bluuebunny/crossref_metadata_2025 huggingface dataset:
Image performance evaluation of a cone beam O-arm imaging	system
Authors: Zhang Jie , Zhang Da
Published: December 2019

Image performance of a cone beam O-arm system with the use of a Varian flat panel detector (PaxScan 4030CB) was evaluated. Modulation Transfer Function (MTF), Noise Power Spectrum (NPS), and tube output characteristics were measured. Image quality measurements were performed with a CATPHAN 424 phantom using a 120 kVp beam filtered with 1 mm Al and 0.1 mm Cu and three preset protocols at different exposure levels. The CPT445 Module was used to measure MTF. Water phantom images were used to calculate NPS. Then the NPS was normalized by dividing the square of the mean signal. The Photon fluence at each exposure (q) was estimated using the SpekCalc. The MTF indicates that the reconstruction filter of the O-arm is overenhancing, meaning that it yields values greater than unity. The system has a 10% MTF at 0.45 mm. The NPS shows the low frequency structured noise. The evaluation of image performance of the O-arm imaging system helps its future improvements and clinical applications.
Liver specific phase of perflubutane microbubbles	contrast-enhanced ultrasound for potential use in the diagnosis of focal liver	lesions
Authors: Ji Qiao , Liu Guihua , Sun Xiangzhou , Liu Guangjian , Lu Mingde , Xie Xiaoyan , Xu Ming , Zhang Yuanyuan , Zheng Shuguang
Published: December 2019

The purpose of this study was to distinguish passive retention of microbubbles in liver sinusoids from active intracellular retaining, and to provide further evidence of post vascular liver specific phase of perflubutane microbubble contrast-enhanced ultrasound for potential use in the detection of focal liver lesions. Fifty-four rats were divided into three groups: saline group (G1, as a control, n=6), sulphur hexafluoride microbubble group (G2, n=24) and perflubutane microbubble group (G3, n=24). The livers were perfused at 2, 5, 10 and 20 min after injection of perflubutane or sulphur hexafluoride gas-filled microbubbles or normal saline. Changes in contrast-enhanced images within the liver were quantified. After perfusion, the echogenicity of the liver in the saline group increased from −49.44 ± 0.08 dB to − 44.37 ± 1.02 dB (p< 0.05). In G2, the enhancement decreased significantly after perfusion at 2 and 5 min, and increased at 10 and 20 min (all p< 0.05). In G3, the enhancement decreased from −18.05 ± 2.28 dB to − 26.76 ± 1.69 dB only at 2 min after perfusion (p < 0.05). Perflubutane microbubbles provided a post vascular liver specific phase on contrast-enhanced ultrasound, which could begin as early as 5 min after administration of the contrast agent in rats. This study suggests that perflubutane microbubbles could result in a liver specific phase and provide valuable information for diagnosis and detection of focal liver lesions which may improve the efficiency of contrast-enhanced ultrasound in clinical diagnoses of liver diseases.
Comparison of aspiration-sclerotherapy versus laparoscopic	decortication in management of symptomatic simple renal cysts
Authors: Shao Qiang , Xu Jianfeng , Adams Tamara , Tao Sha , Cui Yon , Shen Hua , Cao Wenzhou , Xie Jianjun , Fan Youzhang , Zhang Yuanyuan , Huang Min
Published: December 2019

PURPOSE: To perform a retrospective study to compare the efficiency, safety and costs using aspiration-sclerotherapy with 95% ethanol vs. laparoscopic decortications in management of symptomatic simple renal cysts.

MATERIALS AND METHODS: Patients with simple renal cysts (diamante ⩾ 4 cm) were recruited from our hospital between October 2008 and October 2012. A total of 986 patients (Group 1) underwent aspiration-sclerotherapy with 95% ethanol and 208 patients (Group 2) underwent laparoscopic decortication. All patients were followed up with ultrasonography or computerized tomography (CT) for one year. Regression rates, recurrence rates and costs were compared.

RESULTS: Similarity in symptoms (back pain, cloudy urine or mass in abdomen), renal cyst size, and cyst distribution, complete regression rate after treatment between the two groups; A higher recurrence rate, but shorter procedure times and lower cost in Group 1 compared to Group 2. The procedures used for both groups were safe and had minimum complications.

CONCLUSION: Aspiration-sclerotherapy, as well as laparoscopic decortication are effective and safe therapy for symptomatic simple renal cysts. Aspiration-sclerotherapy is more suitable for medium size of renal cysts, while Laparoscopic decortication is superior to the cysts in large sizes.
EDART, a discrete algebraic reconstructing technique for	experimental data obtained with high resolution computed tomography
Authors: Brabant L. , Dierick M. , Pauwels E. , Boone M.N. , Van Hoorebeke L.
Published: December 2019

A novel reconstruction method is presented to improve the image quality of three dimensional (3D) datasets for samples consisting of only one material and surrounding air, obtained with high resolution X-ray Computed Tomography (μCT). It combines discrete tomography with iterative reconstruction algorithms, it is applicable for routine μCT applications and is referred to as the Experimental Discrete Algebraic Reconstruction Technique (EDART). A fast and intuitive method to estimate the attenuation coefficient and segmentation threshold, in case these are unknown, is included. Experimental results illustrate that EDART allows the improvement of the reconstruction quality as compared to standard iterative reconstruction when few projections are available, without significantly increasing the reconstruction time.
Adaptive zooming in X-ray computed tomography
Authors: Dabravolski Andrei , Batenburg Kees Joost , Sijbers Jan
Published: December 2019

BACKGROUND: In computed tomography (CT), the source-detector system commonly rotates around the object in a circular trajectory. Such a trajectory does not allow to exploit a detector fully when scanning elongated objects.

OBJECTIVE: Increase the spatial resolution of the reconstructed image by optimal zooming during scanning.

METHODS: A new approach is proposed, in which the full width of the detector is exploited for every projection angle. This approach is based on the use of prior information about the object's convex hull to move the source as close as possible to the object, while avoiding truncation of the projections.

RESULTS: Experiments show that the proposed approach can significantly improve reconstruction quality, producing reconstructions with smaller errors and revealing more details in the object.

CONCLUSIONS: The proposed approach can lead to more accurate reconstructions and increased spatial resolution in the object compared to the conventional circular trajectory.
A tensor PRISM algorithm for multi-energy CT reconstruction and	comparative studies
Authors: Li Liang , Chen Zhiqiang , Wang Ge , Chu Jiyang , Gao Hao
Published: December 2019

Different from the single-energy CT (SECT), multi-energy CT (MECT) acquires projection data at different energy spectra, which makes that the MECT has more sparsity among the data of separate energy and over energy. In order to maximize utilization of all these sparse characteristics, this paper proposed a new tensor PRISM model to consistently treat a priori knowledge of the low rank, intensity and sparsity with the higher-dimensional tensor technique. The priori knowledge of low rank corresponds to the stationary background and similarity over the energy, and the intensity and sparsity represents the rest of image features at single energy. Then, the regularization and convex minimization problem was solved by tensor unfolding and an extended tensor-based split-Bregman algorithm. Different from the previous PRISM algorithm, the new algorithm mixed and treated different constraints consistently. Numerical experiments have shown that our tensor PRISM approach performs much better than the popular $l_{1}$ regularization algorithm in terms of image quality for MECT.
Modulation of β-adrenergic receptor in rat lung after gamma irradiation
Authors: Qiang Yong-Gang , Liao Yong-Hua , Zhang Xiu-Ping , Li Jian , Huang Zheng
Published: December 2019

OBJECTIVES: To study the effect of γ irradiation on β-adrenergic receptors of the lung.

MATERIALS AND METHODS: Healthy Sprague-Dawley rats were used as an animal model. Cell membrane proteins of lung tissue were harvested after the whole lung received 20 Gy of $^{60}$ Co γ irradiation. $^{125}$ I-labeled iodopindolol ( $^{125}$ I-IPIN) was used as a ligand of β-adrenergic receptors. The numbers of the β-adrenergic receptors were determined by radioligand-receptor binding assay (RBA). Data were compared with irreversible blockage using antagonist bromoacetylalprenololmenthan (BAAM).

RESULTS: The post-radiation RBA assay showed that the number of β-adrenergic receptors in lung tissue decreased at a steady rate. It decreased to 48% of the normal level at the 15th day after irradiation. At 40 days after radiation the level of β-adrenergic receptors started to increase at a steady rate and reached to the normal level around 70 days after radiation. There were significant differences in receptor synthesis, degradation and regeneration rates between irradiation group and BAMM group.

CONCLUSIONS: The whole lung irradiation could severely affect the levels of β-adrenergic receptors. The potential clinical implications of radiation-induced changes of β-adrenergic receptors warrant further investigation.
Multi-energy image sequence fusion based on variable energy X-ray imaging
Authors: Liu Bin , Han Yan , Pan Jinxiao , Chen Ping
Published: December 2019

For complicated structural components characterized by wide X-ray attenuation ranges, the conventional fixed-energy imaging mode cannot obtain all structural information using a single tube voltage. This limitation results in information shortage, because the effective thickness of components along the orientation of the X-ray penetration exceeds the limit of the dynamic range of the X-ray imaging system. To solve this problem, multi-energy image sequence fusion technology has been advanced. In this new method, the tube voltage is adjusted several times by matching the voltage and the effective thickness to obtain all the effective local information on an object. Then, the subset sequences in the multi-energy image sequence are extracted based on the recursive template, and that are fused to reconstruct the full projection information based on linear weighting. An accompanying experiment demonstrates that the new technology can extend the dynamic range of X-ray imaging and provide a complete representation of the internal structure of complicated structural components.
Integration of 3D scale-based pseudo-enhancement correction and	partial volume image segmentation for improving electronic colon cleansing in	CT colonograpy
Authors: Zhang Hao , Li Lihong , Zhu Hongbin , Han Hao , Song Bowen , Liang Zhengrong
Published: December 2019

Orally administered tagging agents are usually used in CT colonography (CTC) to differentiate residual bowel content from native colonic structures. However, the high-density contrast agents tend to introduce pseudo-enhancement (PE) effect on neighboring soft tissues and elevate their observed CT attenuation value toward that of the tagged materials (TMs), which may result in an excessive electronic colon cleansing (ECC) since the pseudo-enhanced soft tissues are incorrectly identified as TMs. To address this issue, we integrated a 3D scale-based PE correction into our previous ECC pipeline based on the maximum a posteriori expectation-maximization partial volume (PV) segmentation. The newly proposed ECC scheme takes into account both the PE and PV effects that commonly appear in CTC images. We evaluated the new scheme on 40 patient CTC scans, both qualitatively through display of segmentation results, and quantitatively through radiologists' blind scoring (human observer) and computer-aided detection (CAD) of colon polyps (computer observer). Performance of the presented algorithm has shown consistent improvements over our previous ECC pipeline, especially for the detection of small polyps submerged in the contrast agents. The CAD results of polyp detection showed that 4 more submerged polyps were detected for our new ECC scheme over the previous one.
Image quality and dose efficiency of high energy phase sensitive	x-ray imaging: Phantom studies
Authors: Wong Molly Donovan , Wu Xizeng , Liu Hong
Published: December 2019

The goal of this preliminary study was to perform an image quality comparison of high energy phase sensitive imaging with low energy conventional imaging at similar radiation doses. The comparison was performed with the following phantoms: American College of Radiology (ACR), contrast-detail (CD), acrylic edge and tissue-equivalent. Visual comparison of the phantom images indicated comparable or improved image quality for all phantoms. Quantitative comparisons were performed through ACR and CD observer studies, both of which indicated higher image quality in the high energy phase sensitive images. The results of this study demonstrate the ability of high energy phase sensitive imaging to overcome existing challenges with the clinical implementation of phase contrast imaging and improve the image quality for a similar radiation dose as compared to conventional imaging near typical mammography energies. In addition, the results illustrate the capability of phase sensitive imaging to sustain the image quality improvement at high x-ray energies and for breast simulating phantoms, both of which indicate the potential to benefit fields such as mammography. Future studies will continue to investigate the potential for dose reduction and image quality improvement provided by high energy phase sensitive imaging.
Edge guided image reconstruction in linear scan CT by weighted	alternating direction TV minimization
Authors: Cai Ailong , Wang Linyuan , Zhang Hanming , Yan Bin , Li Lei , Xi Xiaoqi , Li Jianxin
Published: December 2019

Linear scan computed tomography (CT) is a promising imaging configuration with high scanning efficiency while the data set is under-sampled and angularly limited for which high quality image reconstruction is challenging. In this work, an edge guided total variation minimization reconstruction (EGTVM) algorithm is developed in dealing with this problem. The proposed method is modeled on the combination of total variation (TV) regularization and iterative edge detection strategy. In the proposed method, the edge weights of intermediate reconstructions are incorporated into the TV objective function. The optimization is efficiently solved by applying alternating direction method of multipliers. A prudential and conservative edge detection strategy proposed in this paper can obtain the true edges while restricting the errors within an acceptable degree. Based on the comparison on both simulation studies and real CT data set reconstructions, EGTVM provides comparable or even better quality compared to the non-edge guided reconstruction and adaptive steepest descent-projection onto convex sets method. With the utilization of weighted alternating direction TV minimization and edge detection, EGTVM achieves fast and robust convergence and reconstructs high quality image when applied in linear scan CT with under-sampled data set.
Micro X-ray computed tomography of pits and fissures
Authors: Arhatari Benedicta D. , Andrewartha Kathy , White Maurice
Published: December 2019

BACKGROUND: Most tooth cavities start to develop inside pits and fissures where brushing, saliva, fluoride toothpaste or mouthwashes have no access. Therefore, 3D morphology of pits and fissures is an important subject to be studied in relation to maintaining proper oral hygiene.

OBJECTIVE: This study aimed to present high resolution images of pits and fissures in human teeth using a laboratory-based micro X-ray Computed Tomography (mXCT) and also to present the basic structure evaluation that could be obtained.

METHODS: Three human wisdom teeth were examined. Two different set-ups were used in this study achieving resolution of 14.59 μm (Field of View of 14.9 mm) and resolution of 4.43 μm (FOV of 4.5 mm) respectively. Automated segmentation was performed for further evaluation to distinguish between empty space (pits and fissures) and the filled space (enamel).

RESULTS: The 3D tomography results demonstrate detailed morphology with accurate dimensions and the locations of the pits and fissures, which is important to investigate the relationship with tooth decay that mostly starts deep inside pits and fissures.

CONCLUSIONS: Segmentation from the mXCT imaging of pits and fissures provides obvious visual evidence to help in promotion of oral health and to improve personal tooth care in preventive treatment protocols.
Fan beam image reconstruction with generalized fourier slice	theorem
Authors: Zhao Shuangren , Yang Kang , Yang Kevin
Published: December 2019

For parallel beam geometry the Fourier reconstruction works via the Fourier slice theorem (or central slice theorem, projection slice theorem). For fan beam situation, Fourier slice can be extended to a generalized Fourier slice theorem (GFST) for fan-beam image reconstruction. We have briefly introduced this method in a conference. This paper reintroduces the GFST method for fan beam geometry in details. The GFST method can be described as following: the Fourier plane is filled by adding up the contributions from all fanbeam projections individually; thereby the values in the Fourier plane are directly calculated for Cartesian coordinates such avoiding the interpolation from polar to Cartesian coordinates in the Fourier domain; inverse fast Fourier transform is applied to the image in Fourier plane and leads to a reconstructed image in spacial domain. The reconstructed image is compared between the result of the GFST method and the result from the filtered backprojection (FBP) method. The major differences of the GFST and the FBP methods are: (1) The interpolation process are at different data sets. The interpolation of the GFST method is at projection data. The interpolation of the FBP method is at filtered projection data. (2) The filtering process are done in different places. The filtering process of the GFST is at Fourier domain. The filtering process of the FBP method is the ramp filter which is done at projections. The resolution of ramp filter is variable with different location but the filter in the Fourier domain lead to resolution invariable with location. One advantage of the GFST method over the FBP method is in short scan situation, an exact solution can be obtained with the GFST method, but it can not be obtained with the FBP method. The calculation of both the GFST and the FBP methods are at O(N $^3$ ), where N is the number of pixel in one dimension.
Concentration homeostasis and elements in hair and dried serum	observed by X-ray fluorescence analysis using synchrotron radiation
Authors: Chikawa Jun-ichi , Mouri Yoshitaka , Shima Hiroki , Yamada Kousaku , Yamamoto Hitoshi , Yamamoto Shingo
Published: December 2019

Elemental concentrations in hair and dried serum have been evaluated by X-ray fluorescence analysis using relative concentration independent of specimen thickness. Dried serum samples from 5 male and 5 female subjects given two-week Ca supplementation showed the same concentration for Ca, and for each of the other elements Cl, K, S and P under renal control by parathyroid hormone (PTH). Hair concentrations of these elements have been evaluated for 50 randomly-selected females aged between 30 and 80. It was found that each element has two distinct levels in hair. The content of an element in growing hair must be equal to the inflow of that element into the hair-making cells from serum. Using this principle, the two levels can be attributed to the gating and closing of the ion channels in cell membranes and given as functions of the dried serum standard concentrations. Especially, the difference between [Ca] and [Sr] in hair shows whether Ca channels are gating or closing. The lower level of hair [Ca] $_H$ is normal and is equal to 1/2 of the dried serum [Ca]; only the Ca on serum protein is to be incorporated into the hair in steady-state growth. Store-operated Ca channel gating occurs so as to maintain the normal [Ca] $_H$ . The higher level is seen in cases of calcium deficiency, and implicated in other disease states. Prolonged Ca deficiency causes a higher hair [Ca] $_H$ with Ca channel closing. PTH-operated Ca channel gating induces the Ca $^{2+}$ inflow into the cells to form the hair [Ca] $_H$ upper level and to deteriorate cell functions such as excretion of excess metals by hepatocytes. Hair analysis provides a new diagnostic tool based on cell ion channels.
Combination of CT imaging and endoscopy in diagnosis of	appendicovesical fistula caused by appendiceal adenocarcinoma
Authors: Wang Wenying , Wang Li , Xu Jianfeng , Shi Shufang , Tian Ye , Zhang Yuanyuan
Published: December 2019

The appendiceal diseases, particularly appendicitis, are the most common disorders in the digestive system localized at the right lower quadrant area. However, appendiceal carcinoma with vesico-appendiceal fistula is a rare clinical phenomenon. Lacking specific symptoms, appendiceal carcinomas with fistula formations are often misdiagnosed as acute appendicitis cases. The purpose of this study is to increase awareness of appendiceal neoplasms and appendicovesical fistulas. We reported our experiences in three complex cases related to digestive and urological systems, and reviewed the literature on diagnosis with various X-ray imaging techniques for this lesion. In this report, the first case failed to be diagnosed. The other two patients with appendicovesical fistulas secondary to appendiceal adenocarcinomas were successfully detected with computed tomography (CT) and cystoscopy. The patients recovered after right hemicolectomies and en bloc partial cystectomies and survived without tumor metastasis up to 7-year follow-up. In conclusion, a combined use of CT imaging and endoscopy techniques provides an accurate diagnostic alternative for appendicovesical fistula secondary to appendiceal adenocarcinoma.
The effects of Labisia pumila on postmenopausal	osteoporotic rat model: Dose and time-dependent micro-CT analysis
Authors: Effendy Nadia Mohd , Khamis Mohd Fadhli , Soelaiman Ima Nirwana , Shuid Ahmad Nazrun
Published: December 2019

BACKGROUND: Postmenopausal osteoporosis is best treated and prevented by estrogen replacement therapy (ERT). Although effective, ERT may cause breast cancer, uterine cancer and cardiovascular problems. Labisia pumila var. alata (LP), a herb with phytoestrogenic, antioxidative and anti-inflammatory effects has potential as an ERT alternative.

OBJECTIVE: This study aimed to evaluate micro-CT analysis on the effects of LP supplementation on the trabecular microarchitecture of postmenopausal osteoporosis rat model. Micro-CT is an effective tool in detecting changes in trabecular bone structure and providing a three dimensional information which may replace other conventional bone analysis methods.

METHODS: Ninety-six female Sprague-Dawley rats (4 to 5 months old) were randomly divided into six groups of baseline group (BL) Sham-operated (Sham), ovariectomised control (OVXC), ovariectomised with 64.5 μg/kg of Premarin (ERT), ovariectomised with 20 mg/kg of LP (LP20) and ovariectomised with 100 mg/kg of LP at (LP100). The vehicle (deionized water), Premarin and LP were given via daily oral gavages for three, six and nine weeks of treatment periods. Rats in BL group were euthanized before the start of the study, while other rats were euthanized after completion of their treatments. Femora were dissected out and trabecular bone microarchitecture analysed with micro-CT.

RESULTS: Micro-CT analysis of OVXC rats revealed significant osteoporotic changes in connectivity density, trabecular bone volume, trabecular thickness, trabecular separation and trabecular number. Both ERT and LP were able to reverse all the OVX-induced bone changes with the best results seen with 100 mg/kg of LP for nine weeks duration of treatment.

CONCLUSION: Micro-CT provides accurate and reliable information on trabecular bone parameters which aid in the diagnosis and treatment of osteoporosis. LP supplementation at 100 mg/kg was more effective than ERT in reversing ovariectomy-induced bone changes. Further studies are required to explore the potential of LP as ERT alternative in the treatment and prevention of postmenopausal osteoporosis.
A microelectronic portal imaging device for image guided conformal	microirradiation of murine cancer models
Authors: Price Samantha G. , Silvius Alexander A. , Izaguirre Enrique W.
Published: December 2019

Image guided conformal small animal orthovoltage microirradiators are currently under development to perform radiobiological experiments with preclinical cancer models. An important component of these instruments is the treatment delivery image guidance system, a microelectronic portal imaging device (μEPID). Here, we present the design and implementation of a μEPID, specifically designed and constructed for small animal orthovoltage microirradiators. The μEPID can acquire images in the range of 60 kVp to 320 kVp x-ray photon energies and can endure high doses from orthovoltage beams without radiation damage. The μEPID can acquire 200 μm resolution images at a rate of 17 frames per second for online in vivo co-registration between irradiation beams and small animal anatomy. An exposure with less than 1% of a 2 Gy treatment field is required for imaging, which is an adequate ratio between imaging dose and treatment dose to avoid undesired irradiation of healthy tissue or alteration of the preclinical cancer model. The μEPID was calibrated for microdosimetry with a precision of 4.1% with respect to an ion chamber, used as a gold standard. To validate the in vivo device performance, irradiations of lung, brain, and xenograft breast cancer preclinical models were performed and analyzed.
Analyzed outcome for embolization of hepatic carcinoma by C-arm	angiographic computed tomography
Authors: Kuo Jen-Chen , Lu Nan-Han , Huang Yung-Hui , Hshiao Ming-Hong , Lin Yao-Nan , Lee Chen-Chang , Chao Shih-Yu , Chen Tai-Been
Published: December 2019

PURPOSE: This study evaluated and monitored the outcome of angiographic embolization of hepatic carcinoma by real-time C-arm angiographic computed tomography under number of tumors, size of tumors, and patient's age.

METHODS AND MARTIALS: In total, 142 patients underwent angiographic embolization of hepatic carcinoma. The control group, 71 patients, underwent conventional angiographic (CA) embolization of hepatic carcinoma. The experimental group, 71 patients, underwent C-arm angiographic computed tomography (CCT) embolization of hepatic carcinoma. The numbers of angiographic embolization, number of tumors, size of tumors, and patients ages were recorded for comparisons between groups by analysis of variance (ANOVA) with cross-interaction and the chi-square test (cross table).

RESULTS: The age ranges were 20–84 and 35–84 years old for the experimental and control groups respectively. Average number of angiographic embolizations of hepatic carcinomas were 2.63 ± 1.84 and 5.32 ± 2.01 for the experimental and control groups. The number of angiographic embolizations under number of tumors, size of tumors, and patients ages between groups were significantly different (P< 0.05). The effective analyses of transcatheter arterial chemoembolization (TACE) by CCT were significant by chi-square test (P< 0.05) under ⩽ 3 cm and patients aged ⩽ 60.

CONCLUSION: The main advantage by CCT for undergoing TACE under tumor size smaller than 3 cm and numbers of tumor smaller 3 times were more significantly effective than those by CA. The CCT combined with TACE had high potentially reduced numbers of undergoing TACE.
Top-level design and pilot analysis of low-end CT scanners based	on linear scanning for developing countries
Authors: Liu Fenglin , Yu Hengyong , Cong Wenxiang , Wang Ge
Published: December 2019

The goal is to develop new architectures for computed tomography (CT) which are at an ultra-low-cost for developing countries, especially in rural areas. The proposed general scheme is inspired by the recently developed compressive sensing and interior tomography techniques, where the data acquisition system targets a region of interest (ROI) to acquire limited and truncated data. Similar to linear tomosynthesis, the source and detector are translated in opposite directions but in contrast to conventional tomosynthesis, our proposal is for either ROI reconstruction with one or more localized linear scans or global reconstruction by combining multiple ROI reconstructions. In other words, the popular slip ring is replaced by a translation based setup, and the instrumentation cost is reduced by a relaxation of the imaging speed requirement. The various translational scanning modes are theoretically analyzed, and the scanning parameters are optimized. The numerical simulation results from different numbers of linear scans confirm the feasibility of the proposed scheme, and suggest two preferred low-end systems for horizontal and vertical patient positions respectively. Ultra-low-cost x-ray CT is feasible with our proposed combination of linear scanning, compressive sensing, and interior tomography. The proposed architecture can be tailored into permanent, movable, or reconfigurable systems as desirable. Advanced image registration and spectral imaging features can be included as well.
Aortic dual-energy CT angiography with low contrast medium	injection rate
Authors: Liu Jie , Lv Pei-Jie , Wu Runze , Zhang Yong-Gao , Hu Li-Li , Hou Ping , Gao Jian-Bo
Published: December 2019

The contrast medium (CM) induced nephropathy required new CT imaging protocol. This study evaluated the feasibility of low contrast medium (CM) volume and injection flow using aortic dual-energy CT (DECT) angiography with non-linear blending technique. Sixty patients were randomly assigned to two groups: control group (n=30), single-energy CT 70 ml CM at injection rate of 5 ml/s; study group (n=30), DECT mode, 0.5 ml per kg of patient weight CM at injection rate=(weight × 0.5 ml/kg)/(4+scan time). Non-linear blending technique was used for dual-energy images. Mean attention, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of aorta were compared. The level of visible renal artery branches was scored. There was no significant difference between the two groups in the mean aortic attention, SNR and CNR (all P > 0.05). Significant difference was showed in CM injection rate (p < 0.001) and volume (P < 0.001). The renal artery score had no statistically significant difference (P=0.771). Compared conventional scan and CM injection protocol, DECT with non-linear blending technique maintained the image quality of aortic CT angiography with reduced CM volume and flow rate, which could reduce the risks associated with CM injection.
Scattering correction algorithm in the PET sinogram using the	factorial design of experimental method: A phantom study
Authors: Chen Huei-Yung , Lu Nan-Han , Huang Yung-Hui , Chen Tai-Been
Published: December 2019

Positron emission tomography (PET) had been utilized to image gene therapy, estimate tumor growth, detect neural function of the brain, and diagnose disease. However, sinogram noise always results inaccurate PET images. The factorial design of experiment (DOE), a statistical method, was applied to investigate, correct and estimate the fraction of scattering of 2D sinogram in PET. The DOE was included as factors of angle views and scatter media with two levels designed. The PET sinogram after scattering correction was then reconstructed by filtered back projection (FBP). Both Ge-68 uniform phantom and Jaszczak anthropomorphic torso phantom were applied to exam the performance of presented scattering correction algorithm. The signal-to-noise ratio (SNR), standard deviation (STD) of background, and full width at half maximum (FWHM), and uniformity test were applied to validate the performance of presented method. The proposed method provides a narrower FWHM, smaller STD of the background, higher SNR and better uniformity than those of original protocols. This method should be tested for accuracy and feasibility with three-dimensional phantoms or real animal studies and consideration effects of cross-talk between slices in future work.
Convex hull matching and hierarchical decomposition for	multimodality medical image registration
Authors: Yang Jian , Fan Jingfan , Fu Tianyu , Ai Danni , Zhu Jianjun , Li Qin , Wang Yongtian
Published: December 2019

This study proposes a novel hierarchical pyramid strategy for 3D registration of multimodality medical images. The surfaces of the source and target volume data are first extracted, and the surface point clouds are then aligned roughly using convex hull matching. The convex hull matching registration procedure could align images with large-scale transformations. The original images are divided into blocks and the corresponding blocks in the two images are registered by affine and non-rigid registration procedures. The sub-blocks are iteratively smoothed by the Gaussian kernel with different sizes during the registration procedure. The registration result of the large kernel is taken as the input of the small kernel registration. The fine registration of the two volume data sets is achieved by iteratively increasing the number of blocks, in which increase in similarity measure is taken as a criterion for acceptation of each iteration level. Results demonstrate the effectiveness and robustness of the proposed method in registering the multiple modalities of medical images.
Energetic electrons, hard x-ray emission and MHD activity studies	in the IR-T1 tokamak
Authors: Agah K. Mikaili , Ghoranneviss M. , Elahi A. Salar
Published: December 2019

Determinations of plasma parameters as well as the Magnetohydrodynamics (MHD) activity, energetic electrons energy and energy confinement time are essential for future fusion reactors experiments and optimized operation. Also some of the plasma information can be deduced from these parameters, such as plasma equilibrium, stability, and MHD instabilities. In this contribution we investigated the relation between energetic electrons, hard x-ray emission and MHD activity in the IR-T1 Tokamak. For this purpose we used the magnetic diagnostics and a hard x-ray spectroscopy in IR-T1 tokamak. A hard x-ray emission is produced by collision of the runaway electrons with the plasma particles or limiters. The mean energy was calculated from the slope of the energy spectrum of hard x-ray photons.
Studies of Multilayers and Thin-Foil X-Ray Mirrors Using a Soft X-Ray Diffractometer
Authors: Christensen F. E. , Hornstrup A. , Frederiksen P. , Grundsøe P. , Henrichsen S. , Jacobsen E. , Jonasson P. , Madsen M. M. , Nilsson C. , Schnopper H. W. , Westergaard N. J. , Ørup P.
Published: December 2019

A versatile x-ray diffractometer is described in detail. Two applications to the study of x-ray optical elements are presented. The first is a Bragg reflection study of state-of-the-art multilayers deposited both on conventional Si-wafer substrates and on superpolished substrates such as fused quartz and electroless nickel. These data are compared to data previously obtained at FeKα. The second study is a reflectivity and scattering study of various thin-foil x-ray reflectors proposed for up-coming x-ray satellite missions. All the data have been obtained at MgKα = 1.2536 keV.
Focusing and Collimation of X Rays Using Microchannel Plates: An Experimental Investigation
Authors: Chapman H. N. , Nugent K. A. , Wilkins S. W. , Davis T. J.
Published: December 2019

Focusing and collimation of 8 keV x rays has been demonstrated using microchannel plate (MCP) blanks with cylindrical channels. The focusing effect arises from total external reflection of x rays at the interior surfaces of the channels of a MCP and has been described previously by the authors. Point to point focusing was observed with flat and curved MCPs, and collimation from a point source to a quasi-parallel beam was observed with a curved MCP. Intensity profiles at the image plane and at other planes behind a flat MCP were obtained for a 20 × 40 μm2 x-ray source, and agree well with theoretical predictions. The flux in a 40-μm-diameter collector in the image plane was compared with the flux in the same plane, but without a MCP. The relative gain in flux increases linearly with the source to MCP distance, as predicted. A maximum relative gain in flux of 18 ± 1 was observed for a source to detector distance of 50 cm.
Thermal X-Ray Emission from Ion-Beam-Heated Matter
Authors: Murakami M. , Meyer-Ter-Vehn J. , Ramis R.
Published: December 2019

The conversion of ion beam energy into thermal x-ray radiation by means of stretched cylindrical plasma volumes is studied by analytic modeling and numerical simulation. The analysis is restricted to one-dimensional radiation hydrodynamics. Scaling relations for different materials are derived. Due to equation-of-state properties, high-Z material turns out superior for achieving high conversion efficiency. The paper provides practical answers for thermal x-ray generation with intense heavy ion beams. Deposition powers in the order of 10l6 W/g are required for applications to ion beam inertial confinement fusion.
Characterization of Pinhole Transmission Gratings
Authors: Eidmann K. , Kühne M. , Müller P. , Tsakiris G. D.
Published: December 2019

Gold pinhole transmission gratings fabricated by Heidenhain GmbH primarily for the purpose of studying the radiation of intense soft x-ray sources have been tested with the synchrotron radiation of BESSY. Typical results for the spectral dependence of the grating efficiency into the various diffraction orders are presented in a wavelength region ranging from 4 to 20 nm. Also the influence of grating irregularities has been studied. With appropriate grating parameters quite good agreement between the experimental results and theoretical Calculations is Obtained.
X-Ray Study of State-of-the-Art Small (d-Spacing W/B4C Multilayers
Authors: Christensen F. E. , Shou-Hua Zhu , Hornstrup A. , Schnopper H. W. , Plag P. , Wood J.
Published: December 2019

Two small d-spacing W/B4C multilayers have been studied at three different x-ray energies CuKα1, AlKα, and FeLα. Measurements of total reflection, specular and mosaic Bragg reflection, and high resolution studies were made at Cu Kα1. Multilayer parameters are deduced from the data and the perfection of the multilayer structure is evaluated by Comparison with model Calculations.
Influence of Exposure Time on the Sensitivity of Kodak 101 X-Ray Film
Authors: Nishimura H. , Eidmann K. , Sugimoto K. , Schwanda W. , Toyoda T. , Taniguchi K. , Kato Y. , Nakai S.
Published: December 2019

The sensitivity of Kodak 101-07 film to 1-keV x-ray photons was measured at extremely different dose rates by using two sources: a laser-produced plasma with nanosecond emission and a CW x-ray source. Whereas almost equal sensitivities were obtained at lower exposures, the γ values and the saturation densities at higher exposures differed in the two cases, showing the existence of reciprocity failure.
Characterization of a Multilayer Coated Laminar Reflection Grating at λ = 0.154 nm
Authors: Puik E. J. , van der Wiel M. J. , Lambooy P. , Verhoeven J. , Christensen F. E. , Padmore H. A.
Published: December 2019

A laminar grating of 1200 1/mm was coated with an x-ray reflecting multilayer coating. The multilayer coating consisted of 41 alternating layers of ReW and C having a period of 2.3 nm. In this paper we report on diffraction measurements of the coated grating at the CuKα emission line. We describe its reflection behavior using a simple theoretical model and derive two diffraction conditions, corresponding to the grating relation and the Bragg law, for which peak intensities are to be observed. We find that grating order efficiencies are modulated by the multilayer reflection.
Tissue Characterization Using Low Angle X-Ray Scattering
Authors: Speller R. D. , Royle G. J.
Published: December 2019

Diffraction studies of polyenergetic x-ray beams at low angles can be used to investigate tissues. Recent evidence on molecular form factors indicates that unique “fingerprints” exist for materials in the form of scattering information at angles between 0° and 10°. We have measured low angle scattering information in the form of energy spectra using a tungsten target x-ray source. It is shown that for certain scattering angles these spectra are highly structured, where this structure can be related to tissue type. We propose that these measurements will be diagnostic for various conditions such as osteoporosis or gall stone disease.
The Detective Quantum Efficiency of Television X-Ray Detectors
Authors: Kalata Kenneth , Stanton Martin , Phillips Walter
Published: December 2019

Television area x-ray detectors measure the incident x-ray flux as a function of position. The detective quantum efficiency (DQE) expresses the precision of the flux measurement relative to that of an ideal detector. The gain, quantum efficiency, and statistical and noise properties of x-ray convertors, image intensifiers, fiber optics or lenses, and CCD sensors or vidicon tubes are described and used to develop a formulation of the DQE for a general television detector.
Multilayer X-Ray Mirror Calibration by an Energy Dispersive Method Using an X-Ray Tube and a Si(Li) Detector: Absolute Reflectivity, Energy Band Pass, and Overlapping Order Determination
Authors: Dhez P. , Duval H. , Malaurent J. C.
Published: December 2019

We describe under which conditions the x-ray energy dispersive method permits absolute reflectivity, energy band pass, and overlapping order determination on artificial multilayers. For such measurements a Si (Li) detector and a simple x-ray tube are used. Examples of experimental results on W/Si and Mo/Si x-ray mirrors are given for the photon energy range from 5 to 40 KeV.
Wafer Cost Analysis for a Soft X-Ray Projection Lithography System
Authors: Ceglio N. M. , Hawryluk A. M.
Published: December 2019

We present a baseline analysis of issues affecting the economic viability of Soft X-Ray Projection Lithography (SXPL). This analysis is intended to serve as a starting point, and to provide an initial assessment of the relative importance of cost factors in a SXPL system. We presume a “conventional” SXPL system design and focus on wafer exposure costs. A baseline model for system component costs and performance specifications is presented, and the dependence of wafer exposure cost on elements of the model is analyzed. Within the guidelines of our model, we find that direct cost items (e.g., cost of the laser driver) are not nearly as critical as technical performance parameters (e.g., mirror reflectivity) in determining wafer exposure costs.
Analysis of Impurity Content and Transport in Tokamak Plasmas Using Low-Resolution XUV Spectra
Authors: Zwicker Andrew P. , Finkenthal Michael , Warren Moos H.
Published: December 2019

Two experiments were performed to determine whether impurity content and transport information could be extracted from low-resolution XUV spectra recorded from a simple spectroscopic diagnostic that utilized a flat multilayer mirror as the dispersive element. The first experiment, at the DIII-D tokamak, compared MLM spectra to higher-resolution spectra and found that the low-resolution MLM spectra were sufficient to distinguish changes in impurity emission patterns. The results demonstrated the feasibility of building simple MLM-based diagnostics for impurity monitors in the harsh environment of future tokamaks. The second experiment, at the Texas Experimental tokamak, compared MLM spectra to those produced by an impurity transport code coupled to a collisional-radiative model. The comparison showed that it is possible to distinguish changes in impurity transport from low-resolution MLM spectra.
The Effect of Linear Interpolation of the Filtered Projections on Image Noise in X-Ray Computed Tomography
Authors: Davis Graham Roy
Published: December 2019

Measured values for image noise variance in x-ray computed tomography were found to be less than half of the values predicted by published formulas. This phenomenon had previously been attributed qualitatively to the use of linear interpolation of the filtered projections in the back projection process. An analysis of the reconstruction process has allowed the derivation of a formula for image noise variance which incorporates the effect of this interpolation, giving results which are less than 50% of the previously predicted values. This formula has been tested with images of a perspex rod produced by an x-ray microtomography scanner and with a similar image derived from mathematically modeled projection data. The predicted noise variance was within 1% of the measured values for both the simulated and the experimental data.
Application of Structural Phase Transitions in X-Ray Spectroscopy
Authors: Geppert U.
Published: December 2019

A method is proposed for measuring different energy ranges of x-ray radiation with the same spectrometer crystal employing structural phase transitions. When the crystal temperature is varied beyond the phase transition temperature, the crystal symmetry is altered predictably and reversibly. Thus, with no change in the angle of glancing incidence, the x-ray beam hits in different crystal phases different lattice planes which correspond to different energy ranges. The advantage is that neither large motions nor exchanging the spectrometer crystal is necessary during observations.
Nondestructive Evaluation of Millimeter Scale Engineered Structures Using Synchrotron X-Ray Microtomography
Authors: Hmelo Anthony B.
Published: December 2019

Synchrotron x-ray microtomography has matured into a practical tool for the metrology of small specimens, featuring a spatial resolution of a few micrometers. In this paper, the author examines the practice of monochromatic x-ray tomography, emphasizing the characteristics of synchrotron radiation sources that have enabled the evolution of this new imaging technology. These principles are illustrated using reconstructions of millimeter scale engineered structures fabricated from low atomic weight materials. These structures include spherical shells, considered as model inertial confinement fusion targets, and examples of laser-welded aluminum alloys.
Large-Area Pressure-Enduring Entrance Windows for Soft X-Ray Regime
Authors: Mutikainen Risto , Viitanen Veli-Pekka , Nenonen Seppo
Published: December 2019

A technology capable of producing large-area pressure-tolerant x-ray entrance windows of submicrometer thickness is presented. It is based on successive tungsten griddings to support a multilayered membrane consisting of polyimide, aluminum, and aluminum nitride. The aspects of design and fabrication processes are discussed with emphasis on the window foil fabrication. The performance of the windows is presented in terms of x-ray transmission, gas leak, pressure endurance, and radiation hardness properties.
X-Ray Sources Based on Subpicosecond-Laser-Produced Plasmas
Authors: Kieffer J. C. , Chaker M.
Published: December 2019

The production of an efficient user friendly ultrafast x-ray source requires an understanding of the role of the various factors which affect the x-ray emission. Here we examine several issues which control the source brightness and the pulse duration. Picosecond time-resolved, high spectral resolution spectroscopy is used to study plasmas produced by a subpicosecond laser pulse with intensity between 1016 W/cm2 and 5 × 1018 W/cm2.