Background:  This study presents patient specific and organ dose estimation in computed tomography (CT) imaging of thorax directly from patient CT image using Monte Carlo simulation.  Patient's CT image is considered as the patient specific phantom and the best representative of patient physical index in order to calculate specific organ dose. Materials and Methods: EGSnrc /BEAMnr...

目的：研究食管癌患者行X射线、CT检查的诊断价值。方法：回顾性研究我院2019年1月-2020年5月间收治的120例食管癌患者，根据“检查方式差异性”随机分CT组（n=60，CT检查）、X射线组（n=60，X射线检查），两组的诊断结果比较。结果：CT组确诊率（91.67%）较X射线组（68.33%）高，CT组误诊率（1.67%）、漏诊率（6.67%）较X射线组（11.67%）、（20.00%）低，与X射线组比较，CT组检查时间更短；CT组灵敏度（94.25%）、特异度（96.26%）、阳性预测值（93.18%）及阴性预测值（98.28%）较X射线组（84.17%）、（94.24%）、（82.36%）、（82.34%）更高，P＜0.05。结论：CT检查诊断食管癌患者能提高确诊率、避免漏诊，值得借鉴。

Introduction: The CT machine utilizes a bowtie filter to shape the X-ray beam and remove lower energy photons. Configuration of this bowtie filter is complex and its geometry is often not available in detail. It causes the CT dose index (CTDI) be with the different values in measurement versus Monte Carlo simulation studies and other analytical calculations. It is important esp...

According as the progress of medical technique, X-ray imaging systems have been progressed. Especially, X-ray CT imaging system have been improved and widely used as general diagnostic methods nowadays in Japan. However, the doses for patients of X-ray CT imaging are relatively higher than of other Xray examinations. The dose estimations and optimizations on X-ray CT are very important for medi...

background and aims. cone-beam computed tomography (cbct) is an imaging system which has many advantages over computed tomography (ct). in ct scan, hounsfield unit (hu) is proportional to the degree of x-ray attenuation by the tissue. in cbct, the degree of x-ray attenuation is shown by gray scale (voxel value). the aim of the present study was to investigate the relationship between gray scale...

Introduction: The CT machine utilizes a bowtie filter to shape the X-ray beam and remove lower energy photons. Configuration of this bowtie filter is complex and its geometry is often not available in detail. It causes the CT dose index (CTDI) be with the different values in measurement versus Monte Carlo simulation studies and other analytical calculations. It is important esp...

BACKGROUND Cancer/testis (CT) antigens are cancer antigens normally expressed in adult testicular germ cells. The expression of chromosome X-encoded CT antigens (CT-X antigens) in human fetal gonads and in testicular seminomas was examined. METHODS The expression of 10 CT-X antigens (MAGEA, NY-ESO-1, GAGE, CT7/MAGEC1, CT10/MAGEC2, CT45, SAGE1, SSX2, NXF2 and SPANX) was studied immunohistochem...