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World Journal of Clinical Cases 2022年第11期10卷 3630-3638页

作者： Wen-Peng Huang Li-Ming Li Jian-Bo Gao Department of Radiology The First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450052Henan ProvinceChina

BACKGROUND Myoepithelial carcinoma(MC)is a clinically rare malignancy,there is controversy regarding its etiology and its biological behavior is not fully *** surgical resection is the main treatment *** describe a case of pleomorphic adenoma(PA)with multiple postoperative recurrences after malignant transformation,and the history of the disease in this patient was more than 20 *** resection during the first surgery of PA and long-term postoperative follow-up is *** SUMMARY A 34-year-old male with PA and a history of 5 postoperative recurrences over 21 years,each surgically removed,presented 15 d ago with headache,nasal congestion,protrusion of the right eyeball and loss of vision in the right eye,with progressively worsening *** patient underwent surgery,and MC was confirmed by pathology examination.A small PA component was locally visible under light *** patient had a recurrence of the tumor 2 mo after surgery and underwent surgical *** During the first operation for PA,care should be taken not to rupture the envelope to prevent tumor cell implantation,and when complete resection is not possible due to the anatomical site,postoperative radiotherapy is necessary to control the lesion and prevent infiltration and malignant transformation of the tumor to *** tomography and magnetic resonance imaging is important for establishing diagnosis and developing a treatment plan.

关键词： Myoepithelial carcinoma Pleomorphic adenoma magnetic resonance

Three-dimensional arterial spin labeling and diffusion kurtosis imaging in evaluating perfusion and infarct area size in acute cerebral ischemia

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World Journal of Clinical Cases 2022年第17期10卷 5586-5594页

作者： Yan-Yan Jiang Zhi-Lin Zhong Min Zuo Department of magnetic resonance Wuhan Asia General HospitalWuhan 430056Hubei ProvinceChina Department of Radiology Wuhan Yaxin General HospitalWuhan 430056Hubei ProvinceChina Department of Radiology Wuhan Hanyang HospitalWuhan University of Science and TechnologyWuhan 430050Hubei ProvinceChina

BACKGROUND Early thrombolytic therapy is crucial to treat acute cerebral infarction,especially since the onset of thrombolytic therapy takes 1-6 ***,early diagnosis and evaluation of cerebral infarction is *** To investigate the diagnostic value of magnetic resonance multi-delay threedimensional arterial spin labeling(3DASL)and diffusion kurtosis imaging(DKI)in evaluating the perfusion and infarct area size in patients with acute cerebral *** Eighty-four patients who experienced acute cerebral ischemia from March 2019 to February 2021 were *** patients in the acute stage underwent magnetic resonance-based examination,and the data were processed by the system’s own *** apparent diffusion coefficient(ADC),average diffusion coefficient(MD),axial diffusion(AD),radial diffusion(RD),average kurtosis(MK),radial kurtosis(fairly RK),axial kurtosis(AK),and perfusion parameters post-labeling delays(PLD)in the focal area and its corresponding area were *** correlation between the lesion area of cerebral infarction under MK and MD and T2-weighted imaging(T2WI)was *** The DKI parameters of focal and control areas in the study subjects were *** ADC,MD,AD,and RD values in the lesion area were significantly lower than those in the control *** MK,RK,and AK values in the lesion area were significantly higher than those in the control *** MK/MD value in the infarct lesions was used to determine the matching ***/MD<5 mm was considered matching and MK/MD≥5 mm was considered ***1.5s and PLD2.5s perfusion parameters in the central,peripheral,and control areas of the infarct lesions in MK/MD-matched and-unmatched patients were not significantly ***1.5s and PLD2.5s perfusion parameter values in the central area of the infarct lesions in MK/MD-matched and-unmatched patients were significantly lower than those in peripheral and control *** MK and MD maps showed a lesio

关键词： magnetic resonance Multi-delay 3D arterial spin labeling Diffusion kurtosis imaging Acute ischemic cerebral infarction Perfusion Nerve function

Dual Radial-Resonant Wide Beamwidth Circular Sector Microstrip Patch Antennas

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Chinese Journal of Electronics 2023年第4期32卷 710-719页

作者： MAO Xiaohui LU Wenjun JI Feiyan XING Xiuqiong ZHU Lei Jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and Telecommunications Key Laboratory of Wireless Sensor Network & Communication Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Department of Electrical and Computer Engineering Faculty of Science and Technology University of Macau

In this article, a design approach to a radial-resonant wide beamwidth circular sector patch antenna is advanced. As properly evolved from a U-shaped d ipole, a prototype magnetic dipole can be fit in the radial direction of a circular sector patch radiator, with its length set as the positive odd-integer multiples of onequarter wavelength. In this way, multiple TM0m(m = 1,2,...) modes resonant circular sector patch antenna with short-circuited circumference and widened E-plane beamwidth can be realized by proper excitation and perturbations. Prototype antennas are then designed and fabricated to validate the design approach. Experimental results reveal that the E-plane beamwidth of a dual-resonant antenna fabricated on air/Teflon substrate can be effectively broadened to 128°/120°, with an impedance bandwidth of 17.4%/7.1%, respectively. In both cases, the antenna heights are strictly limited to no more than 0.03-guided wavelength. It is evidently validated that the proposed approach can effectively enhance the operational bandwidth and beamwidth of a microstrip patch antenna while maintaining its inherent low profile merit.

关键词： Geometry Patch antennas Perturbation methods Prototypes magnetic resonance Microstrip antennas Bandwidth

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Long-term durable response to lenalidomide in a patient with hepatic epithelioid hemangioendothelioma

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World Journal of Gastroenterology 2014年第22期20卷 7049-7054页

作者： Maria Caterina Pallotti Margherita Nannini Claudio Agostinelli Simona Leoni Valerio Di Scioscio Anna Mandrioli Cristian Lolli Maristella Saponara Stefano Pileri Luigi Bolondi Guido Biasco Maria Abbondanza Pantaleo Department of Specialized Experimentaland Diagnostic MedicineS. Orsola-Malpighi HospitalUniversity of Bologna40138 BolognaItaly Hematopathology Section Department of ExperimentalDiagnosticand Specialty MedicineS. Orsola-Malpighi HospitalUniversity of Bologna40138 BolognaItaly Division of Internal Medicine Department of Digestive Disease and Internal MedicineS. Orsola-Malpighi HospitalUniversity of Bologna40138 BolognaItaly Department of Radiology S. Orsola-Malpighi HospitalUniversity of Bologna40138 BolognaItaly InterdepartmentalCentre for Cancer Research "G. Prodi" University of Bologna40138 BolognaItaly

Epithelioid hemangioendothelioma(EH)is a rare tumor arising from the vascular endothelial cells of soft tissue or visceral *** most common visceral site is the liver,where it is often involved in a multifocal man-ner known as hepatic EH(HEH).Surgical resection with curative intent represents the gold standard *** surgery is not feasible,or in cases of metastatic disease,no standard medical treatment is currently *** small series,drugs with anti-angiogenic activity(such as bevacizumab,sorafenib,thalidomide,and lenalidomide)have been proposed with promising *** describe a 73-year-old man with multifocal non-resectable HEH treated with *** status was evaluated by abdominal ultrasound and magnetic resonance every four *** patient was treated for a total of 39 mo with prolonged disease stabilization and,at the time of writing,is still under treatment with a good tolerance *** a short period of treatment discontinuation,the disease showed slight progression that immediately resolved after the reintroduction of *** may represent a valid treatment option for HEH due to its anti-angiogenic and antineoplastic *** preliminary result merits further study in a large series.

关键词： Hepatic epithelioid hemangioendothelioma Liver Lenalidomide magnetic resonance Abdominal ultrasound

Active shim coils design for Halbach magnet based on inverse boundary element method

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magnetic resonance Letters 2022年第3期2卷 159-169页

作者： Yajie Xu Feng Wang Ya Wang Peng Yu Jingzhong Zhang Xiaodong Yang Suzhou Institute of Biomedical Engineering and Technology Chinese Academy of SciencesSuzhou215163China School of Electronics and Information Engineering Changchun University of Science and TechnologyChangchun130022China School of Biomedical Engineering(Suzhou) Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei230026China Jinan Guoke Medical Technology Development Co. LtdJinan250101China

With advantages of small volume,high field strength,and compact stray field,the Halbach array magnet is of great potential in desktop NMR ***,field inhomogeneity poses a main obstacle to its *** shimming is necessary for improving the field *** active shim coil design method for cylindrical Halbach magnet based on inverse boundary element method(iBEM)is introduced in this *** coils targeting 1st~3rd and Z4/Z5/Z6 spherical harmonic(SH)terms were designed with constraints of field accuracy,resistance,inductance,and current *** loops and symmetric property influence were discussed to further improve the performance of high-order shim ***,with the prototype of the shim coils constructed,field pattern and SH transformation proved that the coils designed could fit the target SH distribution,though contamination from low-order components existed in highorder terms.A practical shimming experiment on the Halbach magnet has improved the homogeneity from 40.3 ppm to 3.8 ppm in radius 2.5 mm,height 5 mm cylindrical sample space,verifying the coils'compensation *** work provides a flexible inverse coil design method for cylindrical Halbach magnet and discusses the high-order shim coil design and implementation,which is potential in nuclear magnetic resonance applications based on Halbach magnet arrays.

关键词： Active shimming iBEM Halbach magnetic resonance

Autoimmune pancreatitis in the context of IgG4-related disease:Review of imaging findings

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World Journal of Gastroenterology 2014年第41期20卷 15177-15189页

作者： Leslie K Lee Dushyant V Sahani Division of Abdominal Imaging and Intervention Department of RadiologyMassachusetts General HospitalHarvard Medical School

Current understanding of autoimmune pancreatitis (AIP) recognizes a histopathological subtype of the disease to fall within the spectrum of IgG4-related disease. Along with clinical, laboratory, and histopathological data, imaging plays an important role in the diagnosis and management of AIP, and more broadly, within the spectrum of IgG4-related disease. In addition to the defined role of imaging in consensus diagnostic protocols, an array of imaging modalities can provide complementary data to address specific clinical concerns. These include contrast-enhanced computed tomography (CT) and magnetic resonance (MR) imaging for pancreatic parenchymal lesion localization and characterization, endoscopic retrograde and magnetic resonance cholangiopancreatography (ERCP and MRCP) to assess for duct involvement, and more recently, positron emission tomography (PET) imaging to assess for extra-pancreatic sites of involvement. While the imaging appearance of AIP varies widely, certain imaging features are more likely to represent AIP than alternate diagnoses, such as pancreatic cancer. While nonspecific, imaging findings which favor a diagnosis of AIP rather than pancreatic cancer include: delayed enhancement of affected pancreas, mild dilatation of the main pancreatic duct over a long segment, the “capsule” and “penetrating duct” signs, and responsiveness to corticosteroid therapy. Systemic, extra-pancreatic sites of involvement are also often seen in AIP and IgG4-related disease, and typically respond to corticosteroid therapy. Imaging by CT, MR, and PET also play a role in the diagnosis and monitoring after treatment of involved sites.

关键词： Autoimmune pancreatitis IgG4-related disease Pancreatic cancer Imaging Computed tomography magnetic resonance Positron emission tomography Review

MR image denoising method for brain surface 3D modeling

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Optoelectronics Letters 2014年第6期10卷 477-480页

作者：赵德新刘朋杰张德干 Tianjin Key Laboratory of Intelligent Computing & Novel Software Technology Key Laboratory of Computer Vision and System Ministry of Education Tianjin University of Technology

Three-dimensional(3D) modeling of medical images is a critical part of surgical simulation. In this paper, we focus on the magnetic resonance(MR) images denoising for brain modeling reconstruction, and exploit a practical solution. We attempt to remove the noise existing in the MR imaging signal and preserve the image characteristics. A wavelet-based adaptive curve shrinkage function is presented in spherical coordinates system. The comparative experiments show that the denoising method can preserve better image details and enhance the coefficients of contours. Using these denoised images, the brain 3D visualization is given through surface triangle mesh model, which demonstrates the effectiveness of the proposed method.

关键词： magnetic resonance magnetic resonance imaging Medical imaging Three dimensional computer graphics Wavelet analysis

MRI Characteristics and Transverse Relaxation Time Measurements in Normal Growing Cartilage

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Journal of Huazhong University of Science and Technology(Medical Sciences) 2004年第4期24卷 411-413页

作者：李小明王仁发李勇刚唐立华徐安辉胡军武 Department of Radiology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology

To determine the characteristics of magnetic resonance (MR) signals of normal growing cartilage and identify the difference in transverse relaxation times between physeal and epiphyseal cartilage in vivo. 24 distal femora of 12 two-week-old piglets were imaged on a 1.5 Tesla GE MR scanner. Comparison was made between signal intensity on MR images and the structure shown in corresponding histologic sections. T 2 values were measured in eight piglets by means of multiecho spin-echo sequences. Our results showed that MR imaging delineated five regions between the secondary ossification center and the metaphysis, which histologically correspond to the zone of provisional calcification of the secondary ossification center, physis of the secondary ossification center, epiphyseal cartilage, physis and zone of provisional calcification. The T 2 value in the physeal cartilage was much larger than that in the epiphyseal cartilage (P<0.05). It is concluded that MRI findings could differentiate the different regions of growing cartilage. T 2 is longer in physeal than in epiphyseal cartilage, perhaps reflecting differences in water binding by proteoglycans.

关键词： magnetic resonance cartilage growth and development

Three-dimensional dynamic contrast-enhanced MR angiography for evaluating recipient vessels in orthotopic liver transplantation

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Hepatobiliary & Pancreatic Diseases International 2008年第5期7卷 476-480页

作者： Bian, Jie Sha, Lin Yang, Chao Sun, Chuan-Shu Dalian Med Univ Affiliated Hosp 2 Dept Radiol Dalian 116027 Peoples R China

BACKGROUND: With the improvement of MR technology, three-dimensional dynamic contrast-enhanced MR angiography (3D-DCE-MRA) may be the optimal vascular imaging method for preoperative evaluation of liver transplantation candidates. This study was undertaken to determine the value of 3D-DCE-MRA in the assessment of recipient vessels in orthotopic liver transplantation (OLT). METHODS: The surgical and pathological records were taken as the 'gold standards'. Eighteen cases of OLT were retrospectively analyzed to assess the image quality of MRA, including the signal-to-noise ratio (SNR) in arteries and veins, depiction of vascular variation and vessel disease, and the accuracy of vascular diameter measurement. RESULTS: 3D-DCE-MRA of 34 cases was carried out before OLT. The rates (excellent and good) showing hepatic arteries and portal vein for 3D-DCE-MRA were 94.1% (32/34) and 88.2% (30/34), respectively. The SNRs of the celiac axis and portal vein measurements from 3D-DCE-MRA were 20.58 +/- 3.74 and 13.43 +/- 4.12, and the mean diameters were 3.4 +/- 0.3 rum and 13.1 +/- 3.2 mm, respectively. There were 5 cases of vessel variation according to the Michel's classification. Of the 34 patients, 18 were compared radiologically and pathologically. The accuracy of depiction of the hepatic artery and portal vein with 3D-DCE-MRA was 100% for both; 3D-DCE-MRA precisely assessed 4 cases of more than moderate stenosis in hepatic arteries, 2 cases of small-caliber hepatic artery, 3 cases of venous stenosis at the second porta hepatis, 6 cases of collateral vasculature, I case of portal vein thrombosis and I case of portal vein aneurysm; all were confirmed pathologically. CONCLUSION: 3D-DCE-MRA may be the first choice for recipient vascular assessment before OLT.

关键词： magnetic resonance angiography liver transplantation

Correlation between muscular strength and basal nuclei ischemic/hemorrhagic stroke-induced corticospinal tract injury,as detected by diffusion tensor imaging and tractography

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Neural Regeneration Research 2010年第13期5卷 1010-1014页

作者： Shangwen Xu Ziqian Chen Jinhua Chen Youqiang Ye Yuning Lin Ping Ni Hui Xiao Gennian Qian Department of Medical Imaging Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA Fuzhou 350025 Fujian Province China Statistical Division of Department of Medical Affairs Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA Fuzhou 350025 Fujian Province China Department of Medical Bioengineering Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA Fuzhou 350025 Fujian Province China

BACKGROUND： Conventional neuroimaging diagnosis does not assist with the monitoring or evaluation of basal nuclei ischemic and hemorrhagic stroke, or motor functional recovery. magnetic resonance, diffusion tensor imaging, and diffusion tensor tractography have all been used to observe features of cerebral white matter fibrous structures. In addition, diffusion tensor tractography is the only non-invasive imaging method to display the corticospinal tract in vivo. OBJECTIVE： To evaluate the impairment degree of corticospinal tract induced by basal nuclei ischemic and hemorrhagic stroke through the use of magnetic resonance, diffusion tensor imaging, and diffusion tensor tractography, and to analyze the correlation to muscular strength. DESIGN, TIME AND SETTING： A retrospective case analysis was performed at the Department of Medical Imaging, Neurology and Neurosurgery, Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA between November 2002 and June 2008. PARTICIPANTS： A total of 15 patients with acute or subacute cerebral ischemic stroke and nine with hemorrhagic stroke in the basal nuclei were selected. METHODS： magnetic resonance, diffusion tensor imaging, and diffusion tensor tractography results and data were analyzed. Fractional anisotropy and directionally encoded color maps were obtained. Three-dimensional tractography of bilateral corticospinal tract was created, and corticospinal tract integrity was graded. Fractional anisotropy of infarct region and corresponding contralateral normal regions were measured, and hematoma volume in hemorrhagic stroke patients was determined. Hand motor function ability was evaluated using Brunstorm criteria. MAIN OUTCOME MEASURES： Fractional anisotropy of infarct region and corresponding contralateral normal regions; hematoma volume in hemorrhagic stroke patients; correlation between muscular strength and corticospinal tract impairment degree in ischemic stroke and hemorrhagic stroke patients before and a

关键词： ischemic stroke hemorrhagic stroke magnetic resonance diffusion tensor imaging tractography brain injury neural regeneration