Brief Report: Increasing Prevalence of Ground-Glass Nodules and Semisolid Lung Lesions on Outpatient Chest Computed Tomography Scans.

Introduction: The increased use of cross-sectional imaging frequently identifies a growing number of lung nodules that require follow-up imaging studies and physician consultations. We report here the frequency of finding a ground-glass nodule (GGN) or semisolid lung lesion (SSL) in the past decade within a large academic health system. Methods: A radiology system database review was performed on all outpatient adult chest computed tomography (CT) scans between 2013 and 2022. Radiology reports were searched for the terms "ground-glass nodule," "subsolid," and "semisolid" to identify reports with findings potentially concerning for an adenocarcinoma spectrum lesion. Results: A total of 175,715 chest CT scans were performed between 2013 and 2022, with a steadily increasing number every year from 10,817 in 2013 to 21,916 performed in the year 2022. Identification of GGN or SSL on any outpatient CT increased from 5.9% in 2013 to 9.2% in 2022, representing a total of 2019 GGN or SSL reported on CT scans in 2022. The percentage of CT scans with a GGN or SSL finding increased during the study period in men and women and across all age groups above 50 years old. Conclusions: The total number of CT scans performed and the percentage of chest CT scans with GGN or SSL has more than doubled between 2013 and 2022; currently, 9% of all chest CT scans report a GGN or SSL. Although not all GGN or SSL radiographic findings represent true adenocarcinoma spectrum lesions, they are a growing burden to patients and health systems, and better methods to risk stratify radiographic lesions are needed.

Cardiothoracic complications of immune checkpoint inhibitors.

A paradigm shift in cancer treatment occurred with the advent of immune checkpoint inhibitors (ICI). ICI therapy has improved tumor response and increased overall survival in patients with solid tumors and hematologic malignancies. While ICI therapy has improved overall patient outcomes in oncology, it has also introduced novel adverse effects called immune-related adverse effects (irAEs). Studies have shown that the development of irAEs is associated with improved overall survival, but certain irAEs like pneumonitis and myocarditis are life threatening, and could result in death if not identified and treated early. Therefore, it is important for radiologists to be aware of complications arising from ICI administration, especially those related to the heart and lungs as they are associated with greater mortality. This paper will review the imaging features of cardiothoracic toxicities, recurrent and chronic irAEs, and atypical tumor responses associated with irAEs.

A Multiclass Radiomics Method-Based WHO Severity Scale for Improving COVID-19 Patient Assessment and Disease Characterization From CT Scans.

OBJECTIVES: The aim of this study was to evaluate the severity of COVID-19 patients' disease by comparing a multiclass lung lesion model to a single-class lung lesion model and radiologists' assessments in chest computed tomography scans. MATERIALS AND METHODS: The proposed method, AssessNet-19, was developed in 2 stages in this retrospective study. Four COVID-19-induced tissue lesions were manually segmented to train a 2D-U-Net network for a multiclass segmentation task followed by extensive extraction of radiomic features from the lung lesions. LASSO regression was used to reduce the feature set, and the XGBoost algorithm was trained to classify disease severity based on the World Health Organization Clinical Progression Scale. The model was evaluated using 2 multicenter cohorts: a development cohort of 145 COVID-19-positive patients from 3 centers to train and test the severity prediction model using manually segmented lung lesions. In addition, an evaluation set of 90 COVID-19-positive patients was collected from 2 centers to evaluate AssessNet-19 in a fully automated fashion. RESULTS: AssessNet-19 achieved an F1-score of 0.76 ± 0.02 for severity classification in the evaluation set, which was superior to the 3 expert thoracic radiologists (F1 = 0.63 ± 0.02) and the single-class lesion segmentation model (F1 = 0.64 ± 0.02). In addition, AssessNet-19 automated multiclass lesion segmentation obtained a mean Dice score of 0.70 for ground-glass opacity, 0.68 for consolidation, 0.65 for pleural effusion, and 0.30 for band-like structures compared with ground truth. Moreover, it achieved a high agreement with radiologists for quantifying disease extent with Cohen κ of 0.94, 0.92, and 0.95. CONCLUSIONS: A novel artificial intelligence multiclass radiomics model including 4 lung lesions to assess disease severity based on the World Health Organization Clinical Progression Scale more accurately determines the severity of COVID-19 patients than a single-class model and radiologists' assessment.

Diseases of the pulmonary arteries: imaging appearances and pearls.

A wide spectrum of pathology, both congenital and acquired, can affect the pulmonary arteries. While some of these are commonly seen in everyday clinical practice, some are rare. These entities may be discovered incidentally at imaging for other reasons in an asymptomatic patient, however patients may go on to develop symptoms over the course of their lifetime. Although an enlarged pulmonary artery can be visualized on chest X-ray (CXR), for the most part, CXR is insensitive for detecting abnormalities of the pulmonary arteries. Contrast-enhanced chest CT (CECT) is a better test to evaluate the pulmonary arteries as it is readily available, quick to perform, able to provide multiplanar reformatted images, and noninvasive. CECT is not only able to assess the lumen and wall of the pulmonary artery, but also provides a detailed evaluation of the entire thorax, including the heart, mediastinal structures, and lungs, often times picking up associated findings, and is the mainstay for evaluating disorders of the pulmonary vasculature. MRI allows for detailed evaluation of the vessel wall which can be especially helpful in cases where malignancy or vasculitis are suspected, and is also able to provide useful physiologic data such as quantification of flow. It is important for the radiologist to be aware of the many conditions which affect the pulmonary arteries, as some may require urgent treatment. This article will review normal pulmonary artery anatomy and physiology, as well as the various imaging findings of pulmonary vascular pathologies.

Early-stage COVID-19 pandemic observations on pulmonary embolism using nationwide multi-institutional data harvesting.

We introduce a multi-institutional data harvesting (MIDH) method for longitudinal observation of medical imaging utilization and reporting. By tracking both large-scale utilization and clinical imaging results data, the MIDH approach is targeted at measuring surrogates for important disease-related observational quantities over time. To quantitatively investigate its clinical applicability, we performed a retrospective multi-institutional study encompassing 13 healthcare systems throughout the United States before and after the 2020 COVID-19 pandemic. Using repurposed software infrastructure of a commercial AI-based image analysis service, we harvested data on medical imaging service requests and radiology reports for 40,037 computed tomography pulmonary angiograms (CTPA) to evaluate for pulmonary embolism (PE). Specifically, we compared two 70-day observational periods, namely (i) a pre-pandemic control period from 11/25/2019 through 2/2/2020, and (ii) a period during the early COVID-19 pandemic from 3/8/2020 through 5/16/2020. Natural language processing (NLP) on final radiology reports served as the ground truth for identifying positive PE cases, where we found an NLP accuracy of 98% for classifying radiology reports as positive or negative for PE based on a manual review of 2,400 radiology reports. Fewer CTPA exams were performed during the early COVID-19 pandemic than during the pre-pandemic period (9806 vs. 12,106). However, the PE positivity rate was significantly higher (11.6 vs. 9.9%, p < 10-4) with an excess of 92 PE cases during the early COVID-19 outbreak, i.e., ~1.3 daily PE cases more than statistically expected. Our results suggest that MIDH can contribute value as an exploratory tool, aiming at a better understanding of pandemic-related effects on healthcare.

Standardizing the Reporting of Incidental, Non-Lung Cancer (Category S) Findings Identified on Lung Cancer Screening Low-Dose CT Imaging.

Lung cancer screening is slowly but steadily entering the realm of preventive health maintenance. Standardization of reporting of positive findings identified on screening low-dose CT (LDCT) scans, specifically lung nodules, is a key element of high-quality lung cancer screening. The American College of Radiology developed the Lung CT Screening Reporting and Data System (Lung-RADS) system for this purpose. In addition to detailed categorization of lung nodules, Lung-RADS identifies category S for other incidental findings identified on screening LDCT scans. In contrast to the highly structured reporting for nodules, category S findings are reported at the discretion of individual readers, with the potential for high variability of reporting. Incidental findings on lung cancer screening studies are common, may trigger unwarranted evaluation with potential harm and cost, and may precipitate patient distress. In response to these concerns, our multidisciplinary lung cancer screening program developed a structured system for standardized reporting of category S findings based on recommendations of the American College of Radiology and relevant specialty societies.

COVID-19 ARDS: a review of imaging features and overview of mechanical ventilation and its complications.

The first cluster of cases of COVID-19 pneumonia was reported on December 31, 2019. Since then, this disease has spread rapidly across the world, and as of September 17, 2021, there are 226,844,344 cases of COVID-19 worldwide with 4,666,334 deaths related to COVID-19. While most COVID-19 cases are mild, some cases are severe with patients developing acute respiratory distress syndrome (ARDS). The pathophysiology of ARDS includes damage to the alveolar epithelium that leads to increased permeability of the alveolar epithelial barrier causing hyaline membrane formation, interstitial edema, and alveolar edema that results in severe hypoxia. Patients with COVID-19 ARDS are supported by non-invasive or invasive mechanical ventilation with an aim to improve oxygenation and maintain adequate blood oxygen levels. Increased intra-alveolar pressure while on mechanical ventilation may lead to alveolar rupture and thus barotrauma-related injuries such as lung tension cysts, pulmonary interstitial emphysema (PIE), pneumomediastinum, pneumopericardium, and pneumothorax. Recent studies have shown that the rate of barotrauma-related events is higher in patients with COVID-19 ARDS compared to patients with ARDS secondary to other etiologies. Radiologists should be aware of the imaging features of COVID-19 ARDS as well as the complications of mechanical ventilation. This educational manuscript will review the features of COVID-19 ARDS, discuss imaging of patients on mechanical ventilation, and review the imaging features of complications related to mechanical ventilation, including ventilator-associated lung injuries.

Imaging in the Evaluation of Chest Pain in the Primary Care Setting, Part 1: Cardiovascular Etiologies.

Chest pain is a common presenting complaint in the primary care setting. Imaging plays a key role in the evaluation of the multiple organ systems that can be responsible for chest pain. With numerous imaging modalities available, determination of the most appropriate test and interpretation of the findings can be a challenge for the clinician. In this 2-part series, we offer resources to guide primary care physicians in the selection of imaging studies and present the imaging findings of various causes of nonemergent chest pain. In Part 1, we focus on a discussion of the basic concepts of each imaging technique and the appearance of common cardiovascular etiologies of chest pain.

Imaging in the Evaluation of Chest Pain in the Primary Care Setting, Part 2: Sources of Noncardiac Chest Pain.

Chest pain is a common presenting complaint in the primary care setting. Imaging plays a key role in the evaluation of the multiple organ systems that can be responsible for chest pain. With numerous imaging modalities available, determination of the most appropriate test and interpretation of the findings can be a challenge for the clinician. In this 2-part series, we offer resources to guide primary care physicians in the selection of imaging studies and present the imaging findings of various causes of nonemergent chest pain. In Part 2, we focus on the radiologic appearance of common noncardiac sources of chest pain, including gastrointestinal, pulmonary, and musculoskeletal etiologies.

Radiologic-Pathologic Correlation for Nondiagnostic CT-Guided Lung Biopsies Performed for the Evaluation of Lung Cancer.

OBJECTIVE. For nondiagnostic CT-guided lung biopsies, we tested whether radiologicpathologic correlation could identify patients who may benefit from repeat biopsy. MATERIALS AND METHODS. In this retrospective study, 1525 lung biopsies were performed between July 2013 and June 2017, 243 of which were nondiagnostic. Of these 243 lung biopsies, 98 were performed to evaluate for lung malignancy; 17 were excluded because of insufficient follow-up, leaving a total of 81 cases. The Brock and Herder models were used to calculate risk; in addition, cases were independently blindly reviewed by two thoracic radiologists who assigned a score from 1 (probably benign) to 5 (probably malignant). The final diagnosis was established by pathology results or benignancy was established if the lesion resolved or remained stable for at least 2 years. RESULTS. Of the 81 nondiagnostic lung biopsies, initial pathology results included 33 cases of inflammation, 28 cases of normal lung tissue or insufficient sample, 10 cases of organizing pneumonia, and 10 cases of atypical cells. 42% (34/81) of cases were eventually determined to be malignant (negative predictive value [NPV] of 58%). Pathology results of organizing pneumonia had the lowest rate of malignancy (2/10 = 20%), and pathology results of atypical cells had the highest rate of malignancy (5/10 = 50%, p = 0.51). Within this highly selected cohort, the Brock and Herder models were not predictive of malignancy, with areas under the ROC curve (AUCs) of 0.52 and 0.52, respectively. Evaluation by thoracic radiologists yielded AUCs of 0.85 and 0.77. When radiologist-assigned scores of 1 and 2 were considered as benign, the NPV was 90% and 95%. CONCLUSION. Review of nondiagnostic lung biopsies for radiologic-pathologic concordance by thoracic radiologists can triage patients who may benefit from repeat biopsy.

Social Distancing with Portable Chest Radiographs During the COVID-19 Pandemic: Assessment of Radiograph Technique and Image Quality Obtained at 6 Feet and Through Glass.

PURPOSE: To develop a technique that allows portable chest radiography to be performed through the glass door of a patient's room in the emergency department. MATERIALS AND METHODS: A retrospective review of 100 radiographs (50 [mean age 59.4 ± 17.3, range 22-87; 30 women] performed with the modified technique in April 2020, randomized with 50 [mean age 59 ± 21.6, range 19-100; 31 men] using the standard technique was completed by three thoracic radiologists to assess image quality. Radiation exposure estimates to patient and staff were calculated. A survey was created and sent to 32 x-ray technologists to assess their perceptions of the modified technique. Unpaired Ttests were used for numerical data. A P value < .05 was considered statistically significant. RESULTS: The entrance dose for a 50th percentile patient was the same between techniques, measuring 169 µGy. The measured technologist exposure from the modified technique assuming a 50th percentile patient and standing 6 feet to the side of the glass was 0.055 µGy, which was lower than standard technique technologist exposure of 0.088 µGy. Of the 100 portable chest radiographs evaluated by three reviewers, two reviewers rated all images as having diagnostic quality, while the other reviewer believed two of the standard images and one of the modified technique images were non-diagnostic. A total of 81% (26 of 32) of eligible technologists completed the survey. Results showed acceptance of the modified technique with the majority feeling safer and confirming conservation of PPE. Most technologists did not feel the modified technique was more difficult to perform. CONCLUSIONS: The studies acquired with the new technique remained diagnostic, patient radiation doses remained similar, and technologist dose exposure were decreased with modified positioning. Perceptions of the new modified technique by frontline staff were overwhelmingly positive.

Traumatic Rib Injury: Patterns, Imaging Pitfalls, Complications, and Treatment.

The ribs are frequently affected by blunt or penetrating injury to the thorax. In the emergency department setting, it is vital for the interpreting radiologist to not only identify the presence of rib injuries but also alert the clinician about organ-specific injury, specific traumatic patterns, and acute rib trauma complications that require emergent attention. Rib injuries can be separated into specific morphologic fracture patterns that include stress, buckle, nondisplaced, displaced, segmental, and pathologic fractures. Specific attention is also required for flail chest and for fractures due to pediatric nonaccidental trauma. Rib fractures are associated with significant morbidity and mortality, both of which increase as the number of fractured ribs increases. Key complications associated with rib fracture include pain, hemothorax, pneumothorax, extrapleural hematoma, pulmonary contusion, pulmonary laceration, acute vascular injury, and abdominal solid-organ injury. Congenital anomalies, including supernumerary or accessory ribs, vestigial anterior ribs, bifid ribs, and synostoses, are common and should not be confused with traumatic pathologic conditions. Nontraumatic mimics of traumatic rib injury, with or without fracture, include metastatic disease, primary osseous neoplasms (osteosarcoma, chondrosarcoma, Ewing sarcoma, Langerhans cell histiocytosis, and osteochondroma), fibrous dysplasia, and Paget disease. Principles of management include supportive and procedural methods of alleviating pain, treating complications, and stabilizing posttraumatic deformity. By recognizing and accurately reporting the imaging findings, the radiologist will add value to the care of patients with thoracic trauma. Online supplemental material is available for this article. ©RSNA, 2017.

Is patent foramen ovale closure effective in reducing migraine symptoms? A controlled study.

OBJECTIVES: We investigated the prevalence of migraine in patients with patent foramen ovale (PFO), and the effect of PFO closure on migraine symptoms and medications. BACKGROUND: Studies have shown an association between migraine and PFO. Data have recently suggested a reduction in migraine symptoms following PFO closure. Most of these studies had no controls. METHODS: Subjects were divided into three groups: No PFO (Controls, n = 65), PFO with no intervention ("Open PFO", n = 63), and PFO treated with percutaneous closure ("Closed PFO", n = 41). We measured the frequency, severity, and impact of migraine on quality of life employing MIDAS scores. Comparisons were made preceding and 90 days after either transesophageal echocardiography (Controls and "Open PFO") or PFO closure ("Closed PFO"). We compared the use of abortive medications between the two time points. RESULTS: Migraine, especially with aura, was more prevalent in both PFO groups (P < 0.05). Migraine frequency was reduced by 83% in Closed PFO compared with 0% of Open PFO and 10% of control patients (P < 0.0001). Migraine severity and MIDAS scores were reduced by PFO closure when compared to the other two groups (P < 0.0001, P = 0.035 respectively). Reduction in abortive medications was noted in 71% after closure, 5% of Open PFO, and 10% of Controls (P < 0.001). CONCLUSIONS: In this controlled study, migraine, especially with aura, is more frequent in subjects with PFO. PFO closure is associated with a reduction in migraine frequency and severity, as well as an improvement in MIDAS scores. PFO closure was associated with a significant reduction in the use of abortive medications.

Variant angina associated with bitter orange in a dietary supplement.

The Food and Drug Administration has banned the sale of ephedrine-based weight-loss products because of their association with many cardiovascular adverse effects. Bitter orange is now being used as a stimulant in "ephedra-free" weight-loss supplements but was recently implicated in adverse cardiovascular sequelae. To our knowledge, this report describes the first case of variant angina associated with bitter orange in a dietary supplement.