ObjectiveTo investigate the value of magnetic resonance (MR) imaging in the assessment of bile duct complications after cholecystectomy. MethodsFifty patients of having bile duct complications after cholecystectomy underwent MR imaging and had some positive manifestations. The indication for cholecystectomy was symptometic cholelithiasis in all cases. MR imaging was performed with a 1.5T clinical imager including all of the sequences of: ①T1 weighted imaging (T1WI) was performed in transverse and coronal plane before and after gadolinium-enhanced. ②T2 weighted imaging (T2WI) was performed in transverse plane. ③A true fast imaging with steadystate precession sequence (True fisp) was performed in coronal plane. ④MR cholangiopancreatography was also obtained. ResultsThe bile duct complications after cholecystectomy including: 22 cases of cholelithiasis, 15 cases of chronic cholangitis with or without bile duct abscess. Bile duct strictures or abruption at the confluence of hepatic and common bile duct in 6 and 3 cases respectively. Tumors of bile duct or pancreas in 9 cases. The other complications after cholecystectomy including bile leak with choleperitonitis and/or biloma and acute pancreatitis.ConclusionMR imaging was a valuable method for the assessment of bile duct complications after cholecystectomy. MR imaging could assess the etiology of bile duct complications. If there were bile duct obstruction, MR imaging could assess the location and the severe of obstruction. For bile duct or pancreatic tumors, MR imaging could assess the areas of tumor infiltration and resection and was helpful to select treatment methods. Before lapatoscopic cholecystectomy, the overall and careful imaging assessment for bile duct and gallbladder and its adjacent hepatic tissue and pancreas so to avoid missing the relative tumors.
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.
Objective To evaluate the value of magnetic resonanace imaging (MRI) on the diagnosis of complex anal fistula. Methods The preoperative digital examination and MRI with the phased-array coil were implemented for 22 patients who were clinically suspected with complex anal fistula. The final diagnosis were based on surgical findings. Outcomes of MRI and digital examination were compared with surgical results. Results Eighteen patients were diagnosed as complex anal fistula, 1 case of presacral cyst and 3 cases of chronic anorectal fistula combined with perianal mucinous adenocarcinoma. All the patients were correctly diagnosed by MRI, while the patients with presacral cyst and perinaal mucinous adenocarcinoma could not be diagnosed correctly by digital examination. According to the Parks classification, 3 patients suffered from transsphincteric fistula, 11 cases of supra-sphincteric and 5 cases of extra-sphincteric fistula. The diagnosis rates of the internal opening with digital examination and MRI were 33.3% and 72.2%, the rates of the primary tract were 83.3% and 100%, and the rates of the secondary extensions were 16.7% and 88.9%, respectively. The differences in detection of internal opening and secondary extensions between MRI and digital examination were significant (P=0.019, P=0.000), the difference in detection of primary tract was no significant (P=0.072). Conclusion MRI with the phased-array coil can develope the high accuracy in the diagnosis of complex anal fistulas, and reveal the relationship between anorectal sphincters and the complex fistula.
【Abstract】ObjectiveTo investigate the relationship of magnetic resonance diffusion-weighted imaging (DWI) to histology in the patients of chronic viral hepatitis. MethodsThirty-five patients of chronic viral hepatitis who received liver biopsy and 10 healthy volunteers were included in this study. All of them underwent DWI on a 3.0T MRI device. Apparent diffusion coefficient (ADC) of the liver were measured respectively when b value were set as 100, 400, 600 and 800 s/mm2. Biopsy specimens were scored for fibrosis and necroinflammation according to the Knodell histology activity index (HAI). ResultsWhen b value was set as 800 s/mm2, statistical difference was showed between the fibrosis group and the nonfibrosis group, statistical difference was also shown among the different degrees of necroinflammation and fibrosis. ConclusionDWI is a valuable method for grading and staging of chronic viral hepatitis.
【摘要】 目的 探讨脑后部可逆性脑病综合征（posterior reversible encephalopathy syndrome，PRES）的临床及MRI表现，提高对PRES的认识。 方法 回顾性分析2007年1月-2010年12月期间5例PRES患者的MRI资料并进行追踪随访。5例PRES患者中男1例，女4例，肾性高血压及产后子痫各1例、妊娠高血压3例。5例均行MRI多序列平扫检查及弥散加权成像（diffusion weighted imaging，DWI），其中4例同时行磁共振血管造影（magnetic resonance angiography，MRA），2例行MRI增强检查。 结果 5例发病时均有高血压，以突发头痛、子痫或癫痫发作、意识障碍及视觉障碍为临床特点，及时正确治疗后症状于3~5 d左右消失，1例遗留肢体功能障碍。MRI显示5例多发病灶主要位于双侧顶枕叶皮质下白质内，额叶及颞叶后部各2例，两侧小脑及脑干1例，皮质受累2例，病变呈长T1、长T2信号、液体衰减反转恢复序列呈高信号，5例患者病灶DWI图呈高或等信号，表观弥散系数（apparent diffusion coefficient，ADC）图呈略高信号；1例顶叶及1例基底节区部分病灶DWI图呈高信号，ADC图呈低信号，提示弥散受限。2例增强无强化，脑膜呈线状强化。随访MRI显示3例病灶完全消失。1例左侧基底节区部分病灶发展为脑梗死。 结论 PRES是一种临床-影像综合征，正确认识这一综合征对其早期诊断和治疗具有非常重要的意义。MRI能够提供较为可靠明确的诊断，其扩散成像对判断PRES预后亦很有价值。【Abstract】 Objective To investigate the clinical features and MRI manifestations of patients with posterior reversible encephalopathy syndrome (PRES), in order to improve its recognition. Methods From January 2007 to December 2010, MRI data of 5 patients with PRES were retrospectively analyzed and the patients were followed up. Among them, one was male and four were female. There were one case of postpartum eclampsia, one of renal hypertention, and 3 of pregnancy-induced hypertension. All the five patients were examined by MRI diffusion weighted imaging (DWI), among whom four underwent additional magnetic resonance angiography (MRA) and one underwent enhanced MRI. Results All the five patients with PRES had hypertension and their clinical symptoms were characterized by sudden occurrence of headache, eclampsia or seizure of epilepsy, altered mental status, and visual disturbances. Clinical symptoms vanished about 3-5 days after prompt and appropriate treatment except one case of residual body function failure. MRI scanning demonstrated multifocal subcortical white lesions in bilateral parieto-occipital lobes in five patients, in bilateral frontal lobes in two patients, in bilateral post temporal lobes in two patients, in bilateral cerebellum in one patient, and in bilateral brainstem in one patient, and cortical involvement occurred in one patient. Lesions appeared as hyperintense signals on fluid attenuated inversion recovery (FLAIR) and T2-weighted images, hypointense signals on T1-weighted images, normal or increased intensity on DWI, and mild hypointensity on apparent diffusion coefficient (ADC) maps. Some lesions in parietal lobes or basal ganglia showed hyperintensity on DWI and isointensity on ADC maps. The lesions in two patients appeared unenhanced with gadolinium enhancement and the meninges assumed the linear strengthening. Follow-up MRI showed that foci in three patients vanished completely, and the focus in the left basal ganglia in one patient developed into cerebral infarction. Conclusions PRES is a clinical-neuroradiological transient condition. Correctly understanding this syndrome is meaningful for its early diagnosis. MRI can provide a more reliable diagnosis, and its proliferation image formation is also valuable in predicting the PERS prognosis.
Abdominal imaging is one of the important clinical applications of magnetic resonance imagining, but image degradation due to respiratory motion remains a major problem. Retrospective respiratory navigator gating technique is an effective approach to alleviate such degradation but is subject to long scan time and low signal-to-noise ratio (SNR) efficiency. In this study, a modified retrospective navigator gating technique with variable over-sampling ratio acquisition and weighted average reconstruction algorithm is presented. Experiments in phantom and the imaging results of seven volunteers demonstrated that the proposed method provided an enhanced SNR and reduced ghost-to-image ratio compared to the conventional method. The proposed method can also be used to reduce imaging time while maintaining comparable image quality.
目的 采用低场MRI非增强扫描探讨强直性脊柱炎（AS）累及脊柱的MRI表现。 方法 从2010年3月－2013年3月间就诊的76例AS患者的MRI图像中选取19例脊柱受累者资料，对病变部位MRI图像进行分析，评价AS累及脊柱在低场MRI非增强扫描状态下的MRI表现特点。 结果 19例患者中颈椎病变3例，胸椎病变9例，腰椎病变7例；MRI表现为椎体终板炎17例、椎间盘炎13例、脊柱滑膜关节炎15例、椎旁韧带炎11例、韧带骨化和骨性强直9例。 结论 低场MRI非增强扫描能直观显示AS脊柱病变，主要表现为椎体终板炎、椎间盘炎、脊柱滑膜关节炎、椎旁韧带炎、韧带骨化和骨性强直，压脂T2WI序列对活动性炎性病变显示良好，T1WI、T2WI序列能较好显示结构性病变。
【摘要】 目的 探讨低场磁共振弥散加权成像（DWI）诊断急性脑梗死的价值。 方法 2007年7月-2009年9月对48例脑梗死患者行常规MRI扫描和DWI，分析不同时期脑梗死的DWI表现。 结果 在发病的超急性期及急性期，DWI病灶显示率均为100.0%，T2WI病灶显示率分别为37.5%、73.7%、100.0%。 结论 低场DWI对急性脑梗死的诊断准确率高，明显优于常规MRI。【Abstract】 Objective To investigate the diagnostic value of diffusion weighted imaging (DWI) in acute cerebral infarction. Methods From July 2007 to September 2009, 48 patients with ischemic stroke underwent conventional MRI and DWI, and the characteristics of DWI were analyzed. Results Abnormal DWI signals were displayed in all patients at hyperacute stage or acute stage, abnormal T2WI signals existed in 37.5%, 73.7%, and 100.0%, respectively. Conclusion DWI in low field MR is highly accurate in diagnosing acute cerebral infarction, which is superior to conventional MRI.
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 CMDiI(Cell TrackerTM 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.