著者

Shota Kondo Yuko Nakamura Toru Higaki Takashi Nishihara Masahiro Takizawa Toru Shirai Motoshi Fujimori Yoshitaka Bito Keigo Narita Takahiro Sueoka Yukiko Honda Chihiro Tani Kazuo Awai

出版者

Japanese Society for Magnetic Resonance in Medicine

雑誌

Magnetic Resonance in Medical Sciences (ISSN:13473182)

巻号頁・発行日

pp.mp.2022-0041, (Released:2022-06-01)

参考文献数

26

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Purpose: The wavelet denoising with geometry factor weighting (g-denoising) method can reduce the image noise by adapting to spatially varying noise levels induced by parallel imaging. The aim of this study was to investigate the clinical applicability of g-denoising on hepatobiliary-phase (HBP) images with gadoxetic acid.Methods: We subjected 53 patients suspected of harboring hepatic neoplastic lesions to gadoxetic acid-enhanced HBP imaging with and without g-denoising (g+HBP and g–HBP). The matrix size was reduced for g+HBP images to avoid prolonging the scanning time. Two radiologists calculated the SNR, the portal vein-, and paraspinal muscle contrast-to-noise ratio (CNR) relative to the hepatic parenchyma (liver-to-portal vein- and liver-to-muscle CNR). Two other radiologists independently graded the sharpness of the liver edge, the visibility of intrahepatic vessels, the image noise, the homogeneity of liver parenchyma, and the overall image quality using a 5-point scale. Differences between g–HBP and g+HBP images were determined with the two-sided Wilcoxon signed-rank test.Results: The liver-to-portal- and liver-to-muscle CNR and the SNR were significantly higher on g+HBP- than g–HBP images (P < 0.01), as was the qualitative score for the image noise, homogeneity of liver parenchyma, and overall image quality (P < 0.01). Although there were no significant differences in the scores for the sharpness of the liver edge or the score assigned for the visibility of intrahepatic vessels (P = 0.05, 0.43), with g+HBP the score was lower in three patients for the sharpness of the liver edge and in six patients for the visibility of intrahepatic vessels.Conclusion: At gadoxetic acid-enhanced HBP imaging, g-denoising yielded a better image quality than conventional HBP imaging although the anatomic details may be degraded.

著者

Taichi Kamo Keiichi Kuroda Shota Kondo Usaki Hayashi Satoshi Fudo Tomoki Yoneda Akiko Takaya Michiyoshi Nukaga Tyuji Hoshino

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.69, no.12, pp.1179-1183, 2021-12-01 (Released:2021-12-01)

参考文献数

29

被引用文献数

3

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Metallo-β-lactamases (MBLs) are significant threats to humans because they deteriorate many kinds of β-lactam antibiotics and are key enzymes responsible for multi-drug resistance of bacterial pathogens. As a result of in vitro screening, two compounds were identified as potent inhibitors of two kinds of MBLs: imipenemase (IMP-1) and New Delhi metallo-β-lactamase (NDM-1). The binding structure of one of the identified compounds was clarified by an X-ray crystal analysis in complex with IMP-1, in which two possible binding poses were observed. Molecular dynamics (MD) simulations were performed by building two calculation models from the respective binding poses. The compound was stably bound to the catalytic site during the simulation in one pose. The binding model between NDM-1 and the compound was constructed for MD simulation. Calculation results for NDM-1 were similar to those of IMP-1. The simulation suggested that the binding of the identified inhibitory compound was also durable in the catalytic site of NDM-1. The compound will be a sound basis for the development of the inhibitors for MBLs.