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find Keyword "磁共振成像" 293 results
  • Magnetic Resonance Imaging Evaluation of The Gallbladder

    胆囊作为贮存和浓缩胆汁的器官,其内的胆汁易于析出、凝集而形成结石。胆囊最常见的疾病多与结石相关,如胆石症、急慢性胆囊炎、胆囊癌等; 其他影响胆囊的病理状态还包括胆道动力障碍、术后改变等。超声对胆囊结石及胆囊炎的诊断有较高的敏感性及特异性,还可通过摄取高脂食物前后对比评价胆囊功能,是胆囊疾病的传统影像检查手段,但对肥胖患者其图像质量及解剖细节显示较差。目前,常规MRI已经成为重要的胆囊成像方法之一,并可引入经胆道排泄的造影剂进一步清晰显示其解剖及生理。对于超声不能很好评价的胆囊疾病患者应首选MRI检查。

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  • THE APPLICATION OF MAGNETIC RESONANCE CHOLANGIOPANCREATOGRAPHY TO DIAGNOSIS OF OBSTRUCTIVE JAUNDICE

    Objective To evaluate the diagnostic value of magnetic resonance cholangiopancreatography (MRCP) in obstructive jaundice. Methods Forty eight consecutive patients with obstructive jaundice were examined by MRCP, all results were testified during and /or after operation. Results Different causes of obstruction had their own characteristic manifestations. Level of obstruction was accurate in 100%, the accuracy in distinguishing obstructive causes was 93.8%. Conclusion MRCP is quite effective, safe and reliable in diagnosis of obstructive jaundice.

    Release date:2016-09-08 02:01 Export PDF Favorites Scan
  • Diffusion Weighted Imaging Diagnosing Cystic Meningioma

    目的 探讨囊性脑膜瘤的磁共振表现、表观弥散系数(ADC)图的影像特点、ADC值与病理分级的关系及ADC值对判断不同病理亚型脑膜瘤的价值。 方法 回顾性分析2003年3月-2007年12月18例经病理证实的囊性脑膜瘤患者的磁共振表现,其中男8例,女10例,平均年龄45.6岁。在ADC图上分别测量肿瘤实质、瘤周水肿、囊变区的平均ADC值(均取4~6个区域,取平均值),比较不同病理亚型、不同病理分级的肿瘤实质、瘤周水肿、囊变区的ADC值差异是否有统计学意义。 结果 良恶性脑膜瘤肿瘤实质ADC值差异无统计学意义(P>0.05);囊性脑膜瘤各亚型间的肿瘤实质、瘤周水肿的ADC值差异无统计学意义(P>0.05);肿瘤实质、囊变区与瘤周水肿平均ADC值相比差异均有统计学意义(P<0.05)。 结论 ADC值可区分肿瘤实质、囊变区及瘤周水肿,但对脑膜瘤亚型及良恶性的甄别需结合常规MRI与增强的征象。Objective To explore the MRI imaging manifestation, features of apparent diffusion coefficient (ADC) map and the relationships among ADC value, pathologic grading and pathologic subtype of cystic meningioma. Methods The clinical data of 18 patients (8 males and 10 females, with an average age of 45.6 years) with cystic meningiomas confirmed by pathologically examination were retrospectively analyzed. The ADC values of tumor parenchyma, peritumoral edema, cystic regions and the contralateral normal brain of the tumor parenchyma were measured and analyzed.The ADC value of the tumor parenchyma, peritumoral edema, cystic region were measured and then compared with the pathological findings. P value of less than 0.05 was considered as having a statistically significant difference. Results There was no significant difference in ADC values between benign and malignant meningioma and also among the tumor parenchyma, periedema and cystic region in different pathological subtypes. The difference in ADC values amongst tumor parenchyma, peritumoral edema and cystic region were statistically significant (P<0.05). Conclusions Although ADC quantitative measurement allows the differentiation of the tumor parenchyma, cystic region and peri-edema, it is need to combined with conventional MR examination to assess tumor malignancy as well as grading in cystic meningioma.

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  • Assessing the Effects of Simultaneous Antegrade/Retrograde Cardioplegia on Myocardial Perfusion and Energy Metabolism in Ischemic Myocardium

    Abstract: Objective To assess the effects of simultaneous antegrade/retrograde cardioplegia (SARC) on myocardial perfusion and energy metabolism in ischemic myocardium using magnetic resonance imaging (MRI). Methods After the hearts were harvested from 18 domestic pigs, left anterior descending artery, aorta, anterior ascending cardiac vein and coronary sinus were cannulated to establish the perfusion routes. 6 hearts were used to assess the effects of SARC on myocardial perfusion. Energy metabolism was observed in the other 12 pig hearts. MRI was used to monitor the distribution of contrast agent (gadoliniumdiethylenetriamine penlaacetic acid, Gd-DTPA) in the myocardium after its injection through arterial and retrograde perfusion routes. The efficacies in sustaining myocardial perfusion and energy metabolism were evaluated by using phosphorus-31 magnetic resonance spectroscopy (31P MRS) during antegrade cardioplegia (AC) and SARC respectively. Results It was found that injection of Gd-DTPA into the aorta during AC did not result in signal increase in the ischemic myocardium on MRI. During SARC, however, Gd-DTPA was found in the ischemic region as well as in the other regions, no matter if it was given into the aorta or into the coronary sinus. Moreover,31P spectra showed that occlusion of LAD during AC resulted in severe decrease of the levels of phosphocreatine (PCr) and adenosine triphosphate (ATP), while the level of inorganic phosphate (Pi) increased in LAD-support myocardium. The abnormal metabolic changes were completely abolished by use of SARC. Conclusion It is concluded that SARC can deliver cardioplegic solution to the myocardium distal to a coronary occlusion and can sustain normal energy metabolism in the jeopardized myocardium.

    Release date:2016-08-30 06:13 Export PDF Favorites Scan
  • 国际抗癫痫联盟诊断方法委员会儿科手术治疗协作组报告——诊断性检查在可外科治疗的儿童癫痫中的应用

    对于经过严格筛选的儿童耐药性局灶性癫痫病例, 外科手术是取得无痫性发作的成功手段。医学技术的发展使癫痫患者可以获得更精准的术前评估, 同时患者获得癫痫外科手术治疗的机会也有所增加。如今已在临床应用的癫痫灶评估方法不仅耗费资源而且在特定病例中不起作用, 抑或是副作用大。因此有必要及时制定标准化的术前评估流程。各项检查在特定临床病理类型的病例中的作用尚缺乏1级或2级证据支持。基于这一现状, 国际抗癫痫联盟(ILAE)的诊断与儿科学组的儿童癫痫外科协作组将各成员间的共识总结为专家建议发表。旨在减少将各项检查的利用不足, 同时促进临床更灵活地运用各项检查, 使现有的儿童癫痫中心尽可能标准化地进行癫痫的术前评估。

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  • Abnormal spontaneous brain functional activity in adult patients with amblyopia: a resting-state functional magnetic resonance imaging study

    Amblyopia is a visual development deficit caused by abnormal visual experience in early life, mainly manifesting as defected visual acuity and binocular visual impairment, which is considered to reflect abnormal development of the brain rather than organic lesions of the eye. Previous studies have reported abnormal spontaneous brain activity in patients with amblyopia. However, the location of abnormal spontaneous activity in patients with amblyopia and the association between abnormal brain function activity and clinical deficits remain unclear. The purpose of this study is to analyze spontaneous brain functional activity abnormalities in patients with amblyopia and their associations with clinical defects using resting-state functional magnetic resonance imaging (fMRI) data. In this study, 31 patients with amblyopia and 31 healthy controls were enrolled for resting-state fMRI scanning. The results showed that spontaneous activity in the right angular gyrus, left posterior cerebellum, and left cingulate gyrus were significantly lower in patients with amblyopia than in controls, and spontaneous activity in the right middle temporal gyrus was significantly higher in patients with amblyopia. In addition, the spontaneous activity of the left cerebellum in patients with amblyopia was negatively associated with the best-corrected visual acuity of the amblyopic eye, and the spontaneous activity of the right middle temporal gyrus was positively associated with the stereoacuity. This study found that adult patients with amblyopia showed abnormal spontaneous activity in the angular gyrus, cerebellum, middle temporal gyrus, and cingulate gyrus. Furthermore, the functional abnormalities in the cerebellum and middle temporal gyrus may be associated with visual acuity defects and stereopsis deficiency in patients with amblyopia. These findings help explain the neural mechanism of amblyopia, thus promoting the improvement of the treatment strategy for amblyopia.

    Release date:2022-10-25 01:09 Export PDF Favorites Scan
  • CLINICAL FEATURES OF SPONTANEOUS SPINAL EPIDURAL HEMATOMA AND INFLUENTIAL FACTORS OF ITS PROGNOSIS

    Objective To explore the clinical features of spontaneous spinal epidural hematoma (SSEH) and to find out factors influencing its prognosis. Methods From September 1998 to October 2006, 23 patients with SSEH (10 males and 13 females) were treated. Their ages ranged from 10 to 69 years. The primary neurological status were classified as grade A in 7 patients,B in 2 patients, C in 4 patients, D in 9 patients and E in 1 patients accordingto ASIA grading system. The progressive intervals of their symptoms were divided as four period: less than 12 hours (12 patients), 12 to 24 hours(2 patients), 24 to 48 hours(3 patients) and more than 48 hours(6 patients). SSEH was diagnosedby MRI or by histopathological examination. The cases history, laboratory examination, radiological image, treatment, pathological result and prognosis were recorded and analyzed after 3 month. Results In 23 patients, there were 1 case of deterioration, 8 cases of no change, 9cases of improvement and 5 cases of complete recovery. The gender had no correlationwith prognosis(P>0.05). In the patients who had shorter progressive interval and more severe edema of spinal cord, the prognosis was worse(P<0.05). Inthe patients who had mild neurological deficit, the prognosis was good (P<0.01). In 17 patients undergoing surgery, the scores for prognosis was 1 point in 1 case, 2 points in 5 cases, 3 points in 6 cases and 4 points in 5 cases; the operation time had no correlation with prognosis(r=0.056, P>0.05). In6patients undergoing conservative treatment, the scores for prognosis were 2 points and 3 points in 3 cases respectively. Conclusion Prognosis of patient with SSEH is influenced by his primary neurological status, progressive interval, spinal edema and size of hematoma. The major treatment is surgical evacuation of hematoma as early as possible to break the aggravation of spinal function. Conservative treatment is not considered unless the neurological defects recovered in the early period.

    Release date:2016-09-01 09:22 Export PDF Favorites Scan
  • Three-dimensional reconstruction of carp brain tissue and brain electrodes for biological control

    In order to accurately implant the brain electrodes of carp robot for positioning and navigation, the three-dimensional model of brain structure and brain electrodes is to be proposed in the study. In this study, the tungsten electrodes were implanted into the cerebellum of a carp with the aid of brain stereotaxic instrument. The brain motor areas were found and their three-dimensional coordinate values were obtained by the aquatic electricity stimulation experiments and the underwater control experiments. The carp brain and the brain electrodes were imaged by 3.0 T magnetic resonance imaging instrument, and the three-dimensional reconstruction of carp brain and brain electrodes was carried out by the 3D-DOCTOR software and the Mimics software. The results showed that the brain motor areas and their coordinate values were accurate. The relative spatial position relationships between brain electrodes and brain tissue, brain tissue and skull surface could be observed by the three-dimensional reconstruction map of brain tissue and brain electrodes which reconstructed the three-dimensional structure of brain. The anatomical position of the three-dimensional reconstructed brain tissue in magnetic resonance image and the relationship between brain tissue and skull surface could be observed through the three-dimensional reconstruction comprehensive display map of brain tissue. The three-dimensional reconstruction model in this study can provide a navigation tool for brain electrodes implantation.

    Release date:2020-12-14 05:08 Export PDF Favorites Scan
  • The relationship between the manifestation of the tumor of optic pathway in MRI and the affection on the visual function

    Objective To investigate the MRI characteristics of the tumor of optic pathway and damage degree of visual function. Methods Analysis of 119 cases surgically and pathologically proved tumor suffering from optic pathway was carried out retrospectively. The patients included:36 ones with tumors in anterior segment of optic pathway,70 ones in middle segment of optic pathway,and 13 ones in posterior segment of optic pathway. The MRI examination series were transverse T-1WI SE,transverse and coronal T-2WI TSE,coronal T-2WI SPIR,and transverse,sagittal,coronal T-1WI SE after Gd-DTPA enhancement. Results The tumors of optic pathway included:the primary tumors of the optic pathway and the tumors of any other part of the body which invaded the optic pathway. There was a special MRI feature on the each tumor suffering from optic pathway,but the pituitary adenoma which affects visual function was the most common tumor. Conclusion MRI is an effective method in the diagnosis of optic-pathway tumor. (Chin J Ocul Fundus Dis, 2002, 18: 101-103)

    Release date:2016-09-02 06:01 Export PDF Favorites Scan
  • The Experimental Study of Imaging and Redistribution of Bone Marrow Mesenchymal Stem Cells Transplanted into Coronary Artery in Vivo

    Objective To investigate the feasibility of imaging of bone marrow mesenchymal stem cells (BMMSCs) labeled with superparamagnetic iron oxide(SPIO) transplanted into coronary artery in vivo using magnetic resonance imaging (MRI), and the redistribution of the cells into other organs. Methods BMMSCs were isolated, cultured from bone marrow of Chinese mini swine, and double labeled with SPIO and CMDiI(Cell TrackerTM C-7001). The labeled cells were injected into left anterior descending coronary artery through a catheter. The injected cells were detected by using MRI at 1 week,3weeks after transplantation. And different organs were harvested and evaluated the redistribution of transplanted cells through pathology. Results The SPIO labeled BMMSCs injected into coronary artery could be detected through MRI and confirmed by pathology and maintained more than 3 weeks. The SPIO labeled cells could be clearly imaged as signal void lesions in the related artery. The pathology showed that the injected cells could be distributed into the area of related artery, and the cells injected into coronary artery could be found in the lung, spleen, kidney, but scarcely in the liver, the structures of these organs remained normal. Conclusion The SPIO labeled BMMSCs injected into coronary artery can be detected by using MRI, the transplanted cells can be redistributed into the non-targeted organs.

    Release date:2016-08-30 06:08 Export PDF Favorites Scan
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