犬脑栓塞溶栓前后磁共振内镜术比较研究

目的应用磁共振仿真内镜(magneticresonancevirtualendoscopy,MRVE)技术对家犬脑栓塞模型及溶栓治疗后效果进行观察,探讨MRVE在超急性脑梗塞前后血管诊断效果。方法于数字减影血管造影术(DSA)下,用自体凝血块栓塞30只家犬脑部供血动脉,迅速行MR扫描,数据传输至工作站,进行MRVE检查,观察脑部血管,然后将栓塞家犬利用尿激酶进行溶栓治疗,再重新行MR扫描,观察比较栓塞前后及溶栓前后MRVE的改变。结果30只家犬于DSA下进行人工栓塞后(DSA为金标准,显示血栓100%),MRVE观察达优率867%(达到4或3级),准确率800%(与DSA结果相比),达良率100%(达到1或2级),达差率33%(达到“-”级);溶栓后,DSA显示再通25例,MRVE观察达优率700%,准确率560%,达良率33%,达差率267%,溶栓后较溶栓前MRVE观察效果差(χ2=70177,P<001)。结论MRVE对大脑栓塞后观察效果明显差,溶栓治疗后观察效果最差,故MRVE不适于溶栓后血管的观察。

磁共振仿真内镜在胆总管梗阻性病变中的应用

目的 :评价MR仿真内镜 (MRVE)对胆总管梗阻性病变的诊断作用。方法 :将 61例行 3DTSEMRCP检查的胆总管梗阻病例的原始图像资料传送至工作站 ,利用专用的仿真内镜软件进行仿真内镜重建 ,观察不同病变的仿真内镜表现。结果 :所有 61例均得到较好的仿真内镜图像 ,3 2例结石及 7例壶腹癌基础上合并结石、壶腹癌 11例、十二指肠乳头炎 6例、胰头癌 6例、胰腺炎 4例均得到清楚的显示 ,同时有 12例泥沙样结石MIP图像未见显示而仿真内镜上得到清楚的显示 ,但有 1例胆道乳头状癌的诊断需结合平扫图像 ;MRVE的空间分辨率低、无法真正显示病变的色彩改变及无法显示粘膜的细微改变为MRVE的应用局限性。结论 :MRVE能直观地显示扩张胆总管内表面及病变情况 。

肾、输尿管结石磁共振仿真内镜与输尿管肾镜对照的离体研究

目的 对照输尿管肾镜检查,探讨不同源影像技术MR仿真内镜诊断肾、输尿管结石的价值与限度。方法 9个5mm以内直径大小的尿路结石,经输尿管离断端置入因配型问题放弃移植的离体肾之输尿管肾盂内,以生理盐水、3％马根微显溶液充分充盈输尿管肾盂后,分别采用多层薄层快速自旋回波单激发(SS-FSE)、重T2(HT2-FSE)序列行磁共振水成像和采用3D、2D快速扰流梯度重聚(FSPGR)行磁共振尿路造影(MRU)。磁共振扫描源影像数据在工作站用导航软件作内镜成像重建(VE)。影像检查完成后摄X片和输尿管肾镜检查,然后正中冠状切开肾与榆尿管,再次观察结石数目、大小和位置。结果 5个结石为输尿管镜准确检出,其后方肾小盏内另4个结石未显示;VE检出的结石源于不同扫描序列不同,源于HT2-FSE序列者5个(5／9)、多层薄层SS-FSE序列者4个(4／9)、3D及2D FSPGR序列者均为4个(4／9)。VE检出的最小结石直径为2mm。几种方法对结石检出率无显著差异(P>0.5)。VE图像质量尤其管道内腔及结石表面细节显示度比输尿管镜的差(P<0.005),其基于长T2加权像MRH技术优于基于钆增强短T1加权像MRU技术(P<0.05),但其所示结石均稍有变形。 结论 尿路磁共振仿真内镜成像能够检出直径2mm以上结石.以HT2-FSE技术为佳,但其对结石的检出率和图像质量仍不及输尿?

胆系磁共振仿真内镜的临床应用评价

目的 :评价磁共振仿真内镜 (MRVE)对胆系梗阻性疾病的诊断价值。方法 :47例胆系梗阻性病变的患者行MRVE检查。将快速自旋回波 (FSE)和单次激发快速自旋回波 (SSFSE)获得的二维T2 WI数据传输至工作站 ,用导航软件显示胆管内腔。结果 :MRVE清晰显示了胆管内解剖结构、梗阻部位和梗阻端的表面形态 ,FSE序列的MRVE和SS FSE序列的MRVE对病变的定位准确率都为 10 0 % ,检出病变的敏感性分别为 92 .2 %和 96.0 %。结论 :FSE序列的MRVE和SSFSE序列的MRVE都能显示胆系腔内结构。MRVE是对磁共振胆胰管造影 (MRCP)技术的有益补充 。

蛛网膜下腔MR仿真内镜成像技术与临床意义

目的 探讨蛛网膜下腔磁共振仿真内镜 (MRVE)成像技术、方法及临床价值。资料与方法 对临床要求常规序列检查的患者采用二维快速自旋回波重T2 序列 (2DHT2 FSE)加行磁共振水成像 (MRH) ,其中颅脑 15例 ,脊椎 11例 ,源影像数据传输至工作站利用导航软件行仿真内镜 (VE)后处理重建成像。结果 在 2DHT2 FSE图像上 ,脑脊液呈高信号亮色 ,明显高于邻近组织结构信号 ,采用“黑底白影”阈值方式、2 5 0～ 110 0阈值重建获得了蛛网膜下腔VE图像。VE准确三维地展示了蛛网膜下腔及其邻近和穿行其间的脑、颅内腔、脊髓、椎管内腔、神经、血管与病变 ,对脑、脊髓表面结构 ,脑垂体、松果体和脑血管 ,部分颅神经起源、走行等显示颇佳 ,并可靠检出了小脑扁桃体下疝、听神经瘤、脊髓圆锥低位和椎管肿瘤、椎间盘突出等病变。结论 MRH是蛛网膜下腔VE有效的源影像技术 ,VE为评价蛛网膜下腔、脑、脊髓及其血管、神经正常解剖、变异与病变提供了一种安全、无创性。

磁共振仿真内镜技术在三叉神经痛显微血管减压术中的应用

目的 探讨磁共振仿真内镜（MRVE）技术联合三维时间飞跃法成像（3D-TOF）序列、三维稳态进动快速成像（3D-FIESTA）序列在三叉神经痛显微血管减压术（MVD）中的应用价值.方法 回顾性纳入2012年8月至2015年4月湖州市中心医院神经外科采用MVD治疗的76例原发性三叉神经痛患者,所有患者均于术中确认病因.术前患者均采用3.0T磁共振行3D-TOF、3D-FIESTA序列扫描,并行MRVE后处理,评估MRVE技术联合3D-TOF、3 D-FIESTA序列的诊断及术中的价值.结果 76例患者中,术前3D-TOF＋ FIESTA序列诊断有责任血管压迫者63例,与手术确认的符合率为83％,漏诊13例（17％）;3D-TOF＋ FIESTA＋ MRVE序列诊断有责任血管压迫者72例,符合率为95％,漏诊4例（5％）,P =0.04.2种联合序列诊断符合者均主要为责任血管是动脉的患者,漏诊者均主要为责任血管是静脉的患者,其中1例蛛网膜粘连增厚者2种方法均漏诊.结论 MRVE技术联合3D-TOF、3D-FIESTA序列能清晰显示责任血管与神经的三维空间关系,提高责任血管判断的准确率.

3.0 T MR三维高分辨成像序列联合MRVE在三叉神经痛术前评估中的应用

目的探讨3.0 T MR三维高分辨成像联合MR仿真内镜(MRVE)在三叉神经痛术前评估中的应用价值。方法回顾性分析2016年4月—2017年12月40例因原发性三叉神经痛(PTN)行微血管减压术(MVD)病人的资料,其中男21例,女19例,年龄37~86岁,平均(59.6±2.2)岁。所有病人均行3.0 T MR三维高分辨成像,进行双激发平衡式稳态自由进动(3D-FIESTA-c)和三维时间飞跃法MR血管成像(3D-TOF-MRA)序列扫描,并进行MRVE重建。采用χ2检验比较三维高分辨成像及三维高分辨成像联合MRVE预判断责任血管的阳性率,并以手术结果作为金标准,分析上述2种成像方法对责任血管的检出率。结果术前40例病人采用2种成像方法检查,MR三维高分辨成像联合MRVE成像对责任血管压迫显示的阳性率(95%,38/40例)高于MR三维高分辨成像(85%,34/40例)(χ2=1.826,P=0.04)。术中发现40例PTN病人均存在责任血管压迫,其中动脉压迫33例(82.5%)、单纯静脉压迫3例(7.5%)、动静脉混合压迫4例(10.0%)。2种成像方法对动脉压迫的检出率均为100%。MR三维高分辨成像联合MRVE成像对静脉及动静脉混合压迫的检出率(71.4%,5/7)高于单独MR三维高分辨成像(14.3%,1/7)。结论 MR三维高分辨成像序列联合MRVE技术能有效显示神经与血管的三维空间关系,能够对三叉神经痛的病因诊断提供重要价值。

Diagnostic procedures for submucosal tumors in the gastrointestinal tract

This review is part one of three, which will present an update on diagnostic procedures for gastrointestinal (GI) submucosal tumors (SMTs). Part two identifies the classification and part three the therapeutic methods regarding GI SMTs. Submucosal tumors are typically asymptomatic and therefore encountered incidentally. Advances in diagnostic tools for gastrointestinal submucosal tumors have emerged over the past decade. The aim of this paper is to provide the readers with guidelines for the use of diagnostic procedures, when a submucosal tumor is suspected. Literature searches were performed to find information on diagnostics for gastrointestinal submucosal tumors. Based on the searches, the optimal diagnostic procedures and specific features of the submucosal tumors could be outlined. Standard endoscppy, capsule endoscopy and push-and-pull enteroscopy (PPE) together with barium contrast X-ray do not alone provide sufficient information, when examining submucosal tumors. Endoscopic ultrasound (EUS), computed tomography (CT), magnetic resonance imaging (MRI) and fluorodeoxyglucose-labeled positron emission tomography (FDG-PET) are recommended as supplementary tools.

Endoscopic ultrasound and magnetic resonance imaging for re-staging rectal cancer after radiotherapy

AIM： To compare the sensitivity and specificity of two imaging techniques, endoscopic ultrasound （EUS） and magnetic resonance imaging （MRI）, in patients with rectal cancer after neoadjuvant chemoradiation therapy. And we compared EUS and MRI data with histological findings from surgical specimens. METHODS： Thirty-nine consecutive patients （51.3% Male; mean age： 68.2 ＋ 8.9 years） with histologically confirmed distal rectal cancer were examined for staging. All patients underwent EUS and MRI imaging before and after neoadjuvant chemoradiation therapy. RESULTS： After neoadjuvant chemoradiation, EUS and MRI correctly classified 46% （18/39） and 44% （17/39） of patients, respectively, in line with their histological T stage （P 〉 0.05）. These proportions were higher for both techniques when nodal involvement was considered： 69% （27/39） and 62% （24/39）. When patients were sorted into T and N subgroups, the diagnostic accuracy of EUS was better than MRI for patients with T0-T2 （44% vs 33%, P 〉 0.05） and NO disease （87% vs 52%, P = 0.013）. However, MRI was more accurate than EUS in T and N staging for patients with more advanced disease after radiotherapy, though these differences did not reach statistical significance. CONCLUSION： EUS and MRI are accurate imaging techniques for staging rectal cancer, However, after neoadjuvant RT-CT, the role of both methods in the assessment of residual rectal tumors remains uncertain.

Diagnosis of mild chronic pancreatitis (Cambridge classification):Comparative study using secretin injection-magnetic resonance cholangiopancreatography and endoscopic retrograde pancreatography

AIM： To investigate the usefulness of secretin injection- MRCP for the diagnosis of mild chronic pancreatitis.METHODS： Sixteen patients having mild chronic pancreatitis according to the Cambridge classification and 12 control subjects with no abnormal findings on the pancreatogram were examined for the diagnostic accuracy of secretin injection-MRCP regarding abnormal branch pancreatic ducts associated with mild chronic pancreatitis （Cambridge Classification）, using endoscopic retrograde cholangiopancreatography （ERCP） for comparison.RESULTS： The sensitivity and specificity for abnormal branch pancreatic ducts determined by two reviewers were respectively 55%-63% and 75%-83% in the head, 57%-64% and 82%-83% in the body, and 44%-44% and 72%-76% in the tail of the pancreas. The sensitivity and specificity for mild chronic pancreatitis were 56%-63% and 92%-92%, respectively. Interobserver agreement （K statistics） concerning the diagnosis of an abnormal branch pancreatic duct and of mild chronic pancreatitis was good to excellent.CONCLUSION： Secretin injection-MRCP might be useful for the diagnosis of mild chronic pancreatitis.

Adult-to-adult right lobe living donor liver transplantation:Comparison of endoscopic retrograde cholangiography with standard T2-weighted magnetic resonance cholangiography for evaluation of donor biliary anatomy

AIM: To compare the value of endoscopic retrograde cholangiography (ERC) and standard T2-weighted magnetic resonance cholangiography (MRC) in the evaluation process as adult-to-adult right lobe living donor liver transplantation (LDLTx) demands a successful outcome, and exact knowledge of the biliary tree is implicated to avoid biliary complications, postoperatively.METHODS: After starting the LDLTx program, 18 liver transplant candidates were selected for LDLTx by a stepwise evaluation process. ERC and standard T2-weighted MRC were performed to evaluate the biliary system of the donor liver. The anatomical findings of ERC and MRC mapping were compared using the Ohkubo classification. RESULTS: ERC allowed mapping of the whole biliary system in 15/15 (100%) cases, including 14/15 (93.3%) with biliary variants while routine MRC was only accurate in 2/13 (15.4%) cases. MRC was limited in depicting the biliary system proximal of the hepatic bifurcation. Postoperative biliary complications occurred in 2 donors and 8 recipients. Biliary complications were associated with Ohkubo type C, E or G in 6/8 recipients, and 2/3 recipients with biliary leak received a graft with multiple (≥2) bile ducts. CONCLUSION: Pretransplant ERC is safe and superior over standard MRC for detection of biliary variations that occur with a high frequency. However, precise knowledge of biliary variants did not reduce the incidence of postoperative biliary complications.

Pancreatic hyperechogenicity on endoscopic ultrasound examination

There is an ongoing discussion on how to diagnose a hyperechogenic pancreas and what is the clinical significance of diffusely hyperechogenic pancreas. Computerized tomography and magnetic resonance imaging are the more appropriate methods to diagnose pancreatic hyperechogenicity when compared with transcutaneous or endoscopic ultrasound examination. More importantly, pancreatic hyperechogenicity may not be a certain indicator of pancreatic fat infiltration. Even if it is true, we do not know the clinical significances of pancreatic fat accumulation. Some suggested that excess fat in the pancreas is associated with chronic pancreatitis. However, several histological studies on human alcoholic chronic pancreatitis did not prove the presence of fatty pancreas in such cases. Thus, except for aging, it is very rare to have truly steatotic pancreas in the absence of certain human diseases.

Endoscopic papillectomy of minor papillar adenoma associated with pancreas divisum

Tumors of the minor papilla of the duodenum are quite rare.We successfully and safely treated an 18-mm adenoma of the minor papilla associated with pancreas divisum using endoscopic papillectomy.A 64-year-old man was admitted to our hospital for treatment of an asymptomatic mass in the minor papilla detected by upper gastrointestinal endoscopy.Endscopic analysis showed an 18-mm,whitish,sessile mass,located in the duodenum proximal to a normal-appearing major papilla.Endoscopic retrograde pancreatography did not reveal the pancreatic duct.Magnetic resonance cholangiopancreatography showed a lack of the ventral pancreatic duct.We suspected this case was associated with pancreatic divisum;therefore,we performed endoscopic papillectomy of the minor papilla tumor.Subsequently,endoscopic pancreatic stent placement in the minor papilla was done to prevent drainage disturbance.The patient has been asymptomatic without recurrence of tumor or stenosis of the Santorini orifice upon endoscopic examination for the past 2 years.

Clinical significance of magnetic resonance cholangiopancreatography utilizing half-Fourier acquisition single-shot fast spin-echo in diagnosing bile duct diseases

Objective: To investigate the clinical significance of magnetic resonance cholangiopancreatography (MRCP) utilizing half-Fourier acquisition single-shot fast spin-echo (HASTE) in the diagnosis of bile duct diseases. Methods: Forty-three patients with obstructive jaundice and 4 without were enrolled in this study. The underlying diseases included bile duct calculi ( 13 cases) , chronic cholangitis ( 14 cases) malignant tumors (18 cases) and congenital biliary cysts (2 cases). All patients underwent examinations with magnetic resonance imaging (MRI) and MRCP, and 39 were also examined with B-type ultrasonography, 33 with CT and 25 with ERCP and PTC. Three-dimensional image reconstruction was performed using volume-rendered technique ( VRE) on the basis of the data obtained by MRCP. Results: The biliary calculi were displayed as circular filling defects in MRCP images, with the proximal end of dilated bile duct taking the form of the mouth of a cup. The bile duct of patients with chronic cholangitis showed distal end dilation and thinner proximal end without discontinuity. Interception of the bile ducts was most frequent (72. 2% ) in cases of malignant bile duct obstruction, in which the ducts may also be mastoid or resembling rat tails. 72. 2% of the cases had severe dilation of the bile ducts, which occur in only 16. 0% of the benign cases, with significant difference between them (P <0. 01) . In images of intrahepatic biliary cyst, intrahepatic duct dilated in the shape of a bursa in connection with the duct. By MRCP, 20 malignant obstructions of the bile ducts were identified with 2 misdiagnoses, and in 25 cases of benign obstructions identified by MRCP, only 1 misdiagnoses occurred. Thus MRCP had the sensitivity, specificity and accuracy of 90.0% , 96.3% and 93.6% respectively in discriminating benign and malignant diseases of the bile ducts, showing a total diagnostic accuracy of 94. 0% that was similar to that of ERCP (92.0% ) but significantly higher than those of both CT (75. 0% ) and B-type ultrasonic examination (74. 0% ). Conclusion: In diagnosing obstructive jaundice, HASTE MRCP is similar to ERCP but better than CT and B-type ultrasonography , with the merits of fast imaging and high resolution as an ideal sequence for MRCP imaging.

血管压迫性三叉神经痛责任血管的MR仿真内镜重建研究

目的探讨血管压迫性三叉神经痛的MR仿真内镜重建(MRVE)技术对责任血管的评估价值。方法对57例三叉神经痛患者采用双激发平衡式稳态自由进动序列(3D-FEISTA-C)扫描,经原始图像及MRVE分析判断责任血管与神经的关系,将45例与微血管减压术(MVD)结果比较对照,一致性检验采用Kappa分析,并计算出原始图像及运用MRVE技术在检测责任血管的敏感性、特异性、阳性预测值及阴性预测值。结果 57例采用3D-FIESTA-C联合MRVE显示血管神经无接触5例,接触13例,压迫39例;责任血管为小脑上动脉43例,岩静脉8例,椎基底动脉4例,小脑前下动脉2例;其中责任血管为两支者5例;接触及压迫部位发生于神经出脑干段45例,脑池段12例。57例中45例3D-FIESTA-C及联合MRVE显示血管神经接触及压迫、责任血管以及压迫部位与MVD术中所见一致性检验(K值分别为0.325、0.639)。运用3D-FIESTA-C及联合运用MRVE技术检测责任血管的敏感性分别为88.89%、97.78%,特异性分别为33.33%、58.33%,阳性预测值分别为85.11%、89.80%,阴性预测值分别50%、87.50%。结论运用MRVE技术能够为临床提供在一定空间范围内三维可视化图像,可作为术前评价重要的辅助工具。