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@#【Objectives】 To comparatively analyze the diagnostic performance of transrectal real- time elastography（TRTE）and magnetic resonance diffusion- weighted imaging （DWI）in differentiating benign from malignant prostatic lesions，to evaluate the value of the two methods in guided prostate biopsy，and to investigate the correlation between the two methods and Gleason scores. 【Methods】 A total of 126 patients with suspected prostate cancer underwent prostate biopsy. Preoperative tests of TRTE and DWI were performed in all of the included patients. Combined with pathological results，the diagnostic efficacy of TRTE and DWI for prostate cancer and the effects of prostate biopsy guided by the two methods were compared ，and the relationship between the elastography score and ADC value and Gleason scores were also evaluated.【Results】 The sensitivity，specificity，accuracy of diagnosing prostate cancer by TRTE were 78.8% ，78.3% ，78.6% ，the sensitivity，specificity，accuracy of diagnosing prostate cancer by DWI were 87.9% ，90% ，88.9% ， there was no significant difference of sensitivity and specificity between the two groups（P > 0.05），and the accuracy was statistically different（P < 0.05）. The AUC of elastography score and ADC value were 0.859 and 0.906，the accuracy of the diagnosis of benign and malignant prostate lesions by ADC value method was higher than elastography score ，but there was no statistically significant difference （P > 0.05）. A significant positive correlation was found between elastography score and Gleason scores，while a significant negative correlation was found between ADC value and Gleason scores.【Conclusions】TRTE and DWI is valuable in diagnosis of prostatic lesions. Biopsy guided by the two methods can improve the detection rate of prostate cancer and can provide indicative evidence for tumor differentiation analysis.
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Objective To investigate the differences in tumor volume and metastatic tumors of the liver and regional lymph nodes between contrast-enhanced computed tomography (CT) and diffusion-weighted magnetic resonance imaging (DWMRI) through a comparative analysis,as well the useful information for target volume delineation,and to guide radiotherapy in clinical practice.Methods A total of 40 patients with pancreatic cancer were enrolled and underwent contrast-enhanced CT and DWMRI in the same position.The target volume was delineated,the major axis of the maximum tumor section was measured,and the numbers of liver metastatic tumors and metastatic tumors of the lymph nodes with a diameter of 5-8 mm or＞8 mm were measured based on the CT and DWMRI images.The analysis was performed by using paired t-test or paired Wilcoxon rank sum test.Results The mean gross tumor volume (GTV) delineated by contrast-enhanced CT and DWMRI was 54.95 cm3 and 41.67 cm3(P =0.000),and the mean value-different value was 13.28 cm3.The major axis of the maximum tumor section measured by contrast-enhanced CT and DWMRI were 4.18 cm and 3.94 cm (P=0.000),respectively,and in two patients,dCT was smaller than dDWMRI.A total of 83 liver metastatic tumors were identified by contrast-enhanced CT,and 112 were identified by DWMRI;the liver metastatic tumors detected by contrast-enhanced CT accounted for 74％ of those detected by DWMRI.As for the metastatic tumors of the lymph nodes with a diameter of 5-8 mm or＞8 mm,103 or 46 were detected by contrast-enhanced CT,and 200 or 56 were detected by DWMRI,and the tumors detected contrast-enhanced CT accounted for 52％ or 82％ of those detected by DWMRI.There were significant differences in all data between contrast-enhanced CT and DWMRI.Conclusions GTV and the major axis of the maximum tumor section measured by DWMRI are lower than those measured by contrast-enhanced CT,and contrast-enhanced CT is sensitive in detecting the metastatic tumors of the liver and lymph nodes.However,it is necessary to conduct further controlled experiments with reference to pathology.
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@#Objective To study the MRI of cervical spinal cord injury without fracture and dislocation and explore of the apparent diffusion coefficient (ADC) of injured site related to the severity of injury. Methods 46 patients with cervical spinal cord injury without fracture and dislocation and 20 healthy controls were scaned with routine MRI and diffusion weighted imaging. The ADC value of site of injury and grades of Frankel's classification were analyze with the correlation. Results There were 22 cases with spinal cord edema, 8 cases with intramedullary hemorrhage, 14 cases with edema and hemorrhage, 2 cases without abnormal finding. The ADC of controls and patients were (1.05±0.12)×10-3 mm2/s, (1.21±0.23)×10-3 mm2/s (t=0.704, P<0.05). The ADC values positively correlated with the grades of Frankel's classification (r=0.407, P<0.05). Conclusion MRI may help to find the cervical cord injury in those without fracture and dislocation, and the ADC may be resposible to the severity of injury.
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@#ObjectiveTo study the application of magnetic resonance imaging (MRI) diffusion-weighted imaging (DWI) in brain metastases, and the relationship between DWI results and the primary tumor pathology. Methods76 cases with brain metastases were grouped according to the primary cancer pathology. The apparent diffusion coefficient (ADC) of tumor parenchyma, capsule area, edema around tumors and normal parenchyma were determined; the ratio of high signal on the DWI were calculated (namely diffusion limited) in different tumor. ResultsThe ADC was (1.1364±0.310)×10-3 mm2/s in tumor parenchyma, (2.167±0.472)×10-3 mm2/s in capsule, (1.597±0.238)×10-3 mm2/s in edema and (0.812±0.158)×10-3 mm2/s in normal parenchyma (P<0.05). 15 cases appeared diffusion limited (19.7%), in which the primary tumors were lung cancer in 10 patients (66.6%) (including 5 cases with small cell lung cancer, 5 cases with none small cell lung cancer), breast cancer in 3 cases, and the other 2 cases were colon cancer and teratocarcinoma of testis (P>0.05). The minimum ADC were (0.72±0.16)×10-3 mm2/s in tumor parenchyma with diffuse limited metastases and (0.78±0.21)×10-3 mm2/s without diffuse limited (P=0.325). ConclusionDWI can respond to brain metastases to the microstructure change, but diffusion limited may not be related with the primary histopathology.
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Objective To investigate the value of MR diffusion-weighted imaging (DWI) in differentiating pancreatic carcinoma from chronic focal pancreatitis on 3.0 T MR system. Methods Thirteen patients with proved pancreatic carcinoma, 7 patients with confirmed chronic focal pancreatitis, and 14 healthy volunteers, were included in this study. MR examination including the routine abdomen scanning protocol and DWI was performed for both patients and volunteers. The SE-EPI sequence and ASSET technique were used for DWI. The b values of 400, 600, 800 and 1 000 s/mm2 were selected to acquire the DWI. The corresponding apparent diffusion coefficient (ADC) values were measured in each designated region of interest and statistically analyzed. Results ①DWI of the healthy volunteers showed intermediate signals of pancreas. ②DWI of pancreatic tumor masses showed homogenous high signal intensity relative to the surrounding pancreatic tissue with clear boundary. Under different b values, the tumor ADC values were (1.63?0.235)?10-3 mm2/s, (1.42?0.126)?10-3 mm2/s, (1.36?0.170)?10-3 mm2/s and (1.26?0.178)?10-3 mm2/s respectively, which were significantly lower than those of non-tumor region (2.11?0.444)?10-3 mm2/s, (1.83?0.230)?10-3 mm2/s, (1.81?0.426)?10-3 mm2/s, (1.60?0.230)?10-3 mm2/s and of the normal pancreas (1.85?0.350)?10-3 mm2/s, (1.69?0.290)?10-3 mm2/s, (1.67?0.268)?10-3 mm2/s, (1.42?0.221)?10-3 mm2/s, P
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@#ObjectiveTo explore the relationship between the duration, MRI characters and prognosis in transient ischemic attack (TIA). Methods36 TIA cases were retrospectively analyzed according to the duration and Magnetic Resonance Imaging Diffusion Weighted Imaging(MRI-DWI). They were divided into two groups, Group A (13 cases) in which TIA continued within 1 h and Group B (23cases) in which TIA continued for 1～24 h. The patients were followed up 3 months and 12 months later. ResultsMRI abnormalities could be found with MRI-DWI in 2 cases in Group A, but 17 cases in group B(χ2=11.416,P=0.001). 1 case in Group A and 14 cases in Group B occurred cerebral infarction within a year(χ2=9.663,P=0.004). ConclusionThe longer TIA duration, the worse the prognosis.
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Objective To explore the diagnostic merits of the average apparent diffusion coefficient(ADCav) for leukoencephalopathy in neonates and children.Methods One hundred and fifty-six neonates and children with central nervous system signs or symptoms were classified into 6 groups according to their ages(1 d-0.05).Contrast to the normal,the ADCav of leukoencephalopathy in neonates and children decreased.With increasing age,there showed a linear downtrend in each group.Conclusions The ADCav rises in neonates and children with leukoencephalopathy.The ADCav variation precedes changes in routine MRI.
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Objective To investigate the relationship of magnetic resonance diffusion-weighted imaging (DWI) to histology in the patients of chronic viral hepatitis. Methods Thirty-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/mm~2. Biopsy specimens were scored for fibrosis and necroinflammation according to the Knodell histology activity index (HAI). Results When b value was set as 800 s/mm~2, statistical difference was showed between the fibrosis group and the non-fibrosis group, statistical difference was also shown among the different degrees of necroinflammation and fibrosis. Conclusion DWI is a valuable method for grading and staging of chronic viral hepatitis.