Portable X-ray System Research Articles

Data acquisition system for a newly-built hard x-ray/soft gamma-ray spectrometer imaging system on experimental advanced superconducting tokamak

A portable hard X-ray and soft gamma-ray spectrometer imaging system (HXS) has been constructed to gather physical information about fast electrons confined in the Experimental Advanced Superconducting Tokamak (EAST). The system is installed on the low field side of the mid-plane and provides a viewing field tangential to the toroidal field. The system utilizes a two-dimensional Cadmium Zinc Telluride (CdZnTe) semiconductor detector with 128 channels, and a data acquisition (DAQ) system has been designed for it. The DAQ system features a highly integrated signal processing system with the capability of high-speed processing and digital transmission of signals from 128 channels. In addition, a related DAQ software has been developed using a modular design approach, facilitating tasks such as data reception, storage, and preliminary processing. HXS, which has been applied during the recent EAST campaign, directly obtains the digital energy spectrum of incident photons. The DAQ system is described in detail in this paper. The hardware components and energy calibration have also been described. Experimental data have been successfully obtained and briefly discussed. More physical research will be reported in future publications.

X-ray digital imaging detection system for high-voltage equipment inspection

In 2019 a portable diagnostic X-ray system was developed and tested for the inspection of high-voltage equipment (HVE). The system operates based on discrete radiography and is referred by the authors as the first generation X-ray system. As a result of critical analysis of the first generation system, it was further proposed to create a second generation mobile scanning system for HVE digital radiography which is for the first time applied in the power engineering. A physical and mathematical model was developed to establish the relationship between the energy spectrum of the source X-ray radiation and the contribution of this radiation to the image generation during HVE radiography. Using this model, the authors assess the efficiency of the unique X-ray machine used in the first generation X-ray system. The main technical requirements for the second generation X-ray system, implementing digital scanning radiography, for examining HVE in operation are given.

X-ray technology in civil engineering

X-ray has the unique ability to reveal what inside a structure and interpret it as a human readable image. This key feature makes X-ray imaging to a preferred inspection method for quality control across everything from food, micro electronics to heavy steel constructions. The newest technology developments towards digital X-ray imaging allow for fast and reliable inspection, addressing the high requirements of steel and concrete inspection. In civil engineering X-ray technology is used for weld seem inspection within construction of pipelines, bridges petrol-chemical plants and nuclear facilities. Quality assurance of steel constructions: X-ray inspection of pipelines and other steel structures are not only done during construction where weld seem inspection is one of the main applications for X-ray but also during maintenance where inspection for hidden corrosion and erosion to identify weaknesses before a breakdown occur. Damage assessment: Another important application is assessment of identified damages, as evaluation of identified cracks in steel constructions. With digital imaging it possible to get an immediate inspection result with high sensitivity and resolution. Inspection of concrete: A new emerging application is X-ray inspection of concrete constructions with X-ray. A modern 300kV portable X-ray system combined with digital image system can be used to inspect up to 20 – 25 cm concrete. With X-ray inspection of concrete, it is possible to identify and evaluate the condition of the reinforcement inside the concrete which is pivotal for the strength of the construction. It is also possible to identify the exact position of electrical installations or other features hidden inside the concrete which can prevent unexpected incidents related to drilling. The latest X-ray technology addresses todays and future challenges of quality control in civil engineering.

Alignment control using visual servoing and mobilenet single-shot multi-box detection (SSD): a review

The concept is highly critical for robotic technologies that rely on visual feedback. In this context, robot systems tend to be unresponsive due to reliance on pre-programmed trajectory and path, meaning the occurrence of a change in the environment or the absence of an object. This review paper aims to provide comprehensive studies on the recent application of visual servoing and DNN. PBVS and Mobilenet-SSD were chosen algorithms for alignment control of the film handler mechanism of the portable x-ray system. It also discussed the theoretical framework features extraction and description, visual servoing, and Mobilenet-SSD. Likewise, the latest applications of visual servoing and DNN was summarized, including the comparison of Mobilenet-SSD with other sophisticated models. As a result of a previous study presented, visual servoing and MobileNet-SSD provide reliable tools and models for manipulating robotics systems, including where occlusion is present. Furthermore, effective alignment control relies significantly on visual servoing and deep neural reliability, shaped by different parameters such as the type of visual servoing, feature extraction and description, and DNNs used to construct a robust state estimator. Therefore, visual servoing and MobileNet-SSD are parameterized concepts that require enhanced optimization to achieve a specific purpose with distinct tools.

Impalement Injury Diagnosed at the Scene by a Portable X-Ray System Transported by a Physician-Staffed Helicopter.

Impalement Injury Diagnosed at the Scene by a Portable X-Ray System Transported by a Physician-Staffed Helicopter.

Experience of the Usage of a Portable X-ray System

ObjectiveThe purpose of this study was to introduce the use of a portable X-ray system by the staff members of a doctor helicopter (DH). MethodsFrom January 11 to 18, 2019, we were given temporary access to a portable X-ray system. This period is defined as the investigation term. During the investigation term, a medical chart review was retrospectively performed for all patients who were transported by the DH. We investigated the variables between cases in which an X-ray study had been performed (X-ray group) and had not been performed (control group). ResultsThirteen subjects were classified into the X-ray group, and 17 were classified into the control group. No X-ray studies were performed for patients who underwent interhospital transportation, and the proportion of cases involving patients with exogenous disease in the X-ray group was greater than that in the control group. ConclusionWe reported our experience of DH staff performing X-ray studies at the scene. Further studies are required to determine the indications for using portable X-ray systems in the prehospital setting.

Dosimetry of a portable in vivo x-ray fluorescence system using EBT3 radiochromic film

Purpose. In vivo x-ray fluorescence is a non-invasive analytical technique for determining trace and toxic element exposures. In this work we measure the dose for a portable handheld x-ray system (pXRF). Materials and Methods. We used EBT3 radiochromic film calibrated with a clinical orthovoltage unit for absolute dose measurement. Films were placed on a human phantom and irradiated with the Tracer III-SD pXRF at tube potentials of 40 and 45 kVp with various levels of filtration. Results. Using settings that result in the best detection limits, the highest absorbed point dose to the skin was 0.3 Gy, the equivalent dose to a 1 cm2 area was 54 mSv, and the whole-body effective dose was less than 1 μSv for a standard 3-min in vivo measurement of strontium or lead. Recent work has demonstrated that 1 s and 30 s measurements are feasible for bone strontium measurements, which would lead to significantly lower doses. Conclusions. Our results are in agreement with a previous dosimetry study of another portable x-ray device and indicate that it is safe for in vivo measurements of elements such as strontium and lead, only after appropriate dose validation and with appropriate beam filtration in place.

Abstract 1: Analysis of the Usage of a Portable X-Ray System Transported to the Scene by a Physician-Staffed Helicopter

Abstract 1: Analysis of the Usage of a Portable X-Ray System Transported to the Scene by a Physician-Staffed Helicopter

Predicting Detection Performance on Security X-Ray Images as a Function of Image Quality.

Developing methods to predict how image quality affects the task performance is a topic of great interest in many applications. While such studies have been performed in the medical imaging community, little work has been reported in the security X-ray imaging literature. In this paper, we develop models that predict the effect of image quality on the detection of the improvised explosive device components by bomb technicians in images taken using portable X-ray systems. Using a newly developed NIST-LIVE X-Ray Task Performance Database, we created a set of objective algorithms that predict bomb technician detection performance based on the measures of image quality. Our basic measures are traditional image quality indicators (IQIs) and perceptually relevant natural scene statistics (NSS)-based measures that have been extensively used in visible light image quality prediction algorithms. We show that these measures are able to quantify the perceptual severity of degradations and can predict the performance of expert bomb technicians in identifying threats. Combining NSS- and IQI-based measures yields even better task performance prediction than either of these methods independently. We also developed a new suite of statistical task prediction models that we refer to as quality inspectors of X-ray images (QUIX); we believe this is the first NSS-based model for security X-ray images. We also show that QUIX can be used to reliably predict conventional IQI metric values on the distorted X-ray images.

A case of fatal trauma evaluated using a portable X-ray system at the scene.

Objective: To demonstrate the use of a portable X-ray system at the scene.Patient: A 59-year-old man collapsed under a small power shovel and was discovered by his colleague. The fire department dispatched an ambulance and requested the dispatch of a doctor helicopter (DH) immediately after receiving the emergency call. When the staff of the DH used a portable X-ray system to assess the patient at the rendezvous point, he was found to have experienced a cardiac arrest with deformity of the face. Portable chest X-ray in the ambulance revealed decreased radiolucency of the lung fields without pneumothorax, and tracheal tube insertion was successful. Portable pelvic X-ray also showed no trauma. Portable cranial X-ray revealed orbital fracture. Although we urgently transported the patient to our hospital by the DH, he unfortunately died of circulatory arrest caused by his severe injuries. Based on the portable X-ray findings obtained at the scene, we suspected that the patient’s cardiac arrest had been caused by severe head and/or neck injuries.Conclusion: This portable X-ray system may be able to change and facilitate the management of patients with trauma dramatically by simplifying prehospital diagnoses even in rural areas.

The Bone Structure Index and the requirements for its evaluation with a hand-held x-ray imaging system

The social costs of osteoporosis are huge and keep growing because of increased life expectancy. Although a low bone mineral density is considered to be associated with a higher risk of fracture, densitometry alone has been shown to be inadequate to predict a significant number of fractures, hence the need to develop innovative and inexpensive diagnostic methods to be used together with the consolidated systems. The Bone Structure Index is computed using a patented technique that virtually simulates the application of compressive loads on the trabecular structure’s reconstructions obtained from the patient’s digital radiographs. The radiograms are acquired by a hand-held portable x-ray system equipped with a digital sensor. This configuration presents specific advantages but the use of a handheld portable X-ray device requires safety procedures specifically designed to protect the operator and the patient, which are discussed in the present paper.

Development of cable fed flash X-ray (FXR) system.

Flash X-ray sources driven by pulsed power find applications in industrial radiography, and a portable X-ray source is ideal where the radiography needs to be taken at the test site. A compact and portable flash X-ray (FXR) system based on a Marx generator has been developed with the high voltage fed to the FXR tube via a cable feed-through arrangement. Hard bremsstrahlung X-rays of few tens of nanosecond duration are generated by impinging intense electron beams on an anode target of high Z material. An industrial X-ray source is developed with source size as low as 1 mm. The system can be operated from 150 kV to 450 kV peak voltages and a dose of 10 mR has been measured at 1 m distance from the source window. The modeling of the FXR source has been carried out using particle-in-cell and Monte Carlo simulations for the electron beam dynamics and X-ray generation, respectively. The angular dose profile of X-ray has been measured and compared with the simulation.

Geometry calibration between X-ray source and detector for tomosynthesis with a portable X-ray system

PurposeTomosynthesis is attracting attention as a low-dose tomography technology compared with X-ray CT. However, conventional tomosynthesis imaging devices are large and stationary. Furthermore, there is a limitation in the working range of the X-ray source during image acquisition. We have previously proposed the use of a portable X-ray device for tomosynthesis that can be used for ward rounds and emergency medicine. The weight of this device can be reduced by using a flat panel detector (FPD), and flexibility is realized by the free placement of the X-ray source and FPD. Tomosynthesis using a portable X-ray device requires calibration of the geometry between the X-ray source and detector at each image acquisition. We propose a method for geometry calibration and demonstrate tomosynthesis image reconstruction by this method.MethodsAn image processing-based calibration method using an asymmetric and multilayered calibration object (AMCO) is presented. Since the AMCO is always attached to the X-ray source housing for geometry calibration, the additional setting of a calibration object or marker around or on the patients is not required. The AMCO’s multilayer structure improves the calibration accuracy, especially in the out-of-plane direction.ResultsTwo experiments were conducted. The first was performed to evaluate the calibration accuracy using an XY positioning stage and a gonio stage. As a result, an accuracy of approximately 1 mm was achieved both in the in-plane and out-of-plane directions. An angular accuracy of approximately 0.5^{circ } was confirmed. The second experiment was conducted to evaluate the reconstructed image using a foot model phantom. Only the sagittal plane could be clearly observed with the proposed method.ConclusionWe proposed a tomosynthesis imaging system using a portable X-ray device. From the experimental results, the proposed method could provide sufficient calibration accuracy and a clear sagittal plane of the reconstructed tomosynthesis image.

Precision and accuracy of stress measurement with a portable X-ray machine using an area detector

The use of portable X-ray stress analyzers, which utilize an area detector along with the newly adopted `cosα' or full-ring fitting method, has recently attracted increasing interest. In laboratory conditions, these measurements are fast, convenient and precise because they employ a single-exposure technique that does not require sample rotation. In addition, the effects of grain size and orientation can be evaluated from the Debye ring recorded on the area detector prior to data analysis. The accuracy of the measured stress, however, has been questioned because in most cases just a single reflection is analyzed and the sample-to-detector distances are relatively short. This article presents a comprehensive analysis of the uncertainty associated with a state-of-the-art commercial portable X-ray device. Annealed ferrite reference powders were used to quantify the instrument precision, and the accuracy of the stress measurement was tested by in situ tensile loading on 1018 carbon steel and 6061 aluminium alloy bar samples. The results show that the precision and accuracy are sensitive to the instrument (or sample) tilt angle (ψ0) as well as to the selected hkl reflection of the sample. The instrument, sample and data analysis methods all affect the overall uncertainty, and each contribution is described for this specific portable X-ray system. Finally, on the basis of the conclusions reached, desirable measurement/analysis protocols for accurate stress assessments are also presented.

Computer-aided detection of retained surgical needles from postoperative radiographs.

Foreign objects, such as surgical sponges, needles, sutures, and other surgical instruments, retained in the patient's body can have dire consequences in terms of patient mortality as well as legal and financial penalties. We propose computer-aided detection (CAD) on postoperative radiographs as a potential solution to reduce the chance of retained foreign objects (RFOs) after surgery, thus alleviating one of the major concerns for patient safety in the operation room. A CAD system can function as a second pair of eyes or a prescreener for the surgeon and radiologist, depending on the CAD system design and the workflow. In this work, we focus on the detection of surgical needles on postoperative radiographs.As needles are frequently observed RFOs, a CAD system that can offer high sensitivity and specificity toward detecting surgical needles will be useful. Our CAD system incorporates techniques such as image segmentation, image enhancement, feature analysis, and curve fitting to detect surgical needles on radiographs. A dataset consisting of 108 cadaver images with a total of 116 needles and 100 cadaver "normal" images without needles was acquired with a portable digital x-ray system. A reference standard was obtained by marking the needle locations using an in-house developed graphical user interface. The 108 cadaver images with the needles were partitioned into a training set containing 53 cadaver images with 59 needles and a test set containing 55 cadaver images with 57 needles. All of the 100 cadaver normal images were reserved as a part of the test set and used to estimate the false-positive detection rate. Two operating points were chosen from the CAD system such that it can be operated in two modes, one with higher specificity (mode I) and the other with higher sensitivity (mode II). For the training set, the CAD system with the rule-based classifier achieved a sensitivity of 74.6% with 0.15 false positives per image (FPs/image) in mode I and a sensitivity of 89.8% with 0.36 FPs/image in mode II. For the test set, the CAD system achieved a sensitivity of 77.2% with 0.26 FPs/image in mode I and a sensitivity of 84.2% with 0.6 FPs/image in mode II. For comparison, the CAD system with the neural network classifier achieved a sensitivity of 74.6% with 0.08 FPs/image in mode I and a sensitivity of 88.1% with 0.28 FPs/image in mode II for the training set, and a sensitivity of 75.4% with 0.23 FPs/image in mode I and a sensitivity of 86.0% with 0.57 FPs/image in mode II for the test set. A novel CAD system has been developed for automated detection of needles inadvertently left behind in a patient's body from postsurgery radiographs. The pilot system offers reasonable performance in both the high sensitivity and high specificity modes. This preliminary study shows the promise of CAD as a low-cost and efficient aid for reducing retained surgical needles in patients.

Image enhancement for on-site X-ray nondestructive inspection of reinforced concrete structures.

The use of portable and high-energy X-ray system can provide a very promising approach for on-site nondestructive inspection of inner steel reinforcement of concrete structures. However, the noise properties and contrast of the radiographic images for thick concrete structures do often not meet the demands. To enhance the images, we present a simple and effective method for noise reduction based on a combined curvelet-wavelet transform and local contrast enhancement based on neighborhood operation. To investigate the performance of this method for our X-ray system, we have performed several experiments with using simulated and experimental data. With comparing to other traditional methods, it shows that the proposed image enhancement method has a better performance and can significantly improve the inspection performance for reinforced concrete structures.

An objectively-analyzed method for measuring the useful penetration of x-ray imaging systems

The ability to detect wires is an important capability of the cabinet x-ray imaging systems that are used in aviation security as well as the portable x-ray systems that are used by domestic law enforcement and military bomb squads. A number of national and international standards describe methods for testing this capability using the so called useful penetration test metric, where wires are imaged behind different thicknesses of blocking material. Presently, these tests are scored based on human judgments of wire visibility, which are inherently subjective. We propose a new method in which the useful penetration capabilities of an x-ray system are objectively evaluated by an image processing algorithm operating on digital images of a standard test object. The algorithm advantageously applies the Radon transform for curve parameter detection that reduces the problem of wire detection from two dimensions to one. The sensitivity of the wire detection method is adjustable and we demonstrate how the threshold parameter can be set to give agreement with human-judged results. The method was developed to be used in technical performance standards and is currently under ballot for inclusion in an international aviation security standard.

In brief

PAGE 18 Researchers in Korea have proposed a method to significantly reduce the computation complexity of a phase rotation beamforming technique commonly used in medical ultrasound scanners. They demonstrate that it can be implemented on smartphone hardware and that the technique doesn't sacrifice image quality, either analytically or experimentally. PAGE 29 Optical cloaking of arbitrary cross-section cylindrical structures using scattering cancellation is presented in work from Iran. The approach uses nano-strips of silver in a dielectric host as a cloaking shell around the object and the work explores the effect of the nano-strip parameters on the cloaking efficiency. The computational complexity of the technique is improved sufficiently to run in realtime on a smartphone without compromising quality PAGE 51 A compact Ka-band full bandwidth 3-dB waveguide hybrid has been designed by researchers in China. With high directivity over the full bandwidth of the WR-28 standard waveguide. The hybrid can also be used as a two-way power divider and can be made with excellent repeatability at low-cost. Optical cloaking of cylindrical objects of arbitrary cross-section PAGE 12 Researchers in China present a surface diagnosis approach for large reflector radio astronomy antennas with active surface control systems. Based on microwave holographic techniques, it allows far field patterns to be measured in focus by actively adjusting the primary surface. The 3-dB waveguide hybrid can be fabricated at low-cost with excellent repeatability PAGE 36 A robust, portable stereoscopic system for rapid identification of hidden objects using only a small number of X-ray projections has been demonstrated in work from the US. The system uses a single fixed sensor and obtains different angles using a motion-controlled single X-ray source. With a known system geometry, a series of depth planes can be computed to allow rapid object identification and realtime operation. The approach applies techniques from microwave holography to large reflector radio astronomy antennas The single source, single sensor, portable X-ray system allows rapid identification of hidden objects

XRF Study of Mexican Iron Gall Inks: Historical and Geographical Overview of their Chemistry

ABSTRACTOver 2000 micro-X-Ray Fluorescence (μ-XRF) measurements of iron gall inks were collected at the General Archive of the Nation in Mexico (Archivo General de la Nación, AGN). The portable X-Ray system SANDRA permitted detection of common elements present in all iron gall inks (e.g.Ca, Fe, S, etc.) as well as characteristic traces and impurities (e.g.Cu, Ni, Zn, Pb, etc). The documents in the data set originate from all over Mexico and are dated between the 16thand 19thcenturies. All manuscripts were well preserved.Extensive statistical processing of the relative X-Ray intensities revealed common features in groups of documents with the same provenance. Among the findings, there is a progressive trend to complex mixtures from the beginning of the 16thcentury to the 17th. A reverse trend was observed for the following century. Zinc, lead and seldom arsenic, chromium and mercury seem characteristic for northern areas whereas manganese seems common to the vast majority of studied inks.As a general concern in conservation research, special attention was addressed to copper, as it is known to have additive effects to the degradation of cellulose. This metal seems fairly common to Mexican inks, especially during 18thcentury.To the best of our knowledge, this is the first examination taken to such a large number of inks. This study contributes to the more-focused development of suitable treatments that tailor specific needs, since they are to be based on of ink’s composition. It sets a precedent for the study of these inks in the Americas and allows conservators and historians to gain further insight into the history of their usage in Mexico.

Key Performance Indicators for Comparing the Performance of Portable Radiography: Direct Digital Radiography versus Conventional Machine Computed Radiography—A Study in a Nonacute Hospital

IntroductionPortable radiography traditionally has been performed with a conventional portable x-ray unit with computed radiography (CR) system (conventional-CR combo), and off-site processing of the exposed CR cassettes was time-consuming. The direct digital radiography (DDR) portable x-ray system, with the digital image immediately available for review and wireless transmission as the key merits, is newly installed for portable radiography. Thus, the work flow of portable radiography is changed. This study was performed to quantitatively investigate the performance of portable radiography using the DDR portable x-ray system and conventional-CR combo in terms of efficiency and work flow enhancement. MethodsOne hundred ninety portable x-ray examinations were timed for each procedural step using conventional-CR combo (n=97) and the DDR portable x-ray system. The following key performance indicators were designed for measuring the performance of portable radiography quantitatively: “examination duration,” “time for image becoming available in PACS,” “postacquisition processing time,” and “manpower deployment time.” ResultsProductivity was raised by 96% using the DDR portable x-ray system. “Examination duration” using the DDR portable system was significantly faster (P < .0001), with a mean calculated time of 13.4 ± 7.6 minutes for the DDR portable system and 25.2 ± 10.9 minutes for conventional-CR combo. The “time for image becoming available in PACS” was significantly shorter than that of conventional-CR combo (P < .0001), with a mean time of 6.8 ± 2.6 minutes for the DDR portable system and 19.2 ± 9.7 minutes for conventional-CR combo. The “postacquisition processing time” was measured with slight differences, with a mean time of 2.2 ± 1.1 minutes for the DDR portable system and 1.9 ± 1.0 minutes for conventional-CR combo (P = .1064). Because more portable x-ray examinations could be performed when using the DDR portable x-ray system in each round of service, the mean “manpower deployment time” when using the DDR portable x-ray system was longer (ie, 82.6 ± 46.8 minutes for the DDR portable system and 24.5 ± 11.9 minutes for conventional-CR combo). ConclusionsBy using the new DDR portable x-ray system with work flow changes, the performance of portable radiography was improved in efficiency and work flow was enhanced. Furthermore, the four defined key performance indicators in this study may help provide a framework for measuring the performance of portable radiography in other institutions.