61 results on '"AKIRA BABA"'
Search Results
2. Radiological Imaging Findings of Adrenal Abnormalities in TAFRO Syndrome: A Systematic Review
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Ryo Kurokawa, Akira Baba, Rui Kano, Yo Kaneko, Mariko Kurokawa, Wataru Gonoi, and Osamu Abe
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TAFRO syndrome ,adrenal gland ,computed tomography ,magnetic resonance imaging ,multicentric Castleman disease ,Biology (General) ,QH301-705.5 - Abstract
This systematic review article aims to investigate the clinical and radiological imaging characteristics of adrenal abnormalities in patients with thrombocytopenia, anasarca, fever, reticulin fibrosis, renal dysfunction, and organomegaly (TAFRO) syndrome. We searched the literature in PubMed, the Cochrane Library, and the Web of Science Core Collection. Ultimately, we analyzed 11 studies with 22 patients plus our 1 patient, totaling 23 patients. The mean age was 47.0 ± 12.6 years. There were 20 male and 3 female patients, respectively. The histopathological analysis of lymph nodes was conducted in 15 patients (65.2%), and the diagnosis was consistent with TAFRO syndrome in all 15 patients. Among the 23 patients, 11 patients (18 adrenal glands) showed adrenal ischemia/infarction, 9 patients (13 adrenal glands) showed adrenal hemorrhage, and 4 patients (7 adrenal glands) showed adrenomegaly without evidence of concurrent ischemia/infarction or hemorrhage. One patient demonstrated unilateral adrenal hemorrhage and contralateral adrenomegaly. In patients with adrenal ischemia/infarction, the adrenal glands displayed poor enhancement through contrast-enhanced computed tomography (CT). In patients with adrenal hemorrhage, the adrenal glands revealed high attenuation through non-enhanced CT and hematoma through magnetic resonance imaging. Adrenomegaly, with or without adrenal ischemia/infarction or hemorrhage, was observed in all patients (23/23, 100%). The subsequent calcification of the affected adrenal glands was frequently observed (9/14, 64.3%) when a follow-up CT was performed. Abdominal pain was frequent (15/23, 65.2%), all of which occurred after the disease’s onset, suggesting the importance of considering TAFRO syndrome as a cause of acute abdomen. Given the absence of evidence of adrenal abnormalities in non-TAFRO-idiopathic multicentric Castleman disease (iMCD), they may serve as diagnostic clues for differentiating TAFRO syndrome from non-TAFRO-iMCD.
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- 2024
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3. A rare case of positional changes of carotid artery depicted within a single MR study and a wandering carotid artery depicted on a serial MR studies
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Akira Baba, MD, PhD, Ryo Kurokawa, MD, PhD, Reina Kayama, MD, PhD, Yukiko Tsuneoka, MD, Mariko Kurokawa, MD, Yoshiaki Ota, MD, Taiki Suzuki, DDS, PhD, Hideomi Yamauchi, MD, PhD, Satoshi Matsushima, MD, PhD, and Hiroya Ojiri, MD, PhD
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Retropharyngeal carotid artery ,Retropharyngeal space ,Wandering carotid artery ,MRI ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
The retropharyngeal carotid artery (RCA) is a relatively rare anatomical malposition, and positional changes in the RCA is also extremely rare. In addition, there are some reports of ''wandering carotid artery'' which means that the carotid artery reciprocate positional changes (wandering) between its normal position and retropharyngeal regions, during follow-up evaluations. A male patient in his 50s with a chief complaint of globus pharyngeus. A pulsatile swelling of the posterior pharyngeal wall of the right side was found on clinical examination. In this case, the right carotid artery showed the clinical course of a wandering carotid artery, which reciprocated between its normal position and the retropharyngeal space during three serial MR investigations. Interestingly, both the most recent MR study and the MR study performed 4 years ago showed that the carotid artery at the level of the hyoid bone moved laterally (positional normalization) during the single MR investigation. This is a first case which showed a rare clinical course of a wandering carotid artery on serial follow-up MR studies and positional changes of carotid artery within a single MR study. It is important for clinicians to be aware of these phenomena, in order to avoid fatal and unexpected complications during clinical procedures.
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- 2022
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4. CT and MR imaging of laryngeal metastasis from renal cell carcinoma: A case report
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Akira Baba, MD, PhD, Satoshi Matsushima, MD, PhD, Ryo Kurokawa, MD, PhD, Reina Kayama, MD, PhD, Mariko Kurokawa, MD, Yoshiaki Ota, MD, Hideomi Yamauchi, MD, PhD, Hirokazu Ashida, MD, PhD, Matsusato Tsuyumu, MD, Norihiko Uchio, MD, and Hiroya Ojiri, MD, PhD
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CT ,MRI ,Laryngeal Metastasis ,Renal Cell Carcinoma ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
Laryngeal metastasis is an extremely rare condition. To the best of our knowledge, there has been no previous report on a laryngeal metastasis from renal cell carcinoma, which describes on details of the CT and MR imaging findings. A male patient in his 80s. Laryngoscopy revealed reddish-colored masses in the right false vocal cord and in the subglottic larynx. CT and MR imaging of this case showed multiple hypervascularized lesions with a wash-out effect in the supra and subglottis of the larynx and in the right intervertebral foramen of the cervical spine. Angiography revealed a hypervascular tumor consistent with the subglottic lesion. The histopathology and immunohistochemistry findings were compatible with laryngeal metastasis from renal clear cell carcinoma. A history of postoperative renal clear cell carcinoma about 7 years ago was later confirmed, which was not stated at the time of the initial imaging evaluation. It is a possible differential diagnosis in cases of multiple hypervascular masses in the head and neck region with a history of renal carcinoma. In particular, if the contrast-enhancement pattern of the lesion on the dynamic CT is similar to that of renal cell carcinoma. It is also important to reconfirm the patient's medical history, including postoperative status.
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- 2021
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5. Preoperative prediction by artificial intelligence for mastoid extension in pars flaccida cholesteatoma using temporal bone high-resolution computed tomography: A retrospective study.
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Masahiro Takahashi, Katsuhiko Noda, Kaname Yoshida, Keisuke Tsuchida, Ryosuke Yui, Takara Nakazawa, Sho Kurihara, Akira Baba, Masaomi Motegi, Kazuhisa Yamamoto, Yutaka Yamamoto, Hiroya Ojiri, and Hiromi Kojima
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Medicine ,Science - Abstract
Cholesteatoma is a progressive middle ear disease that can only be treated surgically but with a high recurrence rate. Depending on the extent of the disease, a surgical approach, such as microsurgery with a retroarticular incision or transcanal endoscopic surgery, is performed. However, the current examination cannot sufficiently predict the progression before surgery, and changes in approach may be made during the surgery. Large amounts of data are typically required to train deep neural network models; however, the prevalence of cholesteatomas is low (1-in-25, 000). Developing analysis methods that improve the accuracy with such a small number of samples is an important issue for medical artificial intelligence (AI) research. This paper presents an AI-based system to automatically detect mastoid extensions using CT. This retrospective study included 164 patients (80 with mastoid extension and 84 without mastoid extension) who underwent surgery. This study adopted a relatively lightweight neural network model called MobileNetV2 to learn and predict the CT images of 164 patients. The training was performed with eight divided groups for cross-validation and was performed 24 times with each of the eight groups to verify accuracy fluctuations caused by randomly augmented learning. An evaluation was performed by each of the 24 single-trained models, and 24 sets of ensemble predictions with 23 models for 100% original size images and 400% zoomed images. Fifteen otolaryngologists diagnosed the images and compared the results. The average accuracy of predicting 400% zoomed images using ensemble prediction model was 81.14% (sensitivity = 84.95%, specificity = 77.33%). The average accuracy of the otolaryngologists was 73.41% (sensitivity, 83.17%; specificity, 64.13%), which was not affected by their clinical experiences. Noteworthily, despite the small number of cases, we were able to create a highly accurate AI. These findings represent an important first step in the automatic diagnosis of the cholesteatoma extension.
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- 2022
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6. On/Off Ratio of a Pentacene Field-Effect Transistor with a Discontinuous MoO3 Layer.
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Takumi Kobayashi, Masahiro Minagawa, Akira Baba, Keizo Kato, and Kazunari Shinbo
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- 2023
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7. Improving Rank-N Identification Rate of Palmprint Identification Using Permutation-Based Indexing.
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Mizuho Yoshihira, Ayumi Serizawa, Ryosuke Okudera, Yumo Ouchi, Yuya Shiomi, Naoya Nitta, Masataka Nakahara, Akira Baba, Yutaka Miyake, Tetsushi Ohki, and Masakatsu Nishigaki
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- 2022
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8. Improving Palmprint-Region Estimation for ID-Less Palmprint Recognition.
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Ayumi Serizawa, Ryosuke Okudera, Yumo Ouchi, Mizuho Yoshihira, Yuya Shiomi, Naoya Nitta, Masataka Nakahara, Akira Baba, Yutaka Miyake, Tetsushi Ohki, and Masakatsu Nishigaki
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- 2022
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9. Gold nanostructures/quantum dots for the enhanced efficiency of organic solar cells.
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Apichat Phengdaam, Sopit Phetsang, Sachiko Jonai, Kazunari Shinbo, Keizo Kato, and Akira Baba
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- 2024
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10. Neurological and Neuroradiological Manifestations in Neonates Born to Mothers With Coronavirus Disease 2019
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Mariko Kurokawa, Ryo Kurokawa, Ava Yun Lin, Aristides A. Capizzano, Akira Baba, John Kim, Timothy D. Johnson, Ashok Srinivasan, and Toshio Moritani
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Developmental Neuroscience ,Neurology ,Pediatrics, Perinatology and Child Health ,Neurology (clinical) - Published
- 2023
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11. Utility of dynamic susceptibility contrast MRI for differentiation between paragangliomas and meningiomas in the cerebellopontine angle and jugular foramen region
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Yoshiaki Ota, Eric Liao, Raymond Zhao, Aristides A. Capizzano, Akira Baba, Remy Lobo, Gaurang Shah, and Ashok Srinivasan
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Radiology, Nuclear Medicine and imaging - Published
- 2023
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12. Neuroimaging features of FOXR2‐activated CNS neuroblastoma: A case series and systematic review
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Kenichiro Shimazaki, Ryo Kurokawa, Andrea Franson, Mariko Kurokawa, Akira Baba, Laura Bou‐Maroun, John Kim, and Toshio Moritani
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Radiology, Nuclear Medicine and imaging ,Neurology (clinical) - Published
- 2023
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13. Precise differentiation between jugular foramen paragangliomas and metastases: utility of diffusion-weighted and dynamic contrast-enhanced magnetic resonance imaging
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Yoshiaki Ota, Guillaume Curaudeau, Eric Liao, Jayapalli Bapuraj, Akira Baba, Gaurang Shah, and Ashok Srinivasan
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Radiology, Nuclear Medicine and imaging ,Neurology (clinical) ,Cardiology and Cardiovascular Medicine - Published
- 2023
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14. Comparative evaluation of temporal subtraction computed tomography and non-echoplanar diffusion-weighted imaging for the mastoid extension of middle ear cholesteatoma
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Akira Baba, Sho Kurihara, Ryo Kurokawa, Mariko Kurokawa, Yoshiaki Ota, Satoshi Matsushima, Takeshi Fukuda, Hideomi Yamauchi, Rui Kano, Tomokazu Shoji, Takara Nakazawa, Yutaka Yamamoto, Hiromi Kojima, Ashok Srinivasan, and Hiroya Ojiri
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Diffusion Magnetic Resonance Imaging ,Cholesteatoma, Middle Ear ,Otorhinolaryngology ,Ear, Middle ,Humans ,Surgery ,General Medicine ,Tomography, X-Ray Computed ,Mastoid ,Retrospective Studies - Abstract
Preoperative imaging assessment influences the decision to perform mastoidectomy for the mastoid extension of middle ear cholesteatoma. This study compared the performance of temporal subtraction CT (TSCT) and non-echoplanar diffusion-weighted imaging (non-EP DWI) in evaluating such mastoid extensions.We retrospectively evaluated 239 consecutive patients with surgically proven middle ear cholesteatoma between April 2016 and April 2021. The diagnostic performance of TSCT, wherein the presence of black color indicated progressive bone erosion, and non-EP DWI, wherein high signal intensity in the mastoid region suggested mastoid extension, was compared using Fisher's exact test.In 34 patients with evaluable TSCT images, black color was significantly more common in patients with mastoid extension than in those without; the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of TSCT were 1.00, 0.95, 0.94, 1.00, and 0.97, respectively. In 90 patients with evaluable non-EP DWI, high signal intensity was significantly more common in patients with mastoid extension than in those without; the sensitivity, specificity, PPV, NPV, and accuracy of non-EP DWI were 0.88, 0.85, 0.91, 0.81, and 0.87, respectively. In 16 patients with both evaluable TSCT and non-EP DWI, the diagnostic performance of the TSCT was slightly superior to that of the non-EP DWI for predicting mastoid extension, although the difference was not significant.TSCT images generated using consecutively acquired preoperative high-resolution CT images are useful for predicting mastoid extension of middle ear cholesteatoma, and the diagnostic performance of TSCT is non-inferior to that of non-EP DWI.
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- 2022
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15. Clinical and neuroimaging review of triplet repeat diseases
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Ryo Kurokawa, Mariko Kurokawa, Akihiko Mitsutake, Moto Nakaya, Akira Baba, Yasuhiro Nakata, Toshio Moritani, and Osamu Abe
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Radiology, Nuclear Medicine and imaging - Abstract
Triplet repeat diseases (TRDs) refer to a group of diseases caused by three nucleotide repeats elongated beyond a pathologic threshold. TRDs are divided into the following four groups depending on the pathomechanisms, although the pathomechanisms of several diseases remain unelucidated: polyglutamine disorders, caused by a pathologic repeat expansion of CAG (coding the amino acid glutamine) located within the exon; loss-of-function repeat disorders, characterized by the common feature of a loss of function of the gene within which they occur; RNA gain-of-function disorders, involving the production of a toxic RNA species; and polyalanine disorders, caused by a pathologic repeat expansion of GCN (coding the amino acid alanine) located within the exon. Many of these TRDs manifest through neurologic symptoms; moreover, neuroimaging, especially brain magnetic resonance imaging, plays a pivotal role in the detection of abnormalities, differentiation, and management of TRDs. In this article, we reviewed the clinical and neuroimaging features of TRDs. An early diagnosis of TRDs through clinical and imaging approaches is important and may contribute to appropriate medical intervention for patients and their families.
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- 2022
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16. Unsupervised Noisy Environment Adaptation Algorithm Using MLLR and Speaker Selection
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Miichi, Yamada, Akira, Baba, Shinichi, Yoshizawa, Yuichiro, Mera, Akinobu, Lee, Hiroshi, Saruwatari, Kiyohiro, Shikano, Miichi, Yamada, Akira, Baba, Shinichi, Yoshizawa, Yuichiro, Mera, Akinobu, Lee, Hiroshi, Saruwatari, and Kiyohiro, Shikano
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An unsupervised acoustic model adaptation algorithm using MLLR and speaker selection for noisy environments is proposed. The proposed algorithm requires only one arbitrary utterance and environmental noise data. The adaptation procedure is composed of the following four steps. (1) Speaker selection from a large number of database speakers is carried out using GMM speaker models based on one arbitrary utterance. (2) Initial speaker adapted HMM acoustic models are calculated from the HMM sufficient statistics of the selected speakers, where the sufficient HMM statistics are pre-calculated and stored. (3) A small subset of the clean speech database from the selected speakers and the environment noise data are superimposed. (4) MLLR adaptation is carried out using the noise-superimposed speech database from the selected speakers. The proposed algorithm is evaluated in a 20k vocabulary dictation task for newspaper in noisy environments. We attain 85.7% word correct rate in 25dB SNR, which is slightly better than the matched model by the E-M training using noise superimposed whole speech database. The proposed algorithm is also 7% better than the HMM composition algorithm., EUROSPEECH2001: the 7th European Conference on Speech Communication and Technology, September 3-7, 2001, Aalborg, Denmark.
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- 2023
17. Unsupervised Speaker Adaptation Based on Sufficient HMM Statistics of Selected Speakers
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Shinichi, Yoshizawa, Akira, Baba, Kanako, Matsunami, Yuichiro, Mera, Miichi, Yamada, Kiyohiro, Shikano, Shinichi, Yoshizawa, Akira, Baba, Kanako, Matsunami, Yuichiro, Mera, Miichi, Yamada, and Kiyohiro, Shikano
- Abstract
Describes an efficient method for unsupervised speaker adaptation. This method is based on (1) selecting a subset of speakers who are acoustically close to a test speaker, and (2) calculating adapted model parameters according to the previously stored sufficient HMM statistics of the selected speakers' data. In this method, only a few unsupervised test speaker's data are required for the adaptation. Also, by using the sufficient HMM statistics of the selected speakers' data, a quick adaptation can be done. Compared with a pre-clustering method, the proposed method can obtain a more optimal speaker cluster because the clustering result is determined according to test speaker's data on-line. Experimental results show that the proposed method attains better improvement than MLLR from the speaker independent model. Moreover the proposed method utilizes only one unsupervised sentence utterance, while MLLR usually utilizes more than ten supervised sentence utterances, ICASSP2001: IEEE International Conference on Acoustics, Speech and Signal Processing, May 7-11, 2001, Salt Lake City, Utah, US.
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- 2023
18. Spectral Subtraction in Noisy Environments Applied to Speaker Adaptation Based on HMM Sufficient Statistics
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Shingo, Yamade, Kanako, Matsunami, Akira, Baba, Akinobu, Lee, Hiroshi, Saruwatari, Kiyohiro, Shikano, Shingo, Yamade, Kanako, Matsunami, Akira, Baba, Akinobu, Lee, Hiroshi, Saruwatari, and Kiyohiro, Shikano
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Noise and speaker adaptation techniques are essential to realize robust speech recognition in real noisy environments . In this paper, we applied spectral subtraction to an unsupervised speaker adaptation algorithm in noisy environments. The adaptation algorithm consists of the following five steps. (1) Spectral subtraction is carried out for noise added database. (2) Noise matched acoustic models are trained by using noise added speech database. (3) HMM sufficient statistics for each speaker are calculated from noise added speech database, and stored. (4) According to one arbitrary utterance, speakers close to a test speaker are selected by using speaker GMMs. (5) Speaker adapted acoustic models are constructed from HMM sufficient statistics of the selected speakers. We evaluated our unsupervised speaker adaptation algorithm in noisy environments in the 20k dictation task. The recognition experiments show that our speaker adapted acoustic model can achieve 82% word accuracy in 20dB SNR, which is about 6% higher than that of the noise matched models trained by Forward-Backward algorithm., ICSLP2002: the 7th International Conference on Spoken Language Processing , September 16-20, 2002, Denver, Colorado, USA.
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- 2023
19. Elderly Acoustic Model for Large Vocabulary Continuous Speech Recognition
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Akira, Baba, Shinichi, Yoshizawa, Miichi, Yamada, Akinobu, Lee, Kiyohiro, Shikano, Akira, Baba, Shinichi, Yoshizawa, Miichi, Yamada, Akinobu, Lee, and Kiyohiro, Shikano
- Abstract
In this paper, we evaluate elderly speaker acoustic models in LVCSR, which are trained by the 301 elderly speakers' database from the age of 60 to 90. Each speaker utters 200 sentences. The elderly speaker PTM (Phonetic Tied Mixture) acoustic model attains 88.9% word recognition rate, which is better than 86.0% word recognition rate by the usual adult (an average age of 28.6) PTM acoustic model. To achieve higher recognition rates, we use two types of speaker adaptation methods, which are a supervised MLLR and an unsupervised adaptation method based on the sufficient HMM statistics. In our experimental results, the elderly acoustic model is better as the adaptation baseline HMM model than the usual adult model for elderly speakers., EUROSPEECH2001: the 7th European Conference on Speech Communication and Technology, September 3-7, 2001, Aalborg, Denmark.
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- 2023
20. Evaluation on Unsupervised Speaker Adaptation Based on Sufficient HMM Statictics of Selected Speakers
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Shinichi, Yoshizawa, Akira, Baba, Kanako, Matsunami, Yuichiro, Mera, Miichi, Yamada, Akinobu, Lee, Kiyohiro, Shikano, Shinichi, Yoshizawa, Akira, Baba, Kanako, Matsunami, Yuichiro, Mera, Miichi, Yamada, Akinobu, Lee, and Kiyohiro, Shikano
- Abstract
This paper describes an efficient method of unsupervised speaker adaptation. This method is based on (1) selecting a subset of speakers who are acoustically close to a test speaker, and (2) calculating adapted model parameters according to the previously stored sufficient statistics of the selected speakers' data. In this method, only a few unsupervised test speaker's data are necessary for the adaptation. Also, by using the sufficient HMM statistics of the selected speakers' data, a quick adaptation can be done. Compared with a pre-clustering method, the proposed method can obtain a more optimal cluster because the clustering result is determined according to test speaker's data on-line. Experimental results show that the proposed method attains better improvement than MLLR from the speaker-independent model. The proposed method is evaluated in details and discussed., EUROSPEECH2001: the 7th European Conference on Speech Communication and Technology, September 3-7, 2001, Aalborg, Denmark.
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- 2023
21. Imaging Features of Ectopic Tissues and Their Complications: Embryologic and Anatomic Approach
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Mariko Kurokawa, Ryo Kurokawa, Kentaro Tamura, Akira Baba, Yoshiaki Ota, Moto Nakaya, Kota Yokoyama, John Kim, Toshio Moritani, and Osamu Abe
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Radiology, Nuclear Medicine and imaging - Published
- 2023
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22. MRI features of sinonasal tract angiofibroma/juvenile nasopharyngeal angiofibroma: Case series and systematic review
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Akira Baba, Ryo Kurokawa, Mariko Kurokawa, and Ashok Srinivasan
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Radiology, Nuclear Medicine and imaging ,Neurology (clinical) - Published
- 2023
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23. Neuroimaging of hypophysitis: etiologies and imaging mimics
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Ryo Kurokawa, Mariko Kurokawa, Akira Baba, Moto Nakaya, Shimpei Kato, Jayapalli Bapuraj, Yasuhiro Nakata, Yoshiaki Ota, Ashok Srinivasan, Osamu Abe, and Toshio Moritani
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Radiology, Nuclear Medicine and imaging - Abstract
Hypophysitis is an inflammatory disease affecting the pituitary gland. Hypophysitis can be classified into multiple types depending on the mechanisms (primary or secondary), histology (lymphocytic, granulomatous, xanthomatous, plasmacytic/IgG4 related, necrotizing, or mixed), and anatomy (adenohypophysitis, infundibulo-neurohypophysitis, or panhypophysitis). An appropriate diagnosis is vital for managing these potentially life-threatening conditions. However, physiological morphological alterations, remnants, and neoplastic and non-neoplastic lesions may masquerade as hypophysitis, both clinically and radiologically. Neuroimaging, as well as imaging findings of other sites of the body, plays a pivotal role in diagnosis. In this article, we will review the types of hypophysitis and summarize clinical and imaging features of both hypophysitis and its mimickers.
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- 2023
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24. Cauda Equina Atrophy in Amyotrophic Lateral Sclerosis on Routine Lumbar Magnetic Resonance Imaging
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Satoshi, Matsushima, Shusaku, Omoto, Tetsuya, Shimizu, Akira, Baba, and Hiroya, Ojiri
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Cauda Equina ,Amyotrophic Lateral Sclerosis ,Humans ,Reproducibility of Results ,Radiology, Nuclear Medicine and imaging ,Atrophy ,Magnetic Resonance Imaging ,Retrospective Studies - Abstract
The aim of the study was to evaluate the cross-sectional area of the cauda equina in amyotrophic lateral sclerosis (ALS) on routine lumbar magnetic resonance imaging and investigate the diagnostic accuracy in comparison with age- and sex-matched non-ALS controls.This retrospective study included 15 ALS patients and 15 age- and sex-matched non-ALS controls. Two independent neuroradiologists measured and compared the total cross-sectional area of the cauda equina of ALS patients and the non-ALS controls at the level of the L3 and L4 using axial T2-weighted images. The cutoff value, sensitivity, specificity, and area under the curve were measured. The interobserver reproducibility of the 2 independently obtained measurements was evaluated.The total cross-sectional area of the cauda equina in the ALS group was significantly smaller than that in the non-ALS group (L3: median, 66.73 vs 90.19 mm 2 , P0.001; L4: median, 52.9 vs 67.63 mm 2 , P0.001). The cutoff values at L3 and L4 were 76.95 and 61.04 mm 2 with a sensitivity and specificity of 1 and 0.87 and 0.8 and 0.87, respectively. The area under the curve at L3 and L4 were high at 0.96 and 0.94, respectively. The interobserver reproducibility was 0.88 at L3 and 0.89 at L4.The ALS patients showed significant atrophy of the cauda equina compared with non-ALS patients.
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- 2022
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25. Intramuscular hemangioma in the masseter muscle: A case report and literature review
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Masateru Katayama, Nobuyuki Matsuura, Kazuhiko Hashimoto, Katsuhiko Sakai, Takeshi Nomura, Akira Baba, and Masumi Komatsu
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Pathology ,medicine.medical_specialty ,genetic structures ,business.industry ,Vascular disease ,Skeletal muscle ,medicine.disease ,Intramuscular Hemangioma ,Pathology and Forensic Medicine ,Lesion ,Masseter muscle ,Hemangioma ,Endothelial stem cell ,medicine.anatomical_structure ,Otorhinolaryngology ,medicine ,Vascular tumor ,Surgery ,Oral Surgery ,medicine.symptom ,business - Abstract
Intramuscular hemangioma (IMH) is a rare vascular disease involving the skeletal muscle. Approximately 13.8 % of IMHs occur in the head and neck region and, mostly involve the masseter muscle. This variant of hemangioma is categorized as a vascular tumor in the World Health Organization, classification: however, it is often difficult to determine whether benign vascular lesions are malformations, true neoplasms, or reactive processes. For intramuscular vascular lesions of the masseter muscle, it is likely that these lesions are malformations rather than tumors. We present a case of IMH in the masseter muscle, which was considered to have neoplastic characteristics due to the presence of endothelial cell proliferation. The lesion was excised and there was no recurrence during the 3-year follow-up period. The literature review includes eight cases of IMH in the masseter muscle with histopathological findings.
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- 2022
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26. Neuroimaging features of angiocentric glioma: A case series and systematic review
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Ryo Kurokawa, Akira Baba, Pinarbasi Emile, Mariko Kurokawa, Yoshiaki Ota, John Kim, Aristides Capizzano, Ashok Srinivasan, and Toshio Moritani
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Male ,Adolescent ,Brain Neoplasms ,Seizures ,Humans ,Female ,Neuroimaging ,Radiology, Nuclear Medicine and imaging ,Glioma ,Neurology (clinical) ,Atrophy ,Magnetic Resonance Imaging - Abstract
Angiocentric gliomas (AGs) are epileptogenic low-grade gliomas in young patients. We aimed to investigate the MRI findings of AGs and systematically review previous publications and three new cases.We searched PubMed, Elsevier's abstract and citation database, and Embase databases and included 50 patients with pathologically proven AGs with analyzable preoperative MRI including 3 patients from our institution and 47 patients from 38 publications (median age, 13 years [range, 2-83 years]; 35 men). Two board-certified radiologists reviewed all images. The relationships between seizure/epilepsy history and MRI findings were statistically analyzed. Moreover, clinical and imaging differences were evaluated between supratentorial and brainstem AGs.Intratumoral T1-weighted high-intensity areas, stalk-like signs, and regional brain parenchymal atrophy were observed in 23 out of 50 (46.0%), 10 out of 50 (20.0%), and 14 out of 50 (28.0%) patients, respectively. Intratumoral T1-weighted high-intensity areas were observed significantly more frequently in patients with stalk-like signs (positive, 9/10 vs. negative, 14/40, p = .0031) and regional atrophy (13/14 vs. 10/36, p = .0001). There were significant relationships between the length of seizure/epilepsy history and presence of intratumoral T1-weighted high-intensity area (median 3 years vs. 0.5 years, p = .0021), stalk-like sign (13.5 vs. 1 year, p .0001), and regional atrophy (14 vs. 0.5 years, p .0001). Patients with brainstem AGs (n = 7) did not have a seizure/epilepsy history and were significantly younger than those with supratentorial AGs (median, 5 vs. 13 years, p .0001, respectively).Intratumoral T1-weighted high-intensity areas, stalk-like signs, and regional brain atrophy were frequent imaging features in AG. We also found that affected age was different between supratentorial and brainstem AGs.
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- 2022
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27. Prdm12 regulates inhibitory neuron differentiation in mouse embryonal carcinoma cells
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Akira Baba, Takuya Suwada, Shigeru Muta, Satoru Kuhara, and Kosuke Tashiro
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Clinical Biochemistry ,Biomedical Engineering ,Bioengineering ,Cell Biology ,JAACT Issue ,Biotechnology - Abstract
The epigenetic regulatory system significant influences the fate determination of cells during developmental processes. Prdm12 is a transcriptional regulator that modulates gene expression epigenetically. The Prdm12 gene has been shown to be expressed in neural tissues, specifically during development, but its detailed function is not fully understood. This study investigated the function of the Prdm12 gene in P19 mouse embryonic tumor cells as a model for neural differentiation. A decrease in the expression of neuron-specific genes and the alterations of dendrites and axons morphology was confirmed in Prdm12-knockout P19 cells. In addition, almost no astrocytes were generated in Prdm12-knockout P19 cells. Comprehensive gene expression analysis revealed that there was a reduction in the expression of the inhibitory neuron-specific genes Gad1/2 and Glyt2, but not the excitatory neuron-specific gene VGLUT2, in Prdm12-knockout P19 cells. Furthermore, the expression of inhibitory neuron-related factors, Ptf1a, Dbx1, and Gsx1/2, decreased in Prdm12-knockout P19 cells. Gene expression analysis also revealed that the Ptf1a, Hic1, and Foxa1 genes were candidate targets of Prdm12 during neurogenesis. These results suggest that Prdm12 regulates the differentiation of inhibitory neurons and astrocytes by controlling the expression of these genes during the neural differentiation of P19 cells.
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- 2022
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28. Neurofibromatosis type 2 versus sporadic vestibular schwannoma: The utility of MR diffusion and dynamic contrast‐enhanced imaging
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Yoshiaki Ota, Eric Liao, Aristides A. Capizzano, Akira Baba, Ryo Kurokawa, Mariko Kurokawa, and Ashok Srinivasan
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Adult ,Male ,Neurofibromatosis 2 ,Adolescent ,Contrast Media ,Neuroma, Acoustic ,Middle Aged ,Magnetic Resonance Imaging ,Young Adult ,Diffusion Magnetic Resonance Imaging ,Humans ,Female ,Radiology, Nuclear Medicine and imaging ,Neurology (clinical) ,Child ,Aged ,Retrospective Studies - Abstract
The goal of this study was to assess the utility of diffusion-weighted imaging (DWI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to distinguish sporadic vestibular schwannomas (VSs) from those related to neurofibromatosis type 2 (NF2).We retrospectively reviewed 265 patients pathologically diagnosed with VSs between January 2015 and October 2020 in a single institution. There were 28 patients (male: 19, female: 9; age 11-67 years) including 23 sporadic and five NF2-related VSs, who had pretreatment DWI and DCE-MRI. Normalized mean apparent diffusion coefficient (nADCmean) and DCE-MRI parameters along with tumor characteristics were compared between sporadic and NF2-related VSs as appropriate. The diagnostic performances were calculated based on the receiver operating characteristic curve analysis for the values that showed significant differences. To identify significant modalities, multivariate logistic regression analysis was performed using nADCmean and the combination of statistically significant DCE-MRI parameters.NADCmean, fractional volume of extracellular space (Ve), and forward volume transfer constant (Ktrans) were significantly different between sporadic and NF2-related VSs (nADCmean: median 1.62 vs. 1.16, P = .002; Ve: median 0.40 vs. 0.66, P = .007; Ktrans: median 0.17 vs. 0.33, P = .007), whereas fractional plasma volume (Vp), reverse reflux rate constant (Kep), and tumor characteristics were not. The diagnostic performances of nADCmean, Ve, and Ktrans were 0.93, 0.90, and 0.90 area under the curves with cutoffs of 1.46, 0.51, and 0.29, respectively. nADCmean and the combination of Ve and Ktrans were both chosen as significant differentiators by multivariate logistic regression analysis (P = .027).DWI and DCE-MRI are both promising modalities to distinguish sporadic and NF2-related VSs.
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- 2022
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29. Imaging features of laryngeal chondrosarcomas: A case series and systematic review
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Akira Baba, Ryo Kurokawa, Mariko Kurokawa, Yoshiaki Ota, Remy Lobo, and Ashok Srinivasan
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Radiography ,Chondrosarcoma ,Humans ,Bone Neoplasms ,Radiology, Nuclear Medicine and imaging ,Neurology (clinical) ,Magnetic Resonance Imaging ,Retrospective Studies - Abstract
To comprehensively summarize the characteristics of radiological findings of laryngeal conventional chondrosarcomas.We included patients with pathologically proven laryngeal conventional chondrosarcomas with CT and /or MRI, including 41 cases from 31 publications recruited after a systematic review and 14 cases from our institution. Two board-certified radiologists reviewed and evaluated all the radiological images. The relationship between pathological grade and radiological findings was analyzed.The median long diameter of the lesion was 3.1 cm (range, 1.5-8.5 cm). The most common location was the cricoid (74.5%), followed by the thyroid (12.7%), cricoid and thyroid (7.3%), and arytenoid (5.5%). All lesions showed well-defined margins. Cortical defect/expansion (98.0%), internal low density (89.6%), and calcification (95.8%) with homogeneous and scarce contrast enhancement on contrast-enhanced CT (85.3%) were frequently observed. All cases showed high signal on T2-weighted imaging, low signal on T1-weighted imaging (T1WI), and heterogeneous and mild contrast enhancement on postcontrast T1WI. No significant differences were found between the pathological grades and radiological findings.In our summary of comprehensive CT and MRI findings of laryngeal conventional chondrosarcomas, we found that the knowledge of these radiological features may facilitate prompt diagnosis and appropriate management.
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- 2022
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30. Preoperative prediction for mastoid extension of middle ear cholesteatoma using temporal subtraction serial HRCT studies
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Akira Baba, Ryo Kurokawa, Mariko Kurokawa, Yoshiaki Ota, Satoshi Matsushima, Takeshi Fukuda, Hideomi Yamauchi, Rui Kano, Tomokazu Shoji, Sho Kurihara, Takara Nakazawa, Yutaka Yamamoto, Hiromi Kojima, Ashok Srinivasan, and Hiroya Ojiri
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Cholesteatoma, Middle Ear ,Ear, Middle ,Humans ,Temporal Bone ,Radiology, Nuclear Medicine and imaging ,General Medicine ,Tomography, X-Ray Computed ,Mastoid ,Retrospective Studies - Abstract
This study investigated the utility of temporal subtraction computed tomography (TSCT) obtained with temporal bone high-resolution computed tomography (HRCT) for the preoperative prediction of mastoid extension of middle ear cholesteatomas.Twenty-eight consecutive patients with surgically proven middle ear cholesteatomas were retrospectively evaluated. The presence of black color in the mastoid region on TSCT suggested progressive changes caused by bone erosion. Enlarged width of the anterior part of mastoid on HRCT was interpreted as suggestive of mastoid extension. Fisher's exact test was used to compare the widths and black color on TSCT for cases with and without mastoid extension. The diagnostic accuracy of TSCT and HRCT for detecting mastoid extension and interobserver agreement during the evaluation of black color on TSCT were calculated.There were 15 cases of surgically proven mastoid extension and 13 cases without mastoid extension. Patients with black color on TSCT were significantly more likely to have a mastoid extension (p0.001). The sensitivity and specificity of TSCT were 0.93 and 1.00, respectively. Patients in whom the width of the anterior part of the mastoid was enlarged were significantly more likely to have a mastoid extension (p = 0.007). The sensitivity and specificity of HRCT to detect the width of the anterior part of the mastoid were 0.80 and 0.77, respectively. Interobserver agreement during the evaluation of TSCT findings was good (k = 0.71).This novel TSCT technique and preoperative evaluations are useful for assessing mastoid extension of middle ear cholesteatomas and making treatment decisions.•TSCT shows a clear black color in the mastoid region when the middle ear cholesteatoma is accompanied by mastoid extension. •TSCT obtained with preoperative serial HRCT of the temporal bone is useful for assessing mastoid extension of middle ear cholesteatomas.
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- 2022
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31. A rare case of positional changes of carotid artery depicted within a single MR study and a wandering carotid artery depicted on a serial MR studies
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Satoshi Matsushima, Yukiko Tsuneoka, Akira Baba, Reina Kayama, Ryo Kurokawa, Hiroya Ojiri, Mariko Kurokawa, Hideomi Yamauchi, Taiki Suzuki, and Yoshiaki Ota
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medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Retropharyngeal space ,Carotid arteries ,Hyoid bone ,Pulsatile flow ,Clinical course ,R895-920 ,Case Report ,Physical examination ,Medical physics. Medical radiology. Nuclear medicine ,medicine.anatomical_structure ,Retropharyngeal carotid artery ,Rare case ,medicine ,Wandering carotid artery ,Radiology, Nuclear Medicine and imaging ,Mr studies ,Radiology ,business ,MRI - Abstract
The retropharyngeal carotid artery (RCA) is a relatively rare anatomical malposition, and positional changes in the RCA is also extremely rare. In addition, there are some reports of ''wandering carotid artery'' which means that the carotid artery reciprocate positional changes (wandering) between its normal position and retropharyngeal regions, during follow-up evaluations. A male patient in his 50s with a chief complaint of globus pharyngeus. A pulsatile swelling of the posterior pharyngeal wall of the right side was found on clinical examination. In this case, the right carotid artery showed the clinical course of a wandering carotid artery, which reciprocated between its normal position and the retropharyngeal space during three serial MR investigations. Interestingly, both the most recent MR study and the MR study performed 4 years ago showed that the carotid artery at the level of the hyoid bone moved laterally (positional normalization) during the single MR investigation. This is a first case which showed a rare clinical course of a wandering carotid artery on serial follow-up MR studies and positional changes of carotid artery within a single MR study. It is important for clinicians to be aware of these phenomena, in order to avoid fatal and unexpected complications during clinical procedures.
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- 2022
32. Tunable surface plasmon resonance enhanced fluorescence via the stretching of a gold quantum dot-coated aluminum-coated elastomeric grating substrate
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Patrawadee Yaiwong, Chutiparn Lertvachirapaiboon, Kazunari Shinbo, Keizo Kato, Kontad Ounnunkad, and Akira Baba
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General Chemical Engineering ,General Engineering ,Analytical Chemistry - Abstract
Controlling the fluorescence intensity of AuQDs by shifting the SPR-excitation wavelength was demonstrated by stretching the Al-coated PDMS-grating substrate.
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- 2022
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33. Central Nervous System Systemic Lupus Erythematosus: Pathophysiologic, Clinical, and Imaging Features
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Yoshiaki Ota, Ashok Srinivasan, Aristides A. Capizzano, Jayapalli R. Bapuraj, John Kim, Ryo Kurokawa, Akira Baba, and Toshio Moritani
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Central Nervous System ,Lupus Vasculitis, Central Nervous System ,Prevalence ,Brain ,Humans ,Lupus Erythematosus, Systemic ,Radiology, Nuclear Medicine and imaging - Abstract
Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by multiple immunologic abnormalities and has the potential to involve the central nervous system (CNS). The prevalence of SLE seems to be growing, possibly because of earlier diagnosis and improved survival; however, the associated mortality is still high. The mortality is associated with disease-related risk factors such as lupus disease activity, young age, and organ damage or with antiphospholipid syndrome (APS). Neuropsychiatric SLE (NPSLE), which is caused by SLE-related CNS involvement, comprises a broad range of neurologic and psychiatric manifestations with varying severity, which can make this disease indistinguishable from other conditions that are unrelated to SLE. No unifying pathophysiology has been found in the etiology of NPSLE, suggesting that this condition has multiple contributors such as various immune effectors and the brain-intrinsic neuroimmune interfaces that are breached by the immune effectors. The postulated neuroimmune interfaces include the blood-brain barrier, blood-cerebrospinal fluid barrier, meningeal barrier, and glymphatic system. On the basis of the immunologic, pathologic, and imaging features of NPSLE, the underlying pathophysiology can be classified as vasculitis and vasculopathy, APS, demyelinating syndrome, or autoimmune antibody-mediated encephalitis. Each pathophysiology has different imaging characteristics, although the imaging and pathophysiologic features may overlap. Moreover, there are complications due to the immunocompromised status caused by SLE per se or by SLE treatment. Radiologists and clinicians should become familiar with the underlying mechanisms, radiologic findings, and complications of NPSLE, as this information may aid in the diagnosis and treatment of NPSLE.
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- 2022
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34. Brain MRI Findings of Hemophagocytic Lymphohistiocytosis With a Heterozygous PRF1 Gene Mutation Masquerading As CLIPPERS: A Case Report
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Arisa Tachibana, Ryo Kurokawa, Aristides A Capizzano, David N Irani, Mariko Kurokawa, Akira Baba, John Kim, and Toshio Moritani
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General Engineering - Published
- 2023
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35. Diffusion and Perfusion Imaging in Post-Treatment Evaluation of the Head and Neck
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Akira Baba, Ryo Kurokawa, Roberto Rivera-de Choudens, Mariko Kurokawa, Yoshiaki Ota, and Ashok Srinivasan
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Radiology, Nuclear Medicine and imaging - Published
- 2023
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36. STUDY ON ASH DEPOSITION CHARACTERISTICS OF DIFFERENT TYPES OF COALS
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Miki Shimogori, Noriyuki Ooyatsu, Noboru Takarayama, and Akira Baba
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- 2023
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37. CT and MR imaging of laryngeal metastasis from renal cell carcinoma: A case report
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Hideomi Yamauchi, Satoshi Matsushima, Akira Baba, Hirokazu Ashida, Hiroya Ojiri, Ryo Kurokawa, Mariko Kurokawa, Yoshiaki Ota, Reina Kayama, Norihiko Uchio, and Matsusato Tsuyumu
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Larynx ,medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Laryngoscopy ,Renal Cell Carcinoma ,R895-920 ,Case Report ,medicine.disease ,Metastasis ,Medical physics. Medical radiology. Nuclear medicine ,medicine.anatomical_structure ,Laryngeal Metastasis ,Renal cell carcinoma ,Angiography ,medicine ,Radiology, Nuclear Medicine and imaging ,Radiology ,Differential diagnosis ,Subglottis ,business ,Intervertebral foramen ,CT ,MRI - Abstract
Laryngeal metastasis is an extremely rare condition. To the best of our knowledge, there has been no previous report on a laryngeal metastasis from renal cell carcinoma, which describes on details of the CT and MR imaging findings. A male patient in his 80s. Laryngoscopy revealed reddish-colored masses in the right false vocal cord and in the subglottic larynx. CT and MR imaging of this case showed multiple hypervascularized lesions with a wash-out effect in the supra and subglottis of the larynx and in the right intervertebral foramen of the cervical spine. Angiography revealed a hypervascular tumor consistent with the subglottic lesion. The histopathology and immunohistochemistry findings were compatible with laryngeal metastasis from renal clear cell carcinoma. A history of postoperative renal clear cell carcinoma about 7 years ago was later confirmed, which was not stated at the time of the initial imaging evaluation. It is a possible differential diagnosis in cases of multiple hypervascular masses in the head and neck region with a history of renal carcinoma. In particular, if the contrast-enhancement pattern of the lesion on the dynamic CT is similar to that of renal cell carcinoma. It is also important to reconfirm the patient's medical history, including postoperative status.
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- 2021
38. Differentiation of pilocytic astrocytoma, medulloblastoma, and hemangioblastoma on diffusion-weighted and dynamic susceptibility contrast perfusion MRI
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Ryo Kurokawa, Mariko Kurokawa, Akira Baba, John Kim, Aristides Capizzano, Jayapalli Bapuraj, Ashok Srinivasan, and Toshio Moritani
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Brain Neoplasms ,General Medicine ,Astrocytoma ,Magnetic Resonance Imaging ,Hemangioblastoma ,Diagnosis, Differential ,Perfusion ,Diffusion Magnetic Resonance Imaging ,Humans ,Female ,Child ,Cerebellar Neoplasms ,Medulloblastoma ,Retrospective Studies - Abstract
This study aimed to evaluate the diagnostic performance of dynamic susceptibility contrast (DSC) perfusion magnetic resonance imaging and apparent diffusion coefficient (ADC) for differentiating common posterior fossa tumors, pilocytic astrocytoma (PA), medulloblastoma (MB), and hemangioblastoma (HB). Between January 2016 and April 2022, we enrolled 23 (median age, 7 years [range, 2-26]; 12 female), 13 (10 years [1-24]; 3 female), and 12 (43 years [23-73]; 7 female) patients with PA, MB, and HB, respectively. Normalized relative cerebral blood volume and flow (nrCBV and nrCBF) and normalized mean ADC (nADCmean) were calculated from volume-of-interest and statistically compared. nADCmean was significantly higher in PA than in MB (PA: median, 2.2 [range, 1.59-2.65] vs MB: 0.93 [0.70-1.37], P .001). nrCBF was significantly higher in HB than in PA and MB (PA: 1.10 [0.54-2.26] vs MB: 1.62 [0.93-3.16] vs HB: 7.83 [2.75-20.1], all P .001). nrCBV was significantly different between all 3 tumor types (PA: 0.89 [0.34-2.28] vs MB: 1.69 [0.93-4.23] vs HB: 8.48 [4.59-16.3], P = .008 for PA vs MB; P .001 for PA vs HB and MB vs HB). All tumors were successfully differentiated using an algorithmic approach with a threshold value of 4.58 for nrCBV and subsequent threshold value of 1.38 for nADCmean. DSC parameters and nADCmean were significantly different between PA, MB, and HB. An algorithmic approach combining nrCBV and nADCmean may be useful for differentiating these tumor types.
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- 2022
39. Deadly Fungi: Invasive Fungal Rhinosinusitis in the Head and Neck
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Mariko Kurokawa, Ryo Kurokawa, Akira Baba, John Kim, Christopher Tournade, Jonathan Mchugh, Jonathan D. Trobe, Ashok Srinivasan, Jayapalli Rajiv Bapuraj, and Toshio Moritani
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Cavernous Sinus Thrombosis ,Fungi ,Humans ,COVID-19 ,Mucormycosis ,Radiology, Nuclear Medicine and imaging ,Sinusitis - Abstract
Invasive fungal rhinosinusitis (IFRS) is a serious infection that is associated with high morbidity and mortality rates. The incidence of IFRS has been increasing, mainly because of the increased use of antibiotics and immunosuppressive drugs. Rhino-orbital cerebral mucormycosis has recently reemerged among patients affected by COVID-19 and has become a global concern. The detection of extrasinus involvement in its early stage contributes to improved outcomes; therefore, imaging studies are essential in establishing the degree of involvement and managing the treatment properly, especially in immunocompromised patients. The common sites of extrasinus fungal invasion are the intraorbital, cavernous sinus, and intracranial regions. Fungi spread directly to these regions along the blood vessels or nerves, causing devastating complications such as optic nerve ischemia or compression, optic neuritis or perineuritis, orbital cellulitis, cavernous sinus thrombosis, mycotic aneurysm, vasculitis, internal carotid arterial occlusion, cerebral infarction, cerebritis, and brain abscess. IFRS has a broad imaging spectrum, and familiarity with intra- and extrasinonasal imaging features, such as loss of contrast enhancement of the affected region, which indicates tissue ischemia due to angioinvasion of fungi, and the surrounding anatomy is essential for prompt diagnosis and management. The authors summarize the epidemiology, etiology, risk factors, and complications of IFRS and review the anatomy and key diagnostic imaging features of IFRS beyond the sinonasal regions.
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- 2022
40. Perfusion and diffusion-weighted imaging parameters: Comparison between pre- and postbiopsy MRI for high-grade glioma
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Ryo Kurokawa, Akira Baba, Mariko Kurokawa, Aristides Capizzano, Yoshiaki Ota, John Kim, Ashok Srinivasan, and Toshio Moritani
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Perfusion ,Diffusion Magnetic Resonance Imaging ,Adolescent ,Cerebrovascular Circulation ,Humans ,Female ,General Medicine ,Glioma ,Magnetic Resonance Imaging - Abstract
We aimed to evaluate the differences in dynamic susceptibility contrast (DSC)- magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) parameters between the pre- and postbiopsy MRI obtained before treatment in patients with diffuse midline glioma, H3K27-altered. The data of 25 patients with pathologically proven diffuse midline glioma, H3K27-altered, were extracted from our hospital's database between January 2017 and August 2021. Twenty (median age, 13 years; range, 3-52 years; 12 women) and 8 (13.5 years; 5-68 years; 1 woman) patients underwent preoperative DSC-MRI and DWI before and after biopsy, respectively. The normalized corrected relative cerebral blood volume (ncrCBV), normalized relative cerebral blood flow (nrCBF), and normalized maximum, mean, and minimum apparent diffusion coefficient (ADC) were calculated using the volumes-of-interest of the tumor and normal-appearing reference region. The macroscopic postbiopsy changes (i.e., biopsy tract, tissue defect, and hemorrhage) were meticulously excluded from the postbiopsy measurements. The DSC-MRI and DWI parameters of the pre- and postbiopsy groups were compared using the Mann-Whitney U test. The ncrCBV was significantly lower in the postbiopsy group than in the prebiopsy group [prebiopsy group: median 1.293 (range, 0.513 to 2.547) versus postbiopsy group: 0.877 (0.748 to 1.205), P = .016]. No significant difference was observed in the nrCBF and normalized ADC values, although the median nrCBF was lower in the postbiopsy group. The DSC-MRI parameters differed between the pre- and postbiopsy MRI obtained pretreatment, although the macroscopic postbiopsy changes were carefully excluded from the analysis. The results emphasize the potential danger of integrating and analyzing DSC-MRI parameters derived from pre- and postbiopsy MRI.
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- 2022
41. Inferior vena cava diameter on CT angiography predicts mesenteric angiography positive for extravasation in colonic diverticular bleeding
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Yosuke Nozawa, Kenkichi Michimoto, Hirokazu Ashida, Akira Baba, Takeshi Fukuda, and Hiroya Ojiri
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Radiology, Nuclear Medicine and imaging ,General Medicine - Abstract
Transcatheter arterial embolization (TAE) for colonic diverticular bleeding (CDB), an established procedure for hemostasis, is sometimes complicated by spontaneous hemostasis and unclear bleeding site on angiography despite active arterial bleeding on preoperative computed tomography angiography (CTA). Therefore, to investigate and increase the feasibility of TAE, this retrospective study evaluates the clinical and radiological features related to positive extravasation on angiography.Sixty CDB patients with extravasation on CTA underwent TAE between January 2011 and February 2021 and were divided into extravasation-positive (P-group; n = 25) and -negative groups (N-group; n = 35) based on the superior or inferior mesenteric angiography. Patient characteristics, laboratory findings, the diameter of the inferior vena cava (IVCD), the diameter of superior and inferior mesenteric veins, and technical outcomes were evaluated.TAE was successful in 24 patients in the P-group (96%) and 14 in the N-group (40%) (p 0.001). Univariate analysis revealed "usage of anticoagulant" (p 0.05) and "larger IVCD (p 0.05) on preoperative CTA" to be significant predictors of positive extravasation. In the multivariate analysis, IVCD remained significant with an adjusted odds ratio of 1.17. The IVCD cutoff value was 13.6 mm (area under the curve = 0.72, sensitivity = 84.0%, specificity = 54.3%). There were no significant differences in other parameters.Measurement of IVCD in CDB with the cutoff value of 13.6 mm can be a simple and useful indicator to predict the detectability of extravasation following TAE procedures.
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- 2022
42. Skull metastases and osseous venous malformations: The role of diffusion-weighted and dynamic contrast-enhanced MRI
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Ryo Kurokawa, Mariko Kurokawa, Adam Holmes, Akira Baba, Jayapalli Bapuraj, Aristides Capizzano, John Kim, Ashok Srinivasan, and Toshio Moritani
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Lung Neoplasms ,Skull ,Contrast Media ,Breast Neoplasms ,Middle Aged ,Magnetic Resonance Imaging ,Diffusion Magnetic Resonance Imaging ,Carcinoma, Non-Small-Cell Lung ,Humans ,Radiology, Nuclear Medicine and imaging ,Female ,Neurology (clinical) ,Aged ,Retrospective Studies - Abstract
Skull metastasis (SM) is a common secondary malignancy. We evaluated the diagnostic performance of diffusion-weighted imaging (DWI) and dynamic contrast-enhanced magnetic resonance imaging (MRI) in differentiating SM from osseous venous malformations and SM of various origins.This study included 31 patients with SM (median age, 64 years; range, 41-87 years; 29 women; 24 and 7 patients with breast and non-small cell lung cancer, respectively) and 16 with osseous venous malformations (median age, 68 years; range, 20-81 years; 10 women) who underwent both DWI and dynamic contrast-enhanced MRI between January 2015 and October 2021. Normalized mean apparent diffusion coefficients (ADCs) and dynamic contrast-enhanced MRI parameters were compared between SM and osseous venous malformations, and between breast cancer and non-small cell lung cancer. Multivariate stepwise logistic regression analyses were performed to identify statistically significant parameters.Plasma volume and time-to-maximum enhancement were the most statistically significant parameters for differentiating SM from osseous venous malformations, with an area under the receiver operating characteristic curve of 0.962. The normalized mean ADC and peak enhancement values were the most statistically significant parameters for differentiating breast cancer from non-small cell lung cancer, with an area under the curve of 0.924.Our results highlight the efficacious diagnostic performance of DWI and dynamic contrast-enhanced MRI in distinguishing SM from osseous venous malformations and differentiating SM of various origins.
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- 2022
43. Major Changes in 2021 World Health Organization Classification of Central Nervous System Tumors
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Ryo Kurokawa, Mariko Kurokawa, Akira Baba, Yoshiaki Ota, Emile Pinarbasi, Sandra Camelo-Piragua, Aristides A. Capizzano, Eric Liao, Ashok Srinivasan, and Toshio Moritani
- Subjects
Central Nervous System Neoplasms ,Brain Neoplasms ,Mutation ,Humans ,Radiology, Nuclear Medicine and imaging ,Glioma ,Astrocytoma ,World Health Organization ,Isocitrate Dehydrogenase - Abstract
The World Health Organization (WHO) published the fifth edition of the
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- 2022
44. Intracranial paragangliomas versus schwannomas: Role of dynamic susceptibility contrast perfusion and diffusion MRI
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Yoshiaki Ota, Eric Liao, Aristides A. Capizzano, Akira Baba, Ryo Kurokawa, Mariko Kurokawa, and Ashok Srinivasan
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Paraganglioma ,Perfusion ,Neurofibromatosis 2 ,Diffusion Magnetic Resonance Imaging ,Humans ,Radiology, Nuclear Medicine and imaging ,Neurology (clinical) ,Neurilemmoma ,Retrospective Studies - Abstract
Differentiating paragangliomas from schwannomas and distinguishing sporadic from neurofibromatosis type 2 (NF 2)-related schwannomas is challenging but clinically important. This study aimed to assess the utility of dynamic susceptibility contrast perfusion MRI (DSC-MRI) and diffusion-weighted imaging (DWI) in discriminating infratentorial extra-axial schwannomas from paragangliomas and NF2-related schwannomas.This retrospective study included 41 patients diagnosed with paragangliomas, sporadic schwannomas, and NF2-related schwannomas in the infratentorial extra-axial space between April 2013 and August 2021. All cases had pretreatment DSC-MRI and DWI. Normalized mean apparent diffusion coefficient (nADCmean), normalized relative cerebral blood volume (nrCBV), and normalized relative cerebral blood flow (nrCBF) were compared between paragangliomas and schwannomas and between sporadic and NF2-related schwannomas as appropriate.nrCBV and nrCBF were significantly higher in paragangliomas than in sporadic/NF2-related schwannomas (nrCBV: median 11.5 vs. 1.14/3.74; p lt; .001 and .004, nrCBF: median 7.43 vs. 1.13/2.85; p lt; .001 and .007, respectively), while nADCmean were not. The corresponding diagnostic performances were area under the curves (AUCs) of .99/.92 and 1.0/.90 with cutoffs of 2.56/4.22 and 1.94/3.36, respectively. nADCmean were lower, and nrCBV and nrCBF were higher in NF2-related than in sporadic schwannomas (nADCmean: median 1.23 vs. 1.58, nrCBV: median 3.74 vs. 1.14, nrCBF: median 2.85 vs. 1.13; all p lt; .001), and the corresponding diagnostic performances were AUCs of .93, .91, and .95 with cutoffs of 1.37, 2.63, and 2.48, respectively.DSC-MRI and DWI both can aid in differentiating paragangliomas from schwannomas and sporadic from NF2-related schwannomas.
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- 2022
45. Relationships between contrast-enhanced computed tomography features of hard palate cancer and pathological depth of invasion
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Akira Baba, Ryo Kurokawa, Mariko Kurokawa, Jonathan B. McHugh, Cisley Hines, Yoshiaki Ota, and Ashok Srinivasan
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Palate, Hard ,Neoplasms ,Humans ,Radiology, Nuclear Medicine and imaging ,Dentistry (miscellaneous) ,Surgery ,Oral Surgery ,Tomography, X-Ray Computed ,Pathology and Forensic Medicine ,Retrospective Studies - Abstract
The study aimed to determine the relationships between contrast-enhanced computed tomography (CECT) features of hard palate cancer (radiological depth of invasion [r-DOI], detectability of the lesion, and tumor invasion into the palatal bone) and the pathological DOI (p-DOI) of the tumors.In total, 36 lesions were retrospectively evaluated by 2 board-certified radiologists, who examined CECT scans for the radiological features, and 2 board-certified pathologists, who measured the p-DOI on histopathologic sections. Correlation between r-DOI and p-DOI was calculated. The Youden index was used to calculate the optimal p-DOI cutoff values to distinguish between detectable and undetectable lesions and between tumors with and without bony structure invasion.There was excellent agreement between r-DOI and p-DOI (intraclass correlation coefficient = 0.80). The p-DOI of CECT-detectable lesions was significantly greater than that of CECT-undetectable lesions (P.001), with a p-DOI cutoff value of 4 mm. The p-DOI of lesions that had invaded the palatal bone was significantly larger than that of lesions without invasion (P = .039), with a p-DOI cutoff value of 7 mm.Radiological DOI, tumor detectability, and invasion into the palatal bone can be useful in planning surgical treatment strategies for hard palate cancer.
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- 2022
46. Plasmonic photothermal properties of silver nanoparticle grating films
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Siriporn Anuthum, Fugo Hasegawa, Chutiparn Lertvachirapaiboon, Kazunari Shinbo, Keizo Kato, Kontad Ounnunkad, and Akira Baba
- Subjects
General Physics and Astronomy ,Physical and Theoretical Chemistry - Abstract
The plasmon-induced photothermal effect offers effective light-to-heat conversion systems. In this study, we fabricate plasmonic photothermal silver nanoparticle (AgNP) grating films to produce highly effective plasmon-induced heat generation films. AgNP films provide effective heat generation by localized surface plasmon excitation in the void of the AgNP films. The heat generated at a AgNP film by irradiation of solar light is 3.4 times higher than that generated at the reference flat evaporated-Ag film. Furthermore, simultaneous excitation of localized surface plasmons and propagating surface plasmons is confirmed to be obtained on AgNP grating films by finite-difference time-domain simulation and reflectivity measurements. The AgNP grating film is created by the nanoimprinting technique. The grating structure on AgNPs further enhances electric field intensity in the large area of the film, which results in higher heat generation. Thus, 5.4 times higher heat generation is achieved compared with that of the reference flat evaporated-Ag film.
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- 2022
47. Plasmonic induced light trapping enhancement in silicon nanowires hybrid solar cell using indium tin oxide nanoparticles
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Naraphorn Tunghathaithip, Chutiparn Lertvachirapaiboon, Kazunari Sinbo, Keizo Kato, Duangamol Tungasmita, Sukkaneste Tungasmita, and Akira Baba
- Subjects
Materials Chemistry ,Electrical and Electronic Engineering ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials - Abstract
In this study, silicon nanowires (SiNWs) with different lengths was fabricated using the metal-catalyzed electroless etching method and used as the base structure of an inorganic semiconductor hybrid solar cell. This technique is economically attractive and allows us to easily control the physical nanostructure of the nanowires to match the light trapping mechanism of the 3D-structured hybrid solar cell. The length of the nanowire linearly increases with etching times. For solar cell fabrication, poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) was used as an organic semiconductor part. The plasmonic-induced light-trapping enhancement of indium tin oxide nanoparticles (ITO NPs) and gold nanoparticles (AuNPs) mixed with PEDOT:PSS was adapted to improve solar cell performance. It was found that the hybrid solar cell, fabricated from SiNWs with 5 min-etching time, yielded the highest power conversion efficiency (PCE). Furthermore, using ITO NPs and AuNPs in a hole-transport layer of the SiNWs hybrid solar cell can improve the PCE to 50% more than the reference hybrid solar cell. The hybrid solar cell using the concentration between PEDOT:PSS and ITO NPs of 1:1/5 shows the highest PCE of 8.33%.
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- 2023
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48. Comprehensive radiological features of laryngeal sarcoidosis: cases series and systematic review
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Akira Baba, Ryo Kurokawa, Takeshi Fukuda, Mariko Kurokawa, Matsusato Tsuyumu, Satoshi Matsushima, Yoshiaki Ota, Hideomi Yamauchi, Hiroya Ojiri, and Ashok Srinivasan
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Radiography ,Diffusion Magnetic Resonance Imaging ,Sarcoidosis ,Humans ,Radiology, Nuclear Medicine and imaging ,Neurology (clinical) ,Cardiology and Cardiovascular Medicine ,Tomography, X-Ray Computed ,Magnetic Resonance Imaging ,Retrospective Studies - Abstract
To comprehensively summarize the characteristic radiological findings of laryngeal sarcoidosis.We reviewed patients with laryngeal sarcoidosis who underwent computed tomography (CT) and/or magnetic resonance imaging (MRI) and included 8 cases from 8 publications that were found through a systematic review and 6 cases from our institutions. Two board-certified radiologists reviewed and evaluated the radiological images.Almost all cases exhibited supraglottic lesions 13/14 (92.9%) and most of them involved aryepiglottic folds (12/13, 92.3%), epiglottis (11/14, 78.6%), and arytenoid region (10/14, 71.4%). Most lesions were bilateral (12/14, 85.7%). All cases showed well-defined margins and a diffuse swelling appearance (14/14, 100%). Non-contrast CT revealed a low density (4/5, 80%). The contrast-enhanced CT showed a slight patchy enhancement predominantly at the margin of the lesion in most cases (12/13, 92.3%). In one case, T2-weighted images showed high signal intensity peripherally and low signal intensity centrally (1/1, 100%). Gadolinium-enhanced MRI showed moderate heterogeneous enhancement predominantly at the margin of the lesion (2/2, 100%). In one case, diffusion-weighted imaging showed intermediate signal intensity; the apparent diffusion coefficient value was 2.4 × 10We summarized the CT and MRI findings of patients with laryngeal sarcoidosis. Knowledge of these characteristics is expected to facilitate prompt diagnosis and appropriate management.
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- 2021
49. NIMG-90. DIFFERENTIATION OF INTRACRANIAL SOLITARY FIBROUS TUMOR AND MENINGIOMA ON CONVENTIONAL, DIFFUSION-WEIGHTED, AND DYNAMIC SUSCEPTIBILITY CONTRAST PERFUSION MRI
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Ryo Kurokawa, Mariko Kurokawa, Akira Baba, John Kim, Aristides Capizzano, Jayapalli Bapuraj, Ashok Srinivasan, and Toshio Moritani
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Cancer Research ,Oncology ,Neurology (clinical) - Abstract
BACKGROUND AND PURPOSE To evaluate the differences in the imaging findings of intracranial solitary fibrous tumor (SFT) and meningioma on dynamic susceptibility contrast (DSC) perfusion MRI, apparent diffusion coefficient (ADC), and conventional sequences. METHODS Between January 2016 and April 2022, the study enrolled 14 (median, 46 years [range, 25–74]; six females; seven with DSC-MRI) and 27 patients (median, 53 years [21–83]; 23 females; all with DSC-MRI) with pathologically proven SFT and meningioma, respectively. The normalized relative cerebral blood volume and flow (nrCBV and nrCBF), percentage signal recovery (PSR), normalized mean ADC (nADCmean), and conventional imaging features, including T1-weighted hyperintensity, were evaluated and statistically compared using Bonferonni correction. RESULTS PSR was significantly lower in SFT compared with that in meningioma (median, 22.5 [range, 6.4–48.8] vs. 70.1 [range, 18.6–104.2], p< 0.001). The majority of SFT showed mainly T1-weighted hyperintensities compared to the gray matter, while only one meningioma showed the finding (8/14 [57.1%] vs. 1/27 [3.7%], p< 0.001). No significant difference was observed in nrCBV, nrCBF, or nADCmean. CONCLUSIONS PFS was significantly lower in intracranial SFT compared with that in meningioma, indicating the difference in capillary permeability between the tumors. Comparing the hyperintensity on T1WI of the solid components with that of the cerebral cortex was a simple and useful characteristic to differentiate SFT from meningioma.
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- 2022
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50. Risk heterogeneity of bullous pemphigoid among dipeptidyl peptidase‐4 inhibitors: A population‐based cohort study using Japanese Latter‐Stage Elderly Healthcare Database
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Yumi Harano, Yasutaka Mitamura, Peng Jiang, Takako Fujita, and Akira Babazono
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Bullous pemphigoid ,DPP‐4 inhibitor ,Drug adverse reaction ,Diseases of the endocrine glands. Clinical endocrinology ,RC648-665 - Abstract
ABSTRACT Aims/Introduction Although the association between dipeptidyl peptidase‐4 (DPP‐4) inhibitors and bullous pemphigoid (BP) has begun to be established, some studies have suggested there are risk differences among DPP‐4 inhibitors. We conducted a population‐based cohort study to examine the risk differences. Materials and Methods Using the claims databases of the Fukuoka Prefecture Wide‐Area Association of Latter‐Stage Elderly Healthcare between April 1, 2013 and March 31, 2017, we conducted a retrospective cohort study to compare patients receiving one DPP‐4 inhibitor with those who were prescribed another antidiabetic drug. The primary outcome was an adjusted hazard ratio (HR) of the development of bullous pemphigoid during a 3‐year follow‐up. The secondary outcome was the development of BP requiring systemic steroids immediately after the diagnosis. These were estimated using Cox proportional hazards regression models. Results The study comprised 33,241 patients, of which 0.26% (n = 88) developed bullous pemphigoid during follow‐up. The percentages of patients with bullous pemphigoid who required immediate systemic steroid treatment was 0.11% (n = 37). We analyzed four DPP‐4 inhibitors: sitagliptin, vildagliptin, alogliptin, and linagliptin. Vildagliptin and linagliptin raised the risk of BP significantly (primary outcome, vildagliptin, HR 2.411 [95% confidence interval (CI) 1.325–4.387], linagliptin, HR 2.550 [95% CI 1.266–5.136], secondary outcome, vildagliptin HR 3.616 [95% CI 1.495–8.745], linagliptin HR 3.556 [95% CI 1.262–10.024]). A statistically significant risk elevation was not observed with sitagliptin and alogliptin (primary outcome, sitagliptin, HR 0.911 [95% CI 0.508–1.635], alogliptin, HR 1.600 [95% CI 0.714–3.584], secondary outcome, sitagliptin, HR 1.192 [95% CI 0.475–2.992], alogliptin, HR 2.007 [95% CI 0.571–7.053]). Conclusions Not all the DPP‐4 inhibitors could induce bullous pemphigoid significantly. Therefore, the association warrants further investigations before generalization.
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- 2023
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