Initial assessment of chest X-ray in thoracic trauma patients: Awareness of specific injuries

AIM: To compare the reported injuries on initial assessment of the chest X-ray (CXR) in thoracic trauma patients to a second read performed by a dedicated trauma radiologist. METHODS: By retrospective analysis of a prospective database, 712 patients with an injury to the chest admitted to the University Medical Center Utrecht were studied. All patients with a CXR were included in the study. Every CXR was re-evaluated by a trauma radiologist, who was blinded for the initial results. The findings of the trauma radiologist regarding rib fractures, pneumothoraces, hemothoraces and lung contusions were compared with the initial reports from the trauma team, derived from the original patient files. RESULTS: A total of 516 patients with both thorax trauma and an initial CXR were included in the study. After re-evaluation of the initial CXR significantly more lung contusions (53.3% vs 34.1%, P < 0.001), hemothoraces (17.8% vs 11.0%, P < 0.001) and pneumothoraces (34.4% vs 26.4%, P < 0.001) were detected.During initial assessment significantly more rib fractures were reported (69.8% vs 62.3%, P < 0.001). CONCLUSION: During the initial assessment of a CXR from trauma patients in the emergency department, a significant number of treatment-dictating injuries are missed. More awareness for these specific injuries is needed.

Digital radiography of crush thoracic trauma in the Sichuan earthquake

AIM:To investigate the features of crush thoracic trauma in Sichuan earthquake victims using chest digital radiography(CDR).METHODS:We retrospectively reviewed 772 CDR of 417 females and 355 males who had suffered crush thoracic trauma in the Sichuan earthquake.Patient age ranged from 0.5 to 103 years.CDR was performed between May 12,2008 and June 7,2008.We looked for injury to the thoracic cage,pulmonary parenchyma and the pleura.obtained in 349 patients,the remaining 423 patients underwent only AP CDR.Thoracic cage fractures,pulmonary contusion and pleural injuries were noted in 331(42.9%;95% CI:39.4%-46.4%),67 and 135 patients,respectively.Of the 256 patients with rib fractures,the mean number of fractured ribs per patient was 3.Rib fractures were mostly distributed from the 3rd through to the 8th ribs and the vast majority involved posterior and lateral locations along the rib.Rib fractures had a significant positive association with non-rib thoracic fractures,pulmonary contusion and pleural injuries(P < 0.001).The number of rib fractures and pulmonary contusions were significant factors associated with patient death.CONCLUSION:Earthquake-related crush thoracic trauma has the potential for multiple fractures.The high number of fractured ribs and pulmonary contusions were significant factors which needed appropriate medical treatment.

Monte Carlo simulation for bremsstrahlung and photoneutron yields in high-energy x-ray radiography

This paper reports on the results of calculations using a Monte Carlo code （MCNP5） to study the properties of photons, electrons and photoneutrons obtained in the converted target and their transportations in x-ray radiography. A comparison between measurements and calculations for bremsstrahlung and photoneutrons is presented. The radiographic rule and the effect of the collimator on the image are studied with the experimental model. The results provide exact parameters for the optimal design of radiographic layout and shielding systems.

Thoracic imaging outcomes in COVID-19 survivors

The coronavirus disease 2019(COVID-19)pandemic presents a significant global public health challenge.One in five individuals with COVID-19 presents with symptoms that last for weeks after hospital discharge,a condition termed“long COVID”.Thus,efficient follow-up of patients is needed to assess the resolution of lung pathologies and systemic involvement.Thoracic imaging is multimodal and involves using different forms of waves to produce images of the organs within the thorax.In general,it includes chest X-ray,computed tomography,lung ultrasound and magnetic resonance imaging techniques.Such modalities have been useful in the diagnosis and prognosis of COVID-19.These tools have also allowed for the follow-up and assessment of long COVID.This review provides insights on the effectiveness of thoracic imaging techniques in the follow-up of COVID-19 survivors who had long COVID.

Flash X-ray radiography technique to study the high velocity impact of soft projectile on E-glass/epoxy composite material

In the present paper, the high velocity impact of 9 mm soft lead projectile on 10 mm and 30 mm thick Eglass/epoxy composites was studied using a 450 kV Flash X-ray radiography(FXR) system. The basic parameters of FXR imaging, such as effect of ratio of target to film(TF) and source to target(ST) distances and X-ray penetration thickness of the composite material were optimized based on clarity and the actual dimensions of the objects. The optimized parameters were used in the FXR imaging of the ballistic event of 9 mm soft projectile on E-glass/epoxy composite. The real time deformation patterns of both the projectile and composite target during the ballistic impact were captured and studied at different time intervals. The notable failure modes of the 10 mm thick target with time include fibre breakage, bulging on the back side, delamination, recovery of the bulging, reverse bulging and its recovery. However, with increase in thickness of the target to 30 mm the only failure mechanism observed is the breaking of fibres. The ballistic impact event was also numerically simulated using commercially available LS-DYNA software. The numerically simulated deformation patterns of the projectile and target at different time intervals are closely matching with the corresponding radiographic images.

Radiography Image Classification Using Deep Convolutional Neural Networks

Research has shown that chest radiography images of patients with different diseases, such as pneumonia, COVID-19, SARS, pneumothorax, etc., all exhibit some form of abnormality. Several deep learning techniques can be used to identify each of these anomalies in the chest x-ray images. Convolutional neural networks (CNNs) have shown great success in the fields of image recognition and image classification since there are numerous large-scale annotated image datasets available. The classification of medical images, particularly radiographic images, remains one of the biggest hurdles in medical diagnosis because of the restricted availability of annotated medical images. However, such difficulty can be solved by utilizing several deep learning strategies, including data augmentation and transfer learning. The aim was to build a model that would detect abnormalities in chest x-ray images with the highest probability. To do that, different models were built with different features. While making a CNN model, one of the main tasks is to tune the model by changing the hyperparameters and layers so that the model gives out good training and testing results. In our case, three different models were built, and finally, the last one gave out the best-predicted results. From that last model, we got 98% training accuracy, 84% validation, and 81% testing accuracy. The reason behind the final model giving out the best evaluation scores is that it was a well-fitted model. There was no overfitting or underfitting issues. Our aim with this project was to make a tool using the CNN model in R language, which will help detect abnormalities in radiography images. The tool will be able to detect diseases such as Pneumonia, Covid-19, Effusions, Infiltration, Pneumothorax, and others. Because of its high accuracy, this research chose to use supervised multi-class classification techniques as well as Convolutional Neural Networks (CNNs) to classify different chest x-ray images. CNNs are extremely efficient and successful at reducing the number of parameters while maintaining the quality of the primary model. CNNs are also trained to recognize the edges of various objects in any batch of images. CNNs automatically discover the relevant aspects in labeled data and learn the distinguishing features for each class by themselves.

Effect of cooling rates on the dendritic morphology transition of Mg–6Gd alloy by in situ X-ray radiography

The effect of cooling rate on the transition of dendrite morphology of a Mg-6Gd （wt%） alloy was semiquantitatively analyzed under a constant temperature gradient by using synchrotron X-ray radiographic technique. Results show that equiaxed dendrites, including exotic ＇butterfly-shaped＇ dendrite morphology, dominate at high cooling rate （〉1 K/s）. When the cooling rate decreases in the range of 0.5-1 K/s, the equiaxed-to-columnar transition takes place, and solute segregates at the center of two long dendrite arms （LDA） of the ＇butterfly-shaped＇ dendrite. When the cooling rate is lower than 0.3 K/s, directional solidification occurs and the columnar dendritic growth direction gradually rotates from the crystalline axis to the thermal gradient direction with an increase in cooling rate. Meanwhile, interface moves faster but the dendrite arm spacing decreases. Floating, collision and rotation of dendrites under convection were also studied in this work.2018 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.

Short-pulse laser-driven x-ray radiography

We have developed a new radiography setup with a short-pulse laser-driven x-ray source. Using a radiography axis perpendicular to both long- and short-pulse lasers allowed optimizing the incident angle of the short-pulse laser on the x-ray source target. The setup has been tested with various x-ray source target materials and different laser wavelengths.Signal to noise ratios are presented as well as achieved spatial resolutions. The high quality of our technique is illustrated on a plasma flow radiograph obtained during a laboratory astrophysics experiment on POLARs.

Low Energy Plasma Focus as an Intense X-ray Source for Radiography

Study on X-ray emission from a low energy (1.8 kJ) plasma focus devicepowered by a 9 μF capacitor bank, charged at 20 kV and giving peak discharge current of about 175kA by using a lead-inserted copper-tapered anode is reported. The X-ray yield in different energywindows is measured as a function of hydrogen filling pressure. The maximum yield in 4π-geometry isfound to be (27.3+-1.1) J and corresponding wall plug efficiency for X-ray generation is 1.52+-0.06%. X-ray emission, presumably due to bombarding activity of electrons in current sheath at theanode tip was dominant, which is confirmed by the pinhole images. The feasibility of the device asan intense X-ray source for radiography is demonstrated.

X-Pinches as Broadband Sources of X-Rays for Radiography

Two methods of using the X-pinch as a source of X-ray radiation for radiography of biological objects are presented. X-pinches are found to be a very flexible method for generation of radiation over a wide spectral range and provide a high spatial and temporal resolution.

Development of a monochromatic crystal backlight imager for the recent double-cone ignition experiments

We developed a monochromatic crystal backlight imaging system for the double-cone ignition(DCI) scheme, employing a spherically bent quartz crystal. This system was used to measure the spatial distribution and temporal evolution of the head-on colliding plasma from the two compressing cones in the DCI experiments. The influence of laser parameters on the x-ray backlighter intensity and spatial resolution of the imaging system was investigated. The imaging system had a spatial resolution of 10 μm when employing a CCD detector. Experiments demonstrated that the system can obtain time-resolved radiographic images with high quality, enabling the precise measurement of the shape, size, and density distribution of the plasma.

基于深度学习的胸部X线图像清晰度评价方法

目的 构建深度学习模型对胸部X线图像进行清晰度评价,并与放射科医师的主观评价对比,验证模型的效能。资料与方法 回顾性收集2015年6月—2022年8月安徽省590家医院共9 135幅胸部X线图像,组织放射科医师采用五级评分法对图像清晰度进行多人多次评价,单人评价结果为A、B,多人评价结果为C。构建基于ResNet-50的深度学习模型对胸部X线图像进行清晰度评价,以结果 C作为模型训练和测试数据,模型评价结果为D。由1名放射质控专家对模型评价结果和医师多人评价结果进行审核评价作为图像清晰度的参考标准,评价结果为E。采用Spearman相关、均方根误差(RMSE)和准确率验证模型的效能。结果 与参考标准E相比,D的平均准确率为0.85,高于C的0.84。A、B、C、D与E的ρ分别为0.58(0.54,0.62)、0.59(0.55,0.63)、0.74(0.71,0.77)和0.80(0.78,0.82),D与E的相关性最好。A与B的ρ为0.45(0.41,0.49),两次单人主观评价清晰度相关性较差。A、B、C、D与E的RMSE分别为0.99、0.94、0.72和0.71,D与E的RMSE小于人工评价结果。结论 本研究构建的模型能够准确评价胸部X线图像清晰度,通过深度学习方法可以降低人工评价的主观干扰,为临床放射图像清晰度评价提供有效、客观的工具。

改良肺超声评分用于评估急性呼吸窘迫综合征严重程度

目的提出改良肺超声评分(LUS),观察其用于评估急性呼吸窘迫综合征(ARDS)严重程度的价值。方法回顾性分析33例突发ARDS患者肺超声及X线胸片等资料,根据氧合指数(OI)将患者归入中-重度组(n=16)及轻度组(n=17);比较组间LUS、改良LUS及肺水肿放射学(RALE)评分;绘制受试者工作特征(ROC)曲线,计算曲线下面积(AUC),分析影像学评分评估ARDS严重程度的效能;以Pearson相关分析观察ARDS患者影像学评分与OI的相关性,以及RALE评分与LUS及改良LUS的相关性。结果中-重度组LUS及改良LUS均高于轻度组(P均<0.05);RALE评分组间差异无统计学意义(P>0.05)。以LUS、改良LUS及RALE评分评估ARDS严重程度的AUC分别为0.809、0.853及0.640。ARDS患者LUS及改良LUS均与OI呈中度负相关(r=-0.570,P=0.001;r=-0.708,P<0.001),而RALE评分与OI无明显相关(r=-0.229,P=0.201)。ARDS患者RALE评分与LUS及改良LUS均呈中度正相关(r=0.588,P<0.001;r=0.502,P=0.003)。结论本研究提出的改良LUS可有效评估ARDS严重程度,且其效能优于LUS及RALE评分。

Simulation study on characteristics of information extraction in multiple-image radiography

Simulation experiments were performed to investigate the characteristics of information extraction in multiple-image radiography(MIR) based on geometrical optics approximation. Different Poisson noise levels were added to the simulation, and the results show that Poisson noise deteriorates the extraction results, with the degree of refraction > USAXS > absorption. The effects of Poisson noise are negligible when the detector's photon counts are about 1000 ph/pixel. A wider sampling range allows more accurate extraction results, but a narrower sampling range has a better signal-to-noise ratio for high Poisson noise levels, e.g., PN(10). The sampling interval can be suitably increased with a minor impact on the extraction results for low Poisson noise levels(PN(10000)). The extraction results are incomplete because a portion of the samplerocking curve is beyond the sampling range. This induces artifacts in the images, especially for strong refraction and USAXS signals. The artifacts are not obvious when the refraction angle and standard deviation of the USAXS are smaller than the sampling range by an order of magnitude.In general, the absorption barely affects the extraction results. However, additional Poisson noise will be generated when the sample is made of high-Z elements or has a large size due to the strong absorption. Here, the extraction results will deteriorate, and additional exposure time is required. This simulation provides important details on practical applications of MIR, with improvements in information extraction.

Enhanced K-Edge Radiography Using a High-Spatial-Resolution Cadmium Telluride Array Detector

To confirm the imaging effect of a dual-energy (DE) cadmium telluride (CdTe) array detector (XCounter, Actaeon) and to perform fundamental studies on DE computed tomography, we performed enhanced K-edge radiography using iodine (I) and gadolinium (Gd) media. DE radiography was performed using an X-ray generator with a 0.1-mm-diam-focus tube and a 0.5-mm-thick beryllium window, a 1.0-mm-thick aluminum filter for absorbing extremely low-energy photons, and the CdTe array detector with pixel dimensions of 0.1 × 0.1 mm2. Each pixel has a charge-sensitive amplifier and a dual-energy counter, and the event pulses from the amplifier are sent to the counter to determine two threshold energies. The tube current was a maximum value of 0.50 mA, and the tube voltages for I- and Gd-K-edge radiograms were 60 and 80 kV, respectively. In the I-K-edge radiography of a dog-heart phantom at an energy range of 33 - 60 keV, the muscle density increased, and fine coronary arteries were visible. Utilizing Gd-K-edge radiography of a rabbit head phantom at an energy range of 50 - 80 keV, the muscle density increased, and fine blood vessels in the nose were observed at high contrasts. Using the DE array detector, we confirmed the image-contrast variations with changes in the threshold energy.

A Derived Exposure Chart for Computed Radiography in a Negroid Population

Background: Computed radiography has a wider exposure latitude when compared with film-screen imaging system. Consequently, the risk of dose creep is high. A conscientious effort is there-fore, needed by the radiographer to keep exposure as low as reasonably achievable. Objective: To derive a computed radiography exposure chart for a negroid population using AGFA photostimulable phosphor plates and a GE static X-ray machine. Materials and Method: A static X-ray machine, a digitizer, and photostimulable phosphor plates were used for the X-ray examination. Chest examinations were done at a Focus-Film-Distance (FFD) of 150 - 180 cm while all other examinations were conducted at 90 - 100 cm FFD. The range of exposure factors (kVp, mA and mAs) used by radiog-raphers in the centre was noted and the 90th percentile calculated. Over a three-month period, the patients were examined with the 90th percentile of tube potential (kVp) while keeping other factors constant. The kVp was gradually decreased and halted if radiologists and radiographers uncon-nected with the work expressed misgivings about the quality of the image. A similar procedure was adopted for the tube current (mA). The threshold adopted as low as reasonably achievable was the factor preceding the point of observation by other personnel. Metrics for central tendency from the statistical packages for social sciences, version 17.0 was used to analyze the data. Results: 335 subjects of both gender aged 0 - 92 years were examined by the researchers. Adult exposure factors used by the radiographers (and those derived by the researchers) had a range of 45 - 130 kVp (62 - 94 kVp), 63 - 320 mA (100 - 250 mA) and 4.0 - 25.0 mAs (5.0 - 20.0 mAs) respectively. Pediatric chest (and researchers-derived) factors were 50 - 75 kVp (52 - 65 kVp), 50 - 250 mA (100 - 220 mA) and 3.20 - 10.0 mAs (3.2 - 6.5 mAs) respectively. Conclusion: Upper threshold of adult (and paediatric) exposure factors in computed radiography with comparable equipment and accessories should not exceed 94 kVp (65 kVp), 250 mA (220 mA) and 20.0 mAs (6.5 mAs) respectively. The derived exposure chart is also adequate to address motion unsharpness in chest examinations.

Economic Evaluation of Conventional Radiography with Film and Computed Radiography: Applied at BMC

Conventional radiography with film (CRF) has been in use for diagnostic purposes for a long time now. It has proved to be a great assert for the radiographers in assessing various abnormalities. With recent advances in technology it is now possible to have digital solutions for radiography problems at a very cost effective, environment friendly and also with better image quality in certain applications when compared to CRF. Rather than using a CRF a computed radiography (CR) uses imaging plates to capture the image. The imaging plate contains photosensitive phosphors which contain the latent image. Later this plate is introduced into a reader which is then converted into a digital image. The major advantage and the cost effective element of this system is the ability to reuse the imaging plates unlike the photographic film where in only a single image can be captured and cannot be reused. The computed radiography drastically reduces the cost by eliminating the use of chemicals like film developers and fixers and also the need for a storage room. It also helps to reduce the costs that are involved in the disposal of wastes due to conventional radiography. This paper investigates whether it is cost effective to use computed radiography over film based system at Al-Batnan Medical Center (BMC), Tobruk, Libya by using Cost Benefit Analysis (CBA). Apart from the initial cost of the CR System, based on the data collected from the center, from the year 2008 to 2012 (until June 2012) a total of 581,566 images were produced with the total cost incurred using film based system being USD 4,652,528. If the same number of images were produced using a CR system the total cost incurred would have been USD 82,600. Taking into consideration the cost of a new CR system to be USD 120,000 the overall cost of producing these images is USD 202,600. It is observed that an amount of USD 4,449,928 could have been saved over the period of 5 years starting from 2008 to 2012 by using the CR system at BMC. Using Cost Benefit Analysis, the average value of the net difference between the costs and benefits for the conventional film based system is ?83.38 where as for the Computed System it is 22.06. Based on the principles of Cost Benefit Analysis it can be concluded that the system with a net positive difference is more cost beneficial than the other. With the help of the above two analysis it can be concluded that the use of computed radiography is definitely more cost effective for use at BMC, when compared to the conventional x-ray radiography.

严重急性呼吸综合征(SARS)早期胸部影像学表现

目的:探讨SARS胸部影像的早期变化。方法:观察24例符合SARS临床诊断标准的患者在发病3天之内的胸部平片及CT扫描结果。回顾性分析这些胸部平片及CT图像,观察、对比平片及CT图像1～3天内异常征象的发展,并对异常改变包括病变的数目、位置、大小和分布加以分析。结果:发病当天就诊并摄胸部平片的患者,胸部改变均为阴性,而CT扫描显示均为阳性改变。第二天摄片,大部分胸片为阳性改变,部分为可疑,少数仍为阴性改变。而CT改变较当日明显增大、增多。第三日摄片,胸片大部分为阳性改变。早期SARS病变胸部影像改变为小斑片状阴影,密度小而淡,约1～2cm,极易漏诊,随病变发展,CT出现棉团样改变。结论:根据SARS病情发展快、变化快的特点,早期诊断要定期复查胸片,时间不宜过长,最好每天复查,有条件应做胸部CT扫描。

初治涂阴肺结核胸片复读结果与诊断质量多因素分析

目的分析在我国结核病防治规划实施中,县级结核病防治机构登记的初治涂阴肺结核患者诊断质量和影响因素。方法按照2006年全国初治涂阴肺结核患者的登记率水平,抽取4个省,每个省选择1个地(市),每个地(市)抽取2个县,采取整群抽样的方法,对各县抽取60例涂阴肺结核患者诊断时的X线胸片和收集患者有关临床资料。各县所有复读胸片经数码摄像后,采用国家级专家个人盲法复读和专家组复读。国家级专家包括结核病防治、结核病临床和放射专家各2位。国家级专家组由结核病防治、结核病临床和放射专家各2位组成。各小组和专家对X线胸片复读认为不符合活动性肺结核患者影像学改变者为过诊。并对所有过诊患者的影响因素(共14个变量)分别进行单因素及多因素logistic回归分析,探讨涂阴肺结核诊断质量与相关的影响因素。结果涂阴肺结核总过诊率20.78%(399/1920),8个县X线胸片诊断的平均过诊率为10.83%(26/240)～32.50%(78/240)不等,各专家对胸片复核时,其复核后过诊率在10.21%(49/480)～33.13%(159/480)不等。所有的变量经logistic多因素回归分析,结果显示最终影响过诊的有胸片质量、性别、年龄、病例诊断医生、结核菌素检查、卡介苗接种史及患者来源7个因素。使涂阴肺结核过诊风险增加相关的因素包括:40岁～(OR=2.007,95%CI=1.165～3.535)及60岁以上(OR=1.710,95%CI=1.277～2.940)、女性(OR=1.941,95%CI=1.226～3.102)、门诊医生(OR=2.243,95%CI=1.793～4.27)、结核菌素检查史(OR=1.985,95%CI=1.106～3.564)、卡介苗接种史(OR=2.773,95%CI=1.023～7.515)、胸片质量丙(OR=2.402,95%CI=1.006～6.995)及胸片质量丁(OR=10.694,95%CI=2.348～62.596);涂阴肺结核过诊风险减少的相关的因素包括:诊断小组诊断(OR=0.471,95%CI=0.440～0.643)、转诊(OR=0.521,95%CI=0.313～0.865)、集中推荐(OR=0.437,95%CI=0.206～0.927)。结论我国涂阴肺结核过诊率较高,过诊的发生与多种因素有关。

胸主动脉夹层动脉瘤腔内隔绝术前裂口的评估

为探讨胸主动脉夹层动脉瘤腔内隔绝手术前裂口评估的意义及方法 ,作者分析了 32例以螺旋CT为主要术前检查评估方式、少数采用MRA检查的病例 ,并与术中DSA对比。结果表明 ,第一裂口发现率CT检查为 90 32 % ,MRA为 6 6 7% ,DSA为 10 0 % ;大部分裂口位于断面片时钟位的 3～ 7点 ;多裂口情况下CT与DSA检查结果有一定差异。提示术前准确评估裂口将有利于手术方案、移植物的选择 ;