计算机X线摄影与屏片系统摄影对比分析

目的:评价计算机X线摄影(CR)的应用价值。方法:抽取我院CR照片和常规X线摄影照片各1200 例,由2位主管技师和1位副主任技师对照片进行分析,统计出甲、乙、丙及废片率。并对乙、丙级片及废片产生的 原因进行了分析。结果:①照片影像质量:CR照片甲级片率51.6%,乙级片率35.5%,丙级片率12.2%,废片率 0.7%。常规X线摄影照片甲级片率40.6%,乙级片率42.5%,丙级片率15.2%,废片率1.7%。②摄影条件:数字 比模拟摄影电压高1～5kV,曝光量高20%左右。结论:CR摄影影像质量好于模拟摄影(即甲级片率高,废片率 小),可为临床提供可靠诊断。但曝光条件比屏 片系统高,增加了病人的X线接受剂量。     

CR摄影与屏-片摄影的比较

目的探讨CR摄影与屏-片系统摄影曝光条件及对患者的X射线辐射剂量，评价CR摄影的应用价值。方法取本院CR照片和常规X射线摄影照片各2500份，由2位主管技师和1位副主任技师对照片按部位分组进行分析，统计出甲、乙、丙及废片率；并对乙、丙及废片产生的原因进行分析。结果①照片质量：CR摄影照片甲级片率63．6％，乙级片率27．2％，丙级片率9．2％，废片率0％；屏-片系统摄影照片甲级片率40．2％，乙级片率42．4％，丙级片率15．6％，废片率1．8％。②摄影条件的比较：CR数字摄影比屏．片系统摄影电压需提高1-6kV，曝光量高20％左右。结论CR数字摄影照片质量明显高于屏-片系统摄影，但曝光条件比屏-片系统高，相对增加了患者的X射线辐射剂量。     

床边CR摄影与传统床边摄影的对比研究

目的：评价计算机X线摄影术(CR)在床边照片的应用。方法：抽取我院CR床边按照影像和传统床过照片备1000例，由2位放射学医师及1位主管技师对影像进行分析，分别统计甲、乙、丙及废片率，同时也对条件进行分析评价。结果：(1)CR影像：甲级片率32．1％，乙级片率44.5％，丙级片率23．4％，废片率0％。(2)传统床造影像：甲级片率20．3％，乙级片率53．5％，丙片率16．8％，废片率9．4％。结论：CR床边照片质量明显比传统床边投照优秀，CR床边照片有利于放射诊断。     

CR与屏-胶系统摄影在乳腺疾病诊断中的价值

目的评价X线计算机成像技术在乳腺摄影中的应用价值。方法抽取乳腺CR片和屏-胶乳腺片各500例,由1位副教授和2位主管技师,对摄影条件、照片影像质量及照片影像显示进行对比。结果①CR系统照片影像质量明显高于屏-胶系统;②摄影条件CR数字摄影比屏-胶系统摄影电压高2~3kV,曝光量高35%左右;③照片的X线征象显示率明显高于屏-胶系统。结论CR摄影提高了照片影像质量,为临床提供可靠诊断依据。缺点是曝光条件比屏-胶系统高,相对增加了患者的X线辐射剂量。     

移动DR和CR床旁胸部摄影临床应用对比研究

目的:探讨移动DR床旁胸部摄影临床应用的价值.材料和方法:随机抽取CR和DR床旁胸部摄影各200例患者的胸片进行比较.结果:(1) 照片质量:DR胸片的甲级片率77.5%、乙级片率20.5%、丙级片率2%、无废片.CR胸片的甲级片率53%、乙级片率31.5%、丙级片率12.5%、废片率3%.(2) 胸内各结构的显示:DR明显优于CR.结论:移动DR床旁胸部摄影操作方便,成像快捷,更有利于放射诊断.     

CR系统在X线摄影中的应用原理与临床价值

目的：探讨CR系统在X线摄影中的应用原理与临床价值。方法：对12000张胶片进行影像质量综合评估，分甲级片、乙级片、和废片三类。结果：甲级片占96％、乙级片占3．7％、废片占0．3％。结论：CR系统在X线摄影中其卓越的性能与数字化影像的特征有广泛的临床使用价值。     

直接数字X线摄影技术在小儿胸部摄影中的应用

目的: 探讨直接数字X线摄影技术在小儿胸部摄影中的应用.材料和方法: 回顾性分析我院小儿DR胸片和常规胸片各500张,分别统计甲、乙、丙级片及废片,同时对显示胸部结构进行评价,并进行统计学处理.结果: (1)DR胸片: 甲级片51%、乙级片38%、丙级片10%、废片1%;(2)常规胸片: 甲级片42.4%、乙级片45%、丙级片11%、废片1.6%;(3)DR胸片可根据临床要求经不同后处理技术显示胸部各种结构.结论: 小儿DR胸片质量优于小儿常规胸片.     

乳腺数字化X线射影术、计算机X线射影术和屏-胶片系统影像质量和放射剂量的比较

目的 比较增感屏-胶片乳腺X线摄影、数字乳腺摄影(DR)和计算机乳腺摄影(CR)3种系统的模体影像质量、辐射剂量和临床对疾病诊断的准确率.方法 选择3台临床使用中的屏-胶片、DR和CR乳腺摄影设备,进行性能测试,确保质量符合规定,具有可比性.以屏-胶片系统的辐射剂量为标准,使用DR和CR分别对Manuno-152模体和美国放射学院(ACR)模体摄影.再使用DR和CR的最优模式对模体摄影并记录辐射剂量.所获图像照片按模拟病变结构编号,由8名专业乳腺放射学医师在相同条件下分别进行ACR评分.3种方法的评分结果采用随机区组设计的方差分析进行统计学处理.连续收集一段时期内采用3种检查方法检查,并且有病理诊断结果的患者的影像资料,应用Kappa检验方法进行2种诊断结果一致性检验,并以病理结果为金标准,比较3种影像检查结果诊断的准确率.结果 对于Mammo-152模体,无论DR、CR的辐射剂量是否超过屏一胶片乳腺X线摄影的2.25 mGy乳腺平均剂量,屏-胶片摄影的空间分辨率都最高(7.0～8.0 Lp/mm),DR次之(4.7～5.2 Lp/mm),CR最差(2.5 Lp/mm).增加辐射剂量(27.0%～30.0%),DR的空间分辨率略有改善(上升11.0%),而CR几乎没有改变(上升1.5%).对ACR模体摄影时,DR的辐射剂量没有超过屏-胶片乳腺X线摄影的2.22 mGy乳腺平均剂量,且模拟结构显示度最好.屏-胶片乳腺x线摄影的团块显示优于CR,但CR的纤维和点阵显像优于屏-胶片乳腺X线摄影.CR检查时辐射剂量提高25.0%,纤维和点阵显像接近DR,团块显像接近屏-胶片乳腺x线摄影.3台设备的X线诊断和病理诊断结果的一致性极好(屏-胶片系统的一致率50/56,DR系统83/90,CR系统61/69,P值均<0.01且Kappa值均>0.75),在疾病诊断准确率上差异没有统计学意义[屏-胶片系统的准确率为89.3%(50/56),DR系统为92.2%(83/90),CR系统为88.4%(61/69),PearsonX2值为0.722,P=0.697].结论 屏-胶片乳腺X线摄影分辨率最高,DR的模拟病变显像最好且辐射剂量最低.当CR的辐射剂量与屏-胶片乳腺X线摄影相当时,两者对模拟病变的显像各有优劣;当增加CR的摄影剂量时,其模拟结构显像质量高于屏-胶片乳腺X线摄影,低于DR.在临床对疾病的诊断准确率方面,三者无明显差别.     

CR系统在乳腺钼靶摄影中的临床应用

目的：探讨计算机X线成像系统（CR系统）在乳腺钼靶X线摄影中的应用价值。方法：随机抽查屏／片乳腺片、CR钼靶乳腺图像各100份，比较两组照片的满意率、废片率、检出率和投照剂量。结果：普通钼靶摄影组的满意率、废片率、检出率分别为78％、2．8％和76％；数字化乳腺摄影组的满意率、废片率、检出率分别为99．7％、0和85％。CR系统仅用常规摄影剂量的1／5—1／10。结论：利用CR成像系统与钼靶摄影机的结合可以实现乳腺数字化摄影，效果优于普通屏／片摄影，在提高乳腺疾病的检出率方面更具优势，为临床早发现早治疗乳腺疾病提供了可靠依据。     

计算机X线摄影CR系统在床旁摄片中的应用价值

目的　探讨CR系统在床旁摄片中的应用价值。方法　对 90 0张CR床旁X线平片的影像质量进行综合评价 ,分甲级、乙级和废片三类。结果　 90 0张CR床旁X线平片中 ,甲级 780张 ,占 86 .7%,乙级 116张 ,占 12 .9%,废片 4张 ,占 0 .4%。结论　CR床旁摄片 ,数字影像经多种后处理 ,影像质量优良 ,且图像可作数字化存储和远程传输。     

计算机X线摄影与传统摄片影像质量对比分析

目的：探讨计算机X线摄影(computed radiography,CR)的影像质量及其主要影响因素。材料和方法：参照卫生部“三甲”医院检查采用的标准,评定甲、乙、丙级和废片。对1000份不同部位CR影像片和1000份与前者部位相同的传统片影像的质量进行评定,分析造成非甲级片的成因,对两组影像质量及影响因素进行统计学分析。结果：CR片的甲片率为53．6％,明显高于传统片42．5％的甲片率,造成CR非甲级片主要成因是体位及铅字号码放置缺陷、摄影体部有异物和摄影前患者准备不佳(98．92％),传统片为76．7％;摄影条件不佳、影像处理技术不良(暗室技术)对CR影像质量影响不大(1．08％),而对传统片影像质量的影响为23．3％。CR片的废片率为0．0％(不包括机器故障造成的废片),低于传统片的2．0％废片率。结论：CR片影像质量明显优于传统片的影像质量,可广泛应用于除动态影像检查外的临床影像学检查。     

Evaluation of the diagnostic value of a computed radiography system by comparison of digital hard copy images with screen–film mammography: results of a prospective clinical trial

The purpose of the study was to determine prospectively the diagnostic value of a computed radiography (CR) system by comparing mammographic hard copy images with screen–film mammography (SFM). A series of 100 patients, who came for diagnostic investigation, underwent two-view SFM (Lorad M-IV Platinum) and digital mammography with a CR system (AGFA CR system). The images were obtained by double exposure, i.e. same view without removing compression of the corresponding breast. The CR images were processed with dedicated processing for mammography. Six radiologists read sets of SFM and CR images. The primary efficacy parameter was the overall diagnostic value. The secondary efficacy parameters were lesion conspicuity and lesion details (for masses and micro-calcifications), tissue visibility at chest wall and at skin line, axillary details, overall density and sharpness impression and the overall noise impression. These parameters were scored by a 7-point scoring system. “CR non-inferior to SFM” was concluded if the lower confidence interval bound exceeded 80%. The confidence interval for the overall diagnostic value was between 96.4% and 100%. Pooled analysis of the ten features for image quality comparison demonstrated for all but one feature (lesion details of the calcifications) CR non-inferiority to SFM.     

Image quality of mammography in Croatian nationwide screening program: comparison between various types of facilities

Purpose

The study was aimed to provide objective evidence about the mammographic image quality in Croatia, to compare it between different types of MG facilities and to identify the most common deficiencies and possible reasons as well as the steps needed to improve image quality.

Materials and methods

A total of 420 mammographic examinations collected from 84 mammographic units participating in the Croatian nationwide breast cancer screening program were reviewed in terms of four image quality categories: identification of patient and examination, breast positioning and compression, exposure and contrast, and artifacts. Those were rated using image evaluating system based on American College of Radiology and European Commission proposals. The results were compared among different types of mammographic units, and common image quality deficiencies were identified.

Results

Total image quality scores of 12.8, 16.1, 13.0 and 13.7 were found for general hospitals, university hospitals, private clinics and public healthcare centres, respectively. Average score for all mammographic units was 13.5 (out of 25 points). University hospitals were significantly better than all other mammography units in overall image quality, which was mostly contributed by better breast positioning practices. Private clinics showed the worst results in identification, exposure, contrast and artifacts.

Conclusions

Serious deficiencies in identification and breast positioning, which might compromise breast cancer screening outcome, were detected in our material. They occur mainly due to subjective reasons and could be corrected through additional staff training and improvement of working discipline.     

前交叉韧带斜矢状位MR成像研究

目的观察基于膝关节MR 2DT2WI+fs图像的重建图像对前交叉韧带显示效果,优化扫描程序。方法分析60例前交叉韧带MR检查图像,按检查方法分A、B、C三组进行观察分析。A组:常规扫描标准矢状位图像;B组:基于A组图像的斜矢状位重建图像;C组:斜矢状位扫描图像。观察三组图像对前交叉韧带的显示情况。将图像分二级进行评价:Ⅰ级为前交叉韧带1幅图像完整、清晰显示;Ⅱ级前交叉韧带1幅图像不能完整显示,需连续两幅或三幅图像才能完整显示;最后统计数据进行分析。结果 A组图像:Ⅰ级36例,占60%;Ⅱ级24例,占40%。B组图像:Ⅰ级56例,占93.3%;Ⅱ级4例,占6.7%。C组图像:Ⅰ级5 4例,占90%;Ⅱ级6例,占10%。经计算显示A、B两组图像具显著差异;A、C两组图像具显著差异;B、C两组图像无显著差异。结论基于前交叉韧带MR2DT2WI+fs图像的重建图像对其显示良好,建议膝关节磁共振检查时以标准矢状位扫描所得二维图像进行MPR重建观察,无须特意行斜矢状位扫描或三维成像扫描后重建,可以优化MR检查流程。     

Evaluation of image quality and dose in renal colic: comparison of different spiral-CT protocols

The aim of this study was to test different technical spiral-CT parameters to obtain optimal image quality with reduced X-ray dose. Images were acquired with a spiral-CT system Philips Tomoscan AVE1, using 250 mA, 120 kV, and 1-s rotational time. Three protocols were tested: protocol A with 5-mm thickness, pitch 1.6, slice reconstruction every 2.5 mm; protocol B with 3-mm thickness, pitch 1.6, slice reconstruction every 1.5 mm; and protocol C with 3-mm thickness, pitch 2, slice reconstruction every 1.5 mm. Two phantoms were employed to evaluate the image quality. Axial images were acquired, then sagittal and coronal images were reconstructed. Finally, the absorbed X-ray dose for each protocol was measured. Regarding image quality, 5-mm-thick images (protocol A) showed greater spatial resolution and lower noise compared with 3-mm-thick images (protocols B and C) on the axial plane; 3-mm reconstructed sagittal and coronal images (protocols B and C) showed an improved image quality compared with 5-mm reformatted images (protocol A). Concerning X-ray dose, the mean dose was: protocol A 19.6 +/- 0.8 mGy; protocol B 14.4 +/- 0.6 mGy; protocol C 12.5 +/- 1.0 mGy. Our study supports the use of thin slices (3 mm) combined with pitch of 1.6 or 2 in renal colic for X-ray dose reduction to the patient and good image quality.     

Synchrotron radiation: a new source in x-ray mammography]

This work was aimed at evaluating the image quality obtainable in X-ray mammography using synchrotron radiation monochromatic lines. After a short review of the current mammographic techniques, the main features of synchroton radiation in the X-ray field are analyzed, especially of that emitted by the Adone storage ring. Its features are then compared with the radiation emitted by a Coolidge tube. The experimental unit used in this study, including beamline, monochromator and mammograph, is then described together with the experimental method for carrying out a series of experiments in the mammographic field employing both monochromatic lines (E = 17 keV) and white radiation from conventional sources. The first series of experiments is described, which employed standard phantoms: the dependence of resolution and contrast on both wavelength and thickness of breast specimens is reported. Several mammograms of neoplastic breast specimens were obtained after mastectomy: they were acquired using both synchrotron monochromatic lines and radiation emitted by a conventional tube and employing the same acquisition system. The comparison of the two series of images shows that synchrotron radiation can demonstrate a high number of anatomopathologic details with high definition, contrast and resolution which cannot be obtained by means of a conventional source. Our results appear very promising and suggest synchrotron radiation as the major tool in the early diagnosis of neoplastic breast lesions.     

直接数字摄影系统图像的质量控制

目的:探讨DDR影像质量控制的方法。材料和方法:按顺序抽取我院实行质量控制前、后的DDR照片各400份,依据照片甲片率的判定标准分别统计出甲、乙、丙片率及废片率,并分析非甲级片影响因素。对机器性能、曝光参数、技术员素质、后处理技术四个环节实行质量控制,采用相应有效质控措施。结果:质控组甲片率66%、乙片率29%、丙片率5%。非质控组甲片率41%、乙片率35%、丙片率23%。结论:实施质量控制能显著地提高DDR的影像质量。     

不同能量放射性核素在PET/CT及SPECT采集中的相互影响

目的 利用模型探讨99TcmO4-与18F-氟脱氧葡萄糖(FDG)在图像采集中的相互影响,讨论同一患者是否可以同日分别采用PET/CT及SPECT两种仪器行高低两种能量放射性核素显像.材料与方法 利用统一规格、相同容积( 500ml)的5个塑料瓶(编号A、B、C、D、E),其内均注入500ml蒸馏水制作成模型.A瓶注入0.5mCi 18F-FDG行PET/CT显像;B瓶注入1mCi99TcmO4-行SPECT显像;C瓶内同时注入混合好的0.5mCi18F-FDG和1mCi99TcmO4-;D瓶内先注入1mCi99TcmO4-后再注入0.5mCi18F-FDG;E瓶先注入0.5mCi18F-FDG后再注入1mCi99TcmO4-.然后对C、D、E瓶分别行PET/CT显像和SPECT显像,并判断图像效果.结果 A瓶PET/CT显像和B瓶SPECT显像图像效果为1级;C、D瓶SPECT及PET/CT显像图像均为2级;E瓶SPECT显像图像为3级,PET/CT显像图像为1级.结论 同时加入18F-FDG和99TcmO4-对PET/CT和SPECT图像质量均有影响.先加入18F-FDG后加入99TcmO4-对PET/CT图像质量影响小,但SPECT图像不能分辨.先加入99TcmO4-后加入18F-FDG对PET/CT和SPECT图像质量均有影响.