煤工尘肺的CT诊断

In order to evaluate the usefulness of CT in CWP, 100 coal workers were examined with both chest radiograph and CT scan. Comparison was done, the result indicated that both modalities yielded similar sensitivity to simple CWP. The CT score of simple CWP correlated well with ILO classification and 1986 Chinese criteria for staging of pneumoconiosis, whereas in complicated CWP, the CT scan was significantly superior to chest radiograph. CT scan identified readily large opacities. It could detect large opacities in 40% of simple CWP diagnosed on the basis of chest radiograph. CT scan also identified more cavities and calcifications within large opacities. The CT attenuation values were less reliable. The authors were of the opinion that at present CT attenuation values is not recommended for routine evaluation of CWP.     

电焊工尘肺CT表现分析

【摘要】目的：分析电焊工尘肺CT表现,提高对电焊工尘肺的诊断水平。方法：回顾性分析2015年1月-2020年12月按职业病诊断标准诊断为Ⅰ期及Ⅱ期的电焊工尘肺患者共103例。对其临床资料及影像特征进行总结分析。结果：本组电焊工尘肺CT表现为小叶中心磨玻璃密度微小结节影44例,小叶分支线状影63例,其中小叶分支线状影合并小叶中心磨玻璃密度微小结节影共20例;腺泡磨玻璃结节影7例,弥漫性磨玻璃改变10例,致密微小结节影6例,伴有肺间质纤维化6例、纤维灶10例、肺结核6例、肺气肿15例、肺大泡14例、支气管扩张1例、淋巴结肿大9例、胸膜增厚19例。结论：电焊工尘肺的CT具有特征性的影像表现,小叶中心磨玻璃密度微小结节影及小叶分支线状影为其特征的CT表现,结合职业病史,可做出明确诊断。     

电焊工尘肺的研究探讨

电焊工尘肺是职业病尘肺的重要组成部分，现对我院收治的经CT扫描且经临床确诊的24例电焊工尘肺作一总结，报告如下。     

尘肺某些并发症的CT对照分析

目的 分析尘肺及其并发症的CT表现。方法 24例呼吸系疾病患者被分为3组:8例经X线胸片确诊的尘肺,5例有接尘史,11例无接尘史。全部患者最初均经胸部常规性CT扫描。尘肺组还经薄层扫描及重建肺部HKCT图像。结果 CT显示3组病人或多或少均存在磨玻璃样改变,叶间裂间质增厚,全小叶型肺气肿,以及支气管血管束变细等病变,且未见组间明显差异。小叶间隔增厚与支气管血管束变粗仅见于尘肺组与接尘组。胸膜下肺气肿亦见尘肺组明显多于其他两组。结论 CT扫描不仅能显示X线胸片上所看到的尘肺特有的病变,还能提供尘肺并发症存在的可靠信息,因而有助于及时指导治疗。     

螺旋CT在尘肺诊断中的价值

目的：评价螺旋CT在尘肺影像诊断中的价值。材料和方法：回顾性分析39例尘肺的胸片与螺旋CT的影像表现。结果：螺旋CT检查的39例中有23例出现散在的2—9mm圆形结节影，大于10mm的大结节有12例，29例患者有不同程度的肺气肿，35例显示胸膜病变，ll例分别患有新老肺结核灶，34例有不同组的淋巴结肿大或钙化。纠正胸片误诊的I期尘肺5例，Ⅱ期尘肺l例，发现胸片未能准确分期的Ⅱ期尘肺4例、Ⅲ期尘肺2例。结论：螺旋CT在显示尘肺的直接征象和间接征象上较常规胸片敏感，可以弥补x线平片的许多不足，有利于尘肺的正确诊断和鉴别诊断，特别有利于尘肺的早期诊断。     

低剂量胸部螺旋CT扫描的应用价值

在ＣＴ扫描的各项检查中 ,胸部ＣＴ检查的患者占了很大比例 ,为了减少患者的Ｘ线照射量 ,延长球管的使用寿命 ,同时还要保证影像质量以满足临床诊断的要求 ,我们尝试了采用低剂量胸部螺旋ＣＴ的扫描方法 ,对患有肺部疾病的患者和健康体检人员进行肺癌普查 ,取得了令人满意的结果。1　材料和方法1.1　资料　ＭａｘｃｏｎｉＭｘ80 0 0。我院 2 0 0 1 12 10～ 2 0 0 2 4 10 ,共检查胸部ＣＴ患者 3 46人 ,其中女 12 4人 ,男 2 2 2人 ,年龄 14～ 93岁。1.2　扫描方法　患者仰卧扫描床上 ,手臂抱头 ,先行胸部正位定位像 ,再选择低剂量扫描程序 ,…     

胸部低剂量CT扫描技术的应用价值

ＣＴ具有很高的密度分辨率且具备无组织重叠显像等优点。较Ｘ线平片而言 ,在肺部疾病的诊断中极大地提高了占位病变检出的敏感性和特异性[1] 。但由于对大剂量Ｘ线的要求 ,致使消耗性 (Ｘ线管 )成本较高 ,同时也给受检者带来了大剂量Ｘ线照射的危害 ,因而影响了肺部ＣＴ在日常检查尤其是胸部体检中的广泛应用。近年来 ,应用低剂量扫描技术对肺部作筛选扫描 ,发现病灶后再行局部高分辨率扫描的ＣＴ检查模式已在临床上应用[2 ] 。笔者在分析 4 8例低剂量扫描成像质量的基础上 ,将该技术在胸部检查中的价值作一分析。材料与方法1 一般资料 :选…     

低剂量CT扫描技术的胸部应用

1990年Naidich等 [1]率先提出低剂量CT扫描技术 ,1995年Mayo等[2 ]的研究表明 ,当毫安秒低于 80mAs时 ,图像质量有显著下降。他们的临床应用实践为低剂量CT扫描技术的胸部应用打开了前景。随着CT技术的不断完善 ,在不影响图像质量情况下 ,使得低剂量检查成为可能。笔者在分析60例低剂量扫描成像质量的基础上 ,将该技术在胸部检查中的应用作一评价 ,现报道如下。一、材料和方法1 材料 :选择有咳嗽 ,咯痰 ,胸痛等呼吸道症状者 ,可疑肺内有病变者 60例 ,男 44例 ,女 16例 ,年龄 2 3～ 78岁 ,平均55岁。2 仪器 :北京医疗器械研究所生产的B…     

Strategies for reduction of radiation dose in cardiac multislice CT

Because cardiac computed tomography (CT) (mainly coronary CT angiography) is a very promising technique, used more and more for coronary artery evaluation, the benefits and risks of this new low-invasive technique must be balanced. Radiation dose is a major concern for coronary CT angiography, especially in case of repeated examinations or in particular subgroups of patients (for example young female patients). Radiation dose to patient tends to increase from 16- to 64-slice CT. Radiation exposure in ECG-gated acquisitions may reach up to 40 mSv; considerable differences are attributable to the performance of CT machines, to technical dose-sparing tools, but also to radiological habits. Setting radiation dose at the lowest level possible should be a constant goal for the radiologist. Current technological tools are detailed in regard to their efficiency. Optimisation is necessary, by a judicious use of technological tools and also by individual adaptation of kV or mAs. This paper reviews the different current strategies for radiation dose reduction, keeping image quality constant. Data from the literature are discussed, and future technological developments are considered in regards to radiation dose reduction. The particular case of paediatric patients with congenital heart disease is also addressed.     

CT Radiation Dose Optimization and Estimation: an Update for Radiologists

In keeping with the increasing utilization of CT examinations, the greater concern about radiation hazards from examinations has been addressed. In this regard, CT radiation dose optimization has been given a great deal of attention by radiologists, referring physicians, technologists, and physicists. Dose-saving strategies are continuously evolving in terms of imaging techniques as well as dose management. Consequently, regular updates of this issue are necessary especially for radiologists who play a pivotal role in this activity. This review article will provide an update on how we can optimize CT dose in order to maximize the benefit-to-risk ratio of this clinically useful diagnostic imaging method.     

Effective doses in standard protocols for multi-slice CT scanning

The purpose of this study was to assess the radiation exposure of patients in several standard protocols in multi-slice CT (MSCT). Scanning protocols for neck, chest, abdomen, and spine were examined on a Somatom Plus 4 Volume Zoom MSCT (Siemens, Erlangen, Germany) with changing slice collimation (4×1, 4×2.5, and 4×5 mm), and pitch factors (1, 1.5, and 2). Effective doses were calculated from LiF–TLD measurements at several organ sites using an Alderson-Rando phantom and compared with calculations using the weighted CTDI. Effective dose for MSCT of the neck was 2.8 mSv. For different protocols for MSCT of the chest, 7.5–12.9 mSv were found. In abdominal MSCT protocols, effective dose varied between 12.4 and 16.1 mSv. The MSCT of the spine may lead to 12 mSv. An excellent correlation between the effective dose as determined by LiF–TLD and the calculated effective dose using the weighted CTDI could be demonstrated; however, a difference of up to 30% (mean 14.3%) was noted. Standard protocols for MSCT as measured in this study showed effective doses of up to16 mSv. Phantom measurement data show a good correlation to estimations using the weighted CTDI. Electronic Publication     

高分辨率CT对焊工肺尘埃沉着病的诊断价值

目的 采用高分辨率CT(HRCT)探讨早期焊工肺尘埃沉着病的影像表现,并评估不同病程阶段的影像表现.方法 对76例X线胸片疑似焊工肺尘埃沉着病的工人(工龄1～18年,平均14年)进行常规胸部CT平扫和HRCT检查,分析其HRCT表现,并对不同影像表现的年龄、工龄进行t检验.结果 18例(18/76,23.7%)表现为边缘模糊的小叶中央磨玻璃密度微结节,20例(20/76,26.3%)表现为分支状细线影,磨玻璃密度结节组的平均年龄[(34±7)岁]小于分支状细线影组[(39±9)岁],但差异无统计学意义(t=-1.648,P＞0.05);磨玻璃密度结节组的平均工龄[(10±5)年]低于分支状细线影组[(15±8)年],差异有统计学意义(t=-2.108,P＜0.05).结论 边缘模糊的小叶中央磨玻璃密度微结节和分支状细线影是焊工肺尘埃沉着病常见的表现.其中磨玻璃密度的微结节可能是焊工肺尘埃沉着病的早期表现.HRCT有助于焊工肺尘埃沉着病的早期诊断.     

Effect of reconstruction algorithm on image quality and identification of ground-glass opacities and partly solid nodules on low-dose thin-section CT: Experimental study using chest phantom

Purpose

The purpose of this study was to assess the influence of reconstruction algorithm on identification and image quality of ground-glass opacities (GGOs) and partly solid nodules on low-dose thin-section CT.

Materials and methods

A chest CT phantom including simulated GGOs and partly solid nodules was scanned with five different tube currents and reconstructed by using standard (A) and newly developed (B) high-resolution reconstruction algorithms, followed by visually assessment of identification and image quality of GGOs and partly solid nodules by two chest radiologists. Inter-observer agreement, ROC analysis and ANOVA were performed to compare identification and image quality of each data set with those of the standard reference. The standard reference used 120 mA s in conjunction with reconstruction algorithm A.

Results

Kappa values (κ) of overall identification and image qualities were substantial or almost perfect (0.60 < κ). Assessment of identification showed that area under the curve of 25 mA reconstructed with reconstruction algorithm A was significantly lower than that of standard reference (p < 0.05), while assessment of image quality indicated that 50 mA s reconstructed with reconstruction algorithm A and 25 mA s reconstructed with both reconstruction algorithms were significantly lower than standard reference (p < 0.05).

Conclusion

Reconstruction algorithm may be an important factor for identification and image quality of ground-glass opacities and partly solid nodules on low-dose CT examination.     

多层螺旋CT肺部低剂量与常规剂量检查的放射剂量评估

目的比较多层螺旋CT肺部低剂量与常规剂量检查的X线辐射剂量,为低剂量多层螺旋CT普查早期肺癌提供剂量参数. 资料与方法肺部低剂量与常规剂量多层螺旋CT扫描共54例.其中,低剂量扫描24例,扫描参数为:120 kV,20 mAs,准直器4×5 mm,重建层厚8 mm,床速30 mm/周,螺距为7,扫描时间0.5 s/周;常规剂量扫描30例,扫描参数为:120 kV,90 mAs,准直器4×5 mm,重建层厚8 mm,床速30 mm/周,螺距为7,扫描时间0.5 s/周.观察并计算两种扫描剂量的权重CT剂量指数(CTDIw),有效mAs,总mAs,剂量长度乘积(DLP)及有效辐射剂量. 结果肺部低剂量扫描的CTDIw为1.38 mGy,是常规剂量扫描(6.21 mGy)的22.2%;低剂量扫描的DLP为44 mGy*cm,明显低于常规剂量扫描的189 mGy*cm(P＜0.01);低剂量扫描的总mAs为459,是常规剂量扫描(1 308)的35.1%;低剂量扫描的X线最大有效辐射剂量为0.9 mSv,明显低于常规剂量扫描的4.2 mSv(P＜0.01). 结论多层螺旋CT肺部低剂量扫描(20 mAs)的有效辐射剂量为常规剂量扫描的21.4%,适用于高危人群普查早期肺癌.     

A rational approach to dose reduction in CT: individualized scan protocols

The aim of this study was to demonstrate that dose reduction and constant image quality can be achieved by adjusting X-ray dose to patient size. To establish the relation between patient size, image quality and dose we scanned 19 patients with reduced dose. Image noise was measured. Four radiologists scored image quality subjectively, whereby a higher score meant less image quality. A reference patient diameter was determined for which the dose was just sufficient. Then 22 patients were scanned with the X-ray dose adjusted to their size. Again, image noise was measured and subjective image quality was scored. The dose reduction compared with the standard protocol was calculated. In the first group the measured noise was correlated to the patient diameter (rho=0.78). This correlation is lost in the second group (rho=-0.13). The correlation between patient diameter and subjective image quality scores changes from rho=0.60 (group 1) to rho=-0.69 (group 2). Compared with the standard protocol, the dose was reduced (mean 28%, range 0-76%) in 19 of 22 patients (86%). Dose reduction and constant noise can be achieved when the X-ray dose is adjusted to the patient diameter. With constant image noise the subjective image quality increases with larger patients.     

ASIR算法在宝石CT肝扫描中应用

目的探讨利用GE宝石螺旋CT的ASIR技术,在成人肝检查的扫描方法及临床应用价值。方法采用GE宝石螺旋CT,选取100例肝扫描患者,随机分为2组:A组50例,采用普通滤波反投影法,即FBP法扫描;B组50例,采用自适应统计迭代重建法,即ASiR法扫描。对比分析两组检查的图像可诊断率及辐射剂量。结果 A组图像质量评分为(4.88±0.14)分,B组为(4.90±0.13)分,两组影像可诊断率比较,差异无统计学意义(P>0.05)。A组平均射线剂量为(7.72±1.82)m Sv,B组为(2.68±0.68)m Sv,两组辐射剂量比较,差异有统计学意义(P<0.05)。结论 GE宝石螺旋CT肝检查成像中,应用ASIR技术相对于普通螺旋扫描在保证图像质量的前提下可降低60%的辐射剂量。