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Nakayama R, Tanaka M, Kishi Y, Murakami I. Aftereffect of perceived motion trajectories. iScience 2024; 27:109626. [PMID: 38623326 PMCID: PMC11016753 DOI: 10.1016/j.isci.2024.109626] [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: 10/09/2023] [Revised: 03/07/2024] [Accepted: 03/26/2024] [Indexed: 04/17/2024] Open
Abstract
If our visual system has a distinct computational process for motion trajectories, such a process may minimize redundancy and emphasize variation in object trajectories by adapting to the current statistics. Our experiments show that after adaptation to multiple objects traveling along trajectories with a common tilt, the trajectory of an object was perceived as tilting on the repulsive side. This trajectory aftereffect occurred irrespective of whether the tilt of the adapting stimulus was physical or an illusion from motion-induced position shifts and did not differ in size across the physical and illusory conditions. Moreover, when the perceived and physical tilts competed during adaptation, the trajectory aftereffect depended on the perceived tilt. The trajectory aftereffect transferred between hemifields and was not explained by motion-insensitive orientation adaptation or attention. These findings provide evidence for a trajectory-specific adaptable process that depends on higher-order representations after the integration of position and motion signals.
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Affiliation(s)
- Ryohei Nakayama
- Department of Psychology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku 113-0033, Tokyo, Japan
| | - Mai Tanaka
- Department of Psychology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku 113-0033, Tokyo, Japan
| | - Yukino Kishi
- Department of Psychology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku 113-0033, Tokyo, Japan
| | - Ikuya Murakami
- Department of Psychology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku 113-0033, Tokyo, Japan
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Kawashima T, Nakayama R, Amano K. Theoretical and Technical Issues Concerning the Measurement of Alpha Frequency and the Application of Signal Detection Theory: Comment on Buergers and Noppeney (2022). J Cogn Neurosci 2024; 36:691-699. [PMID: 37255466 DOI: 10.1162/jocn_a_02010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Classical and recent evidence has suggested that alpha oscillations play a critical role in temporally discriminating or binding successively presented items. Challenging this view, Buergers and Noppeney [Buergers, S., & Noppeney, U. The role of alpha oscillations in temporal binding within and across the senses. Nature Human Behaviour, 6, 732-742, 2022] found that by combining EEG, psychophysics, and signal detection theory, neither prestimulus nor resting-state alpha frequency influences perceptual sensitivity and bias in the temporal binding task. We propose the following four points that should be considered when interpreting the role of alpha oscillations, and especially their frequency, on perceptual temporal binding: (1) Multiple alpha components can be contaminated in conventional EEG analysis; (2) the effect of alpha frequency on perception will interact with alpha power; (3) prestimulus and resting-state alpha frequency can be different from poststimulus alpha frequency, which is the frequency during temporal binding and should be more directly related to temporal binding; and (4) when applying signal detection theory under the assumption of equal variance, the assumption is often incomplete and can be problematic (e.g., the magnitude relationships between individuals in parametric sensitivity may change when converted into nonparametric sensitivity). Future directions, including solutions to each of the issues, are discussed.
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Suzuki M, Nakayama R, Namba K, Kawami H, Nara M, Nakamura S. Potential Usefulness a Coronal View using an Automated Breast Ultrasound System in Detecting Breast Lesions. Eur J Breast Health 2024; 20:57-63. [PMID: 38187110 PMCID: PMC10765468 DOI: 10.4274/ejbh.galenos.2023.2023-11-6] [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: 12/04/2023] [Accepted: 12/19/2023] [Indexed: 01/09/2024]
Abstract
Objective An automated breast ultrasound system (ABUS) combined with screening mammography has increased cancer detection rates; however, supplemental ABUS use has increased recall rates. In this study, we aimed to identify an accurate and efficient method of ABUS interpretation and evaluate the potential usefulness of its coronal view versus the conventional transverse view. Materials and Methods This retrospective observer study included comprised 114 ABUS cases (40 normal, 35 benign, 39 malignant). Ten physicians from multiple institutions interpreted the anonymized coronal and transverse views independently. The observers scored their confidence in the lesion detection for each case using a continuous scale and recorded reading times for each coronal and transverse view interpretation. Free-response receiver operating characteristic analysis was employed to compare detection accuracies between views; a paired t-test was used to compare the average reading times. Results Detection accuracy did not differ significantly between the coronal and transverse views (figure of merit=0.740 and 0.745, respectively; p = 0.72). However, the average reading time for the coronal view was significantly shorter than that for the transverse view (149.7 vs. 200.3 seconds per case, p = 0.003). Conclusion The coronal view obtained with the ABUS was useful for interpretation and associated with significantly shorter reading times compared with the conventional transverse view while maintaining breast lesion detection accuracy.
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Affiliation(s)
- Megumi Suzuki
- Center for Breast Diseases and Breast Cancer, Hokuto Hospital, Hokkaido, Japan
| | - Ryohei Nakayama
- Department of Electronic and Computer Engineering, Ritsumeikan University, Shiga, Japan
| | - Kiyoshi Namba
- Center for Breast Diseases and Breast Cancer, Hokuto Hospital, Hokkaido, Japan
| | - Hiroyuki Kawami
- Center for Breast Diseases and Breast Cancer, Hokuto Hospital, Hokkaido, Japan
| | - Mayumi Nara
- Center for Breast Diseases and Breast Cancer, Hokuto Hospital, Hokkaido, Japan
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Port M, Barquinero JF, Endesfelder D, Moquet J, Oestreicher U, Terzoudi G, Trompier F, Vral A, Abe Y, Ainsbury L, Alkebsi L, Amundson S, Badie C, Baeyens A, Balajee A, Balázs K, Barnard S, Bassinet C, Beaton-Green L, Beinke C, Bobyk L, Brochard P, Brzoska K, Bucher M, Ciesielski B, Cuceu C, Discher M, D,Oca M, Domínguez I, Doucha-Senf S, Dumitrescu A, Duy P, Finot F, Garty G, Ghandhi S, Gregoire E, Goh V, Güçlü I, Hadjiiska L, Hargitai R, Hristova R, Ishii K, Kis E, Juniewicz M, Kriehuber R, Lacombe J, Lee Y, Lopez Riego M, Lumniczky K, Mai T, Maltar-Strmečki N, Marrale M, Martinez J, Marciniak A, Maznyk N, McKeever S, Meher P, Milanova M, Miura T, Gil OM, Montoro A, Domene MM, Mrozik A, Nakayama R, O’Brien G, Oskamp D, Ostheim P, Pajic J, Pastor N, Patrono C, Pujol-Canadell M, Rodriguez MP, Repin M, Romanyukha A, Rößler U, Sabatier L, Sakai A, Scherthan H, Schüle S, Seong K, Sevriukova O, Sholom S, Sommer S, Suto Y, Sypko T, Szatmári T, Takahashi-Sugai M, Takebayashi K, Testa A, Testard I, Tichy A, Triantopoulou S, Tsuyama N, Unverricht-Yeboah M, Valente M, Van Hoey O, Wilkins R, Wojcik A, Wojewodzka M, Younghyun L, Zafiropoulos D, Abend M. RENEB Inter-Laboratory Comparison 2021: Inter-Assay Comparison of Eight Dosimetry Assays. Radiat Res 2023; 199:535-555. [PMID: 37310880 PMCID: PMC10508307 DOI: 10.1667/rade-22-00207.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 01/10/2023] [Indexed: 06/15/2023]
Abstract
Tools for radiation exposure reconstruction are required to support the medical management of radiation victims in radiological or nuclear incidents. Different biological and physical dosimetry assays can be used for various exposure scenarios to estimate the dose of ionizing radiation a person has absorbed. Regular validation of the techniques through inter-laboratory comparisons (ILC) is essential to guarantee high quality results. In the current RENEB inter-laboratory comparison, the performance quality of established cytogenetic assays [dicentric chromosome assay (DCA), cytokinesis-block micronucleus assay (CBMN), stable chromosomal translocation assay (FISH) and premature chromosome condensation assay (PCC)] was tested in comparison to molecular biological assays [gamma-H2AX foci (gH2AX), gene expression (GE)] and physical dosimetry-based assays [electron paramagnetic resonance (EPR), optically or thermally stimulated luminescence (LUM)]. Three blinded coded samples (e.g., blood, enamel or mobiles) were exposed to 0, 1.2 or 3.5 Gy X-ray reference doses (240 kVp, 1 Gy/min). These doses roughly correspond to clinically relevant groups of unexposed to low exposed (0-1 Gy), moderately exposed (1-2 Gy, no severe acute health effects expected) and highly exposed individuals (>2 Gy, requiring early intensive medical care). In the frame of the current RENEB inter-laboratory comparison, samples were sent to 86 specialized teams in 46 organizations from 27 nations for dose estimation and identification of three clinically relevant groups. The time for sending early crude reports and more precise reports was documented for each laboratory and assay where possible. The quality of dose estimates was analyzed with three different levels of granularity, 1. by calculating the frequency of correctly reported clinically relevant dose categories, 2. by determining the number of dose estimates within the uncertainty intervals recommended for triage dosimetry (±0.5 Gy or ±1.0 Gy for doses <2.5 Gy or >2.5 Gy), and 3. by calculating the absolute difference (AD) of estimated doses relative to the reference doses. In total, 554 dose estimates were submitted within the 6-week period given before the exercise was closed. For samples processed with the highest priority, earliest dose estimates/categories were reported within 5-10 h of receipt for GE, gH2AX, LUM, EPR, 2-3 days for DCA, CBMN and within 6-7 days for the FISH assay. For the unirradiated control sample, the categorization in the correct clinically relevant group (0-1 Gy) as well as the allocation to the triage uncertainty interval was, with the exception of a few outliers, successfully performed for all assays. For the 3.5 Gy sample the percentage of correct classifications to the clinically relevant group (≥2 Gy) was between 89-100% for all assays, with the exception of gH2AX. For the 1.2 Gy sample, an exact allocation to the clinically relevant group was more difficult and 0-50% or 0-48% of the estimates were wrongly classified into the lowest or highest dose categories, respectively. For the irradiated samples, the correct allocation to the triage uncertainty intervals varied considerably between assays for the 1.2 Gy (29-76%) and 3.5 Gy (17-100%) samples. While a systematic shift towards higher doses was observed for the cytogenetic-based assays, extreme outliers exceeding the reference doses 2-6 fold were observed for EPR, FISH and GE assays. These outliers were related to a particular material examined (tooth enamel for EPR assay, reported as kerma in enamel, but when converted into the proper quantity, i.e. to kerma in air, expected dose estimates could be recalculated in most cases), the level of experience of the teams (FISH) and methodological uncertainties (GE). This was the first RENEB ILC where everything, from blood sampling to irradiation and shipment of the samples, was organized and realized at the same institution, for several biological and physical retrospective dosimetry assays. Almost all assays appeared comparably applicable for the identification of unexposed and highly exposed individuals and the allocation of medical relevant groups, with the latter requiring medical support for the acute radiation scenario simulated in this exercise. However, extreme outliers or a systematic shift of dose estimates have been observed for some assays. Possible reasons will be discussed in the assay specific papers of this special issue. In summary, this ILC clearly demonstrates the need to conduct regular exercises to identify research needs, but also to identify technical problems and to optimize the design of future ILCs.
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Affiliation(s)
- M. Port
- Bundeswehr Institute of Radiobiology, Munich, Germany
| | | | | | - J. Moquet
- UK Health Security Agency, Radiation, Chemical and Environmental Hazards Division, Oxfordshire, United Kingdom
| | | | - G. Terzoudi
- National Centre for Scientific Research “Demokritos”, Health Physics, Radiobiology & Cytogenetics Laboratory, Agia Paraskevi, Greece
| | - F. Trompier
- Institut de Radioprotection et de Surete Nucleaire, Fontenay aux Roses, France
| | - A. Vral
- Ghent University, Radiobiology Research Unit, Gent, Belgium
| | - Y. Abe
- Department of Radiation Biology and Protection, Nagasaki University, Japan
| | - L. Ainsbury
- UK Health Security Agency and Office for Health Improvement and Disparities, Cytogenetics and Pathology Group, Oxfordshire, England
| | - L Alkebsi
- Department of Radiation Measurement and Dose Assessment, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - S.A. Amundson
- Columbia University, Irving Medical Center, Center for Radiological Research, New York, New York
| | - C. Badie
- UK Health Security Agency, Radiation, Chemical and Environmental Hazards Division, Oxfordshire, United Kingdom
| | - A. Baeyens
- Ghent University, Radiobiology Research Unit, Gent, Belgium
| | - A.S. Balajee
- Cytogenetic Biodosimetry Laboratory, Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee
| | - K. Balázs
- Radiation Medicine Unit, Department of Radiobiology and Radiohygiene, National Public Health Centre, Budapest, Hungary
| | - S. Barnard
- UK Health Security Agency, Radiation, Chemical and Environmental Hazards Division, Oxfordshire, United Kingdom
| | - C. Bassinet
- Institut de Radioprotection et de Surete Nucleaire, Fontenay aux Roses, France
| | | | - C. Beinke
- Bundeswehr Institute of Radiobiology, Munich, Germany
| | - L. Bobyk
- Institut de Recherche Biomédicale des Armées (IRBA), Bretigny Sur Orge, France
| | | | - K. Brzoska
- Institute of Nuclear Chemistry and Technology, Warsaw, Poland
| | - M. Bucher
- Bundesamt für Strahlenschutz, Oberschleißheim, Germany
| | - B. Ciesielski
- Medical University of Gdansk, Department of Physics and Biophysics, Gdansk, Poland
| | - C. Cuceu
- Genevolution, Porcheville, France
| | - M. Discher
- Paris-Lodron-University of Salzburg, Department of Environment and Biodiversity, 5020 Salzburg, Austria
| | - M.C. D,Oca
- Università Degli Studi di Palermo, Dipartimento di Fisica e Chimica “Emilio Segrè,” Palermo, Italy
| | - I. Domínguez
- Universidad de Sevilla, Departamento de Biología Celular, Sevilla, Spain
| | | | - A. Dumitrescu
- National Institute of Public Health, Radiation Hygiene Laboratory, Bucharest, Romania
| | - P.N. Duy
- Dalat Nuclear Research Institute, Radiation Technlogy & Biotechnology Center, Dalat City, Vietnam
| | - F. Finot
- Genevolution, Porcheville, France
| | - G. Garty
- Columbia University, Irving Medical Center, Center for Radiological Research, New York, New York
| | - S.A. Ghandhi
- Columbia University, Irving Medical Center, Center for Radiological Research, New York, New York
| | - E. Gregoire
- Institut de Radioprotection et de Surete Nucleaire, Fontenay aux Roses, France
| | - V.S.T. Goh
- Department of Radiobiology, Singapore Nuclear Research and Safety Initiative (SNRSI), National University of Singapore, Singapore
| | - I. Güçlü
- TENMAK, Nuclear Energy Research Institute, Technology Development and Nuclear Research Department, Türkey
| | - L. Hadjiiska
- National Centre of Radiobiology and Radiation Protection, Sofia, Bulgaria
| | - R. Hargitai
- Radiation Medicine Unit, Department of Radiobiology and Radiohygiene, National Public Health Centre, Budapest, Hungary
| | - R. Hristova
- National Centre of Radiobiology and Radiation Protection, Sofia, Bulgaria
| | - K. Ishii
- Department of Radiation Measurement and Dose Assessment, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - E. Kis
- Radiation Medicine Unit, Department of Radiobiology and Radiohygiene, National Public Health Centre, Budapest, Hungary
| | - M. Juniewicz
- Medical University of Gdansk, Department of Physics and Biophysics, Gdansk, Poland
| | - R. Kriehuber
- Department of Safety and Radiation Protection, Forschungszentrum Jülich, Jülich, Germany
| | - J. Lacombe
- University of Arizona, Center for Applied Nanobioscience & Medicine, Phoenix, Arizona
| | - Y. Lee
- Laboratory of Biological Dosimetry, Korea Institute of Radiological & Medical Sciences, Seoul, Republic of Korea
| | | | - K. Lumniczky
- Radiation Medicine Unit, Department of Radiobiology and Radiohygiene, National Public Health Centre, Budapest, Hungary
| | - T.T. Mai
- Dalat Nuclear Research Institute, Radiation Technlogy & Biotechnology Center, Dalat City, Vietnam
| | - N. Maltar-Strmečki
- Ruðer Boškovic Institute, Division of Physical Chemistry, Zagreb, Croatia
| | - M. Marrale
- Università Degli Studi di Palermo, Dipartimento di Fisica e Chimica “Emilio Segrè,” Palermo, Italy
| | - J.S. Martinez
- Institut de Radioprotection et de Surete Nucleaire, Fontenay aux Roses, France
| | - A. Marciniak
- Medical University of Gdansk, Department of Physics and Biophysics, Gdansk, Poland
| | - N. Maznyk
- Radiation Cytogenetics Laboratory, S.P. Grigoriev Institute for Medical Radiology and Oncology of Ukrainian National Academy of Medical Science, Kharkiv, Ukraine
| | - S.W.S. McKeever
- Radiation Dosimetry Laboratory, Oklahoma State University, Stillwater, Oklahoma
| | | | - M. Milanova
- University of Defense, Faculty of Military Health Sciences, Hradec Králové, Czech Republic
| | - T. Miura
- Institute of Radiation Emergency Medicine, Hirosaki University, Hirosaki, Japan
| | - O. Monteiro Gil
- Instituto Superior Técnico/ Campus Tecnológico e Nuclear, Lisbon, Portugal
| | - A. Montoro
- Servicio de Protección Radiológica. Laboratorio de Dosimetría Biológica, Valencia, Spain
| | - M. Moreno Domene
- Hospital General Universitario Gregorio Marañón, Laboratorio de dosimetría biológica, Madrid, Spain
| | - A. Mrozik
- Institute of Nuclear Physics, Polish Academy of Sciences, Krakow, Poland
| | - R. Nakayama
- Institute of Radiation Emergency Medicine, Hirosaki University, Hirosaki, Japan
| | - G. O’Brien
- UK Health Security Agency, Radiation, Chemical and Environmental Hazards Division, Oxfordshire, United Kingdom
| | - D. Oskamp
- Department of Safety and Radiation Protection, Forschungszentrum Jülich, Jülich, Germany
| | - P. Ostheim
- Bundeswehr Institute of Radiobiology, Munich, Germany
| | - J. Pajic
- Serbian Institute of Occupational Health, Belgrade, Serbia
| | - N. Pastor
- Universidad de Sevilla, Departamento de Biología Celular, Sevilla, Spain
| | - C. Patrono
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Rome, Italy
| | | | - M.J. Prieto Rodriguez
- Hospital General Universitario Gregorio Marañón, Laboratorio de dosimetría biológica, Madrid, Spain
| | - M. Repin
- Columbia University, Irving Medical Center, Center for Radiological Research, New York, New York
| | | | - U. Rößler
- Bundesamt für Strahlenschutz, Oberschleißheim, Germany
| | | | - A. Sakai
- Department of Radiation Life Sciences, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - H. Scherthan
- Bundeswehr Institute of Radiobiology, Munich, Germany
| | - S. Schüle
- Bundeswehr Institute of Radiobiology, Munich, Germany
| | - K.M. Seong
- Laboratory of Biological Dosimetry, Korea Institute of Radiological & Medical Sciences, Seoul, Republic of Korea
| | | | - S. Sholom
- Radiation Dosimetry Laboratory, Oklahoma State University, Stillwater, Oklahoma
| | - S. Sommer
- Institute of Nuclear Chemistry and Technology, Warsaw, Poland
| | - Y. Suto
- Department of Radiation Measurement and Dose Assessment, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - T. Sypko
- Radiation Cytogenetics Laboratory, S.P. Grigoriev Institute for Medical Radiology and Oncology of Ukrainian National Academy of Medical Science, Kharkiv, Ukraine
| | - T. Szatmári
- Radiation Medicine Unit, Department of Radiobiology and Radiohygiene, National Public Health Centre, Budapest, Hungary
| | - M. Takahashi-Sugai
- Department of Radiation Life Sciences, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - K. Takebayashi
- Institute of Radiation Emergency Medicine, Hirosaki University, Hirosaki, Japan
| | - A. Testa
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Rome, Italy
| | - I. Testard
- CEA-Saclay, Gif-sur-Yvette Cedex, France
| | - A. Tichy
- University of Defense, Faculty of Military Health Sciences, Hradec Králové, Czech Republic
| | - S. Triantopoulou
- National Centre for Scientific Research “Demokritos”, Health Physics, Radiobiology & Cytogenetics Laboratory, Agia Paraskevi, Greece
| | - N. Tsuyama
- Department of Radiation Life Sciences, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - M. Unverricht-Yeboah
- Department of Safety and Radiation Protection, Forschungszentrum Jülich, Jülich, Germany
| | - M. Valente
- CEA-Saclay, Gif-sur-Yvette Cedex, France
| | - O. Van Hoey
- Belgian Nuclear Research Center SCK CEN, Mol, Belgium
| | | | - A. Wojcik
- Stockholm University, Stockholm, Sweden
| | - M. Wojewodzka
- Institute of Nuclear Chemistry and Technology, Warsaw, Poland
| | - Lee Younghyun
- Laboratory of Biological Dosimetry, Korea Institute of Radiological & Medical Sciences, Seoul, Republic of Korea
| | - D. Zafiropoulos
- Laboratori Nazionali di Legnaro - Istituto Nazionale di Fisica Nucleare, Legnaro, Italy
| | - M. Abend
- Bundeswehr Institute of Radiobiology, Munich, Germany
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Sekita T, Asano N, Kubo T, Mitani S, Hattori N, Yoshida A, Kobayashi E, Komiyama M, Toshikazu U, Nakayama R, Kawai A, Nakamura M, Ichikawa H. 45O Clonal evolution of dedifferentiated liposarcoma. ESMO Open 2023. [DOI: 10.1016/j.esmoop.2023.101082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023] Open
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Nakayama R, Tanaka M, Murakami I. A trajectory aftereffect depending on the perceived trajectory of the double-drift illusion. J Vis 2022. [DOI: 10.1167/jov.22.14.3833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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Nakayama R, Bardin JB, Koizumi A, Motoyoshi I, Amano K. Building a decoder of perceptual decisions from microsaccades and pupil size. Front Psychol 2022; 13:942859. [PMID: 36176801 PMCID: PMC9514321 DOI: 10.3389/fpsyg.2022.942859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 08/17/2022] [Indexed: 11/21/2022] Open
Abstract
Many studies have reported neural correlates of visual awareness across several brain regions, including the sensory, parietal, and frontal areas. In most of these studies, participants were instructed to explicitly report their perceptual experience through a button press or verbal report. It is conceivable, however, that explicit reporting itself may trigger specific neural responses that can confound the direct examination of the neural correlates of visual awareness. This suggests the need to assess visual awareness without explicit reporting. One way to achieve this is to develop a technique to predict the visual awareness of participants based on their peripheral responses. Here, we used eye movements and pupil sizes to decode trial-by-trial changes in the awareness of a stimulus whose visibility was deteriorated due to adaptation-induced blindness (AIB). In the experiment, participants judged whether they perceived a target stimulus and rated the confidence they had in their perceptual judgment, while their eye movements and pupil sizes were recorded. We found that not only perceptual decision but also perceptual confidence can be separately decoded from the eye movement and pupil size. We discuss the potential of this technique with regard to assessing visual awareness in future neuroimaging experiments.
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Affiliation(s)
- Ryohei Nakayama
- Department of Psychology, The University of Tokyo, Tokyo, Japan
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, Osaka, Japan
| | - Jean-Baptiste Bardin
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, Osaka, Japan
- École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Ai Koizumi
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, Osaka, Japan
- Sony Computer Science Laboratories, Inc., Tokyo, Japan
| | - Isamu Motoyoshi
- Department of Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Kaoru Amano
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, Osaka, Japan
- Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, Japan
- *Correspondence: Kaoru Amano,
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Hiraga H, Machida R, Kawai A, Matsumoto Y, Yonemoto T, Nishida Y, Nagano A, Ae K, Yoshida S, Asanuma K, Toguchida J, Huruta D, Nakayama R, Akisue T, Hiruma T, Morii T, Tanaka K, Kataoka T, Fukuda H, Ozaki T. 1482O A phase III study comparing methotrexate (M), adriamycin (A) and cisplatin (P) with MAP + ifosfamide (MAP + IF) for the treatment of osteosarcoma: JCOG0905. Ann Oncol 2022. [DOI: 10.1016/j.annonc.2022.07.1585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Mima Y, Nakayama R, Hizukuri A, Murata K. Tooth detection for each tooth type by application of faster R-CNNs to divided analysis areas of dental panoramic X-ray images. Radiol Phys Technol 2022; 15:170-176. [PMID: 35507126 DOI: 10.1007/s12194-022-00659-1] [Citation(s) in RCA: 3] [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] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 04/19/2022] [Accepted: 04/20/2022] [Indexed: 11/28/2022]
Abstract
This study aimed to propose a computerized method for detecting the tooth region for each tooth type as the initial stage in the development of a computer-aided diagnosis (CAD) scheme for dental panoramic X-ray images. Our database consists of 160 panoramic dental X-ray images obtained from 160 adult patients. To reduce false positives (FPs), the proposed method first extracts a rectangular area including all teeth from a dental panoramic X-ray image with a faster region using a convolutional neural network (Faster R-CNN). From the rectangular area including all teeth, six divided areas are then extracted with Faster R-CNN: top left, top center, top right, bottom left, bottom center, and bottom right. Faster R-CNNs for detecting tooth regions for each tooth type were trained individually for each of the divided areas that narrowed down the target tooth types. By applying these Faster R-CNNs to each divided area, the bounding boxes of each tooth were detected and classified into 32 tooth types. A k-fold cross-validation method with k = 4 was used for training and testing the proposed method. The detection rate for each tooth, number of FPs per image, mean intersection over union for each tooth, and classification accuracy for the 32 tooth types were 98.9%, 0.415, 0.748, and 91.7%, respectively, showing an improvement compared to the application of the Faster R-CNN once to the entire image (98.0%, 1.194, 0.736, and 88.8%).
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Affiliation(s)
- Yuichi Mima
- Graduate School of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan.
| | - Ryohei Nakayama
- Graduate School of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Akiyoshi Hizukuri
- Graduate School of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Kan Murata
- TAKARA TELESYSTEMS Corporation, 1-17-17 Nihonbashi, Chuo-ku, Osaka, 542-0073, Japan
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10
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Nakayama R, Holcombe AO. A dynamic noise background reveals perceptual motion extrapolation: The twinkle-goes illusion. J Vis 2021; 21:14. [PMID: 34673899 PMCID: PMC8543404 DOI: 10.1167/jov.21.11.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
We find that on a dynamic noise background, the perceived disappearance location of a moving object is shifted in the direction of motion. This “twinkle-goes” illusion does not require luminance- or chromaticity-based confusability of the object with the background, or on the amount of background motion energy in the same direction as the object motion. This suggests that the illusion is enabled by the dynamic noise masking the offset transients that otherwise accompany an object's disappearance. While these results are consistent with an anticipatory process that pre-activates positions ahead of the object's current position, additional findings suggest an alternative account: a continuation of attentional tracking after the object disappears. First, the shift increased with speed until over 1.2 revolutions per second (rps), nearing the attentional tracking limit. Second, the shift was greatly reduced when attention was divided between two moving objects. Finally, the illusion was associated with a delay in simple reaction time to the disappearance of the object. We propose that in the absence of offset transients, attentional tracking keeps moving for several tens of milliseconds after the target disappearance, and this causes one to hallucinate a moving object at the position of attention.
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Affiliation(s)
- Ryohei Nakayama
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, Japan.,School of Psychology, University of Sydney, Australia.,
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11
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Kobayashi H, Nakayama R, Hizukuri A, Ishida M, Kitagawa K, Sakuma H. Improving Image Resolution of Whole-Heart Coronary MRA Using Convolutional Neural Network. J Digit Imaging 2021; 33:497-503. [PMID: 31452007 DOI: 10.1007/s10278-019-00264-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Whole-heart coronary magnetic resonance angiography (WHCMRA) permits the noninvasive assessment of coronary artery disease without radiation exposure. However, the image resolution of WHCMRA is limited. Recently, convolutional neural networks (CNNs) have obtained increased interest as a method for improving the resolution of medical images. The purpose of this study is to improve the resolution of WHCMRA images using a CNN. Free-breathing WHCMRA images with 512 × 512 pixels (pixel size = 0.65 mm) were acquired in 80 patients with known or suspected coronary artery disease using a 1.5 T magnetic resonance (MR) system with 32 channel coils. A CNN model was optimized by evaluating CNNs with different structures. The proposed CNN model was trained based on the relationship of signal patterns between low-resolution patches (small regions) and the corresponding high-resolution patches using a training dataset collected from 40 patients. Images with 512 × 512 pixels were restored from 256 × 256 down-sampled WHCMRA images (pixel size = 1.3 mm) with three different approaches: the proposed CNN, bicubic interpolation (BCI), and the previously reported super-resolution CNN (SRCNN). High-resolution WHCMRA images obtained using the proposed CNN model were significantly better than those of BCI and SRCNN in terms of root mean squared error, peak signal to noise ratio, and structure similarity index measure with respect to the original WHCMRA images. The proposed CNN approach can provide high-resolution WHCMRA images with better accuracy than BCI and SRCNN. The high-resolution WHCMRA obtained using the proposed CNN model will be useful for identifying coronary artery disease.
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Affiliation(s)
- Hiroki Kobayashi
- Graduate School of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Ryohei Nakayama
- Graduate School of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan.
| | - Akiyoshi Hizukuri
- Graduate School of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Masaki Ishida
- Department of Radiology, Mie University School of Medicine, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
| | - Kakuya Kitagawa
- Department of Radiology, Mie University School of Medicine, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
| | - Hajime Sakuma
- Department of Radiology, Mie University School of Medicine, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
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12
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Kitahara H, Nagatani Y, Otani H, Nakayama R, Kida Y, Sonoda A, Watanabe Y. A novel strategy to develop deep learning for image super-resolution using original ultra-high-resolution computed tomography images of lung as training dataset. Jpn J Radiol 2021; 40:38-47. [PMID: 34318444 PMCID: PMC8315896 DOI: 10.1007/s11604-021-01184-8] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 07/21/2021] [Indexed: 11/26/2022]
Abstract
PURPOSE To improve the image quality of inflated fixed cadaveric human lungs by utilizing ultra-high-resolution computed tomography (U-HRCT) as a training dataset for super-resolution processing using deep learning (SR-DL). MATERIALS AND METHODS Image data of nine cadaveric human lungs were acquired using U-HRCT. Three different matrix images of U-HRCT images were obtained with two acquisition modes: normal mode (512-matrix image) and super-high-resolution mode (1024- and 2048-matrix image). SR-DL used 512- and 1024-matrix images as training data for deep learning. The virtual 2048-matrix images were acquired by applying SR-DL to the 1024-matrix images. Three independent observers scored normal anatomical structures and abnormal computed tomography (CT) findings of both types of 2048-matrix images on a 3-point scale compared to 1024-matrix images. The image noise values were quantitatively calculated. Moreover, the edge rise distance (ERD) and edge rise slope (ERS) were also calculated using the CT attenuation profile to evaluate margin sharpness. RESULTS The virtual 2048-matrix images significantly improved visualization of normal anatomical structures and abnormal CT findings, except for consolidation and nodules, compared with the conventional 2048-matrix images (p < 0.01). Quantitative noise values were significantly lower in the virtual 2048-matrix images than in the conventional 2048-matrix images (p < 0.001). ERD was significantly shorter in the virtual 2048-matrix images than in the conventional 2048-matrix images (p < 0.01). ERS was significantly higher in the virtual 2048-matrix images than in the conventional 2048-matrix images (p < 0.01). CONCLUSION SR-DL using original U-HRCT images as a training dataset might be a promising tool for image enhancement in terms of margin sharpness and image noise reduction. By applying trained SR-DL to U-HRCT SHR mode images, virtual ultra-high-resolution images were obtained which surpassed the image quality of unmodified SHR mode images.
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Affiliation(s)
- Hitoshi Kitahara
- Department of Radiology, Shiga University of Medical Science, Seta Tsukinowa-Cho, Otsu, Shiga, 520-2192, Japan.
| | - Yukihiro Nagatani
- Department of Radiology, Shiga University of Medical Science, Seta Tsukinowa-Cho, Otsu, Shiga, 520-2192, Japan
| | - Hideji Otani
- Department of Radiology, Shiga University of Medical Science, Seta Tsukinowa-Cho, Otsu, Shiga, 520-2192, Japan
| | - Ryohei Nakayama
- Department of Electronic and Computer Engineering, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Yukako Kida
- Department of Radiology, Shiga University of Medical Science, Seta Tsukinowa-Cho, Otsu, Shiga, 520-2192, Japan
| | - Akinaga Sonoda
- Department of Radiology, Shiga University of Medical Science, Seta Tsukinowa-Cho, Otsu, Shiga, 520-2192, Japan
| | - Yoshiyuki Watanabe
- Department of Radiology, Shiga University of Medical Science, Seta Tsukinowa-Cho, Otsu, Shiga, 520-2192, Japan
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Magawa S, Nii M, Ishida M, Takase S, Nakayama R, Enomoto N, Tanaka H, Kondo E, Sakuma H, Ikeda T. Evaluation of placental oxygenation index using blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) during normal late pregnancy. J Matern Fetal Neonatal Med 2021; 35:5274-5281. [PMID: 33491514 DOI: 10.1080/14767058.2021.1878140] [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] [Indexed: 10/22/2022]
Abstract
AIM Noninvasive blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) has recently been used to evaluate placental oxygenation. However, this method still has unresolved problems, such as long testing times and lack of normal values set. In the present study, we used a shorter protocol in BOLD-MRI and established normal values for placental oxygenation in late pregnancy. METHODS We recruited 18 healthy singleton pregnant women (>32 weeks of gestation) who had a normal body size before pregnancy and a normal course of pregnancy. They underwent BOLD-MRI with three consecutive 4-min periods of different oxygenation: normoxia (21% O2), hyperoxia (10 L O2/min), and then normoxia. Placental time-activity curves were presented as signal intensity change relative to baseline (ΔR2*). The time from starting maternal oxygen administration to peak ΔR2*. To assess the relationship between peak ΔR2* values and placenta-related parameters and fetal development, the correlation between peak ΔR2*, placental weight, and neonatal birth weight was evaluated using Spearman's rank correlation test. RESULTS In all cases, the BOLD signal was elevated by maternal oxygen administration, with the peak resolving within 4 min after the end of oxygen administration. Peak ΔR2* and time to peak ΔR2* during oxygenation were 7.99 ± 2.58, and 458.1 ± 73.9 s, respectively. There was a significant correlation between peak ΔR2* and neonatal birth weight (percentile) (r = 0.537, p = .022), and between placental weight and neonatal birth weight (r = 0.769, p < .01). CONCLUSIONS In all cases, the BOLD signal increased with maternal hyperoxia using this protocol. So, 4 min observation following maternal oxygen administration is sufficient for peak ΔR2* evaluation. These reference values set in this study may be one of the indicators of BOLD signal changes in normal pregnancies after 32 weeks of gestation.
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Affiliation(s)
- Shoichi Magawa
- Department of Obstetrics and Gynecology, Mie University Faculty Medicine, Mie, Japan
| | - Masafumi Nii
- Department of Obstetrics and Gynecology, Mie University Faculty Medicine, Mie, Japan
| | - Masaki Ishida
- Department of Radiology, Mie University Faculty Medicine, Mie, Japan
| | - Shinichi Takase
- Department of Radiology, Mie University Faculty Medicine, Mie, Japan
| | - Ryohei Nakayama
- Department of Electronic and Computer Engineering, Ritsumeikan University, Kyoto, Japan
| | - Naosuke Enomoto
- Department of Obstetrics and Gynecology, Mie University Faculty Medicine, Mie, Japan
| | - Hiroaki Tanaka
- Department of Obstetrics and Gynecology, Mie University Faculty Medicine, Mie, Japan
| | - Eiji Kondo
- Department of Obstetrics and Gynecology, Mie University Faculty Medicine, Mie, Japan
| | - Hajime Sakuma
- Department of Radiology, Mie University Faculty Medicine, Mie, Japan
| | - Tomoaki Ikeda
- Department of Obstetrics and Gynecology, Mie University Faculty Medicine, Mie, Japan
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Abstract
The information used by conscious perception may differ from that which drives certain actions. A dramatic illusion caused by an object's internal texture motion has been put forward as one example. The motion causes an illusory position shift that accumulates over seconds into a large effect, but targeting of the grating for a saccade (a rapid eye movement) is not affected by this illusion. While this has been described as a dissociation between perception and action, an alternative explanation is that rather than saccade targeting having privileged access to the correct position, a shift of attention that precedes saccades resets the accumulated illusory position shift to zero. In support of this possibility, we found that the accumulation of illusory position shift can be reset by transients near the moving object, creating an impression of the object returning to near its actual position. Repetitive luminance changes of the object also resulted in reset of the accumulation, but less so when attention to the object was reduced by a concurrent digit identification task. Finally, judgments of the object's positions around the time of saccade onset reflected the veridical rather than the illusory position. These results suggest that attentional shifts, including those preceding saccades, can update the perceived position of moving objects and mediate the previously reported dissociation between conscious perception and saccades.
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Nishitani Y, Nakayama R, Hayashi D, Hizukuri A, Murata K. Segmentation of teeth in panoramic dental X-ray images using U-Net with a loss function weighted on the tooth edge. Radiol Phys Technol 2021; 14:64-69. [PMID: 33398671 DOI: 10.1007/s12194-020-00603-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [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: 09/19/2020] [Revised: 12/02/2020] [Accepted: 12/07/2020] [Indexed: 10/22/2022]
Abstract
Panoramic dental X-ray imaging is an established method for the diagnosis of dental problems. However, the resolution of panoramic dental X-ray images is relatively low. Thus, early lesions are often overlooked. As the first step in the development of a computer-aided diagnosis scheme for panoramic dental X-ray images, we propose a computerized method for the segmentation of teeth using U-Net with a loss function weighted on the tooth edge. Our database consisted of 162 panoramic dental X-ray images. The training dataset consisted of 102 images, while the remaining 60 images were used as the test dataset. The loss function obtained by the cross entropy (CE) in the entire image is usually used in training U-Net. To improve the segmentation accuracy of the tooth edge, a loss function weighted on the tooth edge is proposed by adding the CE in the tooth edge region to the CE for the entire image. The mean Jaccard index and Dice index for U-Net with the loss function combining the CEs for the entire image and tooth edge were 0.864 and 0.927, respectively, which were significantly larger than those for U-Net with the CE for the entire image (0.802 and 0.890, p < 0.001) and U-Net with the CE for the tooth edge (0.826 and 0.905, p < 0.001). U-Net with the new loss function exhibited a higher segmentation accuracy of the tooth in panoramic dental X-ray images than that obtained by U-Net with the conventional loss function.
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Affiliation(s)
- Yuya Nishitani
- Graduate School of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Ryohei Nakayama
- Graduate School of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan.
| | - Daisei Hayashi
- Graduate School of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Akiyoshi Hizukuri
- Graduate School of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Kan Murata
- TAKARA TELESYSTEMS Corporation, 1-17-17 Nihonbashi, Chuo-ku, Osaka, 542-0073, Japan
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Suzuki M, Nakayama R, Namba K, Kawami H, Nara M, Smathers RL, Nakamura S. Diagnostic performance of coronal view in comparison with transverse view of three-dimensional automated breast ultrasound. Acta Radiol 2021; 62:27-33. [PMID: 32249597 DOI: 10.1177/0284185120913706] [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] [Indexed: 11/15/2022]
Abstract
BACKGROUND Automated breast ultrasound (ABUS) is one of the first ultrasound devices which enables the de-coupling of image acquisition and interpretation. Another feature of ABUS is the coronal view, utilizing three-dimensional volume data reconstructed from two-dimensional transverse images acquired automatically. PURPOSE To assess the diagnostic performance of coronal view interpretation by comparing it with that of the transverse view. MATERIAL AND METHODS This was a retrospective, multi-case, observer study using a cancer-enriched dataset of ABUS images at a single institution with approval by an Institutional Review Board. The 100 scan datasets selected between October 2014 and January 2017 included 70 non-cancer cases and 30 malignancies. In the present observer study, two experienced physicians provided their confidence levels regarding the malignancy of each of the 100 scan datasets independently. The reading times for interpretation of coronal and transverse views were recorded. RESULTS Area under the receiver operating characteristic curves for two observers with the transverse view (0.856) was improved by use of the coronal view (0.917, P = 0.036). The average reading times were 140.4 s with the coronal view and 148.5 s with the transverse view per scan dataset (P = 0.246). CONCLUSION It is conceivable that the accurate use of the coronal view will lead to improvement in diagnostic performance in breast cancer screening, although this needs to be confirmed with a larger prospective study.
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Affiliation(s)
- Megumi Suzuki
- Center for Breast Diseases and Breast Cancer, Hokuto Hospital and Clinic, Hokkaido, Japan
| | - Ryohei Nakayama
- Department of Electronic and Computer Engineering, Ritsumeikan University, Kyoto, Japan
| | - Kiyoshi Namba
- Center for Breast Diseases and Breast Cancer, Hokuto Hospital and Clinic, Hokkaido, Japan
| | - Hiroyuki Kawami
- Center for Breast Diseases and Breast Cancer, Hokuto Hospital and Clinic, Hokkaido, Japan
| | - Mayumi Nara
- Center for Breast Diseases and Breast Cancer, Hokuto Hospital and Clinic, Hokkaido, Japan
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17
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Hizukuri A, Nakayama R, Nara M, Suzuki M, Namba K. Computer-Aided Diagnosis Scheme for Distinguishing Between Benign and Malignant Masses on Breast DCE-MRI Images Using Deep Convolutional Neural Network with Bayesian Optimization. J Digit Imaging 2020; 34:116-123. [PMID: 33159279 DOI: 10.1007/s10278-020-00394-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 10/02/2020] [Accepted: 10/19/2020] [Indexed: 01/23/2023] Open
Abstract
Although magnetic resonance imaging (MRI) has a higher sensitivity of early breast cancer than mammography, the specificity is lower. The purpose of this study was to develop a computer-aided diagnosis (CAD) scheme for distinguishing between benign and malignant breast masses on dynamic contrast material-enhanced MRI (DCE-MRI) by using a deep convolutional neural network (DCNN) with Bayesian optimization. Our database consisted of 56 DCE-MRI examinations for 56 patients, each of which contained five sequential phase images. It included 26 benign and 30 malignant masses. In this study, we first determined a baseline DCNN model from well-known DCNN models in terms of classification performance. The optimum architecture of the DCNN model was determined by changing the hyperparameters of the baseline DCNN model such as the number of layers, the filter size, and the number of filters using Bayesian optimization. As the input of the proposed DCNN model, rectangular regions of interest which include an entire mass were selected from each of DCE-MRI images by an experienced radiologist. Three-fold cross validation method was used for training and testing of the proposed DCNN model. The classification accuracy, the sensitivity, the specificity, the positive predictive value, and the negative predictive value were 92.9% (52/56), 93.3% (28/30), 92.3% (24/26), 93.3% (28/30), and 92.3% (24/26), respectively. These results were substantially greater than those with the conventional method based on handcrafted features and a classifier. The proposed DCNN model achieved high classification performance and would be useful in differential diagnoses of masses in breast DCE-MRI images as a diagnostic aid.
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Affiliation(s)
- Akiyoshi Hizukuri
- Department of Electronic and Computer Engineering, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577,, Japan.
| | - Ryohei Nakayama
- Department of Electronic and Computer Engineering, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577,, Japan
| | - Mayumi Nara
- Department of Breast Surgery, Hokuto Hospital, 7-5 Kisen, Inada-cho, Obihiro-shi, Hokkaido, 080-0833,, Japan
| | - Megumi Suzuki
- Department of Breast Surgery, Hokuto Hospital, 7-5 Kisen, Inada-cho, Obihiro-shi, Hokkaido, 080-0833,, Japan
| | - Kiyoshi Namba
- Department of Breast Surgery, Hokuto Hospital, 7-5 Kisen, Inada-cho, Obihiro-shi, Hokkaido, 080-0833,, Japan
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18
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Nakayama R, Holcombe AO. The “twinkle goes” illusion: Attention-dependent extrapolation of motion. J Vis 2020. [DOI: 10.1167/jov.20.11.1020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Ryohei Nakayama
- National Institute of Information and Communications Technology
- The University of Sydney
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19
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Muramatsu C, Kawashita I, Nakayama R, Kamiya N, Hirahara D. [Progress of Radiological Technology by AI]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2020; 76:1105-1106. [PMID: 33229839 DOI: 10.6009/jjrt.2020_jsrt_76.11.1105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
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20
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Kanii Y, Ichikawa Y, Nakayama R, Nagata M, Ishida M, Kitagawa K, Murashima S, Sakuma H. Usefulness of dictionary learning-based processing for improving image quality of sub-millisievert low-dose chest CT: initial experience. Jpn J Radiol 2019; 38:215-221. [PMID: 31863329 DOI: 10.1007/s11604-019-00912-5] [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: 09/27/2019] [Accepted: 12/14/2019] [Indexed: 11/29/2022]
Abstract
PURPOSE To develop a dictionary learning (DL)-based processing technique for improving the image quality of sub-millisievert chest computed tomography (CT). MATERIALS AND METHODS Standard-dose and sub-millisievert chest CT were acquired in 12 patients. Dictionaries including standard- and low-dose image patches were generated from the CT datasets. For each patient, DL-based processing was performed for low-dose CT using the dictionaries generated from the remaining 11 patients. This procedure was repeated for all 12 patients. Image quality of normal thoracic structures on the processed sub-millisievert CT images was assessed with a 5-point scale (5 = excellent, 1 = very poor). Lung lesion conspicuity was also assessed on a 5-point scale. RESULTS Image noise on sub-millisievert CT was significantly decreased with DL-based image processing (48.5 ± 13.7 HU vs 20.4 ± 7.9 HU, p = 0.0005). Image quality of lung structures was significantly improved with DL-based method (middle level of lung, 2.25 ± 0.75 vs 2.92 ± 0.79, p = 0.0078). Lung lesion conspicuity was also significantly improved with DL-based technique (solid nodules, 3.4 ± 0.6 vs 2.7 ± 0.6, p = 0.0273). CONCLUSION Image quality and lesion conspicuity on sub-millisievert chest CT images may be improved by DL-based post-processing.
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Affiliation(s)
- Yoshinori Kanii
- Department of Radiology, Mie University Hospital, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
| | - Yasutaka Ichikawa
- Department of Radiology, Mie University Hospital, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan.
| | - Ryohei Nakayama
- Department of Electronic and Computer Engineering, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Motonori Nagata
- Department of Radiology, Mie University Hospital, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
| | - Masaki Ishida
- Department of Radiology, Mie University Hospital, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
| | - Kakuya Kitagawa
- Department of Radiology, Mie University Hospital, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
| | - Shuichi Murashima
- Department of Radiology, Matsusaka Chuo General Hospital, 102 Kobou, Kawai, Matsusaka, Mie, 515-8566, Japan
| | - Hajime Sakuma
- Department of Radiology, Mie University Hospital, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
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Nakayama R, Holcombe AO. Attentional updating of perceived position can account for a dissociation of perception and action. J Vis 2019. [DOI: 10.1167/19.10.277a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Ryohei Nakayama
- School of Psychology, The University of Sydney
- Center for Information and Neural Networks (CiNet), NICT
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22
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Nakayama R, Motoyoshi I. Theta-cyclic binding of visual features. J Vis 2018. [DOI: 10.1167/18.10.964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Abstract
Despite the subjective continuity of perception over time, increasing evidence suggests that the human nervous system samples sensory information periodically, a finding strongly exemplified by discretized perception in the alpha-rhythm frequency band. More recently, studies have revealed a theta-band cyclic process that manifests itself as periodical fluctuations in behavioral performance. Here, we used a simple stimulus to demonstrate that the theta-cyclic system can produce a vivid experience of slow discrete visual sampling: a Gabor texture pattern appears as a series of flickering snapshots if its spatial window moves continuously over a carrier grating that remains still or drifts continuously in the opposite direction. While the perceptual magnitude of this illusory saltation varied with the speed difference between grating and window components in head-centered coordinates, the perceived rhythm of saltation remained nearly constant (3–8 Hz) over a wide range of stimulus parameters. Results provide further evidence that the slow cyclic neural processes play a critical role not only in attentional task performance but also in conscious perception.
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Affiliation(s)
- Ryohei Nakayama
- Department of Life Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902, Japan.
| | - Isamu Motoyoshi
- Department of Life Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902, Japan
| | - Takao Sato
- Department of Comprehensive Psychology, Ritsumeikan University, 2-150 Iwakura-cho, Ibaraki, Osaka, 567-8570, Japan
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Nakayama R, Harada D, Kamachi MG, Motoyoshi I. Apparent shift in long-range motion trajectory by local pattern orientation. Sci Rep 2018; 8:774. [PMID: 29335569 PMCID: PMC5768746 DOI: 10.1038/s41598-017-19005-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 12/20/2017] [Indexed: 11/16/2022] Open
Abstract
The present study shows that the apparent direction of a moving pattern is systematically affected by its orientation. We found that the perceived direction of motion of a single Gabor grating changing position in discrete steps interleaved by blank inter-stimulus interval (ISI) is biased toward the orientation of the grating. This orientation-induced motion shift peaks for grating orientations ~±15 deg away from the physical motion trajectory and was profound for relatively short distances. Orientation adaptation revealed that the directional shift is determined by the apparent –not the physical –orientation of the grating, and a subsequent experiment demonstrated that directional shift is also influenced by the orientation of the contrast-defined stimulus envelope. Results provide further evidence that the apparent trajectory of a motion stimulus is determined by interactions between motion and pattern information at relatively high levels of visual processing.
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Affiliation(s)
| | - Daisuke Harada
- Kogakuin University, Tokyo, Japan.,Toppan Printing Co.,Ltd., Tokyo, Japan
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Watanabe R, Namba K, Takeda K, Yamamoto K, Katsuragawa S, Doi K, Nakayama R. An Improved Computer-aided Diagnosis Scheme Using the Nearest Neighbor Criterion for Determining Histological Classification of Clustered Microcalcifications. Methods Inf Med 2018. [DOI: 10.1055/s-0038-1625433] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Summary
Objectives
: Our purpose was to evaluate the potential usefulness of the nearest neighbor case which was assumed to be the similar case in a CAD scheme for determining the histological classification of clustered microcalcifications.
Methods
: Our database consisted of current and previous magnification mammograms obtained from 93 patients before and after three-month follow-up examination. It included 11 invasive carcinomas, 19 noninvasive carcinomas of the comedo type, 25 noninvasive carcinomas of the noncomedo type, 23 mas- topathies, and 15 fibroadenomas. Six objective features on clustered microcalcifications were first extracted from each of the current and the previous images. The nearest neighbor case was then identified by the Euclidean distance in the previous and current feature-space. The histological classification of an unknown new case in question was assumed to be thesame as that of the nearest neighbor case which has the shortest Euclidean distance in our database.
Results
: The classification accuracies were 90.9% for invasive carcinoma, 89.5% for noninvasive carcinoma of the comedo type, 96.0% for noninvasive carcinoma of the noncomedo type, 82.6% for mastopathy, and 93.3% for fibroadenoma. These results were substantially higher than those with our previous CAD scheme.
Conclusion
: The nearest neighbor criterion was useful in a CAD scheme for determining the histological classification.
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Nakayama R, Suzuki N, Maesato M, Nagaoka T, Arita M, Kitagawa H. A compact low-temperature hydrogen ion beam apparatus for in situ physical property measurements. Rev Sci Instrum 2017; 88:123904. [PMID: 29289203 DOI: 10.1063/1.5004517] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A new compact low-temperature hydrogen ion beam apparatus has been developed for in situ physical property measurements. Introduction of hydrogen can significantly alter the physical properties of materials. Conventional methods such as exposure to H2 gas are limited to materials having hydrogen sorption. The present method is, in principle, applicable to any material of interest. Our setup provides a facile way to conduct both low-temperature hydrogen ion beam irradiation and in situ electrical resistivity measurements, which enables observation of novel physical properties induced by the low-temperature irradiation. The lowest temperature of 3.8 K was achieved by utilizing a newly designed rotatable radiation shield and a closed-cycle cryostat, which is advantageous for long-time low-temperature experiments for heavy hydrogen doping and in situ analysis. It was found that the resistivity of ZnO largely decreased by hydrogen ion beam irradiation at 50 K. Furthermore, the in situ measurements revealed an unforeseen irreversible thermal hysteresis for resistivity.
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Affiliation(s)
- R Nakayama
- Department of Chemistry, Kyoto University, Kyoto 606-8502, Japan
| | - N Suzuki
- Department of Chemistry, Kyoto University, Kyoto 606-8502, Japan
| | - M Maesato
- Department of Chemistry, Kyoto University, Kyoto 606-8502, Japan
| | - T Nagaoka
- Department of Materials Science and Engineering, Kyushu University, Fukuoka 819-0395, Japan
| | - M Arita
- Department of Materials Science and Engineering, Kyushu University, Fukuoka 819-0395, Japan
| | - H Kitagawa
- Department of Chemistry, Kyoto University, Kyoto 606-8502, Japan
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Nakayama R, Motoyoshi I. Existence of acceleration sensitive units in pre-attentive visual system. J Vis 2017. [DOI: 10.1167/17.10.425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Shirobe M, Nakayama R, Ohara Y, Endo K, Watanabe Y, Hirano H, Hakuta C. EFFECT OF ORAL HEALTH CARE ON HYPERSENSITIVITY SYNDROME AMONG THE ELDERLY IN LONG-TERM CARE. Innov Aging 2017. [DOI: 10.1093/geroni/igx004.1443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- M. Shirobe
- Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan,
| | - R. Nakayama
- Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Y. Ohara
- Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - K. Endo
- Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Y. Watanabe
- Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan,
| | - H. Hirano
- Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan,
| | - C. Hakuta
- Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
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Abstract
It is widely believed that the human visual system is insensitive to acceleration in moving stimuli. This notion is supported by evidence that detection sensitivity for velocity modulation in moving stimuli is a lowpass function of the velocity modulation's temporal frequency. However, the lowpass function might be a mixture of detection by attention-based tracking and low-level mechanisms sensitive to acceleration. To revisit the issue of acceleration perception in relation to attentive tracking, we measured detection sensitivities for velocity modulations at various temporal frequencies (0.25–8 Hz) by using drifting gratings within long or short spatial windows that make the tracking of grating easier or more difficult respectively. Results showed that modulation sensitivity is lowpass for gratings with long windows but bandpass for gratings with short windows (peak at ~1 Hz). Moreover, we found that lowpass sensitivity becomes bandpass when we removed observer attention by a concurrent letter identification task. An additional visual-search experiment showed that a target dot moving with a velocity modulation at relatively high temporal frequencies (~2–4 Hz) was most easily detected among dots moving at various constant velocities. These results support the notion that high sensitivity to sluggish velocity modulation is a product of attentively tracking of moving stimuli and that the visual system is directly sensitive to accelerations and/or decelerations at the preattentive level.
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Affiliation(s)
- Ryohei Nakayama
- Department of Life Sciences, The University of TokyoTokyo, Japan
| | - Isamu Motoyoshi
- Department of Life Sciences, The University of TokyoTokyo, Japan
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Takeuchi R, Matsumoto H, Arikawa K, Taguchi C, Nakayama R, Nasu I, Hiratsuka K. Phenytoin-induced gingival overgrowth caused by death receptor pathway malfunction. Oral Dis 2017; 23:653-659. [PMID: 28160766 DOI: 10.1111/odi.12651] [Citation(s) in RCA: 2] [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: 07/29/2016] [Revised: 12/02/2016] [Accepted: 01/26/2017] [Indexed: 12/31/2022]
Abstract
OBJECTIVE In this study, we investigated the role of phenytoin (PHT) in death receptor-induced apoptosis of gingival fibroblasts to clarify the mechanism of PHT-induced gingival overgrowth. METHODS Human gingival fibroblasts were cultured to semiconfluence and treated with PHT (0.025, 0.1, 0.25, and 1.0 μM) for 48 h, and then, the apoptotic cell numbers were relatively determined by absorptiometry. After 24 h of 0.25 μM PHT treatment, caspase activity was measured by absorptiometry, apoptotic and cell cycle phase distribution was analyzed by flow cytometry, expression levels of apoptotic genes were quantified by real-time qPCR, and expression of apoptotic proteins was detected by Western blot analysis. After 48 h of 0.25 μM PHT treatment, appearance of apoptotic cells was detected by TUNEL assay. RESULTS PHT treatment decreased the proportion of apoptotic cells in gingival fibroblasts compared to a serum-free control culture in response to the protein changes as follows: PHT upregulated c-FLIP and, in turn, downregulated FADD, caspase-8, and caspase-3; PHT upregulated c-IAP2 and downregulated TRAF2; PHT downregulated caspase-9 and caspase-3 via decreased RIPK1 activity and increased Bcl-2 activity. CONCLUSION PHT-induced gingival overgrowth may result from the above-mentioned mechanisms involving apoptosis inhibition in gingival fibroblasts.
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Affiliation(s)
- R Takeuchi
- Department of Biochemistry and Molecular Biology, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan
| | - H Matsumoto
- Department of Pharmacology, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan
| | - K Arikawa
- Department of Preventive and Public Oral Health, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan
| | - C Taguchi
- Department of Preventive and Public Oral Health, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan
| | - R Nakayama
- Department of Preventive and Public Oral Health, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan
| | - I Nasu
- Department of Preventive and Public Oral Health, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan
| | - K Hiratsuka
- Department of Biochemistry and Molecular Biology, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan
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Nakayama R, Motoyoshi I, Sato T. Neural correlates of illusory discrete perception: an EEG study. J Vis 2016. [DOI: 10.1167/16.12.1086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Nakayama R, Motoyoshi I, Sato T. The Roles of Non-retinotopic Motions in Visual Search. Front Psychol 2016; 7:840. [PMID: 27313560 PMCID: PMC4887493 DOI: 10.3389/fpsyg.2016.00840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 05/19/2016] [Indexed: 11/30/2022] Open
Abstract
In visual search, a moving target among stationary distracters is detected more rapidly and more efficiently than a static target among moving distracters. Here we examined how this search asymmetry depends on motion signals from three distinct coordinate systems—retinal, relative, and spatiotopic (head/body-centered). Our search display consisted of a target element, distracters elements, and a fixation point tracked by observers. Each element was composed of a spatial carrier grating windowed by a Gaussian envelope, and the motions of carriers, windows, and fixation were manipulated independently and used in various combinations to decouple the respective effects of motion coordinate systems on visual search asymmetry. We found that retinal motion hardly contributes to reaction times and search slopes but that relative and spatiotopic motions contribute to them substantially. Results highlight the important roles of non-retinotopic motions for guiding observer attention in visual search.
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Affiliation(s)
- Ryohei Nakayama
- Department of Psychology, The University of TokyoTokyo, Japan
- *Correspondence: Ryohei Nakayama
| | - Isamu Motoyoshi
- Department of Life Sciences, The University of TokyoTokyo, Japan
| | - Takao Sato
- Department of Psychology, The University of TokyoTokyo, Japan
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Shibusawa M, Nakayama R, Okanami Y, Kashikura Y, Imai N, Nakamura T, Kimura H, Yamashita M, Hanamura N, Ogawa T. The usefulness of a computer-aided diagnosis scheme for improving the performance of clinicians to diagnose non-mass lesions on breast ultrasonographic images. J Med Ultrason (2001) 2016; 43:387-94. [PMID: 27230095 DOI: 10.1007/s10396-016-0718-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [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: 01/12/2016] [Accepted: 04/15/2016] [Indexed: 11/30/2022]
Abstract
PURPOSE The purpose of this study was to evaluate the usefulness of a computer-aided diagnosis (CAD) scheme for improving the performance of clinicians to diagnose non-mass lesions appearing as hypoechoic areas on breast ultrasonographic images. METHODS The database included 97 ultrasonographic images with hypoechoic areas: 48 benign cases [benign lesion with benign mammary tissue or fibrocystic disease (n = 20), fibroadenoma (n = 11), and intraductal papilloma (n = 17)] and 49 malignant cases [ductal carcinoma in situ (n = 17) and invasive ductal carcinoma (n = 32)]. Seven clinicians, three expert breast surgeons, and four general surgeons participated in the observer study. They were asked their confidence level concerning the possibility of malignancy in all 97 cases with and without the use of the CAD scheme. Receiver operating characteristic (ROC) analysis was performed to evaluate the usefulness of the CAD scheme. RESULTS The areas under the ROC curve (AUC) improved for all observers when they used the CAD scheme and increased from 0.649 to 0.783 (P = 0.0167). Notably, the AUC for the general surgeon group increased from 0.625 to 0.793 (P = 0.045). CONCLUSIONS This study showed that the performance of clinicians to diagnose non-mass lesions appearing as hypoechoic areas on breast ultrasonographic images was improved by the use of a CAD scheme.
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Affiliation(s)
- Mai Shibusawa
- Department of Breast Surgery, Mie University Hospital, 2-174 Edobashi, Tsu City, Mie, 514-8507, Japan.
| | - Ryohei Nakayama
- Department of Electronic and Computer Engineering, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu City, Shiga, 525-8577, Japan
| | - Yuko Okanami
- Department of Breast Surgery, Mie University Hospital, 2-174 Edobashi, Tsu City, Mie, 514-8507, Japan
| | - Yumi Kashikura
- Department of Senology, Tsukuba Medical Center Hospital, 1-3-1 Amakubo, Tsukuba City, Ibaraki, 305-8558, Japan
| | - Nao Imai
- Department of Breast Surgery, Mie University Hospital, 2-174 Edobashi, Tsu City, Mie, 514-8507, Japan
| | - Takashi Nakamura
- Department of Breast Surgery, Nabari City Hospital, 1-178 Yurigaokanishi, Nabari City, Mie, 518-0481, Japan
| | - Hiroko Kimura
- Department of Breast Surgery, Mie University Hospital, 2-174 Edobashi, Tsu City, Mie, 514-8507, Japan
| | - Masako Yamashita
- Department of Breast Surgery, Mie University Hospital, 2-174 Edobashi, Tsu City, Mie, 514-8507, Japan
| | - Noriko Hanamura
- Department of Breast Surgery, Mie University Hospital, 2-174 Edobashi, Tsu City, Mie, 514-8507, Japan
| | - Tomoko Ogawa
- Department of Breast Surgery, Mie University Hospital, 2-174 Edobashi, Tsu City, Mie, 514-8507, Japan
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Ishida M, Kitagawa K, Ichihara T, Natsume T, Nakayama R, Nagasawa N, Kubooka M, Ito T, Uno M, Goto Y, Nagata M, Sakuma H. Underestimation of myocardial blood flow by dynamic perfusion CT: Explanations by two-compartment model analysis and limited temporal sampling of dynamic CT. J Cardiovasc Comput Tomogr 2016; 10:207-14. [DOI: 10.1016/j.jcct.2016.01.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Revised: 12/04/2015] [Accepted: 01/11/2016] [Indexed: 11/24/2022]
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Abstract
In binocular rivalry, moving stimulus is dominant over stationary stimulus. This is called motion dominance. The motion here is usually a motion defined on the retina (retinal motion). However, motion can be defined in several different coordinates. It can be defined with respect to objects in the background (object-based motion) or to observers' head or body (spatiotopic motion), as well as to the retinal coordinate. In this study, we examined the role of motions defined by these three coordinates. A dichoptic pair of gratings was presented to create a binocular rivalry, one of which was moving and the other stationary. A fixation point and a reference background were either moving with the grating or stationary, depending on the condition. Different combinations of the three types of motions were created by having the observer track the fixation point or the background when they are moving. It was found that the retinal motion does not necessarily yield motion dominance, and that the motion dominance is determined by the combination of motions defined by different coordinate systems.
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Ishida M, Takase S, Nakayama R, Inoue K, Goto Y, Ichikawa Y, Kitagawa K, Sakuma H. Target volume coronary MRA revisited: usefulness of non-rigid reregistration of multi-frame 3D MRA acquisitions at 3T. J Cardiovasc Magn Reson 2015. [PMCID: PMC4328398 DOI: 10.1186/1532-429x-17-s1-o51] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Nakayama R, Motoyoshi I, Sato T. Directional asymmetry in contrast sensitivity during smooth pursuit eye movement depends on spatial frequency. J Vis 2015. [DOI: 10.1167/15.12.1021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Goto T, Nakayama R, Yamanaka M, Takata M, Takazawa T, Watanabe K, Maruta K, Nagata R, Nagamine J, Tsuchida A, Kato H. Effects of DSP-8658, a Novel Selective Peroxisome Proliferator-activated Receptors a/γ Modulator, on Adipogenesis and Glucose Metabolism in Diabetic Obese Mice. Exp Clin Endocrinol Diabetes 2015; 123:492-9. [DOI: 10.1055/s-0035-1549965] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- T. Goto
- Drug Research Division, Sumitomo Dainippon Pharma Co., Ltd. Osaka, Japan
| | - R. Nakayama
- Drug Research Division, Sumitomo Dainippon Pharma Co., Ltd. Osaka, Japan
| | - M. Yamanaka
- Drug Research Division, Sumitomo Dainippon Pharma Co., Ltd. Osaka, Japan
| | - M. Takata
- Drug Research Division, Sumitomo Dainippon Pharma Co., Ltd. Osaka, Japan
| | - T. Takazawa
- Personnel, Sumitomo Dainippon Pharma Co., Ltd. Osaka, Japan
| | - K. Watanabe
- Drug Research Division, Sumitomo Dainippon Pharma Co., Ltd. Osaka, Japan
| | - K. Maruta
- Drug Development Division, Sumitomo Dainippon Pharma Co., Ltd. Tokyo, Japan
| | - R. Nagata
- Center for Drug Discovery and Development National Institute of Biomedical Innovation, Osaka, Japan
| | - J. Nagamine
- Drug Research Division, Sumitomo Dainippon Pharma Co., Ltd. Osaka, Japan
| | - A. Tsuchida
- Global Strategy & Business Development, Sumitomo Dainippon Pharma Co., Ltd. Tokyo, Japan
| | - H. Kato
- Center for Drug Discovery and Development National Institute of Biomedical Innovation, Osaka, Japan
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Izquierdo C, Velasco R, Vidal N, Sola N, Llufriu S, Sanchez J, Besora S, Nakayama R, Graus F, Bruna J. P11.06 * LYMPHOMATOSIS CEREBRI: A RARE FORM OF PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA. Neuro Oncol 2014. [DOI: 10.1093/neuonc/nou174.229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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40
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Nakayama R, Motoyoshi I, Sato T. Competing motion signals compromise to discrete perception. J Vis 2014. [DOI: 10.1167/14.10.264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Hizukuri A, Nakayama R, Kashikura Y, Takase H, Kawanaka H, Ogawa T, Tsuruoka S. Computerized determination scheme for histological classification of breast mass using objective features corresponding to clinicians' subjective impressions on ultrasonographic images. J Digit Imaging 2014; 26:958-70. [PMID: 23546774 DOI: 10.1007/s10278-013-9594-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
It is often difficult for clinicians to decide correctly on either biopsy or follow-up for breast lesions with masses on ultrasonographic images. The purpose of this study was to develop a computerized determination scheme for histological classification of breast mass by using objective features corresponding to clinicians' subjective impressions for image features on ultrasonographic images. Our database consisted of 363 breast ultrasonographic images obtained from 363 patients. It included 150 malignant (103 invasive and 47 noninvasive carcinomas) and 213 benign masses (87 cysts and 126 fibroadenomas). We divided our database into 65 images (28 malignant and 37 benign masses) for training set and 298 images (122 malignant and 176 benign masses) for test set. An observer study was first conducted to obtain clinicians' subjective impression for nine image features on mass. In the proposed method, location and area of the mass were determined by an experienced clinician. We defined some feature extraction methods for each of nine image features. For each image feature, we selected the feature extraction method with the highest correlation coefficient between the objective features and the average clinicians' subjective impressions. We employed multiple discriminant analysis with the nine objective features for determining histological classification of mass. The classification accuracies of the proposed method were 88.4 % (76/86) for invasive carcinomas, 80.6 % (29/36) for noninvasive carcinomas, 86.0 % (92/107) for fibroadenomas, and 84.1 % (58/69) for cysts, respectively. The proposed method would be useful in the differential diagnosis of breast masses on ultrasonographic images as diagnosis aid.
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Affiliation(s)
- Akiyoshi Hizukuri
- Graduate School of Engineering, Mie University, 1577 Kurimamachiya-cho, Tsu, 514-8507, Japan,
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Ishida M, Nakayama R, Uno M, Ito T, Goto Y, Ichikawa Y, Nagata M, Kitagawa K, Nakamori S, Dohi K, Ito M, Sakuma H. Learning-based super-resolution technique significantly improves detection of coronary artery stenoses on 1.5T whole-heart coronary MRA. J Cardiovasc Magn Reson 2014. [PMCID: PMC4045001 DOI: 10.1186/1532-429x-16-s1-p218] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Takagi W, Miyoshi T, Kajiya M, Iwamoto M, Ohkawa K, Nosaka K, Nakayama R, Takeda K, Hirohata S, Doi M. Impact of serum adipocyte fatty acid-binding protein on clinical outcome in patients with stable angina undergoing percutaneous coronary intervention. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht307.p724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Nakayama R. Risk factors in the never-smoker patients with Coronary Spastic Angina (CSA). Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht309.p3099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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45
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Nakayama R, Motoyoshi I, Sato T. Motion pop-out is determined by extra-retinal coordinate. J Vis 2013. [DOI: 10.1167/13.9.964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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46
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Hizukuri A, Nakayama R, Nakako N, Kawanaka H, Takase H, Yamamoto K, Tsuruoka S. Computerized segmentation method for individual calcifications within clustered microcalcifications while maintaining their shapes on magnification mammograms. J Digit Imaging 2012; 25:377-86. [PMID: 21989574 DOI: 10.1007/s10278-011-9420-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
In a computer-aided diagnosis (CADx) scheme for evaluating the likelihood of malignancy of clustered microcalcifications on mammograms, it is necessary to segment individual calcifications correctly. The purpose of this study was to develop a computerized segmentation method for individual calcifications with various sizes while maintaining their shapes in the CADx schemes. Our database consisted of 96 magnification mammograms with 96 clustered microcalcifications. In our proposed method, a mammogram image was decomposed into horizontal subimages, vertical subimages, and diagonal subimages for a second difference at scales 1 to 4 by using a filter bank. The enhanced subimages for nodular components (NCs) and the enhanced subimages for both nodular and linear components (NLCs) were obtained from analysis of a Hessian matrix composed of the pixel values in those subimages for the second difference at each scale. At each pixel, eight objective features were given by pixel values in the subimages for NCs at scales 1 to 4 and the subimages for NLCs at scales 1 to 4. An artificial neural network with the eight objective features was employed to enhance calcifications on magnification mammograms. Calcifications were finally segmented by applying a gray-level thresholding technique to the enhanced image for calcifications. With the proposed method, a sensitivity of calcifications within clustered microcalcifications and the number of false positives per image were 96.5% (603/625) and 1.69, respectively. The average shape accuracy for segmented calcifications was also 91.4%. The proposed method with high sensitivity of calcifications while maintaining their shapes would be useful in the CADx schemes.
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Affiliation(s)
- Akiyoshi Hizukuri
- Graduate School of Engineering, Mie University, 1577 Kurimamachiya-cho, Tsu, Japan.
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Nakayama R, Motoyoshi I, Kusano T, Sato T. Spatial motion coordinates that determine perceptual dominance in binocular rivalry. J Vis 2012. [DOI: 10.1167/12.9.1264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Abstract
The purpose of this study was to investigate four objective similarity measures as an image retrieval tool for selecting lesions similar to unknown lesions on mammograms. Measures A and B were based on the Euclidean distance in feature space and the psychophysical similarity measure, respectively. Measure C was the sequential combination of B and A, whereas measure D was the sequential combination of A and B. In this study, we selected 100 lesions each for masses and clustered microcalcifications randomly from our database, and we selected five pairs of lesions from 4,950 pairs based on all combinations of the 100 lesions by use of each measure. In two observer studies for 20 mass pairs and 20 calcification pairs, six radiologists compared all combinations of 20 pairs by using a two-alternative forced-choice method to determine the subjective similarity ranking score which was obtained from the frequency with which a pair was considered as more similar than the other 19 pairs. In both mass and calcification pairs, pairs selected by use of measure D had the highest mean value of the average subjective similarity ranking scores. The difference between measures D and A (P = 0.008 and 0.024), as well as that between measures D and B (P = 0.018 and 0.028) were statistically significant for masses and microcalcifications, respectively. The sequential combination of the objective similarity measure based on the Euclidean distance and the psychophysical similarity measure would be useful in the selection of images similar to those of unknown lesions.
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Affiliation(s)
- Ryohei Nakayama
- Kurt Rossmann Laboratories for Radiologic Image Research, Department of Radiology, The University of Chicago, 5841 South Maryland Avenue, MC 2026, Chicago, IL 60637, USA.
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Nakayama R, Abe H, Shiraishi J, Doi K. Potential usefulness of similar images in the differential diagnosis of clustered microcalcifications on mammograms. Radiology 2009; 253:625-31. [PMID: 19789245 DOI: 10.1148/radiol.2533090373] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PURPOSE To evaluate the potential usefulness of images of lesions of a known disease that have a similar appearance to lesions of an unknown disease in distinguishing between benign and malignant clustered microcalcifications on mammograms by removing the unusual cases from the database. MATERIALS AND METHODS Institutional review board approval for this retrospective HIPAA-compliant study of images from a publicly available database was obtained. Unusual lesions, such as malignant-looking benign lesions and benign-looking malignant lesions, were removed from the database. A total of 20 benign and 20 malignant lesions were selected with a stratified randomization method, and it was these lesions that served as unknown cases in this observer study. For each unknown case, eight similar images of benign lesions and eight similar images of malignant lesions were preselected with a computerized scheme. From these preselected images, a breast radiologist subjectively selected the four most similar images of benign lesions and the four most similar images of malignant lesions. Five attending breast radiologists and three breast-imaging fellows participated in the observer study. Observers provided their confidence level regarding malignancy of the unknown case before and after they viewed the similar images. The results were evaluated with multireader multicase receiver operating characteristic (ROC) analysis. RESULTS For all observers, the areas under the ROC curves (AUCs) were improved when similar images were used. The average AUC for all observers increased from 0.692 without use of similar images to 0.790 with use of similar images (P = .0009). CONCLUSION The presentation of similar images can improve radiologists' performance in the differential diagnosis of clustered microcalcifications on mammograms.
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Affiliation(s)
- Ryohei Nakayama
- Kurt Rossmann Laboratories for Radiologic Image Research, Department of Radiology, University of Chicago, 5841 S Maryland Ave, MC 2026, Chicago, IL 60637, USA.
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Nakayama R, Itoh H, Hayasaka J, Tsuchiya Y, Matsumoto K, Ohmori M, Noguchi T, Osano H, Jinbu Y, Kusama M. Three cases of the spindle cell carcinoma. Int J Oral Maxillofac Surg 2007. [DOI: 10.1016/j.ijom.2007.09.179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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