ObjectiveTo detect the metabolites of the serum and joint fluid from rabbits’ osteoarthritis model with 1H nuclear magnetic resonance spectroscopy (NMR) technique, study the metabolic differences and connections of serum, synovial and cartilage of rabbits after the articular cavity injection of sodium hyaluronate, and explore osteoarthritis and metabolic mechanism in the process of treating sodium hyaluronate using sodium hyaluronate, thus provide new ideas and basis of the specific mechanisms in the treatment of osteoarthritis via sodium hyaluronate.MethodsWe selected 30 healthy New Zealand white rabbits, 6 months old, and randomly divided them into three groups as follows: blank control group, model phosphate buffer saline (PBS) liquid injection group and model injection of sodium hyaluronate group, with 10 rabbits in each group. Ten weeks after surgery, all experimental animals were put to death and observed in correlation studies regarding general condition, imaging examination, and histological examination. Metabolites 1H NMR detection and data preprocessing were performed in the serum and joint fluid samples.ResultsThe results considering general condition, general sample observation, imaging examination and histology indicated advantages in sodium hyaluronate group over PBS group. Metabolomics analysis showed statistically significant changes of metabolites in the serum and joint fluid compared with the PBS group and the blank control group (P<0.05). According to the relevant ways of differences metabolites retrieval, analysis found that the effect of sodium hyaluronate on osteoarthritis might be related to protein biosynthesis, amino acid circulation, the metabolic process of pyruvic acid, gluconeogenesis and other metabolic pathways.ConclusionsBased on the research of 1H-NMR metabolomics, the results suggest that the effect of sodium hyaluronate on osteoarthritis is mainly related with the activation of protein metabolism, abnormal lipid and energy metabolic pathways. This study provides new ideas and basis on the concrete mechanism in the treatment of knee osteoarthritis using sodium hyaluronate.
Conventional magnetic resonance (MR) pulse sequences typically have an echo time (TE) of 1 ms or longer, providing an excellent contrast between different soft tissues. However, some short T2 tissues appear dark in conventional MR images because the signal from these tissues has decayed to nearly zero before the center of k-space is acquired. Because of the ability of directly imaging short T2 tissues, ultrashort echo time technique has been widely studied in recent years. An overwhelming majority of the studies were carried out at high fields, while many low-field scanner systems are still used in developing countries. To investigate the effects of the delay between analog-to-digital converter sampling and the readout gradient, the TE of the second echo used to calculate the R2* map, and the undersampling ratio on the results of three-dimensional (3D) ultrashort echo time imaging at a low field, we implemented a 3D ultrashort echo time sequence on a 0.35T scanner. Different parameters were used and the reconstructed images and R2* maps were compared. Images reconstructed with slightly varying delays appeared quite different. Different contrast between short and long T2 tissues were found in R2* maps calculated with different echoes. The result of undersampling study indicated that excessive undersampling could cause unwanted blurring, making it difficult to better visualize the short T2 tissues in the R2* map. The results suggested that cautions should be taken in the choice of these parameters in 3D ultrashort echo time imaging. Short T2 tissues can be visualized with appropriate imaging parameters at this low field.
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.
ObjectiveThis review has summarized in detail the advances in computed tomography (CT) and magnetic resonance imaging (MRI) imaging in evaluating the efficacy of targeted therapy for gastrointestinal stromal tumor (GIST).MethodsTo summarize the image-related guidelines, consensus, international conference reports, and relevant knowledge of clinical research on the evaluation of the efficacy of GIST targeted therapy in recent years.ResultsThe CT and MRI manifestation after targeted treatment of GIST was closely related to pathological changes, including necrosis, cystic degeneration, and bleeding. CT was the preferred imaging method. Functional magnetic resonance imaging, such as diffusion weighted imaging (DWI), had made some progress. The main criteria for evaluating the efficacy of GIST targeted therapy were RECIST 1.1 and Choi criteria.ConclusionCT and MRI play an important role in evaluating the efficacy of targeted therapy for GIST.
Objective To understand and analyze technique development of magnetic resonance elastography (MRE) and its application in chronic liver disease. Method The relevant literatures about the application of MRE in the field of chronic liver disease were reviewed. Results The liver fibrosis was a common pathway of chronic liver disease, which would progress to cirrhosis of the liver if untreated. The diagnosis and assessment of fibrosis was important in the treatment of patients with chronic liver disease. The liver biopsy was considered to be the reference standard for clinical assessment of liver fibrosis. However, this technique was invasive and still had inevitable drawbacks in the clinical practice. With the update of the imaging technology and equipment, the MRE had been developed as a safe and noninvasive examination method for the evaluation of liver fibrosis in the chronic liver disease, early diagnosis of nonalcoholic fatty liver disease, evaluation of focal liver lesions, and other clinical applications. Conclusion MRE is currently regarded as an attractive noninvasive technique in management of chronic liver disease.
OBJECTIVE:To investigate the diagnostic meaning of MRI in intraocular tumors. METHODS:Forty-six cases of confirmed intraocular tumors,including choroidal melanoma(20 cases),retinoblastoma(18 cases),Coats disease(6 cases)and choroidal hemangioma(2 cases),were studied with MRI and compared with ultrasonography and CT. RESULTS:In making discoveries about intraocular tumors,there were no sighificant difference between MRI and B-ultrasonography or CT （P＞0.03，chi;2=1.0716）while there were highly statistic sighificance in dediding characters and position （P＜0.01，deceding character chi;2=29.8314，positionchi;2=13.659）of them. CONCLUSION:Among the examinations to find out about the position,character and secondary pathological insults of in traocular tumors MRI might be more available than CT and ultrasonography. （Chin J Ocul Fundus Dis,1997,13:93-95 ）
ObjectiveTo analyze and conclude CT and MRI imaging features of ectopic pancreas in gastrointestinal tract so as to improve the understanding of the features.MethodsThe clinical, imaging, and pathological data of 12 patients with ectopic pancreas in the gastrointestinal tract confirmed by the pathology in the Sichuan Provincial People’s Hospital from November 2016 to June 2019 were retrospectively analyzed. The characteristics of image presentation were summarized.Results① The anatomical distribution: all patients had a single lesion. Of the 12 cases, 6 cases located in the gastric body lesser curvature, 3 cases located in the gastric angle, 1 case located in the posterior wall of gastric antrum, 1 case occurred in the upper jejunum, and 1 case occurred in the terminal ileum; 8 cases located in the submucosa, 2 cases located in the submucosa and muscular layer simultaneously, 1 case located in the submucosa, muscular and serous layer simultaneously, and 1 case located in the muscular layer. ② Size of the lesions: the maxium dimensions of the lesions were all 3 cm or less, and the long axes of the lesions were parallel to the gastrointestinal tract wall in 10 cases. ③ The internal characteristics: the results of 9 of 11 cases showed the isodensity compared to main pancreas on the plain CT scan. The results of 8 patients with enhanced CT showed the moderate to obvious enhancement, with 2 cases showed the slightly enhanced flaky or tube-like foci. In the arterial phase and portal venous phase, 6 cases showed the isodensity compared to main pancreas respectively. The result of MRI in 1 patient showed the isointensity compared to main pancreas on the plain scan and obviously heterogeneous enhancement.ConclusionCT and MRI could provide some information about location, size, and internal density or intensity of ectopic pancreas, and could be helpful for diagnosis.
ObjectiveTo summarize the research progress of ultrasmall superparamagnetic iron oxide (USPIO) enhanced magnetic resonance imaging (MRI) in normal-sized lymph node metastasis of colorectal cancer.MethodThe relevant literatures published recently at domestic and abroad about USPIO enhanced MRI in normal-sized lymph node metastasis of colorectal cancer were collected and reviewed.ResultsUSPIO, a kind of lymph node targeted magnetic resonance contrast agent, could be used to evaluate lymph node metastasis of malignant tumors. USPIO enhanced MRI could detect normal-sized lymph node metastasis in colorectal cancer effectively compared with normal MRI. It provided a higher diagnostic performance than normal enhanced MRI. In addition, USPIO enhanced MRI could also distinguish inflammatory and metastatic lymph nodes better that were difficult to be distinguished by normal enhanced MRI.ConclusionUSPIO enhanced MRI shows a certain potential for clinical application in detecting normal-sized lymph node metastasis of colorectal cancer, but it has not been widely used in China.
ObjectiveTo summarize the application of magnetic resonance imaging (MRI) in the evaluation of pancreatic exocrine function.MethodIn this paper, we reviewed and summarized the related literatures about the application of MRI in the field of pancreatic exocrine function evaluation in recent years.ResultsA variety of MRI techniques could be used to detect the pancreatic exocrine function. In addition to conventional MRI techniques, there were also MRI stimulated by pancreatic secretions, cine (dynamic) cholangiopancreatography based on space selective reverse recovery pulse, and so on.ConclusionThe new MRI techniques have potential for semi-quantitative and quantitative evaluation of pancreatic exocrine function.
Objective To investigate the application of magnetic resonance imaging (MRI) in preoperative assessment of rectal cancer. Methods Combined with the literatures, the MRI features and measurements of rectal tumor staging, extramural vascular invasion, circumferential margin involvement, and the distance between distal margin of the tumor from the anorectal ring and the anal margin were described. Results On T2-weighted images (T2WI), T1 staging-tumors were those in which the normal submucosa was replaced by the iso-intensity of tumor tissue without invasion of muscularis propria; T2 staging-tumors were those with extension into the muscularis propria, but not invaded the high-intensity of mesorectal fat; T3 staging-tumors manifested as the rectal tumor penetrated into the muscularis propria and invaded the high-intensity of mesorectal fat; T4 staging-tumors manifested as the tumor invaded adjacent structures or organs. The metastatic lymph nodes were showed with irregular boundaries and mixed signals on T2WI. The tumor signals could be found in the extramural vascular on T1-weighted images (T1WI), accompanied by irregular distortion and expansion of the blood vessels. On T2WI, metastatic lymph nodes, extramural vascular invasion, and the distance between the residual tumor and the low-signal of mesorectal fascia was within 1 mm, indicated the positive circumferential margin. On T2WI, the distal margin of the tumor was located at the junction of hyperintense submucosa and iso-signal of tumor, the tip of the iso-signal puborectal muscle was the apex of the anorectal ring, and the lowest point of the iso-signal external sphincter was the anal margin. Conclusion MRI can provide reliable imaging information for preoperative staging, height measurement, and prognosis of rectal cancer, and it is helpful for early diagnosis and treatment of rectal cancer.