Ballistic and Penetrating Injuries of the Chest Ballistic injuries are a major cause of morbidity and mortality in the United States. Unstable patients have high mortality, and only a small subset arrive at the hospital alive. Many patients undergo emergent surgery upon arrival, but a small subset undergo imaging with plain film, computed tomography, and echocardiography. We present a pictorial essay of ballistic and penetrating injuries and their complications with a focus on lung, cardiac, and vascular injury. The authors declare no conflicts of interest. Correspondence to: William Truesdell, MD, Department of Radiology, Long Island Jewish Medical Center, 270-05 76th Ave., Queens, NY 11040 (e-mail: wtruesdel1@northwell.edu). Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved

Dual-Energy Computed Tomography in Thoracic Imaging—Current Practices and Utility: Survey of the Society of Thoracic Radiology Purpose: The purpose of this study was to determine the current practice patterns of utilization of dual-energy computed tomography (DECT) in thoracic imaging. Materials and Methods: In this IRB-approved study, the URL link for an anonymous 26-question survey was sent by email to all the members of the Society of Thoracic Radiology (STR). Survey questions focused on the practice type, case volume, DECT scanner availability, common indications, image types, and perceived utility of DECT. Study data were collected and managed using SurveyMonkey tools and analyzed with χ2 tests. Results: The survey response rate was 11% (104/962). DECT was available in 75% of respondents’ institutions, with 90% of these having 1 to 5 DECT scanners (P<0.001). Seventy percent performed 1 to 500 DECT chest CTs per month (P<0.001). Dual-source was the most common DECT scanner (81%) (P=0.239). DECT was opted depending on the clinical indication in 89% (P=0.433). The technologist reconstructs the additional DECT images in 75% of instances (P<0.001). Acute pulmonary embolism (PE) was the most common indication of DECT (53%) (P=0.006), while chronic PE was considered the most valuable use of DECT (33%) (P<0.001). Iodine map was the most commonly used DECT image (53%) (P<0.001) followed by low-energy virtual monoenergetic image (VMI) (29%). For VMI, 50 keV was the most commonly used energy level for improving vascular contrast (43%) (P=0.048), whereas 120 keV was the most commonly used energy in VMI for decreasing artifacts (25%) (P=0.027). Conclusions: There is wide variability on the utilization of DECT in thoracic imaging. PE is perceived to be the most valuable utility of DECT, and iodine map is considered the most valuable DECT image. The author declares no conflicts of interest. Correspondence to: Prabhakar Rajiah, MBBS, MD, FRCR, Department of Radiology, Mayo Clinic, Rochester, MN 55906 (e-mail: Rajiah.Prabhakar@mayo.edu). Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved

Image Quality and Reliability of a Novel Dark-Blood Late Gadolinium Enhancement Sequence in Ischemic Cardiomyopathy Purpose: The aim of this study was to assess the reliability of a 2D dark-blood phase-sensitive late gadolinium enhancement sequence (2D-DBPSLGE) compared with 2D phase-sensitive inversion recovery late gadolinium enhancement sequence (2D-BBPSLGE) in patients with ischemic cardiomyopathy (ICM). Materials and Methods: A total of 73 patients with a clinical history of ICM were prospectively enrolled. The following endpoints were evaluated: (a) comparison of image quality between 2D-BBPSLGE and 2D-DBPSLGE for differentiation between blood pool-late gadolinium enhancement (LGE), remote myocardium-LGE, and blood pool-remote myocardium; (b) diagnostic accuracy of 2D-DBPSLGE compared with gold standard 2D-BBPSLGE for the evaluation of infarcted segments; (c) diagnostic accuracy of 2D-DBPSLGE for the evaluation of microvascular obstruction (MVO); (d) comparison of transmurality index between 2D-BBPSLGE and 2D-DBPSLGE; (e) comparison of papillary muscle hyperenhancement between 2D-BBPSLGE and 2D-DBPSLGE; inter-reader agreement for depiction of hyperenhanced segments in both LGE sequences. Data were analyzed using paired t test, Wilcoxon test, and McNemar test, and η2 coefficient and intercorrelation coefficient (ICC). Results: Image quality was superior for 2D-DBPSLGE for differentiation of blood pool-LGE (P<0.001). 2D-DBPSLGE, compared with 2D-BBPSLGE, showed a sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of 96.93%, 99.89%, 99.71%, 98.78, and 99.04%, respectively. Concerning MVO detection, 2D-DBPSLGE showed a sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of 66.67%, 100.00%, 100.00%, 80.95%, and 86.21%, respectively. 2D-DBPSLGE underestimated the transmurality (P=0.007) and identified papillary muscle hyperenhancement (P<0.001). Both LGE sequences showed comparable interobserver agreement for the evaluation of infarcted areas (2D-BBPSLGE: ICC 0.99;2D-DBPSLGE: ICC 0.99). Conclusions: Compared with 2D-BBPSLGE, 2D-DBPSLGE sequences provide better differentiation between LGE and blood-pool, while underestimating LGE trasmurality and the presence of MVO. The authors declare no conflicts of interest. Correspondence to: Gianluca Pontone, MD, PhD, FESC, FSCCT, Via C. Parea 4, Milan 20138, Italy (e-mail: gianluca.pontone@ccfm.it). Online date: September 13, 2019 Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved

A Case of Pulmonary Langerhans Cell Histiocytosis With Acute Progressive Nodular Lesions Depicted on High-Resolution Computed Tomography No abstract available

A Case of Diffuse Intrapulmonary Malignant Mesothelioma No abstract available

Imaging in Cardio-oncology: An Overview of an Emerging Medical Discipline The world of cardio-oncology is an evolving field involving the assessment of cardiovascular disease in patients suffering from cancer. Cancer and cardiovascular diseases are the two leading causes of morbidity and mortality in the developed world. Globally, cancer is diagnosed in 12.7 million patients annually, and cancer incidence is projected to increase by 40% in high-income countries from 2008 to 2030. Chemotherapy is the main treatment for most cancers and improves survival, but is associated with significant cardiotoxicity. In recent years, the introduction of new biological anti-cancer treatments in addition to “classic” chemotherapy has further improved survival, but has also introduced new cardiovascular side effects beyond “pure” myocardial damage. The increasing number of patients with cancer and cancer survivors, and the growing complexity of cancer treatment and cardiovascular side effects, call for teamwork including cardiologists with specific training and expertise working in teams with oncologists, hematologists, and others. The purpose of this review was to describe the clinical background and importance of cardio-oncology, with an emphasis on the use of imaging in this clinical setting. The authors declare no conflicts of interest. Correspondence to: Dan Gilon, MD, Heart Institute, Hadassah-Hebrew University Medical Center, Jerusalen 91120, Israel (e-mail: dangi@ekmd.huji.ac.il). Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved

Magnetic Resonance Imaging for the Follow-up of Treated Thymic Epithelial Malignancies Purpose: The purpose of this article was to compare magnetic resonance imaging (MRI) depiction of thymic malignancy progression/recurrence with that of computed tomography (CT). Methods: We retrospectively reviewed all surgically treated thymic epithelial malignancy (TEM) patients between 2011 and 2018 who were followed-up with chest CT and MRI. We compared the detection of recurrence and metastatic disease between the CT and MRI scans in each of these patients. Results: Of 187 patients treated in our institution for TEM, 22 were followed-up with both CT and MRI. TNM stage at diagnosis was as follows: I (n=14), II (n=1), IIIa (n=4), IIIb (n=2), IVa (n=1), and IVb (n=0). Patients were followed-up for a mean of 6.2 years, range 0.7 to 17.7 years. The mean interval between CT and MRI was 5.4 (range, 1 to 15) months. Most patients had no recurrence (n=16), 4 had recurrence after R0 or R1 resection, 1 had stable disease, and 1 had progression of disease after R2 resection. CT and MRI performed equally in the identification of pleural spread (n=5), lymphadenopathy (n=4), and pulmonary metastases (n=1). Retrosternal recurrence (n=1) was identified by MRI despite sternotomy wire artifacts. MRI identified bone involvement and extension of disease into the thecal sac earlier and more readily. Three patients had an indeterminate mediastinal finding on CT that was correctly identified as a benign cyst or pericardial fluid collection by MRI. Conclusion: MRI is an alternative option to follow-up patients after treatment for TEM. However, for those with metallic sternotomy wires, we recommend alternating the follow-up with CT as well. E.M.M. served as a lecturer for Bristol-Myers Squibb and for Boehringer Ingelheim. The authors declare no conflicts of interest. Correspondence to: Ariel Kerpel, MD, The Chaim Sheba Medical Center, 2 Derech Sheba St, Ramat Gan 5265601, Israel (e-mail: arikerp@gmail.com). Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved

Radiomics Toolkit: Available Chest Computed Tomography Data Sets No abstract available

Using Quantitative Computed Tomographic Imaging to Understand Chronic Obstructive Pulmonary Disease and Fibrotic Interstitial Lung Disease: State of the Art and Future Directions Computed tomography (CT) is commonly used in the evaluation and management of patients with diffuse lung pathologies, including chronic obstructive pulmonary disease (COPD) and fibrotic interstitial lung disease (ILD). In clinical practice, the qualitative (visual) assessment of CT images by a radiologist provides insight into the diagnosis of diffuse lung disease, estimates disease severity, and supports the identification of complications. Quantitative CT (qCT) is an emerging technique that provides some advantages over qualitative assessment. qCT can allow early and accurate detection of emphysema and airway disease, as well as aiding the evaluation of disease burden in both COPD and ILD. This approach is starting to be used as a surrogate biomarker in clinical trials to assess response to therapy. Artificial intelligence techniques have recently been incorporated into qCT, with such rapid evolution that it is currently difficult to determine the exact role it will eventually play in evaluating patients with COPD or pulmonary fibrosis. This article reviews the current state of the art for qualitative and qCT assessment of both COPD and fibrotic ILD. Current areas of controversy and limitations of these techniques are discussed, along with the potential future role of artificial intelligence. Recommendations are provided with regard to the current use of these techniques in the management of patients with diffuse lung disease. C.J.R. received grants and honoraria from Boehringer Ingelheim and Hoffmann-La Roche. The remaining authors declare no conflicts of interest. Correspondence to: Cameron J. Hague, MD, Department of Radiology, St. Paul’s Hospital, 1081 Burrard Street, Vancouver, BC, Canada V6Z 1Y6 (e-mail: cameron.hague@vch.ca). Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved

Application of Artificial Intelligence–based Image Optimization for Computed Tomography Angiography of the Aorta With Low Tube Voltage and Reduced Contrast Medium Volume Purpose: The purpose of this study was to evaluate the impact of artificial intelligence (AI)-based noise reduction algorithm on aorta computed tomography angiography (CTA) image quality (IQ) at 80 kVp tube voltage and 40 mL contrast medium (CM). Materials and Methods: After obtaining institutional review board approval and 8 written informed consents, 60 patients (35 men, 25 women; age range: 18 to 85 y) referred for aorta CTA examination were assigned to 2 groups at random. Group A underwent an 80 kVp protocol with 40 mL CM (320 mg I/mL). Group A reconstructed with iterative reconstruction was named as group A1 and further AI-based noise reduction was named as group A2. Group B was scanned with standard 120 kVp, 80 mL CM, and iterative reconstruction algorithm. The quantitative assessment of IQ included aorta CT attenuation, noise, signal-to-noise ratio, and contrast-to-noise ratio. A 5-point scale (5—excellent, 1—poor) was used by 2 radiologists independently for qualitative IQ analysis. Results: The image noise significantly decreased while signal-to-noise ratio and contrast-to-noise ratio significantly increased in the order of group A1, B, and A2 (all P<0.05). Compared with group B, the subjective IQ score of group A1 was significantly lower (P<0.05), while that of group A2 had no significant difference (P>0.05). The effective dose and CM volume of group A were reduced by 79.18% and 50%, respectively, than that of group B. Conclusions: The AI-based noise reduction could improve the IQ of aorta CTA with low kV and reduced CM, which achieved the potential of radiation dose and contrast media reduction compared with conventional aorta CTA protocol. Y.W. and M.Y. contributed equally to this work. Supported by National Natural Science Foundation of China (Grant NO. 81471725, 2015); and the Beijing Municipal Natural Science Foundation Interdisciplinary cooperation project (Grant NO. Z171100001117136, 2017); and the MOST “13th Five Year” National Key Research Project of China (Grant NO. 2016YFC1300402, 2016). The authors declare no conflicts of interest. Correspondence to: Zhengyu Jin, MD, PhD, Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 1 Shuaifuyuan, Dongcheng District, Beijing 100730, China (e-mail: jinzy_pumch@126.com). Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved