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Objective To investigate the factors influencing the image quality of prostate magnetic resonance spectroscopy (MRS),and to put forward quality control measures to improve MRS in success ratio and image quality.Methods Totally 1 255 patients with prostate diseases confirmed pathologically from October 2009 to December 2015 had their MRS data analyzed retrospectively.MRS was executed with multi-voxel 3D chemical shift imaging technique,and special-purpose software was involved in for post processing.Re-scanning would be performed in case of baseline clutter,low SNR and etc.Results There were 1 218 patients had MRS executed well in preparedness,positioning,parameters setup,post processing,baseline and chemical shift,one patient underwent unsuccessful MRS due to incorrect bed mode,9 ones due to unstable baseline resulting from unsatisfactory preparedness,26 ones due to unstable baseline resulting from bad shimming and 1 case due to non-standard post processing.Conclusion Prostate SRS depends on patient preparedness,positioning,parameters setup,shimming and post processing.
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Objective To investigate the effects of ribs in high intensity focused ultrasound (HIFU)beam path on formation of coagulative necrosis in cattle liver in vitro in the same acoustic power. Methods The HIFU ablation was carried out in the manner of a single dot in the liver in vitro. The liver was ablated by HIFU in free field,then the ribs were placed between the focal plane and transducer,directing the beam axis through the intercostals space, lied at the rib edge and on the centre of middle rib. For each of these axial arrangements,the plane of the front surface of ribs was placed 3 cm,6 cm or 9 cm in front of the focus. After HIFU exposure,the tissue necrosis rate(TNR),the maximum length,width,depth and position of the coagulated necrosis in the liver were measured. Results ①The TNR was 100% in the free field. When the ribs were placed 3 cm in front of the focal plane,directing the beam axis through the intercostals space, the TNR was 100%. When directing the beam axis lied at the rib edge and on the centre of middle rib,the TNR decreased sharply. When the ribs were placed 6cm and 9cm in front of the focal plane, the TNR was more than 50%. ②When the ribs were placed in HIFU beam path, the volume of necrosis decreased compared with those in free field. The relationship between the ribs and beam axis, the location of ribs placed away from the focal plane different,the volume,length,width and position of the coagulated necrosis different. ③ When the ribs were close to the focal plane,unacceptable damage could been observed on the surface of ribs.When the ribs were far away from the focal plane, the ribs were safe. Conclusions The volume of necrosis decrease when the ribs are placed in HIFU beam path. The relative location of ribs and HIFU beam axis, the location of ribs away from the focal plane are relative with the volume of the coagulated necrosis. When directing the beam axis through the intercostals space, the volume of necrosis is large, and the shape of coagulated necrosis is regulated. When the ribs are closed with the focal plane,ribs are damaged probably.
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Objective To investigate the expression, relationship, significance of cyclooxygenase_2 (COX-2) and malonic dialdehyde (MDA) after cerebral ischemic-reperfusion injury and provide basis of treatment. Methods The focal cerebral ischemic-reperfusion model was established with thread embolish of middle cerebral artery. Western blotting, barhituric acid method and neurological evaluation were used to examine the expression of COX-2, MDA in cortex and the changes of neurological function;TTC staining was used to observe the changes of cerebral infarction volume. Results COX-2 prorein expression was correclated well with the MDA(r=0.910,P＜0.01). The content of COX-2 and MDA was very low in sham operation group, they were increased significantly at I2h/R6h model group, with the increase of reperfusion time,they remarkably reached its peak at I2h/R24h,they were slightly lower at I2h/R48h, but still maintained at a high level;Compared with model group, in tetramethylpyrazine(TMP) treatment group, the content of MDA and cerebral infarction volume were markedly decreased(P＜0.01). Conclusion The expression of COX-2 and MDA increases in cerebral ischemic-reperfusion injury.It indicates they may play an important role in the mechanisms of cerebral ischemic-reperfusion injury;TMP has neuroprotective effect.