【摘要】目的 探讨低磁场MRI诊断胰腺癌的价值。方法 回顾性分析我院78例经手术和病理证实的胰腺癌的MRI表现。结果 肿瘤的低磁场MRI主要表现为胰腺出现局部软组织肿块或全部肿大，轮廓、信号异常，T1加权像呈等或低信号，信号不均匀，T2加权像信号不均匀增高； 肝内外胆管、胰管扩张，邻近组织及器官受累。结论 低磁场MRI能较好地显示胰腺癌的大小、形态和继发的胆、胰管梗阻、扩张以及肿瘤转移、侵袭范围，有利于肿瘤的诊断。
摘要:目的:探讨伽玛刀治疗颅内肿瘤并发放射性脑损伤的MRI影像表现及其组织病理学基础。方法:回顾性分析8例经手术及病理证实的放射性脑损伤的MRI表现;其中,星形胶质细胞瘤4例,转移性腺癌2例,血管母细胞瘤1例,鼻咽癌1例。结果:病变位于小脑半球、额叶、颞叶及顶叶,8例9个病灶共有2种MRI表现:5例6个病灶平扫T1WI呈低、等信号,T2WI呈稍高、高信号,增强扫描呈“结节状”、“花环状”强化;3个病灶平扫为类圆形,T1WI呈均匀低信号,T2WI呈高信号,边界清楚,增强扫描囊腔无强化,囊壁轻度均匀强化。所有病例均有占位效应。结论:伽玛刀所致放射性脑损伤具有一定的特征性,特别是囊状坏死。
【Abstract】ObjectiveTo evaluate the value of MR imaging with a contrast-enhanced multi-phasic isotropic volumetric interpolated breath-hold examination (VIBE) in diagnosis of primary liver carcinoma. MethodsThirty-two consecutive patients with surgical-pathologically confirmed 42 foci of primary carcinoma of liver underwent comprehensive MR examination of the upper abdomen, routine two-dimensional (2D) T1WI and T2WI images were acquired before administration of Gd-DTPA for contrast enhancement. Then, contrast-enhanced multi-phasic VIBE was acquired followed by 2D T1WI images. The lesion appearances on hepatic arterial, portal venous and equilibrium phases of VIBE sequence were carefully observed along with delineation of hepatic arterial and portal venous structures. The lesion detection rates and lesion characterization ability were compared among various MR sequences. Results33(78.6%), 30(71.4%), 38(90.5%) and 42(100%) foci were displayed respectively on T2WI, non-enhanced T1WI, enhanced T1WI and enhanced 3D-VIBE images (P＜0.05). The hepatic arterial anatomy of 30 patients （93.8%） and the portal venous structure of 31 patients （96.9%） were clearly depicted on enhanced 3D-VIBE images. Using MIP and MPR reconstruction techniques, the feeding arteries of 14 foci and draining vein of 12 foci were clearly displayed.ConclusionHigh-quality 3D-VIBE images are not only better than 2D images in lesion detection and characterization for primary liver carcinoma, but also able to provide much more information about hepatic vascular anatomy.
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。
目的 探讨磁共振扩散加权成像（DWI）、动脉自旋标记技术（ASL）、磁共振血管成像（MRA）联合应用在缺血性脑血管病诊断中的价值。 方法 对2010年3月－2012年5月经临床和影像学诊断的104例缺血性脑血管病患者，行常规MRI、液体衰减反转恢复序列、DWI及ASL、MRA序列检查，分析DWI、ASL、MRA多种技术显示病变的信号特征、面积大小及与血管关系。 结果 DWI对急性及亚急性脑梗死的检出率为100%，对大、小面积梗死病灶检出率无明显差异；ASL对大、小面积的急性及亚急性脑梗死的检出率有差异，对大面积梗死检出率为100%，对小面积梗死的检出率为70%；DWI和ASL对短暂性脑缺血发作的检出率分别为0%、70%，液体衰减反转恢复序列对短暂性脑缺血发作患者大脑皮层下斑状缺血灶检出最敏感。 结论 DWI和ASL均可用于急性脑梗死的早期诊断，ASL对大、小面积的急性及亚急性脑梗死的检出率有差异，DWI、ASL及MRA联合应用可准确评估缺血半暗区及侧支血管情况，在缺血性脑血管病诊断中有重要价值。
Objective To investigate the MRI features of the autoimmune pancreatitis （AlP）. Methods MRI data of 8 patients with AIP were retrospectively analyzed. Results MRI showed that diffuse swelling of the pancreas in 8 cases. T1WI signal intensity homogeneous or inhomogeneous decreased， and T2WI signals intensity homogeneous or inhomogeneous increased. In arterial phase the enhancement of the lesion was not obviously，in portal venous phase there was gradual increase of enhancement. There was coated sample annular enhancement around pancreas， and the degree of enhancement was slightly lower than the pancreatic parenchyma. Pancreatic duct was irregular narrow. Conclusion AIP is a special kind of chronic pancreatitis，MRI features of AIP are helpful for the diagnosis and treatment of AIP．
Chronic kidney disease (CKD) is now recognized as a worldwide public health challenge, and the incidence rate and hospitalization rate have significantly increased in recent years. Without prompt diagnoses and effective treatment in the early renal function damage of CKD, the symptoms will continue to worsen and eventually develop into end-stage renal disease. Functional imaging techniques such as single photon emission computed tomography (SPECT), contrast-enhanced ultrasound (CEUS), computerized tomography perfusion (CTP), and magnetic resonance perfusion weighted imaging (MR-PWI) could be used to quantitatively analyze renal perfusion and renal filtration function. Their diagnostic values are increasingly evident and have become the research hotspot in evaluating renal function. The aim of this review is to briefly evaluate the research and application advances in the early renal function damage assessment of CKD, so as to raise the efficiency of clinical applications.
Objective To investigate the value of a new double action MR contrast agent——Gd-BOPTA in the diagnosis of focal nodular hyperplasia (FNH) of the liver with correlation of pathology. Methods Dedicated MRI scans were performed for 5 patients suspected to have liver FNH on clinical and imaging basis (six lesions). The MR imaging protocol included axial T1W and T2W plain scan, coronal T2 weighted imaging, 3D MRCP, Gd-BOPTA enhanced LAVA dynamic tri-phasic acquisitions (scanning at 15 s, 55 s and 90 s respectively), enhanced 2D T1W scan, enhanced LAVA in delay phase (at 5 and 10 min) and in the hepatobiliary phase (at 40 and 80 min). The imaging features on each MR sequence were compared with surgical and pathological findings. Results Six lesions in 5 FNH patients were all correctly diagnosed (5 conformed by surgery and 1 by needle biopsy). ①The hemodynamic phase: The parenchyma of 5 lesions were markedly enhanced in the arterial phase, being isointense or slight hypointense in both the portal venous and delay phases, while 1 lesion was isointense in all phases except being slight hyperintense in the arterial phase; The central scar of 5 lesions were not enhanced in the dynamic phase, but showed delayed enhancement. ②The hepatobiliary (excretory) phase: The parenchyma of all 6 lesions were slight hyperintense or isointense, and tree-like bile ducts with hyperintensity were seen within one lesion. The scar showed no enhancement. ③Pathology: The parenchyma was consisted of disarranged normal hepatocytes but with cytoedema, lack of portal tracts and cholestatic change. The central scar showed rich fibrous tissue, a very thick-walled arteriole, proliferative bile ducts, infiltration of inflammatory cells and myxomatous changes. Conclusion As a dual-phase MR contrast agent capable of depicting both the hemodynamic attributes and hepatobiliary excretion, Gd-BOPTA enhanced MRI can reflect the pathological features of FNH and reach a high diagnostic accuracy.
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 (gadoliniumdiethylenetriamine 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.