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Generalized Nonconvex Low-Rank Algorithm for Magnetic Resonance Imaging (MRI) Reconstruction
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作者 吴新峰 刘且根 +2 位作者 卢红阳 龙承志 王玉皞 《Journal of Donghua University(English Edition)》 EI CAS 2017年第2期316-321,共6页
In recent years,utilizing the low-rank prior information to construct a signal from a small amount of measures has attracted much attention.In this paper,a generalized nonconvex low-rank(GNLR) algorithm for magnetic r... In recent years,utilizing the low-rank prior information to construct a signal from a small amount of measures has attracted much attention.In this paper,a generalized nonconvex low-rank(GNLR) algorithm for magnetic resonance imaging(MRI)reconstruction is proposed,which reconstructs the image from highly under-sampled k-space data.In the algorithm,the nonconvex surrogate function replacing the conventional nuclear norm is utilized to enhance the low-rank property inherent in the reconstructed image.An alternative direction multiplier method(ADMM) is applied to solving the resulting non-convex model.Extensive experimental results have demonstrated that the proposed method can consistently recover MRIs efficiently,and outperforms the current state-of-the-art approaches in terms of higher peak signal-to-noise ratio(PSNR) and lower high-frequency error norm(HFEN) values. 展开更多
关键词 magnetic resonance imaging(mri) low-rank approximation nonconvex optimization alternative direction multiplier method(ADMM)
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Semantic Segmentation of Lumbar Vertebrae Using Meijering U-Net(MU-Net)on Spine Magnetic Resonance Images
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作者 Lakshmi S V V Shiloah Elizabeth Darmanayagam Sunil Retmin Raj Cyril 《Computer Modeling in Engineering & Sciences》 SCIE EI 2025年第1期733-757,共25页
Lower back pain is one of the most common medical problems in the world and it is experienced by a huge percentage of people everywhere.Due to its ability to produce a detailed view of the soft tissues,including the s... Lower back pain is one of the most common medical problems in the world and it is experienced by a huge percentage of people everywhere.Due to its ability to produce a detailed view of the soft tissues,including the spinal cord,nerves,intervertebral discs,and vertebrae,Magnetic Resonance Imaging is thought to be the most effective method for imaging the spine.The semantic segmentation of vertebrae plays a major role in the diagnostic process of lumbar diseases.It is difficult to semantically partition the vertebrae in Magnetic Resonance Images from the surrounding variety of tissues,including muscles,ligaments,and intervertebral discs.U-Net is a powerful deep-learning architecture to handle the challenges of medical image analysis tasks and achieves high segmentation accuracy.This work proposes a modified U-Net architecture namely MU-Net,consisting of the Meijering convolutional layer that incorporates the Meijering filter to perform the semantic segmentation of lumbar vertebrae L1 to L5 and sacral vertebra S1.Pseudo-colour mask images were generated and used as ground truth for training the model.The work has been carried out on 1312 images expanded from T1-weighted mid-sagittal MRI images of 515 patients in the Lumbar Spine MRI Dataset publicly available from Mendeley Data.The proposed MU-Net model for the semantic segmentation of the lumbar vertebrae gives better performance with 98.79%of pixel accuracy(PA),98.66%of dice similarity coefficient(DSC),97.36%of Jaccard coefficient,and 92.55%mean Intersection over Union(mean IoU)metrics using the mentioned dataset. 展开更多
关键词 Computer aided diagnosis(CAD) magnetic resonance imaging(mri) semantic segmentation lumbar vertebrae deep learning U-Net model
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Magnetic resonance imaging techniques for lithium-ion batteries:Principles and applications
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作者 Hongxin Lin Yanting Jin +4 位作者 Mingming Tao Yingao Zhou Peizhao Shan Danhui Zhao Yong Yang 《Magnetic Resonance Letters》 2024年第2期22-39,共18页
Operando monitoring of internal and local electrochemical processes within lithium-ion batteries(LIBs)is crucial,necessitating a range of non-invasive,real-time imaging characterization techniques including nuclear ma... Operando monitoring of internal and local electrochemical processes within lithium-ion batteries(LIBs)is crucial,necessitating a range of non-invasive,real-time imaging characterization techniques including nuclear magnetic resonance(NMR)techniques.This review provides a comprehensive overview of the recent applications and advancements of non-invasive magnetic resonance imaging(MRI)techniques in LIBs.It initially introduces the principles and hardware of MRI,followed by a detailed summary and comparison of MRI techniques used for characterizing liquid/solid electrolytes,electrodes and commercial batteries.This encompasses the determination of electrolytes'transport properties,acquisition of ion distribution profile,and diagnosis of battery defects.By focusing on experimental parameters and optimization strategies,our goal is to explore MRI methods suitable to a variety of research subjects,aiming to enhance imaging quality across diverse scenarios and offer critical physical/chemical insights into the ongoing operation processes of LIBs. 展开更多
关键词 Lithium-ion batteries magnetic resonance imaging(mri) Electrolytes ELECTRODES Commercial batteries
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Magnetic resonance imaging after anterior cruciate ligament reconstruction:A practical guide 被引量:7
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作者 Alberto Grassi James R Bailey +4 位作者 Cecilia Signorelli Giuseppe Carbone Andy Tchonang Wakam Gian Andrea Lucidi Stefano Zaffagnini 《World Journal of Orthopedics》 2016年第10期638-649,共12页
Anterior cruciate ligament(ACL) reconstruction is one of the most common orthopedic procedures performed worldwide. In this regard, magnetic resonance imaging(MRI) represents a useful pre-operative tool to confirm a d... Anterior cruciate ligament(ACL) reconstruction is one of the most common orthopedic procedures performed worldwide. In this regard, magnetic resonance imaging(MRI) represents a useful pre-operative tool to confirm a disruption of the ACL and to assess for potential associated injuries. However, MRI is also valuable postoperatively, as it is able to identify, in a non-invasive way, a number of aspects and situations that could suggest potential problems to clinicians. Graft signal and integrity, correct tunnel placement, tunnel widening, and problems with fixation devices or the donor site could all compromise the surgical outcomes and potentially predict the failure of the ACL reconstruction. Furthermore, several anatomical features of the knee could be associated to worst outcomes or higher risk of failure. This review provides a practical guide for the clinician to evaluate the post-surgical ACL through MRI, and to analyze all the parameters and features directly or indirectly related to ACL reconstruction, in order to assess for normal or pathologic conditions. 展开更多
关键词 ANTERIOR CRUCIATE LIGAMENT reconstruction magnetic resonance imaging GRAFT Tunnel Failures COMPLICATIONS ANATOMIC
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Deep learning-based magnetic resonance imaging reconstruction for improving the image quality of reduced-field-of-view diffusionweighted imaging of the pancreas 被引量:1
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作者 Yukihisa Takayama Keisuke Sato +3 位作者 Shinji Tanaka Ryo Murayama Nahoko Goto Kengo Yoshimitsu 《World Journal of Radiology》 2023年第12期338-349,共12页
BACKGROUND It has been reported that deep learning-based reconstruction(DLR)can reduce image noise and artifacts,thereby improving the signal-to-noise ratio and image sharpness.However,no previous studies have evaluat... BACKGROUND It has been reported that deep learning-based reconstruction(DLR)can reduce image noise and artifacts,thereby improving the signal-to-noise ratio and image sharpness.However,no previous studies have evaluated the efficacy of DLR in improving image quality in reduced-field-of-view(reduced-FOV)diffusionweighted imaging(DWI)[field-of-view optimized and constrained undistorted single-shot(FOCUS)]of the pancreas.We hypothesized that a combination of these techniques would improve DWI image quality without prolonging the scan time but would influence the apparent diffusion coefficient calculation.AIM To evaluate the efficacy of DLR for image quality improvement of FOCUS of the pancreas.METHODS This was a retrospective study evaluated 37 patients with pancreatic cystic lesions who underwent magnetic resonance imaging between August 2021 and October 2021.We evaluated three types of FOCUS examinations:FOCUS with DLR(FOCUS-DLR+),FOCUS without DLR(FOCUS-DLR−),and conventional FOCUS(FOCUS-conv).The three types of FOCUS and their apparent diffusion coefficient(ADC)maps were compared qualitatively and quantitatively.RESULTS FOCUS-DLR+(3.62,average score of two radiologists)showed significantly better qualitative scores for image noise than FOCUS-DLR−(2.62)and FOCUS-conv(2.88)(P<0.05).Furthermore,FOCUS-DLR+showed the highest contrast ratio and 600 s/mm^(2)(0.72±0.08 and 0.68±0.08)and FOCUS-DLR−showed the highest CR between cystic lesions and the pancreatic parenchyma for the b-values of 0 and 600 s/mm2(0.62±0.21 and 0.62±0.21)(P<0.05),respectively.FOCUS-DLR+provided significantly higher ADCs of the pancreas and lesion(1.44±0.24 and 3.00±0.66)compared to FOCUS-DLR−(1.39±0.22 and 2.86±0.61)and significantly lower ADCs compared to FOCUS-conv(1.84±0.45 and 3.32±0.70)(P<0.05),respectively.CONCLUSION This study evaluated the efficacy of DLR for image quality improvement in reduced-FOV DWI of the pancreas.DLR can significantly denoise images without prolonging the scan time or decreasing the spatial resolution.The denoising level of DWI can be controlled to make the images appear more natural to the human eye.However,this study revealed that DLR did not ameliorate pancreatic distortion.Additionally,physicians should pay attention to the interpretation of ADCs after DLR application because ADCs are significantly changed by DLR. 展开更多
关键词 Deep learning-based reconstruction magnetic resonance imaging Reduced field-of-view Diffusion-weighted imaging PANCREAS
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Application of dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)combined with magnetic resonance spectroscopy(MRS)in prostate cancer diagnosis 被引量:1
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作者 Yakun He Min Wang +1 位作者 Heping Deng Jin Ren 《Oncology and Translational Medicine》 CAS 2021年第1期31-34,共4页
Objective The aim of the study was to investigate the application of dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)combined with magnetic resonance spectroscopy(MRS)in prostate cancer diagnosis.Methods ... Objective The aim of the study was to investigate the application of dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)combined with magnetic resonance spectroscopy(MRS)in prostate cancer diagnosis.Methods In the outpatient department of our hospital(Sichuan Cancer Hospital,Chengdu,China),60 patients diagnosed with prostate disease were selected randomly and included in a prostate cancer group,60 patients with benign prostatic hyperplasia were included in a proliferation group,and 60 healthy subjects were included in a control group,from January 2013 to January 2017.Using Siemens Avanto 1.5 T high-field superconducting MRI for DCE-MRI and MRS scans,after the MRS scan was completed,we used the workstation spectroscopy tab spectral analysis,and eventually obtained the crest lines of the prostate metabolites choline(Cho),creatine(Cr),citrate(Cit),and the values of Cho/Cit,and(Cho+Cr)/Cit.Results Participants who had undergone 21-s,1-min,and 2-min dynamic contrast-enhanced MR revealed significant variations among the three groups.The spectral analysis of the three groups revealed a significant variation as well.DCE-MRI and MRS combined had a sensitivity of 89.67%,specificity of 95.78%,and accuracy of 94.34%.Conclusion DCE-MRI combined with MRS is of great value in the diagnosis of prostate cancer. 展开更多
关键词 prostate cancer magnetic resonance imaging(mri) dynamic contrast-enhanced(DCE) spectroscopy
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Non-iterative image reconstruction from sparse magnetic resonance imaging radial data without priors
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作者 Gengsheng L.Zeng Edward V.DiBella 《Visual Computing for Industry,Biomedicine,and Art》 2020年第1期84-91,共8页
The state-of-the-art approaches for image reconstruction using under-sampled k-space data are compressed sensing based.They are iterative algorithms that optimize objective functions with spatial and/or temporal const... The state-of-the-art approaches for image reconstruction using under-sampled k-space data are compressed sensing based.They are iterative algorithms that optimize objective functions with spatial and/or temporal constraints.This paper proposes a non-iterative algorithm to estimate the un-measured data and then to reconstruct the image with the efficient filtered backprojection algorithm.The feasibility of the proposed method is demonstrated with a patient magnetic resonance imaging study.The proposed method is also compared with the state-of-the-art iterative compressed-sensing image reconstruction method using the total-variation optimization norm. 展开更多
关键词 Tomographic image reconstruction Under-sampled measurements Fast magnetic resonance imaging Analytics reconstruction
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Obstacles Facing the Implementation of Functional Magnetic Resonance Imaging (fMRI) of Brain in Jeddah City
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作者 Abrar Mohammed Shafia M. Noor Hanan Mohammed Alzahrani Zuber Ahmed 《Computer Technology and Application》 2013年第2期123-126,共4页
fMRI (Functional Magnetic Resonance Imaging) is a relatively new technique that uses MRI (Magnetic Resonance Imaging) to measure the hemodynamic response (change in blood flow) related to neural activity in the ... fMRI (Functional Magnetic Resonance Imaging) is a relatively new technique that uses MRI (Magnetic Resonance Imaging) to measure the hemodynamic response (change in blood flow) related to neural activity in the brain. This paper aims to explore and identify the obstacles facing the implementation and applications of IMRI in radiology departments within Jeddah city by analyzing related data received by direct questionnaires and interviews with all the people working in MRI units in Jeddah city and finds that the major obstacle is lacking of awareness of fMRI among medical professionals and their training. 展开更多
关键词 fmri (Functional magnetic resonance imaging brain imaging mri magnetic resonance imaging).
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基于深度学习的复合超分辨率重建算法在膝关节MRI中的临床应用价值
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作者 王超 谢晓亮 +4 位作者 朱熹 黄文诺 尚松安 叶靖 王志军 《放射学实践》 北大核心 2025年第1期67-72,共6页
目的:探讨临床环境中通过优化扫描参数结合基于深度学习的复合超分辨率重建算法在提升膝关节MRI扫描效率和图像质量的可行性。方法:前瞻性搜集110例行膝关节MRI平扫的患者,先后进行常规(常规组)与复合超分辨率重建算法扫描(复合组),采... 目的:探讨临床环境中通过优化扫描参数结合基于深度学习的复合超分辨率重建算法在提升膝关节MRI扫描效率和图像质量的可行性。方法:前瞻性搜集110例行膝关节MRI平扫的患者,先后进行常规(常规组)与复合超分辨率重建算法扫描(复合组),采用双盲法比较两组主客观图像质量。结果:相较常规组,复合组PD和T1序列的骨髓、软骨、半月板、韧带、肌肉、脂肪、关节液的SNR分别提升89.3%、52.5%、65.3%、73.8%、60.3%、103.9%、58.9%和78.0%、172.9%、78.0%、72.5%、75.4%、63.4%、97.0%。相较常规组,复合组PD和T1序列的软骨-关节液、软骨-骨髓、半月板-关节液、韧带-关节液、骨髓-关节液、脂肪-关节液、肌肉-关节液的CNR分别提升119.5%、83.3%、116.2%、109.2%、109.2%、99.3%、116.8%和61.7%、23.1%、78.7%、32.5%、161.7%、44.9%、39.2%。复合组的峰值信噪比(PSNR)相较常规组显著提高(P<0.05),结构相似度(SSIM)均>0.999。主观图像质量评价中复合组病灶边缘区分度、运动伪影和综合诊断度的主观评分显著高于常规组(P<0.05),两组病灶辨别度的主观评分差异无统计学意义(P>0.05)。结论:合理优化扫描参数并结合基于深度学习的复合超分辨率重建算法可在提升扫描效率的同时显著提高膝关节MRI的图像质量和综合诊断效果。 展开更多
关键词 卷积神经网络 深度学习 膝关节 磁共振成像 超分辨率重建
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Magnetic resonance imaging with three-dimensional fast imaging employing steady-state acquisition with phase-cycled and short T1 inversion recovery pulse sequence for evaluating brachial plexus injury 被引量:7
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作者 Dianxiu Ning Meiyu Sun +11 位作者 Bo Sun Li Zhao Weisheng Zhang Lijun Wang Shaowu Wang Ailian Liu Jianlin Wu Zhijin Lang Di Ning Guanfu Liu Xiaochen Ji Xiufeng Wang 《Neural Regeneration Research》 SCIE CAS CSCD 2011年第14期1097-1102,共6页
There is a large amount of fat in the postganglionic segment of the brachial plexus nerve.The use of short T1 inversion recovery pulse sequence may improve signal strength of the brachial plexus postganglionic segment... There is a large amount of fat in the postganglionic segment of the brachial plexus nerve.The use of short T1 inversion recovery pulse sequence may improve signal strength of the brachial plexus postganglionic segment.The present study revealed that the combination of three-dimensional fast imaging employing steady-state acquisition with phase-cycled and short T1 inversion recovery pulse sequence clearly displayed the anatomical morphology and structure of the brachial plexus nerve,together with maximum intensity projection,volume rendering and other three-dimensional reconstruction techniques.Our results suggested that this method is also suitable for providing accurate assessment and diagnosis of the site,severity and scope of brachial plexus injury. 展开更多
关键词 brachial plexus i-njury magnetic resonance imaging pulse sequence reconstruction
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Current and future applications of magnetic resonance imaging and spectroscopy of the brain in hepatic encepha-lopathy 被引量:9
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作者 VP Bob Graver M Alex Dresner +5 位作者 Daniel M Forton Serena Counsell David J Larkman Nayna Patel Howard C Thomas Simon D Taylor-Robinson 《World Journal of Gastroenterology》 SCIE CAS CSCD 2006年第19期2969-2978,共10页
Hepatic encephalopathy (HE) is a common neuropsychiatric abnormality, which complicates the course of patients with liver disease and results from hepatocellular failure and/or portosystemic shunting. The manifestat... Hepatic encephalopathy (HE) is a common neuropsychiatric abnormality, which complicates the course of patients with liver disease and results from hepatocellular failure and/or portosystemic shunting. The manifestations of HE are widely variable and involve a spectrum from mild subclinical disturbance to deep coma. Research interest has focused on the role of circulating gut-derived toxins, particularly ammonia, the development of brain swelling and changes in cerebral neurotransmitter systems that lead to global CNS depression and disordered function. Until recently the direct investigation of cerebral function has been difficult in man. However, new magnetic resonance imaging (MRI) techniques provide a non-invasive means of assessment of changes in brain volume (coregistered MRI) and impaired brain function (fMRI), while proton magnetic resonance spectroscopy (^1H MRS) detects changes in brain biochemistry, including direct measurement of cerebral osmolytes, such as myoinositol, glutamate and glutamine which govern processes intrinsic to cellular homeostasis, including the accumulation of intracellular water. The concentrations of these intracellular osmolytes alter with hyperammonaemia. MRS-detected metabolite abnormalities correlate with the severity of neuropsychiatric impairment and since MR spectra return towards normal after treatment, the technique may be of use in objective patient monitoring and in assessing the effectiveness of various treatment regimens. 展开更多
关键词 Hepatic encephalopathy magnetic resonance imaging magnetic resonance spectroscopy Diffusion weighted imaging Arterial spin labeling Functional mri
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Targeted prostate biopsy: value of multiparametric magnetic resonance imaging in detection of localized cancer 被引量:3
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作者 Jesse D Le Jiaoti Huang Leonard S Marks 《Asian Journal of Andrology》 SCIE CAS CSCD 2014年第4期522-529,共8页
Prostate cancer is the second most common cancer in men, with 1.1 million new cases worldwide reported by the World Health Organization in one recent year. Transrectal ultrasound (TRUS)-guided biopsy has been used f... Prostate cancer is the second most common cancer in men, with 1.1 million new cases worldwide reported by the World Health Organization in one recent year. Transrectal ultrasound (TRUS)-guided biopsy has been used for the diagnosis of prostate cancer for over 2 decades, but the technique is usually blind to cancer location. Moreover, the false negative rate of TRUS biopsy has been reported to be as high as 47%. Multiparametric magnetic resonance imaging (mp-MRI) includes T1- and T2-weighted imaging as well as dynamic contrast-enhanced (DCE) and diffusion-weighted imaging (DWI). mp-MRI is a major advance in the imaging of prostate cancer, enabling targeted biopsy of suspicious lesions. Evolving targeted biopsy techniquesmincluding direct in-bore biopsy, cognitive fusion and software-based MRI-ultrasound (MRI-US) fusion--have led to a several-fold improvement in cancer detection compared to the earlier method. Importantly, the detection of clinically significant cancers has been greatly facilitated by targeting, compared to systematic biopsy alone. Targeted biopsy via MRI-US fusion may dramatically alter the way prostate cancer is diagnosed and managed. 展开更多
关键词 fusion biopsy magnetic resonance imaging mri prostate biopsy prostate cancer targeted biopsy ULTRASOUND
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Magnetic resonance imaging for prostate cancer clinical application 被引量:2
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作者 Bing Li Yong Du +3 位作者 Hanfeng Yang Yayong Huang Jun Meng Dongmei Xiao 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2013年第2期240-249,共10页
As prostate cancer is a biologically heterogeneous disease for which a variety of treatment options are available, the major objective of prostate cancer imaging is to achieve more precise disease characterization. In... As prostate cancer is a biologically heterogeneous disease for which a variety of treatment options are available, the major objective of prostate cancer imaging is to achieve more precise disease characterization. In clinical practice, magnetic resonance imaging (MRI) is one of the imaging tools for the evaluation of prostate cancer, the fusion of MRI or dynamic contrast-enhanced MRI (DCE-MRI) with magnetic resonance spectroscopic imaging (MRSI) is improving the evaluation of cancer locafon, size, and extent, while providing an indication of tumor aggressiveness. This review summarizes the role of MRI in the application of prostate cancer and describes molecular MRI techniques (including MRSI and DCE-MRI) for aiding prostate cancer management. 展开更多
关键词 Prostate cancer magnetic resonance imaging mri fimctional mri molecular MR[
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Nasopharyngeal adenoid cystic carcinoma: magnetic resonance imaging features in ten cases 被引量:8
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作者 Xue-Wen Liu Chuan-Miao Xie +7 位作者 Hui Li Rong Zhang Zhi-Jun Geng Yun-Xian Mo Jing Zhao Mu-Yan Cai Yan-Chun Lv Pei-Hong Wu 《Chinese Journal of Cancer》 SCIE CAS CSCD 2012年第1期19-28,共10页
Nasopharyngeal adenoid cystic carcinoma (NACC) is a rare malignancy with high local invasiveness. To date, there is no consensus on the imaging characteristics of NACC. To address this, we retrospectively reviewed 10 ... Nasopharyngeal adenoid cystic carcinoma (NACC) is a rare malignancy with high local invasiveness. To date, there is no consensus on the imaging characteristics of NACC. To address this, we retrospectively reviewed 10 cases of NACC and summarized the magnetic resonance imaging (MRI) features. MR images of 10 patients with histologically validated NACC were reviewed by two experienced radiologists. The location, shape, margin, signal intensity, lesion texture, contrast enhancement patterns, local invasion, and cervical lymphadenopathy of all tumors were evaluated. Clinical and pathologic records were also reviewed. No patients were positive for antibodies against Epstein-Barr virus (EBV). The imaging patterns of primary tumors were classified into two types as determined by location, shape, and margin. Of all patients, 7 had tumors with a type 1 imaging pattern and 3 had tumors with a type 2 imaging pattern. The 4 tubular NACCs were all homogeneous tumors, whereas 3 (60%) of 5 cribriform NACCs and the sole solid NACC were heterogeneous tumors with separations or central necrosis on MR images. Five patients had perineural infiltration and intracranial involvement, and only 2 had cervical lymphadenopathy. Based on these results, we conclude that NACC is a local, aggressive neoplasm that is often negative for EBV infection and associated with a low incidence of cervical lymphadenopathy. Furthermore, MRI features of NACC vary in locations and histological subtypes. 展开更多
关键词 磁共振成像 腺样囊性癌 淋巴结肿大 恶性肿瘤 磁共振图像 成像模式 信号强度
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Neuromelanin-sensitive magnetic resonance imaging:a promising technique for depicting tissue characteristics containing neuromelanin 被引量:2
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作者 Ken Nakamura Keizo Sugaya 《Neural Regeneration Research》 SCIE CAS CSCD 2014年第7期759-760,共2页
Idiopathic Parkinson's disease (IPD) is a progressive, neurodegenerative movement disorder characterized by bradykinesia, muscular rigidity, pos- tural instability and tremor. IPD is usually diagnosed based on clin... Idiopathic Parkinson's disease (IPD) is a progressive, neurodegenerative movement disorder characterized by bradykinesia, muscular rigidity, pos- tural instability and tremor. IPD is usually diagnosed based on clinical findings, but diagnoses are only 75-90% accurate when compared with autopsy results. Improving diagnostic accuracy is critical for the early dif- ferentiation of IPD from other Parkinsonism-related disorders because of differences in their prognoses and treatment. Furthermore, IPD is clinically heterogeneous, with variable prognosis. Although the biological function of neuromelanin has not yet been determined, the selective vulnerability of neuromelanin-containing neurons in patients with IPD suggests a role for this pigment in neurodegeneration. Recently developed ultra-high-field magnetic resonance imaging (MRI) systems produce Tl-weighted neuro- melanin-sensitive images with very high spatial resolution, enabling the de- piction of tissue containing neuromelanin. Here we review recent advances in neuromelanin-sensitive MRI in IPD and related conditions suggesting that neuromelanin may be a potential diagnostic biomarker for IPD. 展开更多
关键词 IPD Neuromelanin-sensitive magnetic resonance imaging mri BTP
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Recent Advances in ^(19)Fluorine Magnetic Resonance Imaging with Perfluorocarbon Emulsions 被引量:2
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作者 Anne H.Schmieder Shelton D.Caruthers +2 位作者 Jochen Keupp Samuel A.Wickline Gregory M.Lanza 《Engineering》 SCIE EI 2015年第4期475-489,共15页
The research roots of 19fluorine (19F) magnetic resonance imaging (MRI) date back over 35 years. Over that time span, 1H imaging flourished and was adopted worldwide with an endless array of applications and imagi... The research roots of 19fluorine (19F) magnetic resonance imaging (MRI) date back over 35 years. Over that time span, 1H imaging flourished and was adopted worldwide with an endless array of applications and imaging approaches, making magnetic resonance an indispensable pillar of biomedical diagnostic imaging. For many years during this timeframe, 19F imaging research continued at a slow pace as the various attributes of the technique were explored. However, over the last decade and particularly the last several years, the pace and clinical relevance of 19F imaging has exploded. In part, this is due to advances in MRI instrumentation, ~gF/1H coil designs, and ultrafast pulse sequence development for both preclinical and clinical scanners. These achievements, coupled with interest in the molecular imaging of anatomy and physiology, and combined with a cadre of innovative agents, have brought the concept of ~gF into early clinical evaluation. In this review, we attempt to provide a slice of this rich history of research and development, with a particular focus on liquid perfluorocarbon compound-based agents. 展开更多
关键词 FLUORINE magnetic resonance imaging mri dual-tuned coil PERFLUOROCARBON ANGIOGENESIS cell labeling
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Intravoxel incoherent motion magnetic resonance imaging for diagnosis of cervical cancer and evaluation of response of uterine cervical cancer to radiochemotherapy: A pilot study 被引量:1
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作者 Yanchun Wang Shan Hu +7 位作者 Xuemei Hu Jianjun Li Yaqi Shen Xiaoyu Liu Zhi Wang Xiaoyan Meng Zhen Li Daoyu Hu 《Oncology and Translational Medicine》 CAS 2015年第4期164-170,共7页
Objective The aim of this study was to investigate the ability of intravoxel incoherent motion(IVIM) diffusion-weighted magnetic resonance imaging(MRI) to diagnose cervical cancer and to evaluate the response of uteri... Objective The aim of this study was to investigate the ability of intravoxel incoherent motion(IVIM) diffusion-weighted magnetic resonance imaging(MRI) to diagnose cervical cancer and to evaluate the response of uterine cervical cancer to radiochemotherapy(CRT).Methods This prospective study was approved by the institutional review board, and informed consent was obtained from all patients. A total of 23 patients with primary cervical cancer who were undergoing CRT and 16 age-matched healthy subjects were prospectively recruited for IVIM(b = 0–800 s/mm2) and standard pelvic MRI. Bi-exponential analysis was performed to derive f(perfusion fraction), D*(pseudo-diffusion coefficient), and D(true molecular diffusion coefficient) in cervical cancer(n = 23) and the normal cervix(n = 16). The apparent diffusion coefficient(standard ADC) was calculated. The independent-samples t-test and paired-samples t-test were used for comparisons.Results Pre-treatment cervical cancer had the lowest standard ADC(1.15 ± 0.13 × 10-3 mm2/s) and D(0.89 ± 0.10 × 10-3 mm2/s) values, and these were significantly different from the normal cervix and posttreatment cervical cancer(P = 0.00). The f(16.67 ± 5.85%) was lowest in pre-treatment cervical cancer and was significantly different from the normal cervix and post-treatment cervical cancer(p = 0.012 and 0.00, respectively). No difference was observed in D*.Conclusion IVIM is potentially promising for differentiating between the normal cervix and cervical cancer because pre-treated cervical cancer has low perfusion and diffusion IVIM characteristics. Further, the standard ADC, D, and f of cervical cancer showed a tendency to normalize after CRT; thus, IVIM may be useful for monitoring the response to CRT in cervical cancer. 展开更多
关键词 diffusion-weighted imaging magnetic resonance imaging mri investigate the ability of intravoxel incoherent motion (IVIM) cervical cancer RADIOCHEMOTHERAPY
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Comparison of computed tomography and magnetic resonance imaging for the detection of mandibular condylar osteochondroma 被引量:1
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作者 Molun Shen Ling Zhu +2 位作者 Hongbo Yu Lei Zhang Xudong Wang 《Oncology and Translational Medicine》 2018年第3期108-115,共8页
Objective The purpose of this study was to compare computed tomography(CT) and magnetic resonance imaging(MRI) for the detection of mandibular condylar osteochondroma.Methods Preoperative CT and MRI of 33 patients wit... Objective The purpose of this study was to compare computed tomography(CT) and magnetic resonance imaging(MRI) for the detection of mandibular condylar osteochondroma.Methods Preoperative CT and MRI of 33 patients with unilateral condylar osteochondroma were reviewed. The morphology, location, continuity with the parent bone, cartilage cap, perichondrium of tumors, and changes in soft and hard tissues adjacent to the lesions were investigated by two reviewers. Data were analyzed using Mc Nemar test. A P value < 0.05 was considered significant.Results Among the 33 condylar osteochondromas, 11 were of the diffuse type, 10 were of the sessile type, and 12 were of the pedunculated type. Continuity with the cortex and marrow of the host condyle was observed on both CT and MRI. Both modalities had identical detection rates of surface reconstruction of the temporal bone joint, condylar dislocation, and pseudarthrosis formation. However, MRI showed significantly higher detection rates of the cartilage cap and perichondrium than CT(P < 0.05). Furthermore, MRI showed ipsilateral and contralateral temporo-mandibular joint(TMJ) disc displacement in 4 cases and 6 cases, respectively, and ipsilateral and contralateral TMJ effusion in 20 cases and 14 cases, respectively.Conclusion CT can intuitively display the morphology and spatial location of condylar osteochondromas through three-dimensional reconstruction. MRI may be superior to CT in the detection of cartilage cap, perichondrium of the condylar osteochondroma, and changes in the TMJ and adjacent soft tissues. 展开更多
关键词 mandibular condyle OSTEOCHONDROMA computed tomography (CT) magnetic resonance imaging mri
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Prediction of radiosensitivity in primary central nervous system germ cell tumors using dynamic contrast-enhanced magnetic resonance imaging 被引量:3
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作者 Chenlu Feng Peiyi Gao +4 位作者 Xiaoguang Qiu Tianyi Qian Yan Lin Jian Zhou Binbin Sui 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2015年第3期231-238,共8页
Objective: To evaluate the feasibility of dynamic contrast-enhanced magnetic resonance imaging(DCEMRI) for predicting tumor response to radiotherapy in patients with suspected primary central nervous system(CNS) ... Objective: To evaluate the feasibility of dynamic contrast-enhanced magnetic resonance imaging(DCEMRI) for predicting tumor response to radiotherapy in patients with suspected primary central nervous system(CNS) germ cell tumors(GCTs).Methods: DCE-MRI parameters of 35 patients with suspected primary CNS GCTs were obtained prior to diagnostic radiation, using the Tofts and Kermode model. Radiosensitivity was determined in tumors diagnosed 2 weeks after radiation by observing changes in tumor size and markers as a response to MRI. Taking radiosensitivity as the gold standard, the cut-off value of DCE-MRI parameters was measured by receiver operating characteristic(ROC) curve. Diagnostic accuracy of DCE-MRI parameters for predicting radiosensitivity was evaluated by ROC curve.Results: A significant elevation in transfer constant(K^trans) and extravascular extracellular space(Ve)(P=0.000), as well as a significant reduction in rate constant(Kep)(P=0.000) was observed in tumors. K^trans, relative K^trans, and relative Kep of the responsive group were significantly higher than non-responsive groups. No significant difference was found in Kep, Ve, and relative Ve between the two groups. Relative K^trans showed the best diagnostic value in predicting radiosensitivity with a sensitivity of 100%, specificity of 91.7%, positive predictive value(PPV) of 95.8%, and negative predictive value(NPV) of 100%.Conclusions: Relative K^trans appeared promising in predicting tumor response to radiation therapy(RT). It is implied that DCE-MRI pre-treatment is a requisite step in diagnostic procedures and a novel and reliable approach to guide clinical choice of RT. 展开更多
关键词 Dynamic contrast-enhanced magnetic resonance imaging (DCE-mri extravascular extracellular space germ cell tumors (GCTs) RADIOSENSITIVITY rate constant transfer constant
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增强CT联合MRI检查对肾透明细胞癌的预后预测价值分析及与临床特征的相关性
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作者 徐昆峰 邱晓辉 +1 位作者 刘艺超 董修明 《中国医学装备》 2025年第1期30-35,共6页
目的:探讨增强CT联合MRI检查对肾透明细胞癌的预后预测价值及与临床特征的相关性。方法:回顾性选取2019年3月至2023年5月亳州市人民医院收治的80例疑似肾透明细胞癌(ccRCC)患者的增强CT和MRI术后随访资料,依据疾病进展情况将其分为病情... 目的:探讨增强CT联合MRI检查对肾透明细胞癌的预后预测价值及与临床特征的相关性。方法:回顾性选取2019年3月至2023年5月亳州市人民医院收治的80例疑似肾透明细胞癌(ccRCC)患者的增强CT和MRI术后随访资料,依据疾病进展情况将其分为病情进展组(24例)和无进展组(56例)。通过病史采集和体检、增强CT、MRI、实验室检查、病理检查等相关检查诊断病情进展,根据患者临床和影像图像信息将年龄、性别、肿瘤直径、有无癌栓、肿瘤位置以及手术方式进行单因素logistic回归分析,确定独立预测因子。采用受试者工作特征(ROC)曲线分析增强CT联合MRI检查对ccRCC的预后预测价值。采用Pearson线性相关性分析增强CT联合MRI检查结果与预后的相关性。结果:根据随访结果,病情进展组患者皮质期CT值、髓质期CT值及表观弥散系数(ADC)均明显小于无进展组,差异有统计学意义(t=10.610、4.697、2.901,P<0.05),弥散系数(K)明显大于无进展组,差异有统计学意义(t=6.375,P<0.05),两组扩散率(D)比较差异无统计学意义(P>0.05);增强CT、MRI单独检查及联合检查预测ccRCC预后的ROC曲线下面积(AUC)均>0.5,提示两种检查对预测ccRCC预后均具有一定的价值,且联合检查的AUC最高,为0.940,提示联合检查对预测ccRCC预后的价值最高;两组性别、手术方式、癌栓及肿瘤位置例数比较差异均无统计学意义(P>0.05),病情进展组年龄、肿瘤直径均明显大于无进展组,差异有统计学意义(t=4.292、3.219,P<0.05);logistic回归分析显示,患者年龄、肿瘤直径均是ccRCC预后的独立影响因素(HR=2.167、0.689,P<0.05);Pearson相关性分析结果显示,增强CT检查与预后均存在负相关性(r=-0.65,P<0.05),MRI检查与预后均存在正相关性(r=0.72,P<0.05),增强CT检查结果与MRI检查结果之间均存在负相关性(r=-0.58,P<0.05)。结论:增强CT联合MRI检查对肾透明细胞癌的预后预测高于单项检查,且与临床特征存在一定的相关性,但临床还需结合其他影响因素进行综合判断。 展开更多
关键词 增强CT 磁共振成像(mri) 肾透明细胞癌(ccRCC) 预后预测 临床特征
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