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.
This study aims to explore the potential of polyaspartic acid grafted dopamine copolymer (PAsp-g-DA) chelated Fe3+ for magnetic resonance imaging (MRI) visual photothermal therapy. Polyaspartic acid grafted copolymer of covalently grafted dopamine and polyethylene glycol (PAsp-g-DA/PEG) was obtained by the ammonolysis reaction of poly succinimide (PSI), and then chelated with Fe3+ in aqueous solution. The relaxivity in vitro, magnetic resonance imaging enhancement in vivo and photothermal conversion effect at 808 nm were investigated. The results showed that polymeric iron coordination had good near-infrared absorption and photothermal conversion properties, good magnetic resonance enhancement effect, and good longitudinal relaxation efficiency under different magnetic field intensities. In summary, this study provides a new magnetic resonance visual photothermal therapeutic agent and a new research idea for the research in related fields.
Objective To explore the program for calculating the necrotic articular surface area (NASA) and the ratio of NASA to whole articular surface area (WASA) of osteonecrosis of the femoral head (ONFH), to verify the accuracy of this calculation and to predict the collapse of the femoral head clinically using this program. Methods From June 2001 to June 2003, The specimens of the necrotic femoral head from eight patients (13 hips) were obtained by total hip arthroplasty. The magnetic resonance imaging (MRI) was taken in all patients before operation. According to a series of T1-weight pictures, the NASA and the ratio of NASA to WASA were calculated by designing program. The specimens of the necrotic femoral head were sawed into lays similar to MRI pictures using the coordinate paper stick on the auricular surface, the data processing were done by analytic instrument for pictures. The data of both were analyzed statistically by software SPSS 10.0 edition. The NASA and the ratio of NASA to WASA were calculated on MRI in ARCO Stage Ⅰ, Ⅱ 16 patients (25 hips) with non-operation. Follow-up was done to the patients with collapse of the femoral head and to the patients with no collapse for at least 24 months. The data were compared in collapse group and non-collapse group. Results There were no significant differences between MRI pictures calculation and specimens measurement (NASA: 0.412, ratio of NASA to WASA: 0.812, Pgt;0.05). Of the 25 hips followed up, collapse occurred in 17 hips. NASA was 31.06±8.10 cm2, (95% CI: 26.58 to 35.55)，the ratio of NASA to WASA was 58.91%±15.11%, (95% CI: 51.14to 66.68). No collapse appeared in 8 hips. NASA was 14.16±9.32 cm2(95% CI: 6.04 to 21.95), the ratio of NASA to WASA was 29.48%±19.76%(95% CI: 12.97to 45.99). The ratio in the patients with collapse was beyond 33%. Conclusion The NASA and the ratio of NASA to WASA in patients withONFH can be accurately calculated with the MRI pictures. The possibility of collapse can be predicted by this method. As it is complicated in operation, improvement should be made in order to put itinto clinical use.
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.
Objective To summary the principle of magnetic resonance spectroscopy imaging and its application progress in diagnosis and differential diagnosis of pancreatic cancer. Methods The newest related literatures of home and abroad were collected and reviewed. Results Magnetic resonance spectroscopy imaging was a technology using the magnetic resonance phenomena and chemical shift phenomena to measure molecular organization. The spectroscopy most commonly used in clinical and scientific research includes 1H， 31P， and 23Na. Conclusion Magnetic resonance spectroscopy as the only approach to noninvasive quantitative provding biochemical information in vivo， has an important significance to the diagnosis and differential diagnosis of pancreatic cancer.
ObjectiveTo systematic review the diagnostic value of magnetic resonance (MR) for pulmonary embolism (PE).MethodsWe electronically searched databases including EMbase, PubMed, The Cochrane Library, WanFang Data and CNKI from inception to November 2016, to collect the diagnostic studies about MR in the diagnosis of PE. Two reviewers independently screened literature according to the inclusion and exclusion criteria, extracted data, and assessed the risk of bias of included studies, and then meta-analysis was conducted using Stata 12.0 software.ResultsA total of 14 studies involving 1 042 patients were included. The pooled Sen, Spe, +LR, –LR and DOR were 0.90 (95%CI 0.83 to 0.94), 0.95 (95%CI 0.90 to 0.98), 19.8 (95%CI 8.5 to 46.1), 0.10 (95%CI 0.06 to 0.18), 189 (95%CI 69 to 521), respectively. The AUC of SROC were 0.97 (95%CI 0.95 to 0.98).ConclusionMR has a good diagnosis value for PE which can be regarded as an effective and feasible method for suspected PE patients, especially for those who has contraindication of computed tomographic pulmonary angiography.
ObjectiveTo evaluate the sensitivity, specificity, and accuracy of magnetic resonance imaging (MRI) in characterizing cirrhosis-related nodules. MethodsThe databases such as the Cochrane Library, PubMed, EMbase were searched on computer from 1998 to 2012.The reviewers screened the trials according to strict inclusion and exclusion criteria, extracted the data, and assessed the methodology quality.Meta-analysis was performed using the metadisc 1.40 software.The acquired pooled sensitivity, specificity, and summary receiver operating characteristic (SROC) curve were used to describe the diagnostic value.The pooled likelihood ratio was calculated based on the pooled sensitivity and specificity. ResultsSix case-control studies involving 917 patients diagnosed with cirrhosis who were suspected to have hepatic nodules were included and 776 masses were confirmed by the biopsy or postoperative histopathology.The pooled statistical results of meta-analysis showed that the sensitivity and specificity of MRI were 87%(83%-89%) and 79%(73%-84%) respectively, the positive and negative likelihood ratios of MRI were 3.95 and 0.18 respectively, and the area under the SROC curve (AUC) was 0.895 6.The sensitivity and specificity of CT were 69%(65%-73%) and 83%(77%-88%) respectively, the positive and negative likelihood ratios of CT were 3.29 and 0.42 respectively, and the AUC was 0.728 7.The sensitivity, positive likehood ratio, and accuracy of MRI in characterizing cirrhosis-related nodules were higher than those of CT. ConclusionAccording these evidences, the MRI should be the first imaging examination for qualitative diagnosis of cirrhosis-related nodules.
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 discuss the clinical value of whole spine magnetic resonance imaging (WSMRI) in practice of neurosurgical spinal surgery. Method A total of 70 cases examined using WSMRI between January 2015 and December 2016 were collected and analyzed retrospectively. Results All patients got clear images of WSMRI. Eighteen cases got important information, including spinal variation (1 case), multiple lesions (3 cases), combined lesions (6 cases) and large range multi-segmental lesions (8 cases), which were missed by single-segment MRI . Conclusions WSMRI can show all the spine, spinal cord and surrounding tissue in one image at one time. It has high clinical value because of its accurate positioning, comprehensiveness, time saving, and low rate of misdiagnosis and missed diagnosis.
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.