of interval (masked) cancers that would be potentially detected by supplemental imaging. RESULTS Of the models tested, the combined VBD/detectability model offered the highest efficiency for stratification to supplemental imaging. It predicted that 725 supplemental screens would be performed per interval cancer potentially detected, at an operating point that allowed detection of 64% of the interval cancers. In comparison, stratification based on the upper two BI-RADS density categories required 1117 supplemental screenings per interval cancer detected to capture 64% of interval cancers. CONCLUSION The combined VBD/detectability models perform better than BI-RADS and offer a continuum of operating points, suggesting that this model may be effective in guiding a stratified screening environment.
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Affiliation(s)
- Olivier Alonzo-Proulx
- Physical Sciences, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5 Canada
| | - James G. Mainprize
- Physical Sciences, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5 Canada
| | - Jennifer A. Harvey
- Department of Radiology and Medical Imaging, University of Virginia Health System, Charlottesville, VA USA
| | - Martin J. Yaffe
- Physical Sciences, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5 Canada
- Department of Medical Biophysics, University of Toronto, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5 Canada
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16
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Øen SK, Aasheim LB, Eikenes L, Karlberg AM. Image quality and detectability in Siemens Biograph PET/MRI and PET/CT systems-a phantom study. EJNMMI Phys 2019; 6:16. [PMID: 31385052 PMCID: PMC6682841 DOI: 10.1186/s40658-019-0251-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 07/23/2019] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND The technology of modern positron emission tomography (PET) systems continuously improving, and with it the possibility to detect smaller lesions. Since first introduced in 2010, the number of hybrid PET/magnetic resonance imaging (MRI) systems worldwide is constantly increasing. It is therefore important to assess and compare the image quality, in terms of detectability, between the PET/MRI and the well-established PET/computed tomography (CT) systems. For this purpose, a PET image quality phantom (Esser) with hot spheres, ranging from 4 to 20 mm in diameter, was prepared with fluorodeoxyglucose and sphere-to-background activity concentrations of 8:1 and 4:1, to mimic clinical conditions. The phantom was scanned on a PET/MRI and a PET/CT system for both concentrations to obtain contrast recovery coefficients (CRCs) and contrast-to-noise ratios (CNRs), for a range of reconstruction settings. The detectability of the spheres was scored by three human observers for both systems and concentrations and all reconstructions. Furthermore, the impact of acquisition time on CNR and observer detectability was investigated. RESULTS Reconstructions applying point-spread-function modeling (and time-of-flight for the PET/CT) yielded the highest CRC and CNR in general, and PET/CT demonstrated slightly higher values than PET/MRI for most sphere sizes. CNR was dependent on reconstruction settings and was maximized for 2 iterations, a pixel size of less than 2 mm and a 4 mm Gaussian filter. Acquisition times of 97 s (PET/MRI) and 150 s (PET/CT) resulted in similar total net true counts. For these acquisition times, the smallest detected spheres by the human observers in the 8:1 activity concentration was the 6-mm sphere with PET/MRI (CNR = 5.6) and the 5-mm sphere with PET/CT (CNR = 5.5). With an acquisition time of 180 s, the 5-mm sphere was also detected with PET/MRI (CNR = 5.8). The 8-mm sphere was the smallest detected sphere in the 4:1 activity concentration for both systems. CONCLUSION In this experimental study, similar detectability was found for the PET/MRI and the PET/CT, although for an increased acquisition time for the PET/MRI.
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Affiliation(s)
- Silje Kjærnes Øen
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Postbox 8905, N-7491, Trondheim, Norway.
| | - Lars Birger Aasheim
- Department of Radiology and Nuclear Medicine, St. Olavs University Hospital, Olav Kyrres gt 17, N-7006, Trondheim, Norway
| | - Live Eikenes
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Postbox 8905, N-7491, Trondheim, Norway
| | - Anna Maria Karlberg
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Postbox 8905, N-7491, Trondheim, Norway.,Department of Radiology and Nuclear Medicine, St. Olavs University Hospital, Olav Kyrres gt 17, N-7006, Trondheim, Norway
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Ramsthaler F, Schlote J, Gehl A, Cappel-Hoffmann S, Kettner M. Detectability, visualization, and DNA analysis of bloodstains after repainting the walls. Int J Legal Med 2018; 132:1625-34. [PMID: 30094762 DOI: 10.1007/s00414-018-1892-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 07/17/2018] [Indexed: 01/25/2023]
Abstract
A recurrent observation in forensic casework is that culprits and/or their abettors attempt to remove or mask bloodstain patterns, e.g., by painting the walls. The present study was designed to elucidate whether luminol treatment of bloodstains on (a) plastered and (b) wallpapered walls may help with the visualization of respective patterns after being repainted beyond macroscopic recognition. Furthermore, wallpaper punches of luminol-positive spots were analyzed for DNA. The experiments showed that the prospects for visualization after a four- to sixfold paint application declined considerably as the drying time of the paint increased. A compelling explanation for this observation is that paint becomes increasingly resistant to water during the drying process after paint application. In these cases, moistening the surface in question with distilled water for 15 min has been proven to be a promising pretreatment before luminol application. DNA analysis revealed full STR profiles in 74% of luminol-positive wallpaper punches, whereas rubs of the aforementioned positively tested regions (luminol and human blood pretests) demonstrated negative results.
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18
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Werth D, Buckley R. Characterizing the detectability of emission signals from a North Korean nuclear detonation. J Environ Radioact 2017; 169-170:214-220. [PMID: 28157641 DOI: 10.1016/j.jenvrad.2016.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 12/10/2016] [Accepted: 12/11/2016] [Indexed: 06/06/2023]
Abstract
The detectability of emission sources, defined by a low-level of mixing with other sources, was estimated for various locations surrounding the Sea of Japan, including a site within North Korea. A high-resolution meteorological model coupled to a dispersion model was used to simulate plume dynamics for four periods, and two metrics of airborne plume mixing were calculated for each source. While emissions from several known sources in this area tended to blend with others while dispersing downwind, the North Korean plume often remained relatively distinct, thereby making it potentially easier to unambiguously 'backtrack' it to its source.
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Affiliation(s)
- David Werth
- Savannah River National Laboratory, Building 773-A, Aiken, SC 29808, United States.
| | - Robert Buckley
- Savannah River National Laboratory, Building 773-A, Aiken, SC 29808, United States
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Fleury S, Jamet É, Roussarie V, Bosc L, Chamard JC. Effect of additional warning sounds on pedestrians' detection of electric vehicles: An ecological approach. Accid Anal Prev 2016; 97:176-185. [PMID: 27639999 DOI: 10.1016/j.aap.2016.09.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 07/21/2016] [Accepted: 09/05/2016] [Indexed: 06/06/2023]
Abstract
Virtually silent electric vehicles (EVs) may pose a risk for pedestrians. This paper describes two studies that were conducted to assess the influence of different types of external sounds on EV detectability. In the first study, blindfolded participants had to detect an approaching EV with either no warning sounds at all or one of three types of sound we tested. In the second study, designed to replicate the results of the first one in an ecological setting, the EV was driven along a road and the experimenters counted the number of people who turned their heads in its direction. Results of the first study showed that adding external sounds improve EV detection, and modulating the frequency and increasing the pitch of these sounds makes them more effective. This improvement was confirmed in the ecological context. Consequently, pitch variation and frequency modulation should both be taken into account in future AVAS design.
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Affiliation(s)
- Sylvain Fleury
- CRPCC, University of Rennes 2, Place du Recteur Henri Le Moal; CS 24 307; 35043, Rennes, France.
| | - Éric Jamet
- CRPCC, University of Rennes 2, Place du Recteur Henri Le Moal; CS 24 307; 35043, Rennes, France
| | - Vincent Roussarie
- PSA Peugeot-Citroën, Route de Gisy, 78943 Vélizy-Villacoublay Cedex, France
| | - Laure Bosc
- PSA Peugeot-Citroën, Route de Gisy, 78943 Vélizy-Villacoublay Cedex, France
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Zhao J, Deng B, Qin Y, Men C, Wang J, Wei X, Sun J. Weak electric fields detectability in a noisy neural network. Cogn Neurodyn 2017; 11:81-90. [PMID: 28174614 DOI: 10.1007/s11571-016-9409-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 08/16/2016] [Accepted: 09/06/2016] [Indexed: 12/18/2022] Open
Abstract
We investigate the detectability of weak electric field in a noisy neural network based on Izhikevich neuron model systematically. The neural network is composed of excitatory and inhibitory neurons with similar ratio as that in the mammalian neocortex, and the axonal conduction delays between neurons are also considered. It is found that the noise intensity can modulate the detectability of weak electric field. Stochastic resonance (SR) phenomenon induced by white noise is observed when the weak electric field is added to the network. It is interesting that SR almost disappeared when the connections between neurons are cancelled, suggesting the amplification effects of the neural coupling on the synchronization of neuronal spiking. Furthermore, the network parameters, such as the connection probability, the synaptic coupling strength, the scale of neuron population and the neuron heterogeneity, can also affect the detectability of the weak electric field. Finally, the model sensitivity is studied in detail, and results show that the neural network model has an optimal region for the detectability of weak electric field signal.
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Endo T, Morita T, Oiwa M, Suda N, Sato Y, Ichihara S, Shiraiwa M, Yoshikawa K, Horiba T, Ogawa H, Hayashi Y, Sendai T, Arai T. Detectability comparison of modes in dual-mode digital breast tomosynthesis. Breast Cancer 2017; 24:442-50. [PMID: 27585694 DOI: 10.1007/s12282-016-0725-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 08/25/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND The objectives of this study were: (1) to evaluate the detectability of full-field digital mammography (FFDM) plus dual-mode digital breast tomosynthesis (DBT) and compare it with that of FFDM alone and (2) to compare the detectability of high-resolution-mode (HR mode used with 40°-angle imaging, 100-µm pixel size, and higher dose) DBT with that of standard-mode (ST mode used with 15°-angle imaging, 150-µm pixel size, and lower dose) DBT for diagnostic evaluation. MATERIALS The local Institutional Review Board approved this retrospective study of two different sets of cases. All participants gave written informed consent. FFDM and DBT images of 471 women who were recalled were acquired between August 2013 and October 2014. HR mode and ST mode were applied to 155 breasts and 157 breasts, respectively. The cases of both modes were selected randomly. Eight radiologists interpreted the images. The detectability for recall cases and for follow cases, and area under the receiver operating characteristic curve (AUC) were calculated. RESULTS Adding DBT to FFDM significantly increased the detectability for recall cases and AUC relative to those of FFDM alone (HR mode 8.9 %; 95 % confidence interval (CI) 5.7, 15.0 %; P = 0.013 and 4.9 %; 95 % CI 2.1, 7.7 %; P = 0.001; ST mode 8.3 %; 95 % CI 4.1, 12.1 %; P = 0.007 and 2.9 %; 95 % CI 0.5, 5.3 %; P = 0.02), whereas the detectability for follow cases did not significantly differ. The AUC increase was significantly higher in HR mode than in ST mode (1.5 %; 95 % CI 0.5, 3.7 %; P = 0.023). CONCLUSION Adding HR-mode or ST-mode DBT to FFDM significantly improved the detectability for diagnostic evaluation case.
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Suh CH, Jung SC, Kim KW, Pyo J. The detectability of brain metastases using contrast-enhanced spin-echo or gradient-echo images: a systematic review and meta-analysis. J Neurooncol 2016; 129:363-71. [PMID: 27324495 DOI: 10.1007/s11060-016-2185-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 06/11/2016] [Indexed: 01/27/2023]
Abstract
This study aimed to compare the detectability of brain metastases using contrast-enhanced spin-echo (SE) and gradient-echo (GRE) T1-weighted images. The Ovid-MEDLINE and EMBASE databases were searched for studies on the detectability of brain metastases using contrast-enhanced SE or GRE images. The pooled proportions for the detectability of brain metastases were assessed using random-effects modeling. Heterogeneity among studies was determined using χ (2) statistics for the pooled estimates and the inconsistency index, I (2) . To overcome heterogeneity, subgroup analyses according to slice thickness and lesion size were performed. A total of eight eligible studies, which included a sample size of 252 patients and 1413 brain metastases, were included. The detectability of brain metastases using SE images (89.2 %) was higher than using GRE images (81.6 %; adjusted 84.0 %), but this difference was not statistically significant (p = 0.2385). In subgroup analysis of studies with 1-mm-thick slices and small metastases (<5 mm in diameter), 3-dimensional (3D) SE images demonstrated a higher detectability in comparison to 3D GRE images (93.7 % vs 73.1 % in 1-mm-thick slices; 89.5 % vs 59.4 % for small metastases) (p < 0.0001). Although both SE or GRE images are acceptable for detecting brain metastases, contrast-enhanced 3D SE images using 1-mm-thick slices are preferred for detecting brain metastases, especially small lesions (<5 mm in diameter).
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Affiliation(s)
- Chong Hyun Suh
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 86 Asanbyeongwon-Gil, Songpa-Gu, Seoul, 138-736, Republic of Korea.,Department of Radiology, Namwon Medical Center, 365, Chungjeong-ro, Namwon-si, Jeollabuk-do, 590-702, Republic of Korea
| | - Seung Chai Jung
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 86 Asanbyeongwon-Gil, Songpa-Gu, Seoul, 138-736, Republic of Korea.
| | - Kyung Won Kim
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 86 Asanbyeongwon-Gil, Songpa-Gu, Seoul, 138-736, Republic of Korea
| | - Junhee Pyo
- Department of Pharmaceutical Science, WHO Collaborating Center for Pharmaceutical Policy and Regulation, Utrecht University, Utrecht, The Netherlands
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Bernotienė R, Palinauskas V, Iezhova T, Murauskaitė D, Valkiūnas G. Avian haemosporidian parasites (Haemosporida): A comparative analysis of different polymerase chain reaction assays in detection of mixed infections. Exp Parasitol 2016; 163:31-7. [PMID: 26821298 DOI: 10.1016/j.exppara.2016.01.009] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 12/22/2015] [Accepted: 01/20/2016] [Indexed: 12/12/2022]
Abstract
Mixed infections of different species and genetic lineages of haemosporidian parasites (Haemosporida) predominate in wildlife, and such infections are particularly virulent. However, currently used polymerase chain reaction (PCR)-based detection methods often do not read mixed infections. Sensitivity of different PCR assays in detection of mixed infections has been insufficiently tested, but this knowledge is essential in studies addressing parasite diversity in wildlife. Here, we applied five different PCR assays, which are broadly used in wildlife avian haemosporidian research, and compared their sensitivity in detection of experimentally designed mixed infections of Haemoproteus and Plasmodium parasites. Three of these PCR assays use primer sets that amplify fragments of cytochrome b gene (cyt b), one of cytochrome oxidase subunit I (COI) gene, and one target apicoplast genome. We collected blood from wild-caught birds and, using microscopic and PCR-based methods applied in parallel, identified single infections of ten haemosporidian species with similar parasitemia. Then, we prepared 15 experimental mixes of different haemosporidian parasites, which often are present simultaneously in wild birds. Similar concentration of total DNA was used in each parasite lineage during preparation of mixes. Positive amplifications were sequenced, and the presence of mixed infections was reported by visualising double-base calling in sequence electropherograms. This study shows that the use of each single PCR assay markedly underestimates biodiversity of haemosporidian parasites. The application of at least 3 PCR assays in parallel detected the majority, but still not all lineages present in mixed infections. We determined preferences of different primers in detection of parasites belonging to different genera of haemosporidians during mixed infections.
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Affiliation(s)
- Rasa Bernotienė
- Nature Research Centre, Akademijos 2, Vilnius 2100, LT-08412, Lithuania.
| | - Vaidas Palinauskas
- Nature Research Centre, Akademijos 2, Vilnius 2100, LT-08412, Lithuania.
| | - Tatjana Iezhova
- Nature Research Centre, Akademijos 2, Vilnius 2100, LT-08412, Lithuania.
| | - Dovilė Murauskaitė
- Nature Research Centre, Akademijos 2, Vilnius 2100, LT-08412, Lithuania.
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Abstract
Prostate cancer is one of the most common forms of cancer among men. Early diagnosis, correct staging, accurate detection of metastasis, and monitoring of the therapy are the key tasks that could greatly benefit from medical imaging. After a review of the main developments in the field of positron emission tomography (PET) tracers for prostate cancer, the impact of improved PET instrumentation with good spatial resolution and high sensitivity is discussed, together with the latest development in PET technology: lutetium oxy-ortho-silicate (LSO) and lutetium-yttrium oxy-ortho-silicate (LYSO) scintillators, resolution recovery, and time-of-flight reconstruction. New directions and multiple approaches in PET instrumentation for prostate cancer are presented and discussed. In particular, improved hardware and noise suppressing reconstruction algorithms allow for higher detectability of small lesions and better spatial resolution in PET/computerized tomography (CT) and PET/magnetic resonance (MR). This can be beneficial for guiding biopsy and surgery and for accurate therapy monitoring.
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Affiliation(s)
- Maurizio Conti
- Siemens Healthcare Molecular Imaging, 810 Innovation Drive, Knoxville, TN, 37932, USA.
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