Research progress of techniques of 7 T MRI system in brain imaging / 生物医学工程学杂志

7 T high field magnetic resonance imaging (MRI) provides a useful tool for microscopic spatial resolution visualizing anatomy. In addition, it enables the observation and analysis of tissue metabolism and function. 7 T MRI is now developing fast both in its technology and in its potential prospective medical applications. This review introduces current applications and possible future developments of the 7 T MRI in the field of human brain imaging for clinical studies and practices.

Voxel based morphometric study of brain structure in patients with posttraumatic stress disorder / 生物医学工程学杂志

Voxel based morphometry (VBM) methods are used to detect the difference in brain structures between the posttraumatic stress disorder (PTSD) sufferers and the normal controls. Standard VBM method can detect the difference of the gray matter or white matter densities while the optimized VBM method can detect the difference of gray matter or white matter volumes in the whole brain. The experiments showed that for the patient group, gray matter density or volumes significantly increased in the right frontal lobe, middle frontal gyrus, vermis, left caudate and parietal lobe, compared with the normal controls. However, in the left frontal lobe and middle frontal gyrus, gray matter density significantly decreased. There is no significant difference in white matter between the two groups. These results are consistent with those of the fMRI, which not only provide the evidence for further study of the pathogeny in PTSD but also validate the efficiency of the VBM methods for detecting the difference in the whole brain structure.

Clinical application of tracheal stent implantation / 中国组织工程研究

Currently,tracheal stents used in clinic include silicone,dynamic and metal types.The metal stents contain Ni-Ti memory alloy,stainless steel,and coating stents,which are cylinder and network structured.These stents are more expensive than silicone stents.The internal stents,mainly metal stents,have been used recently in clinic to treat tracheal stenosis.Tracheal stenting methods are divided into bronchofibroscope and hard lens implantation.Both tracheal and esophageal stent implantations are invasive treatment.However,tracheal stent implantation is different from esophageal stent implantation.As patients with airway obstruction are always complicated by dyspnea and hypoxemia,even respiratory failure,which increases risk and difficulty of stent implantation.During tracheal stent implantation,the bronchofibroscope or stent entering the stenosis site may lead to complete tracheal obstruction-induced asphyxia.Corrosion of metal wire of stent to airway mucosa and vessels may result in hemorrhea,leading to postoperative hemoptysis.Stent dislocation is mainly caused by inappropriate selection of stent,inappropriate implantation position or severe cough.Carcinoma tissue growing along stent lumens can induce re-obstruction in stent,resulting in atelectasis relapse.Although there are many unsolved problems and the incidence of complication is 10%-20%,tracheal stent is still a safe,effective and simple therapy for tracheal stenosis.Prevention and treatment of tracheal stenosis following stent implantation and development of novel stents with better effect and fewer side effects is future study focus.

Security of 5-fluorouracil sustained-release reagent under orthoptic endoscope / 中国组织工程研究

OBJECTIVE:To explore security of interstitial chemotherapy by implanting 5-fluorouracil sustained-release reagent into interstitial tissues of oesophageal tumor tissue and tumor peripheral tissue under orthoptic endoscope. METHODS:Relative articles were retrieved from Pubmed database from January 1988 to December 2008 and CNKI database from January 2000 to December 2008. Inclusion criteria:articles which were related to 5-fluorouracil sustained-release reagent for the treatment of esophageal carcinoma were included;Exclusion criteria:Duplicated articles were excluded. A total of 29 patients with grade Ⅲ-Ⅳ esophageal carcinoma who received implantation of 5-fluorouracil sustained-release reagent under orthoptic endoscope were collected from Department of Oncology,Shenyang Red Cross Hospital from March 2001 to December 2007. There were 22 males and 7 females,aging 51-82 years and mean age of 60.2 years. 5-fluorouracil sustained-release particles were implanted into tumor interstitial tissue under orthoptic endoscope. 800 mg 5-fluorouracil sustained-release particles were gradually implanted for 3-5 particles each time. RESULTS:Implantation of 5-fluorouracil sustained-release reagent has been reported to safely and effectively treat esophageal carcinoma. Clinical results indicated complete remission(n=3) ,partial remission(n=16) ,stable pathogenetic condition(n=6) ,and no remission(n=4) . Body mass increased in 21 patients(72.4%) ,and average effectiveness level was 70.9%. Symptoms including hemorrhage,light descent of leukocyte,light malignancy,diarrhea but excluding functional disorder of liver and kidney were found. Easement of pain in 22 patients was 75.8%,and discontinuing analgesics accounted for 50%(P

Image segmentation of hepatic slice by MITK and maximum entropy / 医疗卫生装备

This paper discusses image segmentation of liver by MITK and maximum entropy in VC++ 6.0.MITK supports an extensive set of image processing and 3D visualization algorithms,which is a very convenient tool.After filtered by Wavelet transform,good segmentation results could be obtained by maximum entropy method and MITK interactive segmentation.