Magnetic Resonance in Medical Sciences最新文献

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Interstitial Fluidopathy of the Central Nervous System: An Umbrella Term for Disorders with Impaired Neurofluid Dynamics. 中枢神经系统间质性流体病:中枢神经系统间质性流体病:神经流体动力学受损疾病的总称
IF 3 3区 医学
Magnetic Resonance in Medical Sciences Pub Date : 2024-01-01 Epub Date: 2022-11-25 DOI: 10.2463/mrms.rev.2022-0012
Toshiaki Taoka, Rintaro Ito, Rei Nakamichi, Toshiki Nakane, Hisashi Kawai, Shinji Naganawa
{"title":"Interstitial Fluidopathy of the Central Nervous System: An Umbrella Term for Disorders with Impaired Neurofluid Dynamics.","authors":"Toshiaki Taoka, Rintaro Ito, Rei Nakamichi, Toshiki Nakane, Hisashi Kawai, Shinji Naganawa","doi":"10.2463/mrms.rev.2022-0012","DOIUrl":"10.2463/mrms.rev.2022-0012","url":null,"abstract":"<p><p>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.</p>","PeriodicalId":18119,"journal":{"name":"Magnetic Resonance in Medical Sciences","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10838724/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40512788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Measurement of Turbulent Kinetic Energy in Hypertrophic Cardiomyopathy Using Triple-velocity Encoding 4D Flow MR Imaging. 利用三倍速度编码四维血流磁共振成像测量肥厚型心肌病的湍流动能
IF 3 3区 医学
Magnetic Resonance in Medical Sciences Pub Date : 2024-01-01 Epub Date: 2022-12-13 DOI: 10.2463/mrms.mp.2022-0051
Kotomi Iwata, Tetsuro Sekine, Junya Matsuda, Masaki Tachi, Yoichi Imori, Yasuo Amano, Takahiro Ando, Makoto Obara, Gerard Crelier, Masashi Ogawa, Hitoshi Takano, Shinichiro Kumita
{"title":"Measurement of Turbulent Kinetic Energy in Hypertrophic Cardiomyopathy Using Triple-velocity Encoding 4D Flow MR Imaging.","authors":"Kotomi Iwata, Tetsuro Sekine, Junya Matsuda, Masaki Tachi, Yoichi Imori, Yasuo Amano, Takahiro Ando, Makoto Obara, Gerard Crelier, Masashi Ogawa, Hitoshi Takano, Shinichiro Kumita","doi":"10.2463/mrms.mp.2022-0051","DOIUrl":"10.2463/mrms.mp.2022-0051","url":null,"abstract":"<p><strong>Purpose: </strong>The turbulent kinetic energy (TKE) estimation based on 4D flow MRI has been currently developed and can be used to estimate the pressure gradient. The objective of this study was to validate the clinical value of 4D flow-based TKE measurement in patients with hypertrophic cardiomyopathy (HCM).</p><p><strong>Methods: </strong>From April 2018 to March 2019, we recruited 28 patients with HCM. Based on echocardiography, they were divided into obstructed HCM (HOCM) and non-obstructed HCM (HNCM). Triple-velocity encoding 4D flow MRI was performed. The volume-of-interest from the left ventricle to the aortic arch was drawn semi-automatically. We defined peak turbulent kinetic energy (TKE<sub>peak</sub>) as the highest TKE phase in all cardiac phases.</p><p><strong>Results: </strong>TKE<sub>peak</sub> was significantly higher in HOCM than in HNCM (14.83 ± 3.91 vs. 7.11 ± 3.60 mJ, P < 0.001). TKE<sub>peak</sub> was significantly higher in patients with systolic anterior movement (SAM) than in those without SAM (15.60 ± 3.96 vs. 7.44 ± 3.29 mJ, P < 0.001). Left ventricular (LV) mass increased proportionally with TKE<sub>peak</sub> (P = 0.012, r = 0.466). When only the asymptomatic patients were extracted, a stronger correlation was observed (P = 0.001, r = 0.842).</p><p><strong>Conclusion: </strong>TKE measurement based on 4D flow MRI can detect the flow alteration induced by systolic flow jet and LV outflow tract geometry, such as SAM in patients with HOCM. The elevated TKE is correlated with increasing LV mass. This indicates that increasing cardiac load, by pressure loss due to turbulence, induces progression of LV hypertrophy, which leads to a worse prognosis.</p>","PeriodicalId":18119,"journal":{"name":"Magnetic Resonance in Medical Sciences","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10838723/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10407163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Age-related Decline of Intrinsic Cerebrospinal Fluid Outflow in Healthy Humans Detected with Non-contrast Spin-labeling MR Imaging. 用非对比自旋标记磁共振成像检测健康人脑脊液内流出量与年龄有关的下降。
IF 3 3区 医学
Magnetic Resonance in Medical Sciences Pub Date : 2024-01-01 Epub Date: 2022-12-17 DOI: 10.2463/mrms.mp.2022-0117
Vadim Malis, Won C Bae, Asako Yamamoto, Linda K McEvoy, Marin A McDonald, Mitsue Miyazaki
{"title":"Age-related Decline of Intrinsic Cerebrospinal Fluid Outflow in Healthy Humans Detected with Non-contrast Spin-labeling MR Imaging.","authors":"Vadim Malis, Won C Bae, Asako Yamamoto, Linda K McEvoy, Marin A McDonald, Mitsue Miyazaki","doi":"10.2463/mrms.mp.2022-0117","DOIUrl":"10.2463/mrms.mp.2022-0117","url":null,"abstract":"<p><strong>Purpose: </strong>Clearance of cerebrospinal fluid (CSF) is important for the removal of toxins from the brain, with implications for neurodegenerative diseases. Imaging evaluation of CSF outflow in humans has been limited, relying on venous or invasive intrathecal injections of contrast agents. The objective of this study was to introduce a novel spin-labeling MRI technique to detect and quantify the movement of endogenously tagged CSF, and then apply it to evaluate CSF outflow in normal humans of varying ages.</p><p><strong>Methods: </strong>This study was performed on a clinical 3-Tesla MRI scanner in 16 healthy subjects with an age range of 19-71 years with informed consent. Our spin-labeling MRI technique applies a tag pulse on the brain hemisphere, and images the outflow of the tagged CSF into the superior sagittal sinus (SSS). We obtained 3D images in real time, which was analyzed to determine tagged-signal changes in different regions of the meninges involved in CSF outflow. Additionally, the signal changes over time were fit to a signal curve to determine quantitative flow metrics. These were correlated against subject age to determine aging effects.</p><p><strong>Results: </strong>We observed the signal of the tagged CSF moving from the dura mater and parasagittal dura, and finally draining into the SSS. In addition, we observed a possibility of another pathway which is seen in some young subjects. Furthermore, quantitative CSF outflow metrics were shown to decrease significantly with age.</p><p><strong>Conclusion: </strong>We demonstrate a novel non-invasive MRI technique identifying two intrinsic CSF clearance pathways, and observe an age-related decline of CSF flow metrics in healthy subjects. Our work provides a new opportunity to better understand the relationships of these CSF clearance pathways during the aging process, which may ultimately provide insight into the age-related prevalence of neurodegenerative diseases.</p>","PeriodicalId":18119,"journal":{"name":"Magnetic Resonance in Medical Sciences","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10838716/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10441898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Ultra-short Echo-time MR Angiography Combined with a Modified Signal Targeting Alternating Radio Frequency with Asymmetric Inversion Slabs Technique to Assess Visceral Artery Aneurysm after Coil Embolization. 超短回波时间磁共振血管造影结合改良信号定向交替射频与不对称反转平板技术评估线圈栓塞术后的内脏动脉瘤
IF 3 3区 医学
Magnetic Resonance in Medical Sciences Pub Date : 2024-01-01 Epub Date: 2022-11-17 DOI: 10.2463/mrms.tn.2022-0063
Kohei Hamamoto, Emiko Chiba, Noriko Oyama-Manabe, Hironao Yuzawa, Hiromi Edo, Yohsuke Suyama, Hiroshi Shinmoto
{"title":"Ultra-short Echo-time MR Angiography Combined with a Modified Signal Targeting Alternating Radio Frequency with Asymmetric Inversion Slabs Technique to Assess Visceral Artery Aneurysm after Coil Embolization.","authors":"Kohei Hamamoto, Emiko Chiba, Noriko Oyama-Manabe, Hironao Yuzawa, Hiromi Edo, Yohsuke Suyama, Hiroshi Shinmoto","doi":"10.2463/mrms.tn.2022-0063","DOIUrl":"10.2463/mrms.tn.2022-0063","url":null,"abstract":"<p><p>Contrast-enhanced CT and MR angiography are widely used for follow-up of visceral artery aneurysms after coil embolization. However, potential adverse reactions to contrast agents and image deterioration due to susceptibility artifacts from the coils are major drawbacks of these modalities. Herein, we introduced a novel non-contrast-enhanced MR angiography technique using ultra-short TE combined with a modified signal targeting alternating radio frequency with asymmetric inversion slabs, which could provide a serial hemodynamic vascular image with fewer susceptibility artifacts for follow-up after coil embolization.</p>","PeriodicalId":18119,"journal":{"name":"Magnetic Resonance in Medical Sciences","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10838713/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40689291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Evaluating the Elasticity of Metastatic Cervical Lymph Nodes in Head and Neck Squamous Cell Carcinoma Patients Using DWI-based Virtual MR Elastography. 利用基于 DWI 的虚拟磁共振弹性成像评估头颈部鳞状细胞癌患者转移性颈淋巴结的弹性
IF 3 3区 医学
Magnetic Resonance in Medical Sciences Pub Date : 2024-01-01 Epub Date: 2022-12-16 DOI: 10.2463/mrms.mp.2022-0082
Hye Na Jung, Inseon Ryoo, Sangil Suh, Young Hen Lee, Eunju Kim
{"title":"Evaluating the Elasticity of Metastatic Cervical Lymph Nodes in Head and Neck Squamous Cell Carcinoma Patients Using DWI-based Virtual MR Elastography.","authors":"Hye Na Jung, Inseon Ryoo, Sangil Suh, Young Hen Lee, Eunju Kim","doi":"10.2463/mrms.mp.2022-0082","DOIUrl":"10.2463/mrms.mp.2022-0082","url":null,"abstract":"<p><strong>Purpose: </strong>The assessment of metastatic cervical lymph nodes in head and neck squamous cell carcinoma patients is crucial; as such, many studies focusing on non-invasive imaging techniques to evaluate metastatic cervical lymph nodes have been performed. The aim of our study was to assess the usefulness of elasticity values on diffusion weighted imaging (DWI)-based virtual MR elastography in the evaluation of metastatic cervical lymph nodes from head and neck squamous cell carcinoma.</p><p><strong>Methods: </strong>Two head and neck radiologists measured the elasticity values of 16 metastatic cervical lymph nodes from head and neck squamous cell carcinoma and 13 benign cervical lymph nodes on DWI-based virtual MR elastography maps. Mean, minimum, maximum, and median elasticity values were evaluated for lymph nodes between the two groups and interobserver agreement in measuring the elasticity was also evaluated.</p><p><strong>Results: </strong>The mean, maximum, and median elasticity values of metastatic cervical lymph nodes were significantly higher than those of benign cervical lymph nodes (P = 0.001, 0.01, and 0.002, respectively). Diagnostic accuracy, sensitivity, and specificity of the mean elasticity were 82.8%, 93.8%, and 69.2%, respectively. Interobserver agreement was excellent for the mean and median elasticity (intraclass correlation coefficients were 0.98 for both).</p><p><strong>Conclusion: </strong>Estimated elasticity values based on DWI-based virtual MR elastography show significant difference between benign and metastatic cervical lymph nodes from head and neck squamous cell carcinoma. While precise modulation of MR sequences and calibration parameters still needs to be established, elasticity values can be useful in differentiating between these lymph nodes.</p>","PeriodicalId":18119,"journal":{"name":"Magnetic Resonance in Medical Sciences","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10838712/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10441901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Association between the Putative Meningeal Lymphatics at the Posterior Wall of the Sigmoid Sinus and Delayed Contrast-agent Elimination from the Cerebrospinal Fluid. 乙状结肠窦后壁的假定脑膜淋巴管与脑脊液中对比剂的延迟清除之间的联系
IF 3 3区 医学
Magnetic Resonance in Medical Sciences Pub Date : 2024-01-01 Epub Date: 2023-01-19 DOI: 10.2463/mrms.mp.2022-0110
Shinji Naganawa, Rintaro Ito, Mariko Kawamura, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone
{"title":"Association between the Putative Meningeal Lymphatics at the Posterior Wall of the Sigmoid Sinus and Delayed Contrast-agent Elimination from the Cerebrospinal Fluid.","authors":"Shinji Naganawa, Rintaro Ito, Mariko Kawamura, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone","doi":"10.2463/mrms.mp.2022-0110","DOIUrl":"10.2463/mrms.mp.2022-0110","url":null,"abstract":"<p><strong>Purpose: </strong>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).</p><p><strong>Methods: </strong>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.</p><p><strong>Results: </strong>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<sup>-5</sup> (2.39 × 10<sup>-8</sup> - 0.07; 0.0078) for the PML-PSS and 1.7 × 10<sup>-4</sup> (1.66 × 10<sup>-7</sup> - 0.174; 0.014) for the PVS-BG.</p><p><strong>Conclusion: </strong>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.</p>","PeriodicalId":18119,"journal":{"name":"Magnetic Resonance in Medical Sciences","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10838717/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10599089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Current State of Artificial Intelligence in Clinical Applications for Head and Neck MR Imaging. 人工智能在头颈部MR成像临床应用中的现状。
IF 3 3区 医学
Magnetic Resonance in Medical Sciences Pub Date : 2023-10-01 Epub Date: 2023-08-01 DOI: 10.2463/mrms.rev.2023-0047
Noriyuki Fujima, Koji Kamagata, Daiju Ueda, Shohei Fujita, Yasutaka Fushimi, Masahiro Yanagawa, Rintaro Ito, Takahiro Tsuboyama, Mariko Kawamura, Takeshi Nakaura, Akira Yamada, Taiki Nozaki, Tomoyuki Fujioka, Yusuke Matsui, Kenji Hirata, Fuminari Tatsugami, Shinji Naganawa
{"title":"Current State of Artificial Intelligence in Clinical Applications for Head and Neck MR Imaging.","authors":"Noriyuki Fujima,&nbsp;Koji Kamagata,&nbsp;Daiju Ueda,&nbsp;Shohei Fujita,&nbsp;Yasutaka Fushimi,&nbsp;Masahiro Yanagawa,&nbsp;Rintaro Ito,&nbsp;Takahiro Tsuboyama,&nbsp;Mariko Kawamura,&nbsp;Takeshi Nakaura,&nbsp;Akira Yamada,&nbsp;Taiki Nozaki,&nbsp;Tomoyuki Fujioka,&nbsp;Yusuke Matsui,&nbsp;Kenji Hirata,&nbsp;Fuminari Tatsugami,&nbsp;Shinji Naganawa","doi":"10.2463/mrms.rev.2023-0047","DOIUrl":"10.2463/mrms.rev.2023-0047","url":null,"abstract":"<p><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>","PeriodicalId":18119,"journal":{"name":"Magnetic Resonance in Medical Sciences","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/7d/3a/mrms-22-401.PMC10552661.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9926996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Effect of Saturation Pulse Duration and Power on pH-weighted Amide Proton Transfer Imaging: A Phantom Study. 饱和脉冲持续时间和功率对pH加权酰胺质子转移成像的影响:一项体模研究。
IF 3 3区 医学
Magnetic Resonance in Medical Sciences Pub Date : 2023-10-01 Epub Date: 2022-09-01 DOI: 10.2463/mrms.mp.2021-0109
Chiaki Tokunaga, Tatsuhiro Wada, Osamu Togao, Yasuo Yamashita, Kouji Kobayashi, Toyoyuki Kato
{"title":"Effect of Saturation Pulse Duration and Power on pH-weighted Amide Proton Transfer Imaging: A Phantom Study.","authors":"Chiaki Tokunaga,&nbsp;Tatsuhiro Wada,&nbsp;Osamu Togao,&nbsp;Yasuo Yamashita,&nbsp;Kouji Kobayashi,&nbsp;Toyoyuki Kato","doi":"10.2463/mrms.mp.2021-0109","DOIUrl":"10.2463/mrms.mp.2021-0109","url":null,"abstract":"<p><strong>Purpose: </strong>Amide proton transfer (APT) imaging may detect changes in tissues' pH based on the chemical exchange saturation transfer (CEST) phenomenon, and thus it may be useful for identifying the penumbra in ischemic stroke patients. We investigated the effect of saturation pulse duration and power on the APT effect in phantoms with different pH values.</p><p><strong>Methods: </strong>Five samples were prepared from a 1:10 solution of egg-white albumin in phosphate-buffered saline at pH 6.53-7.65. The APT signal intensity (SI) was defined as asymmetry of the magnetization transfer ratio at 3.5 ppm. We measured the APT SIs in the egg-white albumin samples of different pH values with saturation pulse durations of 0.5, 1.0, 2.0, and 3.0 sec and saturation pulse powers of 0.5, 1.5, and 2.5 μT. The relative change in the APT SI in relation to the saturation duration and power at different pH values was defined as follows: (APT SI <sub>each saturation pulse</sub> - APT SI <sub>shortest or weakest pulse</sub>)/APT SI<sub>shortest or weakest pulse</sub>. The dependence of the APT SI on pH and the relative change in the APT SI were calculated as the slope of the linear regression.</p><p><strong>Results: </strong>The lower the pH, the larger the relative change in the APT SI, due to the change in saturation pulse duration and power. The APT SI was highly correlated with the pH at all saturation pulse durations and powers.</p><p><strong>Conclusion: </strong>The influence of saturation duration and power on the APT effect was greater at lower pH than higher pH. The combination of saturation pulse ≥ 1.0 s and power ≥ 1.5 μT was useful for the sensitive detection of changes in APT effects in the egg-white albumin samples with different pH values.</p>","PeriodicalId":18119,"journal":{"name":"Magnetic Resonance in Medical Sciences","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/2d/59/mrms-22-487.PMC10552662.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40336919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Model-based Deep Learning Reconstruction Using a Folded Image Training Strategy for Abdominal 3D T1-weighted Imaging. 使用折叠图像训练策略进行腹部3D T1加权成像的基于模型的深度学习重建。
IF 3 3区 医学
Magnetic Resonance in Medical Sciences Pub Date : 2023-10-01 Epub Date: 2022-11-08 DOI: 10.2463/mrms.mp.2021-0103
Satoshi Funayama, Utaroh Motosugi, Shintaro Ichikawa, Hiroyuki Morisaka, Yoshie Omiya, Hiroshi Onishi
{"title":"Model-based Deep Learning Reconstruction Using a Folded Image Training Strategy for Abdominal 3D T1-weighted Imaging.","authors":"Satoshi Funayama,&nbsp;Utaroh Motosugi,&nbsp;Shintaro Ichikawa,&nbsp;Hiroyuki Morisaka,&nbsp;Yoshie Omiya,&nbsp;Hiroshi Onishi","doi":"10.2463/mrms.mp.2021-0103","DOIUrl":"10.2463/mrms.mp.2021-0103","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate the feasibility of folded image training strategy (FITS) and the quality of images reconstructed using the improved model-based deep learning (iMoDL) network trained with FITS (FITS-iMoDL) for abdominal MR imaging.</p><p><strong>Methods: </strong>This retrospective study included abdominal 3D T1-weighted images of 122 patients. In the experimental analyses, peak SNR (PSNR) and structure similarity index (SSIM) of images reconstructed with FITS-iMoDL were compared with those with the following reconstruction methods: conventional model-based deep learning (conv-MoDL), MoDL trained with FITS (FITS-MoDL), total variation regularized compressed sensing (CS), and parallel imaging (CG-SENSE). In the clinical analysis, SNR and image contrast were measured on the reference, FITS-iMoDL, and CS images. Three radiologists evaluated the image quality using a 5-point scale to determine the mean opinion score (MOS).</p><p><strong>Results: </strong>The PSNR of FITS-iMoDL was significantly higher than that of FITS-MoDL, conv-MoDL, CS, and CG-SENSE (P < 0.001). The SSIM of FITS-iMoDL was significantly higher than those of the others (P < 0.001), except for FITS-MoDL (P = 0.056). In the clinical analysis, the SNR of FITS-iMoDL was significantly higher than that of the reference and CS (P < 0.0001). Image contrast was equivalent within an equivalence margin of 10% among these three image sets (P < 0.0001). MOS was significantly improved in FITS-iMoDL (P < 0.001) compared with CS images in terms of liver edge and vessels conspicuity, lesion depiction, artifacts, blurring, and overall image quality.</p><p><strong>Conclusion: </strong>The proposed method, FITS-iMoDL, allowed a deeper MoDL reconstruction network without increasing memory consumption and improved image quality on abdominal 3D T1-weighted imaging compared with CS images.</p>","PeriodicalId":18119,"journal":{"name":"Magnetic Resonance in Medical Sciences","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/c7/90/mrms-22-515.PMC10552667.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40453668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Biomarkers Predictive of Distant Disease-free Survival Derived from Diffusion-weighted Imaging of Breast Cancer. 癌症扩散加权成像的生物标志物对远处无病生存的预测。
IF 3 3区 医学
Magnetic Resonance in Medical Sciences Pub Date : 2023-10-01 Epub Date: 2022-08-03 DOI: 10.2463/mrms.mp.2022-0060
Maya Honda, Mami Iima, Masako Kataoka, Yasuhiro Fukushima, Rie Ota, Akane Ohashi, Masakazu Toi, Yuji Nakamoto
{"title":"Biomarkers Predictive of Distant Disease-free Survival Derived from Diffusion-weighted Imaging of Breast Cancer.","authors":"Maya Honda,&nbsp;Mami Iima,&nbsp;Masako Kataoka,&nbsp;Yasuhiro Fukushima,&nbsp;Rie Ota,&nbsp;Akane Ohashi,&nbsp;Masakazu Toi,&nbsp;Yuji Nakamoto","doi":"10.2463/mrms.mp.2022-0060","DOIUrl":"10.2463/mrms.mp.2022-0060","url":null,"abstract":"<p><strong>Purpose: </strong>To investigate whether intravoxel incoherent motion (IVIM) and/or non-Gaussian diffusion parameters are associated with distant disease-free survival (DDFS) in patients with invasive breast cancer.</p><p><strong>Methods: </strong>From May 2013 to March 2015, 101 patients (mean age 60.0, range 28-88) with invasive breast cancer were evaluated prospectively. IVIM parameters (flowing blood volume fraction [f<sub>IVIM</sub>] and pseudodiffusion coefficient [D*]) and non-Gaussian diffusion parameters (theoretical apparent diffusion coefficient [ADC] at a b value of 0 s/mm<sup>2</sup> [ADC<sub>0</sub>] and kurtosis [K]) were estimated using a diffusion-weighted imaging series of 16 b values up to 2500 s/mm<sup>2</sup>. Shifted ADC values (sADC<sub>200-1500</sub>) and standard ADC values (ADC<sub>0-800</sub>) were also calculated. The Kaplan-Meier method was used to generate survival analyses for DDFS, which were compared using the log-rank test. Univariable Cox proportional hazards models were used to assess any associations between each parameter and distant metastasis-free survival.</p><p><strong>Results: </strong>The median observation period was 80 months (range, 35-92 months). Among the 101 patients, 12 (11.9%) developed distant metastasis, with a median time to metastasis of 79 months (range, 10-92 months). Kaplan-Meier analysis showed that DDFS was significantly shorter in patients with K > 0.98 than in those with K ≤ 0.98 (P = 0.04). Cox regression analysis showed a marginal statistical association between K and distant metastasis-free survival (P = 0.05).</p><p><strong>Conclusion: </strong>Non-Gaussian diffusion may be associated with prognosis in invasive breast cancer. A higher K may be a marker to help identify patients at an elevated risk of distant metastasis, which could guide subsequent treatment.</p>","PeriodicalId":18119,"journal":{"name":"Magnetic Resonance in Medical Sciences","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/59/70/mrms-22-469.PMC10552669.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40581004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
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