Updated on 2023/10/12

写真a

 
ITO Rintaro
 
Organization
Graduate School of Medicine Department of Innovative Biomedical Visualization (iBMV) Industry-Academia Collaborative Chair Designated assistant professor
Title
Designated assistant professor

Degree 1

  1. 博士(医学) ( 2017.3   名古屋大学 ) 

Research Interests 4

  1. コンピューター支援診断

  2. 画像診断

  3. Radiology

  4. Artificial Inteligence

Research Areas 1

  1. Life Science / Radiological sciences

Research History 4

  1. UCLA Radiological Sciences   Vissiting Assistant Professor

    2021.10 - 2022.9

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    Country:United States

  2. 名古屋大学大学院医学系研究科 革新的生体可視化技術開発産学協同研究講座   特任助教

    2019.10

  3. Nagoya University Hospital   Assistant professor of hospital

    2017.10

  4. Nagoya University   School of Medicine

    2013.4 - 2017.9

Education 2

  1. Nagoya University   Graduate School, Division of Medical Sciences

    - 2017.3

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    Country: Japan

  2. Nagoya University   Faculty of Medicine

    - 2011.3

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    Country: Japan

Professional Memberships 4

  1. 日本医学放射線学会

  2. 日本肺癌学会

  3. 日本メディカルAI学会

  4. 日本核医学会

 

Papers 43

  1. Current State of Artificial Intelligence in Clinical Applications for Head and Neck MR Imaging

    Fujima Noriyuki, Kamagata Koji, Ueda Daiju, Fujita Shohei, Fushimi Yasutaka, Yanagawa Masahiro, Ito Rintaro, Tsuboyama Takahiro, Kawamura Mariko, Nakaura Takeshi, Yamada Akira, Nozaki Taiki, Fujioka Tomoyuki, Matsui Yusuke, Hirata Kenji, Tatsugami Fuminari, Naganawa Shinji

    Magnetic Resonance in Medical Sciences   Vol. 22 ( 4 ) page: 401 - 414   2023.10

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    Language:English   Publisher:Japanese Society for Magnetic Resonance in Medicine  

    <p>Due primarily to the excellent soft tissue contrast depictions provided by MRI, the widespread application of head and neck MRI in clinical practice serves to assess various diseases. Artificial intelligence (AI)-based methodologies, particularly deep learning analyses using convolutional neural networks, have recently gained global recognition and have been extensively investigated in clinical research for their applicability across a range of categories within medical imaging, including head and neck MRI. Analytical approaches using AI have shown potential for addressing the clinical limitations associated with head and neck MRI. In this review, we focus primarily on the technical advancements in deep-learning-based methodologies and their clinical utility within the field of head and neck MRI, encompassing aspects such as image acquisition and reconstruction, lesion segmentation, disease classification and diagnosis, and prognostic prediction for patients presenting with head and neck diseases. We then discuss the limitations of current deep-learning-based approaches and offer insights regarding future challenges in this field.</p>

    DOI: 10.2463/mrms.rev.2023-0047

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  2. New trend in artificial intelligence-based assistive technology for thoracic imaging.

    Yanagawa M, Ito R, Nozaki T, Fujioka T, Yamada A, Fujita S, Kamagata K, Fushimi Y, Tsuboyama T, Matsui Y, Tatsugami F, Kawamura M, Ueda D, Fujima N, Nakaura T, Hirata K, Naganawa S

    La Radiologia medica   Vol. 128 ( 10 ) page: 1236 - 1249   2023.10

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    Language:English   Publisher:Radiologia Medica  

    Although there is no solid agreement for artificial intelligence (AI), it refers to a computer system with intelligence similar to that of humans. Deep learning appeared in 2006, and more than 10 years have passed since the third AI boom was triggered by improvements in computing power, algorithm development, and the use of big data. In recent years, the application and development of AI technology in the medical field have intensified internationally. There is no doubt that AI will be used in clinical practice to assist in diagnostic imaging in the future. In qualitative diagnosis, it is desirable to develop an explainable AI that at least represents the basis of the diagnostic process. However, it must be kept in mind that AI is a physician-assistant system, and the final decision should be made by the physician while understanding the limitations of AI. The aim of this article is to review the application of AI technology in diagnostic imaging from PubMed database while particularly focusing on diagnostic imaging in thorax such as lesion detection and qualitative diagnosis in order to help radiologists and clinicians to become more familiar with AI in thorax.

    DOI: 10.1007/s11547-023-01691-w

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  3. From FDG and beyond: the evolving potential of nuclear medicine

    Hirata Kenji, Kamagata Koji, Ueda Daiju, Yanagawa Masahiro, Kawamura Mariko, Nakaura Takeshi, Ito Rintaro, Tatsugami Fuminari, Matsui Yusuke, Yamada Akira, Fushimi Yasutaka, Nozaki Taiki, Fujita Shohei, Fujioka Tomoyuki, Tsuboyama Takahiro, Fujima Noriyuki, Naganawa Shinji

    ANNALS OF NUCLEAR MEDICINE     2023.9

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    Language:English   Publisher:Annals of Nuclear Medicine  

    The radiopharmaceutical 2-[fluorine-18]fluoro-2-deoxy-d-glucose (FDG) has been dominantly used in positron emission tomography (PET) scans for over 20 years, and due to its vast utility its applications have expanded and are continuing to expand into oncology, neurology, cardiology, and infectious/inflammatory diseases. More recently, the addition of artificial intelligence (AI) has enhanced nuclear medicine diagnosis and imaging with FDG-PET, and new radiopharmaceuticals such as prostate-specific membrane antigen (PSMA) and fibroblast activation protein inhibitor (FAPI) have emerged. Nuclear medicine therapy using agents such as [177Lu]-dotatate surpasses conventional treatments in terms of efficacy and side effects. This article reviews recently established evidence of FDG and non-FDG drugs and anticipates the future trajectory of nuclear medicine.

    DOI: 10.1007/s12149-023-01865-6

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  4. Evaluation of alterations in interstitial fluid dynamics in cases of whole-brain radiation using the diffusion-weighted image analysis along the perivascular space method

    Taoka Toshiaki, Ito Rintaro, Nakamichi Rei, Nakane Toshiki, Kawamura Mariko, Ishihara Shunichi, Ichikawa Kazushige, Kawai Hisashi, Naganawa Shinji

    NMR IN BIOMEDICINE     page: e5030   2023.9

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    Language:English   Publisher:NMR in Biomedicine  

    In the current study, we assessed changes in interstitial fluid dynamics resulting after whole-brain radiotherapy using the diffusion-weighted image analysis along the perivascular space (DWI-ALPS) method, which is a simplified variation of the diffusion tensor image ALPS (DTI-ALPS) method using diffusion-weighted imaging (DWI) with orthogonal motion-probing gradients (MPGs). This retrospective study included 47 image sets from 22 patients who underwent whole-brain radiotherapy for brain tumors. The data for the normal control group comprised 105 image sets from 105 participants with no pathological changes. DWI was performed with the three MPGs applied in an orthogonal direction to the imaging plane, and apparent diffusion coefficient images for the x-, y-, and z-axes were retrospectively generated. The ALPS index was calculated to quantify interstitial fluid dynamics. The independent t-test was used to compare the ALPS index between normal controls and patients who underwent whole-brain radiotherapy. Patients were compared in all age groups and individual age groups (20–39, 40–59, and 60–84 years). We also examined the correlation between biologically equivalent doses (BEDs) and the ALPS index, as well as the correlation between white matter hyperintensity and the ALPS index. In the comparison of all age groups, the ALPS index was significantly lower (p < 0.001) in the postradiation group (1.32 ± 0.16) than in the control group (1.44 ± 0.17), suggesting that interstitial fluid dynamics were altered in patients following whole-brain radiotherapy. Significant age group differences were found (40–59 years: p < 0.01; 60–84 years: p < 0.001), along with a weak negative correlation between BEDs (r = −0.19) and significant correlations between white matter hyperintensity and the ALPS index (r = −0.46 for periventricular white matter, r = −0.38 for deep white matter). It was concluded that the ALPS method using DWI with orthogonal MPGs suggest alteration in interstitial fluid dynamics in patients after whole-brain radiotherapy. Further systematic prospective studies are required to investigate their association with cognitive symptoms.

    DOI: 10.1002/nbm.5030

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  5. Fairness of artificial intelligence in healthcare: review and recommendations.

    Ueda D, Kakinuma T, Fujita S, Kamagata K, Fushimi Y, Ito R, Matsui Y, Nozaki T, Nakaura T, Fujima N, Tatsugami F, Yanagawa M, Hirata K, Yamada A, Tsuboyama T, Kawamura M, Fujioka T, Naganawa S

    Japanese journal of radiology     2023.8

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    Language:English   Publisher:Japanese Journal of Radiology  

    In this review, we address the issue of fairness in the clinical integration of artificial intelligence (AI) in the medical field. As the clinical adoption of deep learning algorithms, a subfield of AI, progresses, concerns have arisen regarding the impact of AI biases and discrimination on patient health. This review aims to provide a comprehensive overview of concerns associated with AI fairness; discuss strategies to mitigate AI biases; and emphasize the need for cooperation among physicians, AI researchers, AI developers, policymakers, and patients to ensure equitable AI integration. First, we define and introduce the concept of fairness in AI applications in healthcare and radiology, emphasizing the benefits and challenges of incorporating AI into clinical practice. Next, we delve into concerns regarding fairness in healthcare, addressing the various causes of biases in AI and potential concerns such as misdiagnosis, unequal access to treatment, and ethical considerations. We then outline strategies for addressing fairness, such as the importance of diverse and representative data and algorithm audits. Additionally, we discuss ethical and legal considerations such as data privacy, responsibility, accountability, transparency, and explainability in AI. Finally, we present the Fairness of Artificial Intelligence Recommendations in healthcare (FAIR) statement to offer best practices. Through these efforts, we aim to provide a foundation for discussing the responsible and equitable implementation and deployment of AI in healthcare.

    DOI: 10.1007/s11604-023-01474-3

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  6. Recent advances in artificial intelligence for cardiac CT: Enhancing diagnosis and prognosis prediction.

    Tatsugami F, Nakaura T, Yanagawa M, Fujita S, Kamagata K, Ito R, Kawamura M, Fushimi Y, Ueda D, Matsui Y, Yamada A, Fujima N, Fujioka T, Nozaki T, Tsuboyama T, Hirata K, Naganawa S

    Diagnostic and interventional imaging     2023.7

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    Language:English   Publisher:Diagnostic and Interventional Imaging  

    Recent advances in artificial intelligence (AI) for cardiac computed tomography (CT) have shown great potential in enhancing diagnosis and prognosis prediction in patients with cardiovascular disease. Deep learning, a type of machine learning, has revolutionized radiology by enabling automatic feature extraction and learning from large datasets, particularly in image-based applications. Thus, AI-driven techniques have enabled a faster analysis of cardiac CT examinations than when they are analyzed by humans, while maintaining reproducibility. However, further research and validation are required to fully assess the diagnostic performance, radiation dose-reduction capabilities, and clinical correctness of these AI-driven techniques in cardiac CT. This review article presents recent advances of AI in the field of cardiac CT, including deep-learning-based image reconstruction, coronary artery motion correction, automatic calcium scoring, automatic epicardial fat measurement, coronary artery stenosis diagnosis, fractional flow reserve prediction, and prognosis prediction, analyzes current limitations of these techniques and discusses future challenges.

    DOI: 10.1016/j.diii.2023.06.011

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  7. Clinical applications of artificial intelligence in liver imaging

    Yamada Akira, Kamagata Koji, Hirata Kenji, Ito Rintaro, Nakaura Takeshi, Ueda Daiju, Fujita Shohei, Fushimi Yasutaka, Fujima Noriyuki, Matsui Yusuke, Tatsugami Fuminari, Nozaki Taiki, Fujioka Tomoyuki, Yanagawa Masahiro, Tsuboyama Takahiro, Kawamura Mariko, Naganawa Shinji

    RADIOLOGIA MEDICA   Vol. 128 ( 6 ) page: 655 - 667   2023.6

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    Language:English   Publisher:Radiologia Medica  

    This review outlines the current status and challenges of the clinical applications of artificial intelligence in liver imaging using computed tomography or magnetic resonance imaging based on a topic analysis of PubMed search results using latent Dirichlet allocation. LDA revealed that “segmentation,” “hepatocellular carcinoma and radiomics,” “metastasis,” "fibrosis," and "reconstruction" were current main topic keywords. Automatic liver segmentation technology using deep learning is beginning to assume new clinical significance as part of whole-body composition analysis. It has also been applied to the screening of large populations and the acquisition of training data for machine learning models and has resulted in the development of imaging biomarkers that have a significant impact on important clinical issues, such as the estimation of liver fibrosis, recurrence, and prognosis of malignant tumors. Deep learning reconstruction is expanding as a new technological clinical application of artificial intelligence and has shown results in reducing contrast and radiation doses. However, there is much missing evidence, such as external validation of machine learning models and the evaluation of the diagnostic performance of specific diseases using deep learning reconstruction, suggesting that the clinical application of these technologies is still in development.

    DOI: 10.1007/s11547-023-01638-1

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  8. The Glymphatic System in Humans: Investigations With Magnetic Resonance Imaging. International journal

    Shinji Naganawa, Toshiaki Taoka, Rintaro Ito, Mariko Kawamura

    Investigative radiology     2023.3

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    Language:English   Publishing type:Research paper (scientific journal)  

    The concept of the glymphatic system was proposed more than a decade ago as a mechanism for interstitial fluid flow and waste removal in the central nervous system. The function of the glymphatic system has been shown to be particularly activated during sleep. Dysfunction of the glymphatic system has been implicated in several neurodegenerative diseases. Noninvasive in vivo imaging of the glymphatic system is expected to be useful in elucidating the pathophysiology of these diseases. Currently, magnetic resonance imaging is the most commonly used technique to evaluate the glymphatic system in humans, and a large number of studies have been reported. This review provides a comprehensive overview of investigations of the human glymphatic system function using magnetic resonance imaging. The studies can be divided into 3 categories, including imaging without gadolinium-based contrast agents (GBCAs), imaging with intrathecal administration of GBCAs, and imaging with intravenous administration of GBCAs. The purpose of these studies has been to examine not only the interstitial fluid movement in the brain parenchyma, but also the fluid dynamics in the perivascular and subarachnoid spaces, as well as the parasagittal dura and meningeal lymphatics. Recent research has even extended to include the glymphatic system of the eye and the inner ear. This review serves as an important update and a useful guide for future research directions.

    DOI: 10.1097/RLI.0000000000000969

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  9. Association between the Putative Meningeal Lymphatics at the Posterior Wall of the Sigmoid Sinus and Delayed Contrast-agent Elimination from the Cerebrospinal Fluid.

    Shinji Naganawa, Rintaro Ito, Mariko Kawamura, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine   Vol. advpub ( 0 )   2023.1

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Japanese Society for Magnetic Resonance in Medicine  

    PURPOSE: To investigate the characteristics of the putative meningeal lymphatics located at the posterior wall of the sigmoid sinus (PML-PSS) in human subjects imaged before and after intravenous administration (IV) of a gadolinium-based contrast agent (GBCA). The appearance of the PML-PSS and the enhancement of the perivascular space of the basal ganglia (PVS-BG) were analyzed for an association with gender, age, and clearance of the GBCA from the cerebrospinal fluid (CSF). METHODS: Forty-two patients with suspected endolymphatic hydrops were included. Heavily T2-weighted 3D-fluid attenuated inversion recovery (hT2w-3D-FLAIR) and 3D-real inversion recovery (IR) images were obtained at pre-administration, immediately post-administration, and at 4 and 24 hours after IV-GBCA. The appearance of the PML-PSS and the presence of enhancement in the PVS-BG were analyzed for a relationship with age, gender, contrast enhancement of the CSF at 4 hours after IV-GBCA, and the washout ratio of the GBCA in the CSF from 4 to 24 hours after IV-GBCA. RESULTS: The PML-PSS and PVS-BG were seen in 23 of 42 and 21 of 42 cases, respectively, at 4 hours after IV-GBCA. In all PML-PSS positive cases, hT2w-3D-FLAIR signal enhancement was highest at 4 hours after IV-GBCA. A multivariate analysis between gender, age, CSF signal elevation at 4 hours, and washout ratio indicated that only the washout ratio was independently associated with the enhancement of the PML-PSS or PVS-BG. The odds ratios (95% CIs; P value) were 4.09 × 10-5 (2.39 × 10-8 - 0.07; 0.0078) for the PML-PSS and 1.7 × 10-4 (1.66 × 10-7 - 0.174; 0.014) for the PVS-BG. CONCLUSION: The PML-PSS had the highest signal enhancement at 4 hours after IV-GBCA. When the PML-PSS was seen, there was also often enhancement of the PVS-BG at 4 hours after IV-GBCA. Both observed enhancements were associated with delayed GBCA excretion from the CSF.

    DOI: 10.2463/mrms.mp.2022-0110

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  10. Peripheral Retinal Leakage after Intravenous Administration of a Gadolinium-based Contrast Agent: Age Dependence, Temporal and Inferior Predominance and Potential Implications for Eye Homeostasis.

    Shinji Naganawa, Rintaro Ito, Mariko Kawamura, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine   Vol. 22 ( 1 ) page: 45 - 55   2023

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Japanese Society for Magnetic Resonance in Medicine  

    PURPOSE: Peripheral retinal leakage (PRL) of contrast medium from the ora serrata (i.e., the peripheral part of the retina) was recently reported in normal eyes using ultra-widefield fluorescein angiography. We occasionally see PRL of gadolinium-based contrast agents (GBCAs) in the vitreous from the temporal and inferior sides of the ora serrata on MR images of subjects without ophthalmic disease. In this study, we retrospectively evaluated these MR images to determine if PRL was associated with aging. We also evaluated whether the initial leakage appeared in the temporal and inferior sides, and whether there was uniform distribution within the vitreous after 24 hours. METHODS: In 127 subjects (9 volunteers, 85 patients with sudden deafness, and 33 patients with a suspicion of endolymphatic hydrops), pre- and post-contrast-enhanced heavily T2-weighted 3D-fluid attenuated inversion recovery (FLAIR) images were obtained. The presence or absence of PRL was subjectively evaluated. For patients with a suspicion of endolymphatic hydrops, 3D-real inversion recovery (IR) images were also obtained at pre-, 10 mins, 4 hours, and 24 hours after intravenous administration (IV) of GBCA. Four circular ROIs were placed in the vitreous humor and the signal intensity was measured. RESULTS: In the cases with PRL (n = 88) and without PRL (n = 47), the median age was 59 and 47 years, respectively (P = 0.001). At 4 hours after IV-GBCA, the mean signal increase in the inferior temporal ROI was greater than all the other ROIs. At 24 hours after IV-GBCA, no significant difference in signal intensity was observed for the four ROIs. CONCLUSION: PRL of GBCA is age-dependent and occurs mainly from the inferior temporal side of the ora serrata. The contrast effect was uniformly distributed at 24 hours after IV-GBCA. Future observations in a variety of diseases will determine the clinical significance of these findings.

    DOI: 10.2463/mrms.mp.2021-0100

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  11. Parasagittal Cystic Lesions May Arise from the Pial Sheath around the Cortical Venous Wall.

    Shinji Naganawa, Rintaro Ito, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine   Vol. 22 ( 1 ) page: 143 - 146   2023

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Japanese Society for Magnetic Resonance in Medicine  

    It has been reported that perivenous cystic structures near the parasagittal dura are associated with the leakage of gadolinium-based contrast agents at 4 hours after intravenous administration. The origin of such cystic structures remains unknown. While reading many cases of MR cisternography, we noticed that some of the cystic structures appeared to connect to the perivenous subpial space. This new imaging finding might facilitate future research of the waste clearance system for the central nervous system.

    DOI: 10.2463/mrms.bc.2021-0141

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  12. Interstitial Fluidopathy of the Central Nervous System: An Umbrella Term for Disorders with Impaired Neurofluid Dynamics.

    Toshiaki Taoka, Rintaro Ito, Rei Nakamichi, Toshiki Nakane, Hisashi Kawai, Shinji Naganawa

    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine   Vol. advpub ( 0 )   2022.11

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Japanese Society for Magnetic Resonance in Medicine  

    Interest in interstitial fluid dynamics has increased since the proposal of the glymphatic system hypothesis. Abnormal dynamics of the interstitial fluid have been pointed out to be an important factor in various pathological statuses. In this article, we propose the concept of central nervous system interstitial fluidopathy as a disease or condition in which abnormal interstitial fluid dynamics is one of the important factors for the development of a pathological condition. We discuss the aspects of interstitial fluidopathy in various diseases, including Alzheimer's disease, Parkinson's disease, normal pressure hydrocephalus, and cerebral small vessel disease. We also discuss a method called "diffusion tensor image analysis along the perivascular space" using MR diffusion images, which is used to evaluate the degree of interstitial fluidopathy or the activity of the glymphatic system.

    DOI: 10.2463/mrms.rev.2022-0012

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  13. Diffusion-weighted image analysis along the perivascular space (DWI-ALPS) for evaluating interstitial fluid status: age dependence in normal subjects.

    Toshiaki Taoka, Rintaro Ito, Rei Nakamichi, Toshiki Nakane, Mayuko Sakai, Kazushige Ichikawa, Hisashi Kawai, Shinji Naganawa

    Japanese journal of radiology   Vol. 40 ( 9 ) page: 894 - 902   2022.9

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    PURPOSE: The purpose of this study was to evaluate the interstitial fluid status in a wide range of age groups using diffusion-weighted image analysis along the perivascular space (DWI-ALPS) method, which is a simplified variation of diffusion tensor image analysis along the perivascular space (DTI-ALPS). MATERIALS AND METHODS: This retrospective study included data from 128 patients who underwent clinical magnetic resonance imaging (MRI) studies, including DWI, and were found to have no abnormal findings in the brain on MRI. Three motion-probing gradients of the DWI were applied in an orthogonal direction to the imaging plane. Apparent diffusion coefficient images in the x-, y-, and z-axes were retrospectively generated, and composite color images were created to locate the projection and association fiber area on the slice including the body of the lateral ventricle. ALPS indices were calculated, and correlations with age were evaluated using linear and second-degree regression analysis. Linear regression analysis was also performed for a subgroup of patients older than 40 years. In addition, an analysis of variance (ANOVA) test among the generations was performed. RESULTS: The linear regression analysis between age and the ALPS index showed a correlation coefficient of -0.20 for all age group and -0.51 for the subgroup older than 40 years. The second-degree regression analysis showed a correlation coefficient of 0.39. ANOVA showed that the 40's generation showed a statistically significant higher value of ALPS index compared to all other generations except for the 30's generation. While, the 70's generation showed a statistically significant lower value of the ALPS index compared to all other generations. CONCLUSIONS: The analysis of the DWI-APLS method showed a correlation between age and the ALPS index in second-degree distribution which peaked in the 40's generation. This finding in normal subjects may be fundamental in the analysis of disease cases. We tried to evaluate the glymphatic system status in a wide range of age groups using diffusion-weighted image analysis along the perivascular space (DWI-ALPS) method, and the results showed a correlation between age and the ALPS index in second-degree distribution which peaked in the 40's generation.

    DOI: 10.1007/s11604-022-01275-0

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  14. Letter to editor on the article "A non-invasive, automated diagnosis of Menière's disease using radiomics and machine learning on conventional magnetic resonance imaging: a multicentric, case-controlled feasibility study" by van der Lubbe Mfja et al. International journal

    Shinji Naganawa, Rintaro Ito, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

    La Radiologia medica   Vol. 127 ( 4 ) page: 458 - 459   2022.4

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  15. Reproducibility of diffusion tensor image analysis along the perivascular space (DTI-ALPS) for evaluating interstitial fluid diffusivity and glymphatic function: CHanges in Alps index on Multiple conditiON acquIsition eXperiment (CHAMONIX) study.

    Toshiaki Taoka, Rintaro Ito, Rei Nakamichi, Koji Kamagata, Mayuko Sakai, Hisashi Kawai, Toshiki Nakane, Takashi Abe, Kazushige Ichikawa, Junko Kikuta, Shigeki Aoki, Shinji Naganawa

    Japanese journal of radiology   Vol. 40 ( 2 ) page: 147 - 158   2022.2

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    PURPOSE: The diffusion tensor image analysis along the perivascular space (DTI-ALPS) method was developed to evaluate the brain's glymphatic function or interstitial fluid dynamics. This study aimed to evaluate the reproducibility of the DTI-ALPS method and the effect of modifications in the imaging method and data evaluation. MATERIALS AND METHODS: Seven healthy volunteers were enrolled in this study. Image acquisition was performed for this test-retest study using a fixed imaging sequence and modified imaging methods which included the placement of region of interest (ROI), imaging plane, head position, averaging, number of motion-proving gradients, echo time (TE), and a different scanner. The ALPS-index values were evaluated for the change of conditions listed above. RESULTS: This test-retest study by a fixed imaging sequence showed very high reproducibility (intraclass coefficient = 0.828) for the ALPS-index value. The bilateral ROI placement showed higher reproducibility. The number of averaging and the difference of the scanner did not influence the ALPS-index values. However, modification of the imaging plane and head position impaired reproducibility, and the number of motion-proving gradients affected the ALPS-index value. The ALPS-index values from 12-axis DTI and 3-axis diffusion-weighted image (DWI) showed good correlation (r = 0.86). Also, a shorter TE resulted in a larger value of the ALPS-index. CONCLUSION: ALPS index was robust under the fixed imaging method even when different scanners were used. ALPS index was influenced by the imaging plane, the number of motion-proving gradient axes, and TE in the imaging sequence. These factors should be uniformed in the planning ALPS method studies. The possibility to develop a 3-axis DWI-ALPS method using three axes of the motion-proving gradient was also suggested.

    DOI: 10.1007/s11604-021-01187-5

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  16. Features from MRI texture analysis associated with survival outcomes in triple-negative breast cancer patients.

    Saki Kamiya, Hiroko Satake, Yoko Hayashi, Satoko Ishigaki, Rintaro Ito, Mariko Kawamura, Toshiaki Taoka, Shingo Iwano, Shinji Naganawa

    Breast cancer (Tokyo, Japan)   Vol. 29 ( 1 ) page: 164 - 173   2022.1

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    PURPOSE: The purpose of the study is to evaluate the associations between intratumoral or peritumoral textural features derived from pretreatment magnetic resonance imaging (MRI) and recurrence-free survival (RFS) in triple-negative breast cancer (TNBC) patients. METHODS: Forty-three patients with TNBC who underwent preoperative MRI between February 2008 and March 2014 were included. We performed two-dimensional texture analysis on the intratumoral or peritumoral region of interest (ROI) on axial of T2-weighted image (T2WI), dynamic contrast-enhanced (DCE)-MRI and DCE-MRI subtraction images. We also analyzed histopathological data. Cox proportional hazards models were used to investigate associations with survival outcomes. RESULTS: Twelve of the 43 patients (27.9%) had recurrence disease, at a median of 32.5 months follow-up (1.4-61.5 months). In univariate analysis, nine texture features in T2WI and DCE-MRI subtraction images were significantly associated with RFS. In multivariate analysis, intratumoral difference entropy in DCE-MRI subtraction images in the initial phase (hazard ratio 11.71; 95% confidence interval (CI) [1.41, 97.00]; p value 0.023) and, peritumoral difference variance in DCE-MRI subtraction images in the delayed phase (hazard ratio 9.60; 95% CI [1.98, 46.51]; p value 0.005), were both independently associated with RFS. Moreover, multivariate analysis revealed the presence of lymphovascular invasion as independently associated with RFS (hazard ratio 8.13; 95% CI [2.16, 30.30]; p value 0.002). CONCLUSIONS: At pretreatment MRI, an intratumoral and peritumoral quantitative approach using texture analysis has the potential to serve as a prognostic marker in patients with TNBC.

    DOI: 10.1007/s12282-021-01294-1

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  17. Radiomics in breast MRI: current progress toward clinical application in the era of artificial intelligence

    Satake Hiroko, Ishigaki Satoko, Ito Rintaro, Naganawa Shinji

    RADIOLOGIA MEDICA   Vol. 127 ( 1 ) page: 39 - 56   2022.1

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    Breast magnetic resonance imaging (MRI) is the most sensitive imaging modality for breast cancer diagnosis and is widely used clinically. Dynamic contrast-enhanced MRI is the basis for breast MRI, but ultrafast images, T2-weighted images, and diffusion-weighted images are also taken to improve the characteristics of the lesion. Such multiparametric MRI with numerous morphological and functional data poses new challenges to radiologists, and thus, new tools for reliable, reproducible, and high-volume quantitative assessments are warranted. In this context, radiomics, which is an emerging field of research involving the conversion of digital medical images into mineable data for clinical decision-making and outcome prediction, has been gaining ground in oncology. Recent development in artificial intelligence has promoted radiomics studies in various fields including breast cancer treatment and numerous studies have been conducted. However, radiomics has shown a translational gap in clinical practice, and many issues remain to be solved. In this review, we will outline the steps of radiomics workflow and investigate clinical application of radiomics focusing on breast MRI based on published literature, as well as current discussion about limitations and challenges in radiomics.

    DOI: 10.1007/s11547-021-01423-y

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  18. Cross-sectional Area of the Superior Petrosal Sinus is Reduced in Patients with Significant Endolymphatic Hydrops.

    Shinji Naganawa, Rintaro Ito, Hisashi Kawai, Mariko Kawamura, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine   Vol. 21 ( 3 ) page: 459 - 467   2022

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    PURPOSE: To evaluate the relationship between the size of the venous structures related to the inner ear and the degree of endolymphatic hydrops (EH). METHODS: Thirty-four patients with a suspicion of EH underwent whole brain MR imaging including the inner ear. Images were obtained pre- and post-administration, and at 4 and 24 hours after the intravenous administration of a gadolinium-based contrast agent (IV-GBCA). The cross-sectional areas (CSA) of the internal jugular vein (IJV), superior petrosal sinus (SPS), and inferior petrosal sinus (IPS) were measured on the magnetization prepared rapid acquisition of gradient echo (MPRAGE) images obtained immediately after the IV-GBCA. The grade of EH was determined on the hybrid of reversed image of positive endolymph signal and native image of positive perilymph signal (HYDROPS) images obtained at 4 hours after IV-GBCA as no, mild, and significant EH according to the previously proposed grading system for the cochlea and vestibule, respectively. The ipsilateral CSA was compared between groups with each level of EH grade. P < 0.05 was considered statistically significant. RESULTS: There were no statistically significant differences between EH grades for the CSA of the IJV or that of the IPS in either the cochlea or the vestibule. The CSA of the SPS in the groups with significant EH was significantly smaller than that in the group with no EH, for both the cochlea (P < 0.01) and the vestibule (P < 0.05). In an ROC analysis to predict significant EH, the cut-off CSA value in the SPS was 3.905 mm2 for the cochlea (AUC: 0.8762, 95% confidence interval [CI]: 0.7952‒0.9572) and 3.805 mm2 for the vestibule (AUC: 0.7727, 95% CI: 0.6539‒0.8916). CONCLUSION: In the ears with significant EH in the cochlea or vestibule, the CSA of the ipsilateral SPS was smaller than in the ears without EH.

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  19. MR Imaging of Endolymphatic Hydrops in Five Minutes.

    Shinji Naganawa, Rintaro Ito, Hisashi Kawai, Mariko Kawamura, Toshiaki Taoka, Mayuko Sakai, Kazushige Ichikawa, Tadao Yoshida, Michihiko Sone

    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine   Vol. 21 ( 3 ) page: 401 - 405   2022

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    In this study, we present images acquired by a fast-imaging method for the evaluation of endolymphatic hydrops after intravenous administration of a single dose of gadolinium-based contrast agent. We utilized the hybrid of reversed image of MR cisternography and a positive perilymph signal by heavily T2- weighted 3D-fluid attenuated inversion recovery-multiplied by T2 (HYDROPS2-Mi2) method combined with deep learning reconstruction denoising. The scan time for the fast protocol was approximately 5 mins, which is far shorter than previously reported scan times. The fast acquisition provides similar image quality and less motion artifacts compared to the longer method.

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  20. COVID-19 肺炎におけるAI研究の動向および問題点について

    Medical Imaging and Information Sciences   Vol. 38 ( 2 ) page: 32 - 40   2021.7

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    <p>There have been many studies on the use of AI for the diagnosis of COVID-19 pneumonia. Although these AIs have high performance, there are several points that need to be considered when using them in clinical practice. In this paper, we comprehensively reviewed the AI studies for COVID-19 pneumonia that were registered in PubMed until December 2020. The performance and problems of these AIs were presented.</p>

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  21. Age estimates from brain magnetic resonance images of children younger than two years of age using deep learning. International journal

    Masahiro Kawaguchi, Hiroyuki Kidokoro, Rintaro Ito, Anna Shiraki, Takeshi Suzuki, Yuki Maki, Masaharu Tanaka, Yoko Sakaguchi, Hiroyuki Yamamoto, Yosiyuki Takahashi, Shinji Naganawa, Jun Natsume

    Magnetic resonance imaging   Vol. 79   page: 38 - 44   2021.6

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    The accuracy of brain age estimates from magnetic resonance (MR) images has improved with the advent of deep learning artificial intelligence (AI) models. However, most previous studies on predicting age emphasized aging from childhood to adulthood and old age, and few studies have focused on early brain development in children younger than 2 years of age. Here, we performed brain age estimates based on MR images in children younger than 2 years of age using deep learning. Our AI model, developed with one slice each of raw T1- and T2-weighted images from each subject, estimated brain age with a mean absolute error of 8.2 weeks (1.9 months). The estimates of our AI model were close to those of human specialists. The AI model also estimated the brain age of subjects with a myelination delay as significantly younger than the chronological age. These results indicate that the prediction accuracy of our AI model approached that of human specialists and that our simple method requiring less data and preprocessing facilitates a radiological assessment of brain development, such as monitoring maturational changes in myelination.

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  22. Diffusion analysis of fluid dynamics with incremental strength of motion proving gradient (DANDYISM) to evaluate cerebrospinal fluid dynamics

    Toshiaki Taoka, Hisashi Kawai, Toshiki Nakane, Takashi Abe, Rei Nakamichi, Rintaro Ito, Yuki Sato, Mayuko Sakai, Shinji Naganawa

    Japanese Journal of Radiology   Vol. 39 ( 4 ) page: 315 - 323   2021.4

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    <title>Abstract</title><sec>
    <title>Purpose</title>
    To visualize and analyze the dynamics of cerebrospinal fluid (CSF) motion in the cranium, we evaluated the distribution of motion-related signal dephasing by CSF on Diffusion ANalysis of fluid DYnamics with Incremental Strength of Motion proving gradient (DANDYISM) method, a composite imaging method using various low <italic>b</italic> values.



    </sec><sec>
    <title>Materials and methods</title>
    This study examined ten subjects aged 25–58. We acquired DWIs on a 3T clinical scanner with <italic>b</italic> values 0, 50, 100, 200, 300, 500, 700, and 1000 s/mm<sup>2</sup> in total imaging time of 4 min. We constructed DANDYISM images and evaluated the CSF area distribution with decreased motion-dephasing signal using a scoring method.


    </sec><sec>
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    The DANDYISM images showed statistically significant higher CSF scores in the ventral posterior fossa, suprasellar cistern, and Sylvian vallecula compared to the lateral ventricle and frontal and parietal CSF spaces, indicating greater CSF movement in the former areas.


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    The results indicated prominent CSF motions in the ventral portion of the posterior fossa, suprasellar cistern, and Sylvian fissure but smaller motions in the lateral ventricles and parietal subarachnoid space. This method may provide information of CSF dynamics in the clinical settings within short imaging time.


    </sec>

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  23. Iodine-related attenuation in contrast-enhanced dual-energy computed tomography in small-sized solid-type lung cancers is associated with the postoperative prognosis. International journal

    Shingo Iwano, Shinichiro Kamiya, Rintaro Ito, Shota Nakamura, Shinji Naganawa

    Cancer imaging : the official publication of the International Cancer Imaging Society   Vol. 21 ( 1 ) page: 7 - 7   2021.1

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    BACKGROUND: To investigate the correlation between iodine-related attenuation in contrast-enhanced dual-energy computed tomography (DE-CT) and the postoperative prognosis of surgically resected solid-type small-sized lung cancers. METHODS: We retrospectively reviewed the DE-CT findings and postoperative course of solid-type lung cancers ≤3 cm in diameter. After injection of iodinated contrast media, arterial phases were scanned using 140-kVp and 80-kVp tube voltages. Three-dimensional iodine-related attenuation (3D-IRA) of primary tumors at the arterial phase was computed using the "lung nodule" application software. The corrected 3D-IRA normalized to the patient's body weight and contrast medium concentration was then calculated. RESULTS: A total of 120 resected solid-type lung cancers ≤3 cm in diameter were selected for analysis (82 males and 38 females; mean age, 67 years). During the observation period (median, 47 months), 32 patients showed postoperative recurrence. Recurrent tumors had significantly lower 3D-IRA and corrected 3D-IRA at early phase compared to non-recurrent tumors (p = 0.046 and p = 0.027, respectively). The area under the receiver operating characteristic curve for postoperative recurrence was 0.624 for the corrected 3D-IRA at early phase (p = 0.025), and the cutoff value was 5.88. Kaplan-Meier curves for disease-free survival indicated that patients showing tumors with 3D-IRA > 5.88 had a significantly better prognosis than those with tumors showing 3D-IRA < 5.88 (p = 0.017). CONCLUSIONS: The 3D-IRA of small-sized solid-type lung cancers on contrast-enhanced DE-CT was significantly associated with postoperative prognosis, and low 3D-IRA tumors showed a higher TNM stage and a significantly poorer prognosis.

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  24. Evaluating the Effect of Arterial Pulsation on Cerebrospinal Fluid Motion in the Sylvian Fissure of Patients with Middle Cerebral Artery Occlusion Using Low b-value Diffusion-weighted Imaging

    Toshiaki Taoka, Hisashi Kawai, Toshiki Nakane, Takashi Abe, Rei Nakamichi, Rintaro Ito, Yutaro Sasaki, Ayumi Nishida, Shinji Naganawa

    Magnetic Resonance in Medical Sciences   Vol. 20 ( 4 ) page: 371 - 377   2021

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    <p>Purpose: Decrease in signal of the cerebrospinal fluid (CSF) on low b-value diffusion weighted image (DWI) due to non-uniform flow can provide additional information regarding CSF motion. The purpose of the current study was to evaluate whether arterial pulsations constitute the driving force of CSF motion.</p><p>Methods: We evaluated the CSF signals within the Sylvian fissure on low b-value DWI in 19 patients with unilateral middle cerebral artery (MCA) occlusion. DWI with b-value of 500 s/mm<sup>2</sup> was evaluated for a decrease in CSF signal within the Sylvian fissure including the Sylvian vallecula and lower, middle, and higher Sylvian fissures and graded as follows: the same as contralateral side; smaller signal decrease than that on contralateral side; and no signal decrease. MR angiography (MRA) findings of MCA were graded as follows: the same as contralateral, lower signal than contralateral signal, and no signal. In 15 patients, regional cerebral blood flow (rCBF) was evaluated using single-photon emission computed tomography (SPECT) studies and graded as >90%, 90%–70%, and <70% rCBF compared to contralateral. The correlations between the gradings were evaluated using G likelihood-ratio test.</p><p>Results: There was no statistically significant correlation between the MRA and low b-value DWI gradings of CSF in all areas. There were statistically significant correlations between the decreases in CBF on SPECT and CSF signals in the middle Sylvian fissure.</p><p>Conclusion: The driving force of CSF pulsation in the Sylvian sinus may be related to the pulsations of the cerebral hemisphere rather than direct arterial pulsations.</p>

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  25. Relationship between Time-dependent Signal Changes in Parasagittal Perivenous Cysts and Leakage of Gadolinium-based Contrast Agents into the Subarachnoid Space.

    Shinji Naganawa, Rintaro Ito, Rei Nakamichi, Mariko Kawamura, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine   Vol. 20 ( 4 ) page: 378 - 384   2021

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    PURPOSE: To investigate the association between signal changes over time in perivenous cystic structures near the superior sagittal sinus and leakage of a gadolinium-based contrast agent (GBCA) into the subarachnoid space in patients with suspected endolymphatic hydrops. METHODS: Fifty-one cystic structures in 27 cases were evaluated. The signal intensity of the cystic structures was measured on 3D real inversion recovery (3D-real IR) images obtained at pre-, and at 10 min, 4 hrs and 24 hrs post-intravenous administration (IV) of GBCA. Signal enhancement of the cystic structures from the pre-contrast images at each time point was compared in subjects with leakage (positive) versus those without leakage (negative) using an ANOVA. Fisher's exact probability test was used to compare the maximum contrast-enhanced time point between positive and negative groups. We used 5% as a threshold to determine statistical significance. RESULTS: In leakage positive subjects, mean signal enhancement of the cysts was significantly greater at 4 and 24 hrs compared to 10 min. However, although there was a trend of an increase from 4 to 24 hrs, the difference was not significant. In the leakage negative group, mean signal enhancement of the cysts was significantly higher at 4 hrs compared to 10 min and 24 hrs. There was no significant difference between 10 min and 24 hrs. In the positive group, the maximum signal increase was found in 10/38 and 28/38 cysts at 4 and 24 hrs after IV-GBCA, respectively. In the leakage negative group, the maximum signal increase was found in 10/13 and 3/13 cysts at 4 and 24 hrs, respectively (P = 0.0019). CONCLUSION: There was an association between signal changes over time after IV-GBCA in perivenous cystic structures and leakage of GBCA. Further research to clarify the impact of cystic structures on the function of the waste clearance system of the brain is warranted.

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  26. Relationship between Parasagittal Perivenous Cysts and Leakage of Gadolinium-based Contrast Agents into the Subarachnoid Space around the Cortical Veins after Intravenous Administration. Reviewed

    Shinji Naganawa, Rintaro Ito, Rei Nakamichi, Mariko Kawamura, Hisashi Kawai, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine   Vol. 20 ( 3 ) page: 245 - 252   2021

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    PURPOSE: The purpose of this retrospective study was to investigate the relationship between the number and size of cystic structures around the cortical veins near the superior sagittal sinus and the leakage of gadolinium-based contrast agent (GBCA) around the cortical veins. METHODS: Of 190 patients (91 male and 99 female), that were scanned at 4 h after an intravenous injection of GBCA as a diagnostic examination for endolymphatic hydrops, 6 patients with GBCA leakage were younger than the previously proposed threshold age of 37.3 years for leakage. Six age-matched patients without leakage were also included for reference. In addition, we included 8 cases without leakage that were older than the hypothesized threshold of 37.3 years, as well as 8 age-matched patients with GBCA leakage into the cerebrospinal fluid space. The number of cysts was counted and the sizes were measured in these 28 patients (age: 32-60 years old, 13 men and 15 women). RESULTS: The mean number of cysts surrounding the cortical veins in the parasagittal region was 4.29 ± 1.77 vs. 1.79 ± 1.05 (P = 0.0001) in the subjects with and without GBCA leakage, respectively. The mean size of the largest cysts was at 8.89 ± 3.49 mm vs. 5.69 ± 2.29 (P = 0.009) in the subjects with and without GBCA leakage, respectively. CONCLUSION: The number and size of the perivenous cystic structures near the superior sagittal sinus is greater in subjects with GBCA leakage into the subarachnoid space compared with those without leakage. Future research regarding the histological and functional details of these parasagittal cystic structures is needed.

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  27. Intracranial Distribution of Intravenously Administered Gadolinium-based Contrast Agent over a Period of 24 Hours: Evaluation with 3D-real IR Imaging and MR Fingerprinting. Reviewed

    Shinji Naganawa, Rintaro Ito, Yutaka Kato, Hisashi Kawai, Toshiaki Taoka, Tadao Yoshida, Katsuya Maruyama, Katsutoshi Murata, Gregor Körzdörfer, Josef Pfeuffer, Mathias Nittka, Michihiko Sone

    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine   Vol. 20 ( 1 ) page: 91 - 98   2021

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    PURPOSE: To evaluate the feasibility for the detection of slight contrast effects after intravenous administration of single dose gadolinium-based contrast agent (IV-SD-GBCA), the time course of the GBCA distribution up to 24 h was examined in various fluid spaces and brain parenchyma using 3D-real IR imaging and MR fingerprinting (MRF). METHODS: Twenty-four patients with a suspicion of endolymphatic hydrops were scanned at pre-administration and at 10 min, 4 and 24 h post-IV-SD-GBCA. 3D-real IR images and MRF at the level of the internal auditory canal were obtained. The signal intensity on the 3D-real IR image of the cerebrospinal fluid (CSF) in the cerebellopontine angle cistern (CPA), Sylvian fissure (Syl), lateral ventricle (LV), and cochlear perilymph (CPL) was measured. The T1 and T2 values of cerebellar gray (GM) and white matter (WM) were measured using MRF. Each averaged value at the various time points was compared using an analysis of variance. RESULTS: The signal intensity on the 3D-real IR image in each CSF region peaked at 4 h, and was decreased significantly by 24 h (P< 0.05). All patients had a maximum signal intensity at 4 h in the CPA, and Syl. The mean CPL signal intensity peaked at 4 h and decreased significantly by 24 h (P < 0.05). All patients but two had a maximum signal intensity at 4 h. Regarding the T1 value in the cerebellar WM and GM, the T1 value at 10 min post-IV-GBCA was significantly decreased compared to the pre-contrast scan, but no significant difference was observed at the other time points. There was no significant change in T2 in the gray or white matter at any of the time points. CONCLUSION: Time course of GBCA after IV-SD-GBCA could be evaluated by 3D-real IR imaging in CSF spaces and in the brain by MRF.

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  28. Unexpected radioactive iodine accumulation on whole-body scan after I-131 ablation therapy for differentiated thyroid cancer. Reviewed

    Shingo Iwano, Shinji Ito, Shinichiro Kamiya, Rintaro Ito, Katsuhiko Kato, Shinji Naganawa

    Nagoya journal of medical science   Vol. 82 ( 2 ) page: 205 - 215   2020.5

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    We retrospectively evaluated the frequency of unexpected accumulation of radioactive iodine on the post-therapy whole-body scan (Rx-WBS) after radioactive iodine (RAI) ablation therapy in patients with differentiated thyroid cancer (DTC). We searched our institutional database for Rx-WBSs of DTC patients who underwent RAI ablation or adjuvant therapy between 2012 and 2019. Patients with distant metastasis diagnosed by CT or PET/CT before therapy, and those had previously received RAI therapy were excluded. In total, 293 patients (201 female and 92 male, median age 54 years) were selected. Two nuclear medicine physicians interpreted the Rx-WBS images by determining the visual intensity of radioiodine uptake by the thyroid bed, cervical and mediastinal lymph nodes, lungs, and bone. Clinical features of the patients with and without the metastatic accumulation were compared by chi-square test and median test. Logistic regression analyses were performed to compare the association between the presence of metastatic accumulation and these clinical factors. Eighty-four of 293 patients (28.7%) showed metastatic accumulation. Patients with metastatic RAI accumulation showed a significantly higher frequency of pathological N1 (pN1) and serum thyroglobulin (Tg) > 1.5 ng/ml under TSH stimulation (p = 0.035 and p = 0.031, respectively). Logistic regression analysis indicated that a serum Tg > 1.5 ng/ml was significantly correlated with the presence of metastatic accumulation (odds ratio = 1.985; p = 0.033). In conclusion, Patients with Tg > 1.5 ng/ml were more likely to show metastatic accumulation. In addition, the presence of lymph node metastasis at the initial thyroid surgery was also associated with this unexpected metastatic accumulation.

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  29. White matter microstructural changes in tuberous sclerosis: Evaluation by neurite orientation dispersion and density imaging (NODDI) and diffusion tensor images. Reviewed International journal

    Toshiaki Taoka, Noriko Aida, Yuta Fujii, Kazushi Ichikawa, Hisashi Kawai, Toshiki Nakane, Rintaro Ito, Shinji Naganawa

    Scientific reports   Vol. 10 ( 1 ) page: 436 - 436   2020.1

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    Neurite orientation dispersion and density imaging (NODDI) is a novel diffusion method for evaluating tissue microstructure, and may provide additional information over conventional diffusion tensor imaging (DTI). We evaluated NODDI and DTI parameters in cases of tuberous sclerosis (TS) to assess microstructural changes in the white matter. Eleven cases of tuberous sclerosis and eight age-matched controls underwent NODDI and DTI. We performed qualitative analysis and tract-based spatial statistics (TBSS) analysis of the NODDI parameters (Ficv: intracellular volume fraction, Fiso: isotropic fraction, ODI: orientation dispersion index) as well as DTI parameters (MD: mean diffusivity, FA: fractional anisotropy). We also performed a correlation analysis between clinical symptoms and parameters. The qualitative analysis indicated that the Ficv had a lower value in TS cases particularly in the tubers adjacent to the white matter. The TBSS analysis showed that the TS cases had decreased Ficv in a greater area compared to the other parameters including MD. In particular, the Ficv was decreased in deep white matter, such as the superior longitudinal fascicles (SLF). The application of NODDI to TS cases revealed tissue microstructural changes, and particularly the Ficv could detect more widespread abnormalities in white matter structure compared to DTI parameters.

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  30. The Space between the Pial Sheath and the Cortical Venous Wall May Connect to the Meningeal Lymphatics. Reviewed

    Shinji Naganawa, Rintaro Ito, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine   Vol. 19 ( 1 ) page: 1 - 4   2020

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    We currently obtain pre- and post-contrast enhanced whole brain 3D-real inversion recovery images for the evaluation of endolymphatic hydrops. We noticed that the space between the pial sheath surrounding the cortical veins and the cortical venous wall is enhanced and this enhancement seems to connect to the meningeal lymphatics along superior sagittal sinus. This new anatomical concept regarding the outflow from the glymphatic system might be important for the future research in neuroscience.

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  31. Kinetic volume analysis on dynamic contrast-enhanced MRI of triple-negative breast cancer: associations with survival outcomes. Reviewed International journal

    Yoko Hayashi, Hiroko Satake, Satoko Ishigaki, Rintaro Ito, Mariko Kawamura, Hisashi Kawai, Shingo Iwano, Shinji Naganawa

    The British journal of radiology   Vol. 93 ( 1106 ) page: 20190712 - 20190712   2020

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    OBJECTIVE: To evaluate the associations between computer-aided diagnosis (CAD)-generated kinetic volume parameters and survival in triple-negative breast cancer (TNBC) patients. METHODS: 40 patients with TNBC who underwent pre-operative MRI between March 2008 and March 2014 were included. We analyzed CAD-generated parameters on dynamic contrast-enhanced MRI, visual MRI assessment, and histopathological data. Cox proportional hazards models were used to determine associations with survival outcomes. RESULTS: 12 of the 40 (30.0%) patients experienced recurrence and 7 died of breast cancer after a median follow-up of 73.6 months. In multivariate analysis, higher percentage volume (%V) with more than 200% initial enhancement rate correlated with worse disease-specific survival (hazard ratio, 1.12; 95% confidence interval, 1.02-1.22; p-value, 0.014) and higher %V with more than 100% initial enhancement rate followed by persistent curve type at 30% threshold correlated with worse disease-specific survival (hazard ratio, 1.33; 95% confidence interval, 1.10-1.61; p-value, 0.004) and disease-free survival (hazard ratio, 1.27; 95% confidence interval, 1.12-1.43; p-value, 0.000). CONCLUSION: CAD-generated kinetic volume parameters may correlate with survival in TNBC patients. Further study would be necessary to validate our results on larger cohorts. ADVANCES IN KNOWLEDGE: CAD generated kinetic volume parameters on breast MRI can predict recurrence and survival outcome of patients in TNBC. Varying the enhancement threshold improved the predictive performance of CAD generated kinetic volume parameter.

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  32. Confirmation of Age-dependence in the Leakage of Contrast Medium around the Cortical Veins into Cerebrospinal Fluid after Intravenous Administration of Gadolinium-based Contrast Agent. Reviewed

    Shinji Naganawa, Rintaro Ito, Hisashi Kawai, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine   Vol. 19 ( 4 ) page: 375 - 381   2020

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    PURPOSE: It has been reported previously that intravenously administered gadolinium-based contrast agent (GBCA) leaks into the subarachnoid space around the cortical veins at 4 h after injection in all old people over 37 years, but not in younger people up to 37 years of age in 3D-real IR images. The purpose of this study was to investigate whether there was a strict threshold of 37 years of age for the leakage of the GBCA into the subarachnoid space. METHODS: The subjects included 190 patients, that were scanned for 3D-real IR images at 4 hours after intravenous injection of GBCA as a diagnostic test for endolymphatic hydrops. The patient's age ranged from 14 to 81 years. Two experienced neuroradiologists evaluated the images to determine whether the GBCA leakage around the cortical veins was positive or negative. Any discrepancies between the two observers were discussed and a consensus was obtained.A Mann-Whitney U test and receiver operating characteristic (ROC) curve analysis were used to compare the positive and the negative group and to set the age cut-off value for the prediction of GBCA leakage. RESULTS: The GBCA leakage around the cortical veins was negative in 35 patients and positive in 155 patients. The average age was 33 ± 11 years in the negative group, and 55 ± 12 years in the positive group (P < 0.01). In the ROC analysis for the age and leakage of the GBCA, an area under the curve was 0.905 and the cut-off age was 37.317 years (sensitivity of 0.942 and specificity of 0.771). CONCLUSION: Intravenously administered GBCA leaks into the subarachnoid space around the cortical veins in most patients over 37 years of age. However, it should be noted that it can be found occasionally in patients under 37 years of age.

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  33. A review on the use of artificial intelligence for medical imaging of the lungs of patients with coronavirus disease 2019. Reviewed International journal

    Rintaro Ito, Shingo Iwano, Shinji Naganawa

    Diagnostic and interventional radiology (Ankara, Turkey)   Vol. 26 ( 5 ) page: 443 - 448   2020

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    The results of research on the use of artificial intelligence (AI) for medical imaging of the lungs of patients with coronavirus disease 2019 (COVID-19) has been published in various forms. In this study, we reviewed the AI for diagnostic imaging of COVID-19 pneumonia. PubMed, arXiv, medRxiv, and Google scholar were used to search for AI studies. There were 15 studies of COVID-19 that used AI for medical imaging. Of these, 11 studies used AI for computed tomography (CT) and 4 used AI for chest radiography. Eight studies presented independent test data, 5 used disclosed data, and 4 disclosed the AI source codes. The number of datasets ranged from 106 to 5941, with sensitivities ranging from 0.67-1.00 and specificities ranging from 0.81-1.00 for prediction of COVID-19 pneumonia. Four studies with independent test datasets showed a breakdown of the data ratio and reported prediction of COVID-19 pneumonia with sensitivity, specificity, and area under the curve (AUC). These 4 studies showed very high sensitivity, specificity, and AUC, in the range of 0.9-0.98, 0.91-0.96, and 0.96-0.99, respectively.

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  34. Multimodal Imaging in Bilateral Nature of the Choroidal Osteoma After Intraocular Inflammation Caused by Harada Disease. Reviewed International journal

    Kenji Ozawa, Takeshi Iwase, Yasuki Ito, Masahiro Onda, Ikumi Shiraki, Mitsuki Kumada, Rintaro Ito, Kiyofumi Mochizuki

    Retina (Philadelphia, Pa.)   Vol. 39 ( 9 ) page: E40 - E41   2019.9

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  35. Utility of Metabolic Parameters on FDG PET/CT in the Classification of Early-Stage Lung Adenocarcinoma: Prediction of Pathological Invasive Size. Reviewed International journal

    Shingo Iwano, Shinji Ito, Shinichiro Kamiya, Rintaro Ito, Katsuhiko Kato, Shinji Naganawa

    Clinical nuclear medicine   Vol. 44 ( 7 ) page: 560 - 565   2019.7

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    PURPOSE: This paper aims to explore the role of a metabolic parameter on F-FDG-PET/CT for clinical T-classification in early-stage adenocarcinoma. PATIENTS AND METHODS: One hundred six surgically resected pathological TNM stage (p-stage) 0/I lung adenocarcinomas were retrospectively reviewed. The solid size (SS) measured on thin-section CT and the pathological invasive size (IS) of tumors were recorded. The SUVmax and metabolic tumor volume with SUV ≥1.0 (MTV1.0) derived from PET/CT data were measured on a workstation, and the metabolic tumor diameter with SUV ≥1.0 (MTD1.0) was calculated automatically from MTV1.0. For the correlations between the IS and the SS, MTD1.0, or SUVmax, Pearson's correlation coefficients were compared using the Meng-Rosenthal-Rubin method. Additionally, the reproducibility between the clinical TNM stage (c-stage), based on the SS or MTD1.0, and the p-stage was analyzed using the kappa coefficient (k). RESULTS: For the correlations between the IS and the other parameters, Pearson correlation coefficient was 0.630 for the SS, 0.600 for the SUVmax, and 0.725 for MTD1.0. MTD1.0 correlated significantly and more strongly with the IS than the SS and the SUVmax did (P = 0.040, and P = 0.008, respectively). The reproducibility between p-stage and c-stage based on the SS was moderate (k = 0.529, P < 0.001), whereas that between p-stage and c-stage based on MTD1.0 was substantial (k = 0.676, P < 0.001). CONCLUSIONS: MTD1.0 on FDG-PET/CT was correlated significantly and more strongly with the pathological IS in lung adenocarcinomas than with the SS on thin-section CT. FDG-PET/CT could classify more precisely early-stage lung adenocarcinoma than the presently used T-classification based on thin-section CT findings.

    DOI: 10.1097/RLU.0000000000002591

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  36. Computer-aided Volumetry of Part-Solid Lung Cancers by Using CT: Solid Component Size Predicts Prognosis. Reviewed International journal

    Shinichiro Kamiya, Shingo Iwano, Hiroyasu Umakoshi, Rintaro Ito, Hironori Shimamoto, Shota Nakamura, Shinji Naganawa

    Radiology   Vol. 287 ( 3 ) page: 1030 - 1040   2018.6

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    Purpose To investigate the relationship between the postoperative prognosis of patients with part-solid non-small cell lung cancer and the solid component size acquired by using three-dimensional (3D) volumetry software on multidetector computed tomographic (CT) images. Materials and Methods A retrospective study by using preoperative multidetector CT data with 0.5-mm section thickness, clinical records, and pathologic reports of 96 patients with primary subsolid non-small cell lung cancer (47 men and 49 women; mean age ± standard deviation, 66 years ± 8) were reviewed. Two radiologists measured the two-dimensional (2D) maximal solid size of each nodule on an axial image (hereafter, 2D MSSA), the 3D maximal solid size on multiplanar reconstructed images (hereafter, 3D MSSMPR), and the 3D solid volume of greater than 0 HU (hereafter, 3D SV0HU) within each nodule. The correlations between the postoperative recurrence and the effects of clinical and pathologic characteristics, 2D MSSA, 3D MSSMPR, and 3D SV0HU as prognostic imaging biomarkers were assessed by using a Cox proportional hazards model. Results For the prediction of postoperative recurrence, the area under the receiver operating characteristics curve was 0.796 (95% confidence interval: 0.692, 0.900) for 2D MSSA, 0.776 (95% confidence interval: 0.667, 0.886) for 3D MSSMPR, and 0.835 (95% confidence interval: 0.749, 0.922) for 3D SV0HU. The optimal cutoff value for 3D SV0HU for predicting tumor recurrence was 0.54 cm3, with a sensitivity of 0.933 (95% confidence interval: 0.679, 0.998) and a specificity of 0.716 (95% confidence interval: 0.605, 0.811) for the recurrence. Significant predictive factors for disease-free survival were 3D SV0HU greater than or equal to 0.54 cm3 (hazard ratio, 6.61; P = .001) and lymphatic and/or vascular invasion derived from histopathologic analysis (hazard ratio, 2.96; P = .040). Conclusion The measurement of 3D SV0HU predicted the postoperative prognosis of patients with part-solid lung cancer more accurately than did 2D MSSA and 3D MSSMPR. © RSNA, 2018.

    DOI: 10.1148/radiol.2018172319

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  37. FDG PET/CT Overcomes Discordance Between Clinical and Pathologic TNM Classification of Small-size Primary Lung Cancer: Influence on Postoperative Prognosis. Reviewed International journal

    Hiroyasu Umakoshi, Shingo Iwano, Kohei Yokoi, Shinji Ito, Rintaro Ito, Koji Kawaguchi, Takayuki Fukui, Shinji Naganawa

    Clinical lung cancer   Vol. 19 ( 1 ) page: E37 - E45   2018.1

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    INTRODUCTION: We aimed to determine the concordance between the clinical stage (c-stage) and pathologic stage (p-stage) for patients with small-size lung cancer. Additionally we searched for prognostic factors other than the TNM stage. PATIENTS AND METHODS: We retrospectively reviewed the preoperative multidetector computed tomography (CT) and positron emission tomography/CT reports, surgical records, and pathologic reports of patients with primary lung cancer ≤ 3 cm. The Union for International Cancer Control TNM seventh edition classification of c-stage and p-stage were compared. The tumors were classified into multiple subgroups by concordance or discordance between the c-stage and p-stage. Disease-free survival (DFS) was assessed using survival analysis to assess the tumor characteristics that were predictive of prognosis. RESULTS: A total of 289 surgically resected primary lung cancers were evaluated. The concordance between c-stage and p-stage was 65.4%, with moderate reproducibility (kappa coefficient, 0.467). The upstaging rate from c-stage I to p-stage II-IV was 9.4%, and these patients had significantly worse DFS than those with a concordant stage I classification (P < .001). The main reason for upstaging was an underestimation of metastases to the hilar lymph nodes (n = 7) or mediastinal lymph nodes (n = 11). A multivariate Cox proportional hazards model showed that the significant predictive factors for DFS were p-stage (hazard ratio, 1.342; P = .003) and maximum standardized uptake value on positron emission tomography/CT (hazard ratio, 12.162; P = .001). CONCLUSION: The concordance rate between c-stage and p-stage for small primary lung cancers had moderate reproducibility. Discordance between c-stage I and p-stage II-IV significantly affected DFS. The maximum standardized uptake value of the primary lesion was an independent prognostic factor, and combining it with c-stage might improve the prediction of therapeutic outcomes.

    DOI: 10.1016/j.cllc.2017.05.021

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  38. A comparative analysis of dual-phase dual-energy CT and FDG-PET/CT for the prediction of histopathological invasiveness of non-small cell lung cancer. Reviewed International journal

    Rintaro Ito, Shingo Iwano, Hironori Shimamoto, Hiroyasu Umakoshi, Koji Kawaguchi, Shinji Ito, Katsuhiko Kato, Shinji Naganawa

    European journal of radiology   Vol. 95   page: 186 - 191   2017.10

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    PURPOSE: To compare dual-phase dual-energy CT (DE-CT) with FDG-PET/CT for predicting histopathological locoregional invasiveness of non-small cell lung cancers (NSCLCs). MATERIALS AND METHODS: We selected 63 consecutive patients with NSCLC lesions (37 males, 26 females; age range, 44-85 years; mean age, 69 years) who were evaluated preoperatively by both DE-CT and PET/CT at our institution. Postoperative microscopic invasiveness (lymphatic permeation, vascular invasion, and/or pleural involvement) was reviewed, and we defined locoregionally invasive tumors as those that had at least one positive finding of microscopic invasiveness. DE-CT scanning in the arterial and delayed phases was performed after injection of iodinated contrast media using 140-kVp and 80-kVp tube voltages. Three-dimensional iodine-related attenuation of primary tumors in the arterial and delayed phases was quantified automatically using "syngo Dual Energy Lung Nodules" application software, and the ratio of arterial phase to delayed phase enhancement (A/D ratio) was calculated. The A/D ratio and SUVmax on PET/CT were evaluated with respect to postoperative invasiveness by univariate logistic regression analysis. RESULTS: The A/D ratio was significantly correlated with lymphatic permeation, vascular invasion, and pleural involvement (p=0.011, p=0.021, and p=0.010, respectively). In contrast, the SUVmax was significantly correlated with pleural involvement (p=0.020) but not with lymphatic permeation or vascular invasion (p=0.088 and p=0.100, respectively). In the subgroup of patients with lesion diameters ≤2cm, the A/D ratio was significantly correlated with locoregional invasiveness (p=0.040), while the SUVmax was not (p=0.121). CONCLUSION: For the prediction of microscopic invasiveness of NSCLCs, the diagnostic performance of dual-phase DE-CT may be comparable to that of FDG-PET/CT.

    DOI: 10.1016/j.ejrad.2017.08.010

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  39. Thoracic Temporal Subtraction Three Dimensional Computed Tomography (3D-CT): Screening for Vertebral Metastases of Primary Lung Cancers. Reviewed International journal

    Shingo Iwano, Rintaro Ito, Hiroyasu Umakoshi, Takatoshi Karino, Tsutomu Inoue, Yuanzhong Li, Shinji Naganawa

    PloS one   Vol. 12 ( 1 ) page: e0170309   2017.1

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    PURPOSE: We developed an original, computer-aided diagnosis (CAD) software that subtracts the initial thoracic vertebral three-dimensional computed tomography (3D-CT) image from the follow-up 3D-CT image. The aim of this study was to investigate the efficacy of this CAD software during screening for vertebral metastases on follow-up CT images of primary lung cancer patients. MATERIALS AND METHODS: The interpretation experiment included 30 sets of follow-up CT scans in primary lung cancer patients and was performed by two readers (readers A and B), who each had 2.5 years' experience reading CT images. In 395 vertebrae from C6 to L3, 46 vertebral metastases were identified as follows: osteolytic metastases (n = 17), osteoblastic metastases (n = 14), combined osteolytic and osteoblastic metastases (n = 6), and pathological fractures (n = 9). Thirty-six lesions were in the anterior component (vertebral body), and 10 lesions were in the posterior component (vertebral arch, transverse process, and spinous process). The area under the curve (AUC) by receiver operating characteristic (ROC) curve analysis and the sensitivity and specificity for detecting vertebral metastases were compared with and without CAD for each observer. RESULTS: Reader A detected 47 abnormalities on CT images without CAD, and 33 of them were true-positive metastatic lesions. Using CAD, reader A detected 57 abnormalities, and 38 were true positives. The sensitivity increased from 0.717 to 0.826, and on ROC curve analysis, AUC with CAD was significantly higher than that without CAD (0.849 vs. 0.902, p = 0.021). Reader B detected 40 abnormalities on CT images without CAD, and 36 of them were true-positive metastatic lesions. Using CAD, reader B detected 44 abnormalities, and 39 were true positives. The sensitivity increased from 0.783 to 0.848, and AUC with CAD was nonsignificantly higher than that without CAD (0.889 vs. 0.910, p = 0.341). Both readers detected more osteolytic and osteoblastic metastases with CAD than without CAD. CONCLUSION: Our temporal 3D-CT subtraction CAD software easily detected vertebral metastases on the follow-up CT images of lung cancer patients regardless of the osteolytic or osteoblastic nature of the lesions.

    DOI: 10.1371/journal.pone.0170309

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  40. Correlation between FDG-PET/CT findings and solid type non-small cell cancer prognostic factors: are there differences between adenocarcinoma and squamous cell carcinoma? Reviewed

    Ito R, Iwano S, Kishimoto M, Ito S, Kato K, Naganawa S

    Annals of nuclear medicine   Vol. 29 ( 10 ) page: 897-905   2015.12

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    DOI: 10.1007/s12149-015-1025-z

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  41. Evaluation of lung cancer by enhanced dual-energy CT: association between three-dimensional iodine concentration and tumour differentiation. Reviewed

    Iwano S, Ito R, Umakoshi H, Ito S, Naganawa S

    The British journal of radiology   Vol. 88 ( 1055 ) page: 20150224   2015

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    DOI: 10.1259/bjr.20150224

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  42. Prognostic evaluations of small size lung cancers by 18F-FDG PET/CT and thin-section CT. Reviewed

    Kishimoto M, Iwano S, Ito S, Kato K, Ito R, Naganawa S

    Lung cancer (Amsterdam, Netherlands)   Vol. 86 ( 2 ) page: 180-4   2014.11

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    DOI: 10.1016/j.lungcan.2014.09.006

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  43. Prediction of pathologic prognostic factors in patients with lung adenocarcinomas: comparison of thin-section computed tomography and positron emission tomography/computed tomography. Reviewed

    Iwano S, Kishimoto M, Ito S, Kato K, Ito R, Naganawa S

    Cancer imaging : the official publication of the International Cancer Imaging Society   Vol. 14   page: 3   2014.4

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    DOI: 10.1186/1470-7330-14-3

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MISC 34

  1. 人工知能を応用したバーチャル3D thin-section CTを用いた肺腺癌の充実成分径の計測

    岩野 信吾, 神谷 晋一朗, 伊藤 倫太郎, 工藤 彰, 北村 嘉郎, 中村 圭児, 長縄 慎二

    断層映像研究会雑誌   Vol. 49 ( 2 ) page: 39 - 39   2022.9

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  2. Study on the usefulness of FDG-PET imaging in the diagnosis of GLUT-1 deficiency syndrome

    鈴井良輔, 夏目淳, 夏目淳, 鈴木健史, 川口将宏, 伊藤倫太郎, 成田肇, 光松孝真, 隈井すみれ, 澤村文, 白木杏奈, 伊藤祐史, 山本啓之, 中田智彦, 加藤克彦, 城所博之

    てんかん研究   Vol. 40 ( 2 ) page: 453 - 453   2022

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  3. 鼻腔glomangiopericytomaの2症例

    阿部考志, 伊藤倫太郎, 中道玲瑛, 阿部有美, 川井恒, 田岡俊昭, 佐竹弘子, 長縄慎二

    Japanese Journal of Radiology   Vol. 40 ( Supplement )   2022

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  4. 硬膜下血腫例でのDiffusion Weighted Image Analysis Along the Perivascular Space(DWI-ALPS)の応用

    田岡俊昭, 伊藤倫太郎, 中道玲瑛, 中根俊樹, 市川和茂, 酒井黛呼, 長縄慎二

    日本神経放射線学会プログラム・抄録集   Vol. 51st   2022

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  5. 深層学習を用いた新生児頭部エコー画像による脳室周囲白質軟化症の発症予測

    川口将宏, 城所博之, 白木杏奈, 山本啓之, 中田智彦, 夏目淳, 夏目淳, 高橋義行, 伊藤倫太郎, 野田晴香, 前田剛志, 上田一仁, 伊藤美春, 佐藤義朗, 早川昌弘

    日本小児科学会雑誌   Vol. 126 ( 10 ) page: 1445 - 1445   2022

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  6. 【COVID-19肺炎と肺疾患AI開発のフロントライン】COVID-19肺炎におけるAI研究の動向および問題点について

    伊藤 倫太郎, 岩野 信吾, 長縄 慎二

    医用画像情報学会雑誌   Vol. 38 ( 2 ) page: 32 - 40   2021.7

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    COVID-19が世界中に広まり、COVID-19肺炎の診断に胸部CTや胸部単純X線の有用性が報告され、この画像所見を用いたAI開発が初期の段階から積極的に行われた。高性能なAIが多数存在するが、臨床において用いる際には注意すべき点が複数存在する。COVID-19肺炎に対して開発・使用された画像診断に関連するAI研究について、PubMedに2020年12月までに登録されたものを抽出しレビューを行った。

  7. 2030年放射線科はこう変わる 2030年の放射線医

    伊藤倫太郎, 伊藤倫太郎

    Rad Fan   Vol. 19 ( 2 ) page: 52 - 53   2021

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  8. How to start Medical AI

    伊藤倫太郎

    日本医学放射線学会秋季臨床大会抄録集   Vol. 57th   page: S435 - S435   2021

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  9. 人工知能による胸部単純写真からの肺野画像の生成

    伊藤倫太郎, 岩野慎吾, 長縄慎二

    日本医学放射線学会秋季臨床大会抄録集   Vol. 57th   page: S433 - S433   2021

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  10. The artificial intelligence for COVID-19 pneumonia.

    伊藤倫太郎, 伊藤倫太郎, 岩野信吾, 長縄慎二

    月刊臨床免疫・アレルギー科   Vol. 75 ( 2 ) page: 189 - 193   2021

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    J-GLOBAL

  11. Water Peak MRS:組織中の溶媒の評価の試み

    田岡俊昭, 伊藤倫太郎, 阿部考志, 中道玲瑛, 中根俊樹, 川井恒, 長縄慎二

    日本神経放射線学会プログラム・抄録集   Vol. 50th   2021

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  12. MY BOOK MARK~本当に使いやすい製品がこの中に~File No.8 放射線科診断専門医の私とデバイスについて

    伊藤倫太郎, 伊藤倫太郎

    Rad Fan   Vol. 19 ( 2 ) page: 74 - 77   2021

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  13. COVID-19 肺炎におけるAI研究の動向および問題点について

    伊藤倫太郎, 伊藤倫太郎, 岩野信吾, 岩野信吾, 長縄慎二, 長縄慎二

    医用画像情報学会雑誌(Web)   Vol. 38 ( 2 )   2021

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  14. 深層学習を用いた小児頭部MRIの年齢推定

    川口 将宏, 城所 博之, 伊藤 倫太郎, 白木 杏奈, 鈴木 健史, 牧 祐輝, 田中 雅大, 坂口 陽子, 山本 啓之, 根来 民子, 渡邉 一功, 夏目 淳

    脳と発達   Vol. 52 ( Suppl. ) page: S238 - S238   2020.8

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  15. Multi b-value Diffusion weighted image Diphase Map(MbDDM)による脳脊髄液動態の評価

    田岡俊昭, 田岡俊昭, 伊藤倫太郎, 伊藤倫太郎, 中道玲瑛, 中根俊樹, 川井恒, 長縄慎二

    日本神経放射線学会プログラム・抄録集   Vol. 49th   2020

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  16. Size Measurements of Lung Cancer Using 3D-CT and PET/CT

    岩野信吾, 伊藤信嗣, 伊藤倫太郎, 神谷晋一朗, 加藤克彦, 長縄慎二

    画像診断   Vol. 40 ( 5 ) page: 439 - 446   2020

  17. TNM分類(UICC8版)に基づいた臨床病期I期肺癌の予後評価

    岩野信吾, 馬越弘泰, 神谷晋一朗, 島本宏矩, 伊藤倫太郎, 長縄慎二

    Japanese Journal of Radiology   Vol. 38 ( Supplement ) page: 22 - 22   2020

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  18. FDG-PET/CTの腫瘍代謝容積に基づいた肺腺癌の臨床病期診断の試み

    岩野 信吾, 伊藤 倫太郎, 長縄 慎二

    肺癌   Vol. 59 ( 2 ) page: 189 - 189   2019.4

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  19. FDG-PET/CTの腫瘍代謝容積に基づいた肺腺癌の臨床病期診断の試み

    岩野信吾, 伊藤倫太郎, 長縄慎二

    肺癌(Web)   Vol. 59 ( 2 )   2019

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  20. 原発性肺癌の術前臨床病期診断の正確性

    岩野信吾, 馬越弘泰, 伊藤倫太郎, 島本宏矩, 長縄慎二

    Japanese Journal of Radiology   Vol. 37 ( Supplement ) page: 25 - 25   2019

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  21. 人工知能が医療を変える!医療分野におけるAI研究開発最前線2019 II 領域別・画像診断におけるAI研究開発の最前線 2.胸部領域 胸部画像診断におけるAIと臨床研究について

    伊藤倫太郎, 岩野信吾, 長縄慎二

    Innervision   Vol. 34 ( 7 ) page: 25 - 28   2019

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    2006年から始まった第三次AIブームによりAIの研究が加速度的に進み、現在ではスマートフォンのカメラや音声入力など身近なものに活用されている。放射線医学においては古くから人工知能(AI)を用いた研究が行われ、臨床にも応用されていた。最近では、さらに発展したAIを用いたCADの開発が盛んであり、世界中の研究者が開発を競っている。本稿では、加速度的に進歩するAIと放射線医学とのかかわりについて、主に胸部画像診断の観点から現在の状況と問題点についてまとめ、実際の研究例について提示する。(著者抄録)

    J-GLOBAL

  22. Multi-window levels and widths imaging:画像変換による新たな読影手法の検討

    伊藤倫太郎, 岩野信吾, 小田紘久, 森健策, 長縄慎二

    日本医学放射線学会秋季臨床大会抄録集   Vol. 55th   page: S531 - S532   2019

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  23. Generative Adversarial Networkを用いた肺結節の画像生成について

    伊藤倫太郎, 岩野信吾, 長縄慎二

    日本医学放射線学会秋季臨床大会抄録集   Vol. 54th   page: S561 - S561   2018

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    J-GLOBAL

  24. 非小細胞肺癌の局所浸潤性の予測に関する造影dual energy CTとFDG-PET/CTの比較

    伊藤倫太郎, 岩野信吾, 島本宏矩, 馬越弘泰, 伊藤信嗣, 長縄慎二, 加藤克彦

    Japanese Journal of Radiology   Vol. 36 ( Supplement ) page: 20 - 20   2018

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  25. 胸壁並行断面CTを用いた間質性肺炎の経時的評価

    馬越弘泰, 岩野信吾, 伊藤倫太郎, 島本宏矩, 長縄慎二

    Japanese Journal of Radiology   Vol. 36 ( Supplement ) page: 19 - 19   2018

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  26. PET/CTによる小型肺癌の術後予後予測 臨床病期と病理病期との比較

    岩野 信吾, 伊藤 倫太郎, 長縄 慎二, 川口 晃司, 福井 高幸, 横井 香平

    肺癌   Vol. 57 ( 5 ) page: 453 - 453   2017.9

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    Language:Japanese   Publisher:(NPO)日本肺癌学会  

    J-GLOBAL

  27. 脈絡膜悪性黒色腫の診断におけるIMP SPECT、FDG PET/CT、FDOPA PET/CTの比較

    加藤 克彦, 小田川 哲郎, 阿部 真治, 山口 博司, 伊藤 倫太郎, 伊藤 信嗣, 岩野 信吾, 長縄 慎二

    核医学   Vol. 54 ( Suppl. ) page: S194 - S194   2017.9

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    Language:Japanese   Publisher:(一社)日本核医学会  

  28. PET/CTは小型肺癌のTNM分類に基づく術後予後予測を補助する

    岩野 信吾, 馬越 弘泰, 伊藤 倫太郎, 伊藤 信嗣, 川口 晃司, 福井 高幸, 横井 香平, 加藤 克彦, 長縄 慎二

    核医学   Vol. 54 ( Suppl. ) page: S195 - S195   2017.9

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  29. FDG-PETによる非小細胞肺癌の予後予測因子の検討 SUVmaxと体積を考慮した指標の比較

    伊藤 信嗣, 岩野 信吾, 伊藤 倫太郎, 長縄 慎二, 加藤 克彦

    核医学   Vol. 54 ( 1 ) page: 565 - 565   2017.2

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  30. ドパミントランスポータシンチグラフィにおける解析ソフトの有用性に関する研究

    松澤 伸一郎, 加藤 克彦, 国本 啓太, 本田 将之, 椋本 竜斗, 小田川 哲郎, 阿部 真治, 藤田 尚利, 櫻木 庸博, 伊藤 信嗣, 伊藤 倫太郎, 岩野 信吾, 長縄 慎二

    核医学   Vol. 54 ( 1 ) page: 663 - 663   2017.2

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  31. Dual Energy CTによる小型肺癌の造影評価

    島本宏矩, 岩野信吾, 馬越弘泰, 伊藤倫太郎, 長縄慎二

    Japanese Journal of Radiology   Vol. 35 ( Supplement ) page: 34 - 34   2017

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    Language:Japanese   Publisher:(公社)日本医学放射線学会  

    J-GLOBAL

  32. 脈絡膜悪性黒色腫の診断におけるIMP SPECT,FDG PET/CT,FDOPA PET/CTの比較

    加藤克彦, 小田川哲郎, 阿部真治, 山口博司, 伊藤倫太郎, 伊藤信嗣, 岩野信吾, 長縄慎二

    核医学(Web)   Vol. 54 ( Supplement )   2017

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  33. 胸壁並行断面CTを用いた間質性肺炎の定量的評価

    馬越弘泰, 岩野信吾, 伊藤倫太郎, 長縄慎二

    Japanese Journal of Radiology   Vol. 35 ( Supplement ) page: 34 - 34   2017

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    Language:Japanese   Publisher:(公社)日本医学放射線学会  

    J-GLOBAL

  34. PET/CTは小型肺癌のTNM分類に基づく術後予後予測を補助する

    岩野信吾, 馬越弘泰, 伊藤倫太郎, 伊藤信嗣, 川口晃司, 福井高幸, 横井香平, 加藤克彦, 長縄慎二

    核医学(Web)   Vol. 54 ( Supplement )   2017

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KAKENHI (Grants-in-Aid for Scientific Research) 5

  1. Early diagnosis before onset of disease pioneered by the evaluation of vascular permeability and waste excretion function for the brain and sensory organs

    Grant number:23H02854  2023.4 - 2026.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

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    Authorship:Coinvestigator(s) 

  2. Simulation of past and future images of lung cancer by virtual high-resolution CT using artificial intelligence

    Grant number:22K07692  2022.4 - 2026.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

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    Authorship:Coinvestigator(s) 

  3. A Study on Natural Language Processing Analysis of Radiology Reports using New Artificial Intelligence

    Grant number:21K15843  2021.4 - 2024.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Early-Career Scientists

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    Authorship:Principal investigator 

    Grant amount:\4160000 ( Direct Cost: \3200000 、 Indirect Cost:\960000 )

  4. Development of assessment method for lymphatic system in the brain: Evaluation of the influence by sleep.

    Grant number:21K07563  2021.4 - 2024.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

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    Authorship:Coinvestigator(s) 

  5. 超高精細形態画像と機能画像の統合解析による早期肺癌の次世代予後予測モデルの確立

    Grant number:19K08149  2019.4 - 2023.3

    日本学術振興会  科学研究費助成事業  基盤研究(C)

    岩野 信吾, 中村 彰太, 伊藤 信嗣, 伊藤 倫太郎

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    Authorship:Coinvestigator(s) 

    原発性肺癌の臨床病期分類は胸部CTに様々な画像検査を組み合わせて決定され、最適な治療方針を決定する基盤情報である。しかし限られた空間分解能による形態診断の限界により病理病期分類との間に差を生じることがある。本研究では肺癌症例の膨大な画像・手術・病理データを活用し、浸潤性・予後に関連する超高精細CT、MRI、PETによる新たなバイオマーカー構築を探索し、これらを統合的に解析することで早期肺癌の予後予測の精度向上、次世代の肺癌病期分類改訂に貢献する。
    本研究では、肺癌症例の膨大な画像・手術・病理データを活用し、浸潤性・予後に関連する超高精細CT、MRI、PETによる新たなバイオマーカー構築を探索し、これらを統合的に解析することで早期肺癌の予後予測の精度向上、次世代の肺癌病期分類改訂に貢献することを目的としている。2019年11月より名古屋大学医学部附属病院に超高精細CTが導入され、肺癌症例の超高精細CTを収集中である。特にこれまでの画像診断では診断が難しかった胸壁浸潤癌について新たな知見が得られる見通しがついている。ただし胸壁浸潤癌の手術症例は数が少ないことから2022年3月まで症例収集を追加し、解析予定である。
    またPET/CT、従来型高精細CT、マイクロCTについて画像・臨床データベースから抽出し、それらがTNM分類や予後に与える影響についてレトロスペクティブな解析を行っている。2021年3月からは当施設に呼吸同期撮影可能なPET/CTが導入され、さらなる診断能の向上が期待できる。
    2021年度はDeep Learningを研究手法に取り入れ、5mm厚のcovnentional CT画像から0.6mm厚の高精細3次元CT画像を再構成する人工知能(AI)を開発した。このAIを使うと原発性肺癌のTNM分類のT因子に採用されている充実成分径について、空間分解能の低い5mm厚のCT画像においても高精細CT並みに計測できることが明らかになり、第13回呼吸機能イメージング研究会および欧州放射線学会(ECR 2022)にて発表した。本研究の原著論文について英文雑誌に投稿中である。
    2019年11月には名古屋大学医学部附属病院に超高精細CTが設置され、順調に稼働しており、肺癌症例の収集を開始している。超高精細CTによる胸壁浸潤癌の診断について症例を収集してきたが、もともと胸壁浸潤癌の頻度が低いので症例収集が当初の見込みより遅れてしまった。しかし2022年3月末までに目標症例数に到達したため、結果の解析を始め、今年度中に研究成果を発表できる見込みである。
    2020年初頭からのCOVID-19の世界的流行に伴い、国内・海外学会が軒並み中止・延期もしくはオンライン開催となってしまったため、学会発表について十分に行えておらず、他の研究者とのディスカッションが不十分である。
    本研究は3年の期間を設定し、原発性肺癌、特に早期肺癌の超高精細CT、UTE-MRI、PET画像・臨床データ収集・解析し、最終的に統合したデータを多変量解析し、新たな予後予測因子を探索する。研究代表者は、研究総括とともにCT・MRI画像解析を行い、分担者の中村彰太が肺癌症例のリクルートと臨床・病理解析を、伊藤信嗣はPET画像解析を、伊藤倫太郎はCADの開発とデータ解析を担当する。
    2022年度中は肺癌の超高精細CTによる胸壁浸潤の診断について学会発表と論文化を進める。2022年3月末で目標症例数に到達したため、今後、直ちに学会発表の準備に取り組む予定である。また早期肺癌の高精細CT画像を3次元解析することで、気管支鏡による生検の診断予測ができないかどうかについての新たな研究に着手した。これについても2022年度中に研究成果を発表する予定である。
    COVID-19のパンデミックについて全世界で回復の兆しが見えており、学会活動が回復していくと思われるので積極的に学会に参加して研究成果の発表と研究者たちとのディスカッションを行う予定である。