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.

Quantitative cardiovascular magnetic resonance findings and clinical risk factors predict cardiovascular outcomes in breast cancer patients.

BACKGROUND: Cardiac magnetic resonance (CMR) global longitudinal strain and circumferential strain abnormalities have been associated with left ventricular ejection fraction (LVEF) reduction and cardiotoxicity from oncologic therapy. However, few studies have evaluated the associations of strain and cardiovascular outcomes. OBJECTIVES: To assess CMR circumferential and global longitudinal strain (GLS) correlations with cardiovascular outcomes including myocardial infarction, systolic dysfunction, diastolic dysfunction, arrhythmias and valvular disease in breast cancer patients treated with and without anthracyclines and/or trastuzumab therapy. METHODS: Breast cancer patients with a CMR from 2013-2017 at Yale New Haven Hospital were included. Patient co-morbidities, medications, and cardiovascular outcomes were obtained from chart review. Biostatistical analyses, including Pearson correlations, competing risk regression model, and competing risk survival curves comparing the two groups were analyzed. RESULTS: 116 breast cancer with CMRs were included in our analysis to assess differences between Anthracycline/Trastuzumab (AT) (62) treated versus non anthracycline/trastuzumab (NAT) (54) treated patients in terms of imaging characteristics and outcomes. More AT patients 17 (27.4%) developed systolic heart failure compared to the NAT group 6 (10.9%), p = 0.025. Statin use was associated with a significant reduction in future arrhythmias (HR 0.416; 95% CI 0.229-0.755, p = 0.004). In a sub-group of 13 patients that underwent stress CMR, we did not find evidence of microvascular dysfunction by sub-endocardial/sub-epicardial myocardial perfusion index ratio after adjusting for ischemic heart disease. CONCLUSIONS: In our study, CMR detected signs of subclinical cardiotoxicity such as strain abnormalities despite normal LV function and abnormal circumferential strain was associated with adverse cardiovascular outcomes such as valvular disease and systolic heart failure. Thus, CMR is an important tool during and after cancer treatment to identity and prognosticate cancer treatment-related cardiotoxicity.

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.

Left ventricular myocardial strain and tissue characterization by cardiac magnetic resonance imaging in immune checkpoint inhibitor associated cardiotoxicity.

BACKGROUND: Immune checkpoint inhibitors (ICIs) are highly effective in treating cancer; however, cardiotoxicity can occur, including myocarditis. Cardiac magnetic resonance (CMR) imaging is useful for evaluation of myocarditis, although it has not been well studied in ICI cardiotoxicity. METHODS: We identified patients referred for CMR evaluation of ICI cardiotoxicity from September 2015 through September 2019. We assessed structural and functional parameters, feature tracking (FT) left ventricular and atrial strain, T2- weighted ratios and quantitative late gadolinium enhancement (LGE). We also applied the Updated Lake Louise Criteria for diagnosis of myocarditis. RESULTS: Of the 20 patients referred, the median left ventricular ejection fraction (LVEF) was 52.5% ± 19.1 and 50% had a normal LVEF (≥53%). FT strain analysis revealed an average abnormal global longitudinal strain (GLS) of -9.8%± 4.2%. In patients with a normal LVEF, the average GLS remained depressed at -12.3%± 2.4%. In all patients, GLS demonstrated a significant negative correlation with LVEF (rs = -0.64, p 0.002). Sixteen patients (80%) had presence of LGE (14 non-ischemic pattern and 2 ischemic). Percent LGE did not correlate with any CMR parameters and notably did not correlate with LVEF (rs = -0.29, p = 0.22) or GLS (rs = 0.10, p = 0.67), highlighting the value of tissue characterization beyond functional assessment. Nine patients (45%) met full Updated Lake Louise Criteria and 85% met at least one criterion, suggestive of myocarditis in the correct clinical context. Thirteen patients (65%) were treated for ICI-associated myocarditis and, of these, 54% (n = 7) had recovery of LVEF to normal. There was no correlation between LVEF (p = 0.47), GLS (0.89), or % LGE (0.15) and recovery of LVEF with treatment. CONCLUSION: In patients with suspected ICI cardiotoxicity, CMR is an important diagnostic tool, even in the absence of overt left ventricular dysfunction, as abnormalities in left ventricular strain, T2 signal and LGE can identifying disease.

Progressive Dyspnea and Hypoxemia With Diffuse Pulmonary Infiltrates in a Previously Healthy Woman.

CASE PRESENTATION: A 50-year-old woman presented with 3 months of cough, dyspnea, and fatigue. She also reported new fevers, night sweats, and a rash on her face and torso. On presentation she was tachycardic and tachypneic, with oxygen saturation of 81% on 2 L/min of oxygen. She was in mild respiratory distress. Results of the physical examination were remarkable for tender left cervical and axillary adenopathy and bibasilar pulmonary crackles. She had an acneiform rash on her face, chest, and back, consisting of multiple nonblanching erythematous or violaceous macules and papules (Fig 1) and had conjunctival edema. Admission laboratory test results were significant for a WBC count of 56,000, of which 79.5% were lymphocytes. Hemoglobin and platelet levels were normal. She was admitted for further management.

Multisystem Imaging Manifestations of COVID-19, Part 2: From Cardiac Complications to Pediatric Manifestations.

Infection with severe acute respiratory syndrome coronavirus 2 results in coronavirus disease 2019 (COVID-19), which was declared an official pandemic by the World Health Organization on March 11, 2020. COVID-19 has been reported in most countries, and as of August 15, 2020, there have been over 21 million cases of COVID-19 reported worldwide, with over 800 000 COVID-19-associated deaths. Although COVID-19 predominantly affects the respiratory system, it has become apparent that many other organ systems can also be involved. Imaging plays an essential role in the diagnosis of all manifestations of the disease and its related complications, and proper utilization and interpretation of imaging examinations is crucial. A comprehensive understanding of the diagnostic imaging hallmarks, imaging features, multisystem involvement, and evolution of imaging findings is essential for effective patient management and treatment. In part 1 of this article, the authors described the viral pathogenesis, diagnostic imaging hallmarks, and manifestations of the pulmonary and peripheral and central vascular systems of COVID-19. In part 2 of this article, the authors focus on the key imaging features of the varied pathologic manifestations of COVID-19, involving the cardiac, neurologic, abdominal, dermatologic and ocular, and musculoskeletal systems, as well as the pediatric and pregnancy-related manifestations of the virus. Online supplemental material is available for this article. ©RSNA, 2020.

Multisystem Imaging Manifestations of COVID-19, Part 1: Viral Pathogenesis and Pulmonary and Vascular System Complications.

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) results in coronavirus disease 2019 (COVID-19), which was declared an official pandemic by the World Health Organization on March 11, 2020. The infection has been reported in most countries around the world. As of August 2020, there have been over 21 million cases of COVID-19 reported worldwide, with over 800 000 COVID-19-associated deaths. It has become apparent that although COVID-19 predominantly affects the respiratory system, many other organ systems can also be involved. Imaging plays an essential role in the diagnosis of all manifestations of the disease, as well as its related complications, and proper utilization and interpretation of imaging examinations is crucial. With the growing global COVID-19 outbreak, a comprehensive understanding of the diagnostic imaging hallmarks, imaging features, multisystemic involvement, and evolution of imaging findings is essential for effective patient management and treatment. To date, only a few articles have been published that comprehensively describe the multisystemic imaging manifestations of COVID-19. The authors provide an inclusive system-by-system image-based review of this life-threatening and rapidly spreading infection. In part 1 of this article, the authors discuss general aspects of the disease, with an emphasis on virology, the pathophysiology of the virus, and clinical presentation of the disease. The key imaging features of the varied pathologic manifestations of this infection that involve the pulmonary and peripheral and central vascular systems are also described. Part 2 will focus on key imaging features of COVID-19 that involve the cardiac, neurologic, abdominal, dermatologic and ocular, and musculoskeletal systems, as well as pediatric and pregnancy-related manifestations of the virus. Vascular complications pertinent to each system will be also be discussed in part 2. Online supplemental material is available for this article. ©RSNA, 2020.

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.

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.

Ventricular Myocardial Fat: An Unexpected Biomarker for Long-term Survival?

PURPOSE: To examine the association between myocardial fat, a poorly understood finding frequently observed on non-contrast CT, and all-cause mortality in patients with and without a history of prior MI. MATERIALS AND METHODS: A retrospective cohort from a diverse urban academic center was derived from chronic myocardial infarction (MI) patients (n = 265) and three age-matched patients without MI (n = 690) who underwent non-contrast chest CT between 1 January 2005-31 December 2008. CT images were reviewed for left and right ventricular fat. Electronic records identified clinical variables. Kaplan-Meier and Cox proportional hazard analyses assessed the association between myocardial fat and all-cause mortality. The net reclassification improvement assessed the utility of adding myocardial fat to traditional risk prediction models. RESULTS: Mortality was 40.1% for the no MI and 71.7% for the MI groups (median follow-up, 6.8 years; mean age, 73.7 ± 10.6 years). In the no MI group, 25.7% had LV and 49.9% RV fat. In the MI group, 32.8% had LV and 42.3% RV fat. LV and RV fat was highly associated (OR 5.3, p < 0.001). Ventricular fat was not associated with cardiovascular risk factors. Myocardial fat was associated with a reduction in the adjusted hazard of death for both the no MI (25%, p = 0.04) and the MI group (31%, p = 0.018). Myocardial fat resulted in the correct reclassification of 22% for the no MI group versus the Charlson score or calcium score (p = 0.004) and 47% for the MI group versus the Charlson score (p = 0.0006). CONCLUSIONS: Patients with myocardial fat have better survival, regardless of MI status, suggesting that myocardial fat is a beneficial biomarker and may improve risk stratification. KEY POINTS: • Myocardial fat is commonly found on chest CT, yet is poorly understood • Myocardial fat is associated with better survival in patients with and without prior MI and is not associated with traditional cardiovascular risk factors • This finding may provide clinically meaningful prognostic value in the risk stratification of patients.

Performance of Low-Dose Perfusion Scintigraphy and CT Pulmonary Angiography for Pulmonary Embolism in Pregnancy.

BACKGROUND: The symptoms of normal pregnancy overlap those of pulmonary embolism (PE). Limited literature suggests that low-dose perfusion scanning (LDQ), which yields lower maternal-fetal radiation exposure than CT pulmonary angiography (CTPA), performs well in excluding PE in pregnant patients. METHODS: We performed a retrospective cohort study of sequential pregnant women who underwent imaging for PE with LDQ or CTPA between 2008 and 2013 at Montefiore Medical Center. Our practice recommends LDQ for patients with negative results on chest radiographs. Patients were categorized according to initial imaging modality, and a subgroup analysis was performed in patients with asthma. The primary outcome was the negative predictive value (NPV) of imaging determined by VTE diagnosis within 90 days. RESULTS: Of 322 pregnant women (mean age, 27.3 ± 6.3 years), initial imaging was positive for PE in 2.7% (6 of 225) of LDQs and 4.1% (4 of 97) of CTPAs, negative in 88.0% (198 of 225) of LDQs and 86.6% (84 of 97) of CTPAs, and indeterminate/nondiagnostic in 9.3% (21 of 225) of LDQs and 9.3% (9 of 97) of CTPAs (P = .79). Ten patients (3.1%) were treated for PE. The NPV was 100% for LDQ and 97.5% for CTPA. Subgroup analysis of patients with asthma (23.9% of this population) revealed a high likelihood of a negative study in the LDQ and CTPA groups (74.1% and 87.0%, respectively) and 100% NPV for both modalities. CONCLUSIONS: PE is an uncommon diagnosis in pregnancy. LDQ and CTPA perform well, with less maternal-fetal radiation exposure with LDQ. Therefore, when available, LDQ is a reasonable first-choice modality for suspected PE in pregnant women with a negative result on chest radiograph.