Journal of X-Ray Science and Technology - Volume 28, issue 3

Authors: Lei, Pinggui | Huang, Zhaoshu | Liu, Guoli | Wang, Pingxian | Song, Wen | Mao, Jujiang | Shen, Guiquan | Zhou, Shi | Qian, Wei | Jiao, Jun

Article Type: Research Article

Abstract: OBJECTIVE: To evaluate the clinical and computed tomographic (CT) features in the patients with COVID-19 pneumonia confirmed by the real-time reverse transcriptase polymerase chain reaction (rRT-PCR) amplification of the viral DNA from a sputum sample. MATERIAL AND METHODS: Clinical information and CT findings of a total of 14 patients with COVID-19 infection (age range, 12–83 years; females 6) were analyzed retrospectively. The clinical information includes the history of exposure, laboratory results, and the symptoms (such as fever, cough, headache, etc.); CT findings of chest include the extension and distribution of lesion, the ground-glass opacity (GGO), consolidation, bronchovascular enlarged, …irregular linear appearances, pleural effusion, and lymphadenopathy. RESULTS: Eight patients had the exposure history for recent travel to Wuhan of Hubei province (8/14, 57%), 6 had the exposure to patients with COVID-19 infection. Significant statistical differences were observed in lymphocyte percentage decreased and C-reactive protein elevated (p  = 0.015). Seven patients had fever, 7 had cough, 2 had headache, 3 had fatigue, 1 had body soreness, 3 had diarrhea, and 2 had no obvious symptoms. In chest CT examination, 10 patients were positive (10/14, 71.43%). Among these patients, 9 had lesions involving both lungs (9/10, 90%), 8 had lesions involving 4 to 5 lobes (8/10, 80%). Most of lesions were distributed peripherally and the most significant lesions were observed in the right lower lobe in 9 patients (9/10, 90%). Nodules were observed in 5 patients (5/10, 50%); GGO, consolidation, and bronchovascular enlarged were shown in 9 patients (9/10, 90%); irregular linear appearances were revealed in 7 patients (7/10, 70%); and pleural effusions were exhibited in 2 patients (2/10, 20%). Last, no patients showed lymphadenopathy. CONCLUSION: There were some typical CT features for diagnosis of COVID-19 pneumonia. The radiologists should know these CT findings and clinical information, which could help for accurate analysis in the patients with 2019 novel coronavirus infection. Show more

Keywords: Novel coronavirus, virus pneumonia, COVID-19 infection, computed tomographic findings

DOI: 10.3233/XST-200670

Citation: Journal of X-Ray Science and Technology, vol. 28, no. 3, pp. 369-381, 2020

Authors: Wei, Jiangping | Yang, Hong | Lei, Pinggui | Fan, Bing | Qiu, Yingying | Zeng, Bingliang | Yu, Peng | Lv, Jian | Jian, Yinchao | Wan, Chengfeng

Article Type: Research Article

Abstract: PURPOSE: To analyze clinical and thin-section computed tomographic (CT) data from the patients with coronavirus disease (COVID-19) to predict the development of pulmonary fibrosis after hospital discharge. MATERIALS AND METHODS: Fifty-nine patients (31 males and 28 females ranging from 25 to 70 years old) with confirmed COVID-19 infection performed follow-up thin-section thorax CT. After 31.5±7.9 days (range, 24 to 39 days) of hospital admission, the results of CT were analyzed for parenchymal abnormality (ground-glass opacification, interstitial thickening, and consolidation) and evidence of fibrosis (parenchymal band, traction bronchiectasis, and irregular interfaces). Patients were analyzed based on the evidence of …fibrosis and divided into two groups namely, groups A and B (with and without CT evidence of fibrosis), respectively. Patient demographics, length of stay (LOS), rate of intensive care unit (ICU) admission, peak C-reactive protein level, and CT score were compared between the two groups. RESULTS: Among the 59 patients, 89.8% (53/59) had a typical transition from early phase to advanced phase and advanced phase to dissipating phase. Also, 39% (23/59) patients developed fibrosis (group A), whereas 61% (36/59) patients did not show definite fibrosis (group B). Patients in group A were older (mean age, 45.4±16.9 vs. 33.8±10.2 years) (P  = 0.001), with longer LOS (19.1±5.2 vs. 15.0±2.5 days) (P  = 0.001), higher rate of ICU admission (21.7% (5/23) vs. 5.6% (2/36)) (P  = 0.061), higher peak C-reactive protein level (30.7±26.4 vs. 18.1±17.9 mg/L) (P  = 0.041), and higher maximal CT score (5.2±4.3 vs. 4.0±2.2) (P  = 0.06) than those in group B. CONCLUSIONS: Pulmonary fibrosis may develop early in patients with COVID-19 after hospital discharge. Older patients with severe illness during treatment were more prone to develop fibrosis according to thin-section CT results. Show more

Keywords: COVID-19, severe acute respiratory syndrome, coronavirus, tomography, X-ray computed

DOI: 10.3233/XST-200685

Citation: Journal of X-Ray Science and Technology, vol. 28, no. 3, pp. 383-389, 2020

Authors: Zheng, Qiuting | Lu, Yibo | Lure, Fleming | Jaeger, Stefan | Lu, Puxuan

Article Type: Research Article

Abstract: Recently, COVID-19 has spread in more than 100 countries and regions around the world, raising grave global concerns. COVID-19 transmits mainly through respiratory droplets and close contacts, causing cluster infections. The symptoms are dominantly fever, fatigue, and dry cough, and can be complicated with tiredness, sore throat, and headache. A few patients have symptoms such as stuffy nose, runny nose, and diarrhea. The severe disease can progress rapidly into the acute respiratory distress syndrome (ARDS). Reverse transcription polymerase chain reaction (RT-PCR) and Next-generation sequencing (NGS) are the gold standard for diagnosing COVID-19. Chest imaging is used for cross validation. Chest …CT is highly recommended as the preferred imaging diagnosis method for COVID-19 due to its high density and high spatial resolution. The common CT manifestation of COVID-19 includes multiple segmental ground glass opacities (GGOs) distributed dominantly in extrapulmonary/subpleural zones and along bronchovascular bundles with crazy paving sign and interlobular septal thickening and consolidation. Pleural effusion or mediastinal lymphadenopathy is rarely seen. In CT imaging, COVID-19 manifests differently in its various stages including the early stage, the progression (consolidation) stage, and the absorption stage. In its early stage, it manifests as scattered flaky GGOs in various sizes, dominated by peripheral pulmonary zone/subpleural distributions. In the progression state, GGOs increase in number and/or size, and lung consolidations may become visible. The main manifestation in the absorption stage is interstitial change of both lungs, such as fibrous cords and reticular opacities. Differentiation between COVID-19 pneumonia and other viral pneumonias are also analyzed. Thus, CT examination can help reduce false negatives of nucleic acid tests. Show more

Keywords: 2019-novel Coronaviruses (2019-nCoV), SARS-CoV-2, COVID-19, Computed Tomography (CT), ground glass opacity (GGO), differentiation of pneumonia

DOI: 10.3233/XST-200687

Citation: Journal of X-Ray Science and Technology, vol. 28, no. 3, pp. 391-404, 2020

Authors: Vedantham, Srinivasan | Tseng, Hsin-Wu | Konate, Souleymane | Shi, Linxi | Karellas, Andrew

Article Type: Research Article

Abstract: BACKGROUND: High-resolution, low-noise detectors with minimal dead-space at chest-wall could improve posterior coverage and microcalcification visibility in the dedicated cone-beam breast CT (CBBCT). However, the smaller field-of-view necessitates laterally-shifted detector geometry to enable optimizing the air-gap for x-ray scatter rejection. OBJECTIVE: To evaluate laterally-shifted detector geometry for CBBCT with clinical projection datasets that provide for anatomical structures and lesions. METHODS: CBBCT projection datasets (n  = 17 breasts) acquired with a 40×30 cm detector (1024×768-pixels, 0.388-mm pixels) were truncated along the fan-angle to emulate 20.3×30 cm, 22.2×30 cm and 24.1×30 cm detector formats and correspond to 20, 120, 220 pixels overlap in …conjugate views, respectively. Feldkamp-Davis-Kress (FDK) algorithm with 3 different weighting schemes were used for reconstruction. Visual analysis for artifacts and quantitative analysis of root-mean-squared-error (RMSE), absolute difference between truncated and 40×30 cm reconstructions (Diff ), and its power spectrum (PSDiff ) were performed. RESULTS: Artifacts were observed for 20.3×30 cm, but not for other formats. The 24.1×30 cm provided the best quantitative results with RMSE and Diff (both in units of μ , cm-1 ) of 4.39×10-3 ±1.98×10-3 and 4.95×10-4 ±1.34×10-4 , respectively. The PSDiff (>0.3 cycles/mm) was in the order of 10-14 μ 2 mm3 and was spatial-frequency independent. CONCLUSIONS: Laterally-shifted detector CBBCT with at least 220 pixels overlap in conjugate views (24.1×30 cm detector format) provides quantitatively accurate and artifact-free image reconstruction. Show more

Keywords: Breast, mammography, X-Ray computed tomography (CT), cone-beam CT, breast CT

DOI: 10.3233/XST-200651

Citation: Journal of X-Ray Science and Technology, vol. 28, no. 3, pp. 405-426, 2020

Authors: Cao, Keyan | Meng, Gongjie | Wang, Zhiqiong | Liu, Yefan | Liu, Haoli | Sun, Liangliang

Article Type: Research Article

Abstract: Recently, lung cancer has been paid more and more attention. People have reached a consensus that early detection and early treatment can improve the survival rate of patients. Among them, pulmonary nodules are the important reference for doctors to determine the lung health. With the continuous improvement of CT image resolution, more suspected pulmonary nodule information appears from the impact of chest CT. How to relatively and accurately locate the suspected nodule location from a large number of CT images has brought challenges to the doctor’s daily diagnosis. To solve the problem that the original DBSCAN clustering algorithm needs manual …setting of the threshold, this paper proposes a region growing algorithm and an adaptive DBSCAN clustering algorithm to improve the accuracy of pulmonary nodule detection. The image is roughly processed and ROI (Regions of Interest) region is roughly extracted by CLAHE transform. The region growing algorithm is used to roughly process the adjacent region’s expansibility and the suspected region in ROI , and mark the center point in the region and the boundary point of its point set. The mean value of region range is taken as the threshold value of DBSCAN clustering algorithm. The center of the point domain is used as the starting point of clustering, and the rough set of points is used as the MinPts threshold. Finally, the clustering results are labeled in the initial CT image. Experiments show that the pulmonary nodule detection method proposed in this paper effectively improves the accuracy of the detection results. Show more

Keywords: Pulmonary nodule detection, adaptive DBSCAN, region growing algorithm

DOI: 10.3233/XST-200656

Citation: Journal of X-Ray Science and Technology, vol. 28, no. 3, pp. 427-447, 2020

Authors: Sun, Zongqiong | Hu, Shudong | Ge, Yuxi | Wang, Jun | Duan, Shaofeng | Song, Jiayang | Hu, Chunhong | Li, Yonggang

Article Type: Research Article

Abstract: PURPOSE: To predict programmed death-ligand 1 (PD-L1) expression of tumor cells in non-small cell lung cancer (NSCLC) patients by using a radiomics study based on CT images and clinicopathologic features. MATERIALS AND METHODS: A total of 390 confirmed NSCLC patients who performed chest CT scan and immunohistochemistry (IHC) examination of PD-L1 of lung tumors with clinic data were collected in this retrospective study, which were divided into two cohorts namely, training (n  = 260) and validation (n  = 130) cohort. Clinicopathologic features were compared between two cohorts. Lung tumors were segmented by using ITK-snap kit on CT images. Total 200 …radiomic features in the segmented images were calculated using in-house texture analysis software, then filtered and minimized by least absolute shrinkage and selection operator (LASSO) regression to select optimal radiomic features based on its relevance of PD-L1 expression status in IHC results and develop radiomics signature. Radiomics signature and clinicopathologic risk factors were incorporated to develop prediction model by using multivariable logistic regression analysis. The receiver operating characteristic (ROC) curves were generated and the areas under the curves (AUC) were reckoned to predict PD-L1 expression in both training and validation cohorts. RESULTS: In 200 extracted radiomic features, 9 were selected to develop radiomics signature. In univariate analysis, PD-L1 expression of lung tumors was significantly correlated with radiomics signature, histologic type, and histologic grade (p  < 0.05, respectively). However, PD-L1 expression was not correlated with gender, age, tumor location, CEA level, TNM stage, and smoking (p  > 0.05). For prediction of PD-L1 expression, the prediction model that combines radiomics signature and clinicopathologic features resulted in AUCs of 0.829 and 0.848 in the training and validation cohort, respectively. CONCLUSION: The prediction model that incorporates the radiomics signature and clinical risk factors has potential to facilitate the individualized prediction of PD-L1 expression in NSCLC patients and identify patients who can benefit from anti-PD-L1 immunotherapy. Show more

Keywords: Lung cancer, PD-L1 immunotherapy, radiomics, CT, prediction model

DOI: 10.3233/XST-200642

Citation: Journal of X-Ray Science and Technology, vol. 28, no. 3, pp. 449-459, 2020

Authors: Oumar, Alio Ahmat | Erçelebi, Ergun

Article Type: Research Article

Abstract: OBJECTIVE: Since in-house phantoms may provide effective quality control for gamma cameras in clinical settings, this study aims to assess an in-house phantom designed to perform quality control tests of a gamma camera using locally available, affordable materials. This is of particular importance in developing countries where scientific support may not be readily available. MATERIALS AND METHODS: The phantom was made from cylindrical plexiglass with a diameter of 230 mm and thickness of 60 mm. The phantom design was based on NEMA recommendations and only used materials that are locally available and generally accessible to most nuclear medicine departments and …require minimal engineering instruction. RESULTS: The phantom demonstrated high levels of reliability and accuracy. The integral uniformity range was between 1.93% and 2.40%. The differential uniformity ranged between 1.48% and 1.70%. CONCLUSION: This work demonstrates that in-house phantoms are capable of monitoring gamma camera performance. This approach is particularly useful when scientific support is not easily accessible and when commercial phantoms are not readily available. Show more

Keywords: Gamma camera, phantom, quality control, performance test, uniformity

DOI: 10.3233/XST-190610

Citation: Journal of X-Ray Science and Technology, vol. 28, no. 3, pp. 461-470, 2020

Authors: Sun, Guoliang | Ding, Beichen | Yu, Gan | Chen, Liang | Wang, Zhihua | Wang, Shaogang | Chen, Xiaoping

Article Type: Research Article

Abstract: BACKGROUND: Surgery is usually recommended to treat retroperitoneal tumors. However, complete surgical resections often remain challenging. OBJECTIVE: To assess the assistant role of three-dimensional (3D) imaging and printing model in retroperitoneal tumor resection, as well as compare the difference between 3D printing and computed tomography (CT) in preoperative planning and confidence building. METHODS: We admitted a patient with retroperitoneal mass (13.0×6.4×14.8 cm) adjacent to important abdominal blood vessels whose surgery was thought to be difficult. 3D printing and CT was arranged. A novel questionnaire and scoring system consisting of surgery difficulty and safety were designed to compare …doctors understanding and confidence for surgery based on 3D printing and CT. Twenty-four doctors completed the scoring table based on CT and then 3D imaging, respectively. Paired t-test was applied for statistics analysis. RESULTS: Preoperative evaluation based on 3D printing indicated that the tumor could be removed completely. The operation lasted 120 minutes to successfully remove the tumor and the estimated blood loss was less than 100 ml. Scores based on 3D printing is significantly higher than CT in difficulty and safety of surgery (p  < 0.001). Interestingly, the junior doctors seem to benefit more from 3D printing than the senior doctors. CONCLUSIONS: 3D imaging and printing model provides greater help for preoperative planning and confidence building than using CT in resection of retroperitoneal tumor, especially for the junior doctors. Show more

Keywords: Retroperitoneal tumor, preoperative planning, surgery, three-dimensional printing

DOI: 10.3233/XST-190636

Citation: Journal of X-Ray Science and Technology, vol. 28, no. 3, pp. 471-480, 2020

Authors: Khan, Sajid Ullah | Khan, Imran Ullah | Ullah, Imdad | Saif, Naveed | Ullah, Irfan

Article Type: Research Article

Abstract: In this paper, we present a review of the research literature regarding applying X-ray imaging of baggage scrutiny at airport. It discusses multiple X-ray imaging inspection systems used in airports for detecting dangerous objects inside the baggage. Moreover, it also explains the dual energy X-ray image fusion and image enhancement factors. Different types of noises in digital images and noise models are explained in length. Diagrammatical representations for different noise models are presented and illustrated to clearly show the effect of Poisson and Impulse noise on intensity values. Overall, this review discusses in detail of Poisson and Impulse noise, as …well as its causes and effect on the X-ray images, which create un-certainty for the X-ray inspection imaging system while discriminating objects and for the screeners as well. The review then focuses on image processing techniques used by different research studies for X-ray image enhancement, de-noising, and their limitations. Furthermore, the most related approaches for noise reduction and its drawbacks are presented. The methods that may be useful to overcome the drawbacks are also discussed in subsequent sections of this paper. In summary, this review paper highlights the key theories and technical methods used for X-ray image enhancement and de-noising effect on X-ray images generated by the airport baggage inspection system. Show more

Keywords: Airport baggage inspection, X-ray imaging, poisson noise, image enhancement, noise reduction, noise causes

DOI: 10.3233/XST-200663

Citation: Journal of X-Ray Science and Technology, vol. 28, no. 3, pp. 481-505, 2020

Authors: Wang, Qian | Megherbi, Najla | Breckon, Toby P.

Article Type: Research Article

Abstract: BACKGROUND: Threat Image Projection (TIP) is a technique used in X-ray security baggage screening systems that superimposes a threat object signature onto a benign X-ray baggage image in a plausible and realistic manner. It has been shown to be highly effective in evaluating the ongoing performance of human operators, improving their vigilance and performance on threat detection. OBJECTIVE: With the increasing use of 3D Computed Tomography (CT) in aviation security for both hold and cabin baggage screening a significant challenge arises in extending TIP to 3D CT volumes due to the difficulty in 3D CT volume segmentation and …the proper insertion location determination. In this paper, we present an approach for 3D TIP in CT volumes targeting realistic and plausible threat object insertion within 3D CT baggage images. METHOD: The proposed approach consists of dual threat (source) and baggage (target) volume segmentation, particle swarm optimisation based insertion determination and metal artefact generation. In our experiments, real baggage data collected from airports are used to generate TIP volumes for evaluation. We also propose a TIP quality score metric to automatically estimate the quality of generated TIP volumes. RESULT: In our experiments with real baggage CT volumes and varying threat items, 90.25% of the generated TIP volumes are graded as good by human evaluation, 7% of them are of medium quality with minor flaws and 2.75% of them are bad . CONCLUSION: Qualitative evaluations on real 3D CT baggage imagery show that our approach is able to generate realistic and plausible TIP which are indiscernible from real CT volumes and the TIP quality scores are consistent with human evaluations. Show more

Keywords: Threat image projection, X-ray computed tomography, CT volume segmentation, Baggage security screening, Particle swarm optimisation, TIP quality score

DOI: 10.3233/XST-200654

Citation: Journal of X-Ray Science and Technology, vol. 28, no. 3, pp. 507-526, 2020