ObjectiveTo investigate the feasibility of proton magnetic resonance spectroscopy (1H-MRS) imaging, by which to quantitatively analyze liver fat content for therapeutic evaluation of fatty liver at 3.0 T MRI. MethodsTwenty-six patients who diagnosed with fatty liver were examined with proton MRS at Siemens Trio Tim 3.0 T MRI before treatment and 3, 6 months after treatment, respectively. The water peak, fat peak, water peak area, and fat peak area were detected, and the relative lipid content 1 (RLC1) and relative lipid content 2 (RLC2)were calculated. Fatty liver index (FLI) was referred to the standard which was calculated from triglycerides (TG), gammaglutamyl-transferase (GGT), waist circumference, and body mass index. ResultsThere were significantly different differences of RLC1 and RLC2 among before treatment and 3, 6 months after treatment (Plt;0.05). Compared with before treatment, the RLC1 and RLC2 values significantly decreased on month 3 or 6 after treatment (Plt;0.05). There were positive correlation between RLC1 or RLC2 and FLI (r=0.476, Plt;0.00; r=0.475, Plt;0.001). The intraclass correlation coefficient was more than 0.75 before treatment, the repeatability was better. ConclusionsProton MRS can quantitatively measure liver fat content. It can be reliably used for dynamic monitoring the therapeutic effects for fatty liver. Proton MRS is accurate, and has a good clinical application in dynamically monitoring the progression of fatty liver and evaluating the therapeutic effects of various treatments.
Objective To summarize the principle and application of functional MR imaging of pancreatic carcinoma and chronic mass-forming type pancreatitis. Methods Articles about diffusion-weighted imaging (DWI), magnetic resonance spectrum imaging (MRSI) and dynamic contrast-enhanced MR imaging of pancreatic carcinoma and chronic pancreatitis were reviewed and analyzed. Results Functional MR imaging could reflected the differences in molecules diffusion, metabolism and tissue perfusion between pancreatic carcinoma and chronic pancreatitis. Conclusion As a non-invasive protocol, functional MR imaging can provide useful information in differential diagnosis between chronic mass-forming type pancreatitis and pancreatic carcinoma.
Objective To observe the characteristics of magnetic resonance diffusion tensor imaging（MR-DTI）for optic nerves and optic radiation in blind patients.Methods The optic nerves and optic radiation of 20 blind patients（blind group）and 20 controls（control group） were scanned by MR-DTI. Fractional anisotropy (FA) and directional encoded color (DEC) maps were acquired through postprocessing with the aid of volumeone 1.72 software. The signal intensity of optic nerves and optic radiation were then observed. The FA, mean diffusivity (MD), lambda;∥ and lambda;perp; value of bilateral optic nerves and optic radiation in two groups were measured in the DEC maps.Results While the high signal intensity was found in bilateral optic nerves in FA and DEC maps in control group，the signal decreased markedly in the blind group. The FA and lambda;∥ value of optic nerves in the blind group were declined obviously compared to that in the control group. The difference was statistically significant (t=16.294, 14.660;P=0.000). The MD and lambda;perp; value of optic nerves in the blind group were increased obviously compared to that in the control group, the difference was also statistically significant (t=8.096, 8.538; P=0.000). The high signal intensity was found in bilateral optic radiation in FA and DEC maps in both the blind and control groups. There were no statistic differences in FA and MD value in bilateral optic radiation between the blind and control groups (Left：t=1.456，1.811；P=0.152，0.076. Right：t=0.779，0.073；P=0.440，0.942). Conclusion A low signal intensity of bilateral optic nerves and a high signal intensity of bilateral optic radiation were found in blind patients.
摘要:目的: 探讨臂丛神经磁共振成像的技术方法及其可行性。 方法 :对15例正常志愿者行双侧臂丛神经成像:包括常规快速自旋回波序列T1加权(T1W/TSE)、快速自旋回波序列T2加权(T2W/TSE)、快速自旋回波序列T2加权加SPIR脂肪抑制(T2W/SPIR)冠状位扫描以及弥散加权背景抑制成像序列(DWIBS)轴位扫描。 结果 :T1W/TSE、T2W/TSE、及T2W/SPIR对臂丛节后神经同层显示率分别为533%、567%和833%;DWIBS MIP重建图像对臂丛神经的全貌显示较为完整、清晰、直观;T1W/TSE、T2W/TSE、T2W/SPIR及DWIBS MIP重建图像的对比噪声比分别为109±09、107±13、185±68和299±133,T2W/SPIR序列和DWIBS MIP重建图像的对比噪声比明显高于T1W/TSE和T2W/TSE序列。 结论 :T2W/SPIR序列对臂丛神经的同层显示率及图像的对比噪声比明显高于常规T1W/TSE、T2W/TSE序列, DWIBS MIP重建图像能够显示臂丛神经的全貌,两者为臂丛神经成像较为有效的技术方法,对于臂丛神经病变的诊断即具有十分重要的意义。Abstract: Objective: To determine the optimal sequences of brachial plexus with MRI. Methods : Fifteen volunteers were underwent MRI on 15T scanner, the Sequences of T1W/TSE/COR, T2W/TSE/COR, T2W/SPIR/COR and Diffusionweighted imaging with background body signal suppression were performed. Results : The display rates of brachial plexus postganglionic segment nerve showing at the same slice were 533%, 567% and 833% on T1W/TSE/COR, T2W/TSE/COR, T2W/SPIR/COR. Brachial plexus on DWIBS MIP were clear and complete. Contrastnoise ratio of four sequences was 109±09, 107±13, 185±68 and 299±133,respectively. Contrastnoise ratio of T2W/SPIR/COR and DWIBS MIP was significantly higher than that of the other two sequences. Conclusion : Display rate of brachial plexus and contrastnoise ratio of images on T2W/SPIR/COR were higher than those of routine sequences. Image of DWIBS MIP can show the outline of brachial plexus clearly. The two sequences were reliable and effetive techoniquic in diagnosis of brachial plexus lesion.
摘要:目的: 分析肝脏局灶性结节增生(FNH)的MRI表现和病理特点,探讨两者的相关性,提高FNH诊断的准确率。 方法 :回顾性分析23例(共28个病灶)经手术切除病理证实为FNH的MRI平扫及增强表现,与其病理特点进行对照。 结果 :25个病灶在平扫T1WI上呈等或稍低信号,T2WI上呈等或稍高信号,3个病灶在平扫T1WI及T2WI上均呈稍高信号,增强后所有28病灶动脉期可见明显强化,门脉期及延迟期呈稍高、等或稍低信号,其中12个病灶可见中心纤维瘢痕延迟强化。FNH组织病理上表现为富血供的实质性肿块,肿物内部组织较均匀,没有异型细胞,中心可见纤维瘢痕。 结论 :肝脏MRI平扫及增强检查能很好的反映FNH的组织病理及血供特点,能为FNH的诊断及鉴别诊断提供可靠证据。Abstract: Objective: To analyze the MRI manifestations and pathology characteristic of hepatic focal nodular hyperplasia(FNH),and to investigate their correlation. Methods : A retrospective analysis was made on the unenhanced and dynamic enhanced MR images of 23 patients (totally 28 lesions) with surgical and pathological proved FNH. Results :25 FNH lesions demonstrated isointensity or slightly hypointense on unenhanced T1WI,and isointensity or slightly hyperintense on unenhanced T2WI,3 FNH demonstrated hyperintense on both unenhanced T1WI and T2WI. 28 FNHs were markediyhyperintense in the arterial phase of dynamic contrast enhanced MRI, and isointense or slightly hyperintense in the portal and delayed phase．The seals were shown in 12 lesions, and enhanced in delayed phase．FNH is solid mass with vast blood supply,its inside structure is homogemeous. Typical seal can be found by microscopic examination．〖WTHZ〗Conclusion : MRI could disclose the pathologic features of FNH and its blood supply and improve the accuracy 0f its diagnosis．
摘要:目的:探讨平山病的MRI影像特点及其临床应用价值。方法:5例临床确诊平山病病例组和10例正常对照组进行颈椎自然位及屈颈位MRI检查,矢状位T1WI、T2WI及轴位T2WI,观察颈髓、蛛网膜下腔及硬膜外腔变化情况。结果:病例组的5例平山病均系16~20岁男性。自然位:5例下位颈髓均萎缩变扁,硬膜外间隙未显示增宽。屈颈位:5例C5~7颈髓前移变扁中,将变扁颈髓又分为上中下三段,以中段最窄,上下段渐移行至正常;C5~7蛛网膜下腔亦变窄,硬脊膜伴随前移;而C4~7硬脊膜后间隙则增宽,呈新月形影,增宽程度分为轻、中、重三度,最重者位于C6椎体平面,T2加权像及T1WI增强呈高信号,其中1例内见血管流空信号影。对照组为10例志愿者,自然位: 4例C3~7颈髓形态、大小基本一致,6例颈髓自颈3逐渐移行与胸1脊髓其大小一致;屈颈位:颈髓和蛛网膜下腔大小与自然位比较无明显变化,硬膜后间隙自C3平面向下延至T1平面,T2WI上呈均匀线样高信号影。结论:下位颈髓萎缩变扁,屈颈位颈髓及硬脊膜前移、硬脊膜后间隙增宽呈新月形影等,是临床诊断平山病较特征性的MRI表现。Abstract: Objective: To evaluate clinical value and MRI features of Hirayama disease. Methods: Five cases of hirayama disease, which had been clinically confirmed using siemens sonata 1.5T MRI scan, physiological condition and flexional condition, Sagittal view T1WI, T2WI and Axial View T2WI, and GdDTPA enhanced examination, for MRI changes of spinal cord, subarachnoid cavity, duramater of spinal membrae and extra dural space, etc were studied. Results: In case group of 5 cases of hirayama disease, age was mainly in 16–20 years old, All of 5 cases were men. Which were pressed and become thinner of spinal cord, strictic changes of subarachnoid cavity, new moony shape and enlargement changes and pushed forward of extra duramater space, and higher intensity signal of GdDTPA enhancement, and vascular flow effect (one case ) in C5–C7. but also, for contrast group 10 cases of normal volunteer, physiological condition:4 cases in cervical spinal cord with shape and structure were uniformity, and duramater, subarachnoid cavity, extra duramater space etc in C3–C7 were abnormal. Six cases in cervical spinal cord with shape and structure gradully changed from C3 to T1; flexional condition: 10 cases of MRI changes of spinal cord, subarachnoid cavity were as same as it in physiological condition,all of T2 WI, higher intensity signal were homogeneous of extraduramater space in C3–T1. Conclusion: The feature findings of cervical spinal cord became thinner, and cervical cord, durameter pussed forward, new moony shape and enlargment of extradurameter space, vascular flow effusion, etc in MRI were useful value for clinical diagnosis.
Objective To review the current status of magnetic resonance imaging (MRI) techniques in the evaluation of hepatic fibrosis. Methods The application and recent advances of various kinds of MRI techniques in evaluating hepatic fibrosis were summarized by literature review. Results The state-of-the-art of MRI evaluating of hepatic fibrosis included common contrast-enhanced MRI, double contrast-enhanced MRI, and various functional MRI techniques. Common contrast-enhanced MRI could detect morphological changes of the liver, but little value in phasing. Double contrast-enhanced MRI markedly increased the contrast to noise ratio. Except diagnosis liver fibrosis, functional MRI also could phase it by its serverity. Conclusion MRI techniques, especially those functional MRI techniques, are advancing very fast and have very great potentiality in both the diagnosis and severity assessment of hepatic fibrosis.
Objective To investigate the accuracy of preoperative high-resolution magnetic resonance imaging (MRI) scans to predict tumor stage, lymph node stage, and circumferential resection margin (CRM) involvement. Methods Between September 2006 and May 2009, 42 patients with histologically proven rectal cancer by the colonoscopic biopsy in Peking Union Medical College Hospital were staged preoperatively using MRI. All of the patients underwent total mesorectum excision (TME) operation within 1 week after MRI examination. The specimens were reported according to the 2002 TNM staging system for primary colorectal cancer of the American Joint Committee on Cancer (AJCC). Concordance between radiologic staging of tumor, local lymph node, and CRM involvement and pathologic reporting was assessed by means of the Kappa statistic.Results For all of 42 patients, MRI correctly staged the tumor in 36 patients, understaged in 3 patients and overstaged in 3 patients. Statistically, there was a better correlation between pathologic and radiologic tumor staging (Kappa=0.731, P=0.000). MRI correctly staged lymph node status in 31 patients, understaged in 5 patients and overstaged in 6 patients. Statistically, there was a common correlation between pathologic and radiologic lymph node staging (Kappa=0.410, P=0.009). MRI correctly reported the status of the CRM in 40 patients. Statistically, there was the best correlation between pathologic and radiologic reporting of CRM involvement (Kappa=0.829, P=0.000). Conclusion Preoperative highresolution MRI scans has a good concordance with pathologic tumor stage but common with pathologic lymph node stage. Preoperative highresolution MRI can provide reliable information about CRM and thus help to choose which patient could benefit from the preoperative neoadjuvant therapy.
ObjectiveTo explore the application of cardiac enhanced MRI in acute myocardial infarction with normal result of coronary angiography. MethodsOn October 18, 2013, a male patient underwent coronary angiography under the local anesthesia. Mild coronary stenosis both in left and right side were found in the surgery, but the results of dynamic cardiogram and myocardial markers were abnormal, which accorded with the clinical procedure of myocardial infarction. The patient underwent cardiac enhanced MRI at the 6th day and was finally diagnosed as acute myocardial infarction. We reviewed the database to find out the significance of cardiac enhanced MRI in diagnosis of acute myocardial infarction. ResultsAlthough coronary angiography was the gold standard for the diagnosis of coronary diseases, it had limitations in the diagnosis of coronary eccentric stenosis, branch vascular stenosis and coronary spasm. Cardiac enhanced MRI had the advantages of accurate measurement of the attenuation of myocardium and exhibition of functional changes of ischemic myocardium. ConclusionCardiac enhanced MRI is important for the diagnosis of myocardial infarction with normal result of coronary angiography.
This study aimed to characterize and magnetic resonance imaging (MRI) track the mesenchymal stem cells labeled with polylysine-coated superparamagnetic iron oxide (PLL-SPIO). Rat bone marrow derived mesenchymal stem cells (rMSCs) were labeled with 25, 50 and 100 μg/mL PLL-SPIO for 24 hours. The labeling efficiency was assessed by iron content, Prussian blue staining, electron microscopy and in vitro MR imaging. The labeled cells were also analyzed for cytotoxicity and differentiation potential. Electron microscopic observations and Prussian blue staining revealed that 75%-100% of cells were labeled with iron particles. PLL-SPIO did not show any cytotoxicity up to 100 μg/mL concentration. Both 25 μg/mL and 50 μg/mL PLL-SPIO labeled stem cells did not exhibit any significant alterations in the adipo/osteo/chondrogenic differentiation potential compared to unlabeled control cells. The lower concentration of 25 μg/mL iron labeled cells emitted an obvious dark signal in T1W, T2WI and T2*WI MR image. The novel PLL-SPIO enables to label and track rMSCs for in vitro MRI without cellular alteration. Therefore PLL-SPIO may potentially become a better MR contrast agent especially in tracking the transplanted stem cells and other cells without compromising cell functional quality.