Incidental Apical Pleuroparenchymal Scarring on Computed Tomography: Diagnostic Yield, Progression, Morphologic Features and Clinical Significance.

PURPOSE: Apical pleuroparenchymal scarring (APPS) is commonly seen on chest computed tomography (CT), though the imaging and clinical features, to the best of our knowledge, have never been studied. The purpose was to understand APPS's typical morphologic appearance and associated clinical features. PATIENTS AND METHODS: A random generator selected 1000 adult patients from all 21516 chest CTs performed at urban outpatient centers from January 1, 2016 to December 31, 2016. Patients with obscuring apical diseases were excluded to eliminate confounding factors. After exclusions, 780 patients (median age: 64 y; interquartile range: 56 to 72 y; 55% males) were included for analysis. Two radiologists evaluated the lung apices of each CT for the extent of abnormality in the axial plane (mild: <5 mm, moderate: 5 to 10 mm, severe: >10 mm), craniocaudal plane (extension halfway to the aortic arch, more than halfway, vs below the arch), the predominant pattern (nodular vs reticular and symmetry), and progression. Cohen kappa coefficient was used to assess radiologists' agreement in scoring. Ordinal logistic regression was used to determine associations of clinical and imaging variables with APPS. RESULTS: APPS was present on 65% (507/780) of chest CTs (54% mild axial; 80% mild craniocaudal). The predominant pattern was nodular and symmetric. Greater age, female sex, lower body mass index, greater height, and white race were associated with more extensive APPS. APPS was not found to be associated with lung cancer in this cohort. CONCLUSION: Classifying APPS by the extent of disease in the axial or craniocaudal planes, in addition to the predominant pattern, enabled statistically significant associations to be determined, which may aid in understanding the pathophysiology of apical scarring and potential associated risks.

Barotrauma in COVID 19: Incidence, pathophysiology, and effect on prognosis.

OBJECTIVES: To investigate the incidence, risk factors, and outcomes of barotrauma (pneumomediastinum and subcutaneous emphysema) in mechanically ventilated COVID-19 patients. To describe the chest radiography patterns of barotrauma and understand the development in relation to mechanical ventilation and patient mortality. METHODS: We performed a retrospective study of 363 patients with COVID-19 from March 1 to April 8, 2020. Primary outcomes were pneumomediastinum or subcutaneous emphysema with or without pneumothorax, pneumoperitoneum, or pneumoretroperitoneum. The secondary outcomes were length of intubation and death. In patients with pneumomediastinum and/or subcutaneous emphysema, we conducted an imaging review to determine the timeline of barotrauma development. RESULTS: Forty three out of 363 (12%) patients developed barotrauma radiographically. The median time to development of either pneumomediastinum or subcutaneous emphysema was 2 days (IQR 1.0-4.5) after intubation and the median time to pneumothorax was 7 days (IQR 2.0-10.0). The overall incidence of pneumothorax was 28/363 (8%) with an incidence of 17/43 (40%) in the barotrauma cohort and 11/320 (3%) in those without barotrauma (p ≤ 0.001). In total, 257/363 (71%) patients died with an increase in mortality in those with barotrauma 33/43 (77%) vs. 224/320 (70%). When adjusting for covariates, barotrauma was associated with increased odds of death (OR 2.99, 95% CI 1.25-7.17). CONCLUSION: Barotrauma is a frequent complication of mechanically ventilated COVID-19 patients. In comparison to intubated COVID-19 patients without barotrauma, there is a higher rate of pneumothorax and an increased risk of death.

Combining Initial Radiographs and Clinical Variables Improves Deep Learning Prognostication in Patients with COVID-19 from the Emergency Department.

PURPOSE: To train a deep learning classification algorithm to predict chest radiograph severity scores and clinical outcomes in patients with coronavirus disease 2019 (COVID-19). MATERIALS AND METHODS: In this retrospective cohort study, patients aged 21-50 years who presented to the emergency department (ED) of a multicenter urban health system from March 10 to 26, 2020, with COVID-19 confirmation at real-time reverse-transcription polymerase chain reaction screening were identified. The initial chest radiographs, clinical variables, and outcomes, including admission, intubation, and survival, were collected within 30 days (n = 338; median age, 39 years; 210 men). Two fellowship-trained cardiothoracic radiologists examined chest radiographs for opacities and assigned a clinically validated severity score. A deep learning algorithm was trained to predict outcomes on a holdout test set composed of patients with confirmed COVID-19 who presented between March 27 and 29, 2020 (n = 161; median age, 60 years; 98 men) for both younger (age range, 21-50 years; n = 51) and older (age >50 years, n = 110) populations. Bootstrapping was used to compute CIs. RESULTS: The model trained on the chest radiograph severity score produced the following areas under the receiver operating characteristic curves (AUCs): 0.80 (95% CI: 0.73, 0.88) for the chest radiograph severity score, 0.76 (95% CI: 0.68, 0.84) for admission, 0.66 (95% CI: 0.56, 0.75) for intubation, and 0.59 (95% CI: 0.49, 0.69) for death. The model trained on clinical variables produced an AUC of 0.64 (95% CI: 0.55, 0.73) for intubation and an AUC of 0.59 (95% CI: 0.50, 0.68) for death. Combining chest radiography and clinical variables increased the AUC of intubation and death to 0.88 (95% CI: 0.79, 0.96) and 0.82 (95% CI: 0.72, 0.91), respectively. CONCLUSION: The combination of imaging and clinical information improves outcome predictions.Supplemental material is available for this article.© RSNA, 2020.

Coronary artery calcification in COVID-19 patients: an imaging biomarker for adverse clinical outcomes.

BACKGROUND: Recent studies have demonstrated a complex interplay between comorbid cardiovascular disease, COVID-19 pathophysiology, and poor clinical outcomes. Coronary artery calcification (CAC) may therefore aid in risk stratification of COVID-19 patients. METHODS: Non-contrast chest CT studies on 180 COVID-19 patients ≥ age 21 admitted from March 1, 2020 to April 27, 2020 were retrospectively reviewed by two radiologists to determine CAC scores. Following feature selection, multivariable logistic regression was utilized to evaluate the relationship between CAC scores and patient outcomes. RESULTS: The presence of any identified CAC was associated with intubation (AOR: 3.6, CI: 1.4-9.6) and mortality (AOR: 3.2, CI: 1.4-7.9). Severe CAC was independently associated with intubation (AOR: 4.0, CI: 1.3-13) and mortality (AOR: 5.1, CI: 1.9-15). A greater CAC score (UOR: 1.2, CI: 1.02-1.3) and number of vessels with calcium (UOR: 1.3, CI: 1.02-1.6) was associated with mortality. Visualized coronary stent or coronary artery bypass graft surgery (CABG) had no statistically significant association with intubation (AOR: 1.9, CI: 0.4-7.7) or death (AOR: 3.4, CI: 1.0-12). CONCLUSION: COVID-19 patients with any CAC were more likely to require intubation and die than those without CAC. Increasing CAC and number of affected arteries was associated with mortality. Severe CAC was associated with higher intubation risk. Prior CABG or stenting had no association with elevated intubation or death.

Portable Chest Radiography as an Exclusionary Test for Adverse Clinical Outcomes During the COVID-19 Pandemic.

BACKGROUND: Chest radiography (CXR) often is performed in the acute setting to help understand the extent of respiratory disease in patients with COVID-19, but a clearly defined role for negative chest radiograph results in assessing patients has not been described. RESEARCH QUESTION: Is portable CXR an effective exclusionary test for future adverse clinical outcomes in patients suspected of having COVID-19? STUDY DESIGN AND METHODS: Charts of consecutive patients suspected of having COVID-19 at five EDs in New York City between March 19, 2020, and April 23, 2020, were reviewed. Patients were categorized based on absence of findings on initial CXR. The primary outcomes were hospital admission, mechanical ventilation, ARDS, and mortality. RESULTS: Three thousand two hundred forty-five adult patients, 474 (14.6%) with negative initial CXR results, were reviewed. Among all patients, negative initial CXR results were associated with a low probability of future adverse clinical outcomes, with negative likelihood ratios of 0.27 (95% CI, 0.23-0.31) for hospital admission, 0.24 (95% CI, 0.16-0.37) for mechanical ventilation, 0.19 (95% CI, 0.09-0.40) for ARDS, and 0.38 (95% CI, 0.29-0.51) for mortality. Among the subset of 955 patients younger than 65 years and with a duration of symptoms of at least 5 days, no patients with negative CXR results died, and the negative likelihood ratios were 0.17 (95% CI, 0.12-0.25) for hospital admission, 0.09 (95% CI, 0.02-0.36) for mechanical ventilation, and 0.09 (95% CI, 0.01-0.64) for ARDS. INTERPRETATION: Initial CXR in adult patients suspected of having COVID-19 is a strong exclusionary test for hospital admission, mechanical ventilation, ARDS, and mortality. The value of CXR as an exclusionary test for adverse clinical outcomes is highest among young adults, patients with few comorbidities, and those with a prolonged duration of symptoms.

Spontaneous subcutaneous emphysema and pneumomediastinum in non-intubated patients with COVID-19.

PURPOSE: We describe the presenting characteristics and hospital course of 11 novel coronavirus (COVID-19) patients who developed spontaneous subcutaneous emphysema (SE) with or without pneumomediastinum (SPM) in the absence of prior mechanical ventilation. MATERIALS AND METHODS: A total of 11 non-intubated COVID-19 patients (8 male and 3 female, median age 61 years) developed SE and SPM between March 15 and April 30, 2020 at a multi-center urban health system in New York City. Demographics (age, gender, smoking status, comorbid conditions, and body-mass index), clinical variables (temperature, oxygen saturation, and symptoms), and laboratory values (white blood cell count, C-reactive protein, D-dimer, and peak interleukin-6) were collected. Chest radiography (CXR) and computed tomography (CT) were analyzed for SE, SPM, and pneumothorax by a board-certified cardiothoracic-fellowship trained radiologist. RESULTS: Eleven non-intubated patients developed SE, 36% (4/11) of whom had SE on their initial CXR. Concomitant SPM was apparent in 91% (10/11) of patients, and 45% (5/11) also developed pneumothorax. Patients developed SE on average 13.3 days (SD: 6.3) following symptom onset. No patients reported a history of smoking. The most common comorbidities included hypertension (6/11), diabetes mellitus (5/11), asthma (3/11), dyslipidemia (3/11), and renal disease (2/11). Four (36%) patients expired during hospitalization. CONCLUSION: SE and SPM were observed in a cohort of 11 non-intubated COVID-19 patients without any known cause or history of invasive ventilation. Further investigation is required to elucidate the underlying mechanism in this patient population.

Clinical and Chest Radiography Features Determine Patient Outcomes in Young and Middle-aged Adults with COVID-19.

Background Chest radiography has not been validated for its prognostic utility in evaluating patients with coronavirus disease 2019 (COVID-19). Purpose To analyze the prognostic value of a chest radiograph severity scoring system for younger (nonelderly) patients with COVID-19 at initial presentation to the emergency department (ED); outcomes of interest included hospitalization, intubation, prolonged stay, sepsis, and death. Materials and Methods In this retrospective study, patients between the ages of 21 and 50 years who presented to the ED of an urban multicenter health system from March 10 to March 26, 2020, with COVID-19 confirmation on real-time reverse transcriptase polymerase chain reaction were identified. Each patient's ED chest radiograph was divided into six zones and examined for opacities by two cardiothoracic radiologists, and scores were collated into a total concordant lung zone severity score. Clinical and laboratory variables were collected. Multivariable logistic regression was used to evaluate the relationship between clinical parameters, chest radiograph scores, and patient outcomes. Results The study included 338 patients: 210 men (62%), with median age of 39 years (interquartile range, 31-45 years). After adjustment for demographics and comorbidities, independent predictors of hospital admission (n = 145, 43%) were chest radiograph severity score of 2 or more (odds ratio, 6.2; 95% confidence interval [CI]: 3.5, 11; P < .001) and obesity (odds ratio, 2.4 [95% CI: 1.1, 5.4] or morbid obesity). Among patients who were admitted, a chest radiograph score of 3 or more was an independent predictor of intubation (n = 28) (odds ratio, 4.7; 95% CI: 1.8, 13; P = .002) as was hospital site. No significant difference was found in primary outcomes across race and ethnicity or those with a history of tobacco use, asthma, or diabetes mellitus type II. Conclusion For patients aged 21-50 years with coronavirus disease 2019 presenting to the emergency department, a chest radiograph severity score was predictive of risk for hospital admission and intubation. © RSNA, 2020 Online supplemental material is available for this article.

Portable chest X-ray in coronavirus disease-19 (COVID-19): A pictorial review.

As the global pandemic of coronavirus disease-19 (COVID-19) progresses, many physicians in a wide variety of specialties continue to play pivotal roles in diagnosis and management. In radiology, much of the literature to date has focused on chest CT manifestations of COVID-19 (Zhou et al. [1]; Chung et al. [2]). However, due to infection control issues related to patient transport to CT suites, the inefficiencies introduced in CT room decontamination, and lack of CT availability in parts of the world, portable chest radiography (CXR) will likely be the most commonly utilized modality for identification and follow up of lung abnormalities. In fact, the American College of Radiology (ACR) notes that CT decontamination required after scanning COVID-19 patients may disrupt radiological service availability and suggests that portable chest radiography may be considered to minimize the risk of cross-infection (American College of Radiology [3]). Furthermore, in cases of high clinical suspicion for COVID-19, a positive CXR may obviate the need for CT. Additionally, CXR utilization for early disease detection may also play a vital role in areas around the world with limited access to reliable real-time reverse transcription polymerase chain reaction (RT-PCR) COVID testing. The purpose of this pictorial review article is to describe the most common manifestations and patterns of lung abnormality on CXR in COVID-19 in order to equip the medical community in its efforts to combat this pandemic.

COVID-19: A Multimodality Review of Radiologic Techniques, Clinical Utility, and Imaging Features.

In this article we will review the imaging features of coronavirus disease 2019 (COVID-19) across multiple modalities, including radiography, CT, MRI, PET/CT, and US. Given that COVID-19 primarily affects the lung parenchyma by causing pneumonia, our directive is to focus on thoracic findings associated with COVID-19. We aim to enhance radiologists' understanding of this disease to help guide diagnosis and management. Supplemental material is available for this article. © RSNA, 2020.

COVID-19 ventilator barotrauma management: less is more.

BACKGROUND: COVID-19 patients requiring mechanical ventilation may develop significant pneumomediastinum and sub-cutaneous emphysema without associated pneumothorax (SWAP). Prophylactic chest tube placement or sub-fascial "blowholes" are usually recommended to prevent tension pneumothorax and clinical decline. Risk of iatrogenic lung injury and release of virus into the environment is high. Incidence and conservative management data of such barotraumatic complications during the COVID-19 pandemic are lacking. METHODS: All patients with mediastinal air and SWAP evaluated by the department of Thoracic Surgery at the Mount Sinai Hospital between March 30 and April 10, 2020 were identified. All patients without pneumothorax were treated conservatively with daily chest x-ray and observation. Three patients had prophylactic chest tube placement prior to the study period without thoracic surgery consultation. RESULTS: There were 29 cases of mediastinal air with SWAP out of 171 COVID positive intubated patients (17.0%) who were treated conservatively. Patients were intubated for an average of 2.4 days before SWAP was identified. 12 patients (41%) had improvement or resolution without intervention. Two patients progressed to pneumothorax 3 and 8 days following initial presentation. Both had chest tubes placed without incident before there were any changes in oxygenation, hemodynamics, supportive medications, or ventilator settings. There were 3 patients who had percutaneous tubes placed before the study period all of whom had significant worsening of their sub-cutaneous air and air leak. CONCLUSIONS: Conservative management of massive sub-cutaneous emphysema without pneumothorax in COVID-19 patients is safe and limits viral exposure to healthcare workers. Placement of chest tubes is discouraged unless a definite sizable pneumothorax develops.

Causative factors, imaging findings, and CT course of round atelectasis.

OBJECTIVE: To assess causative factors, associated imaging findings, and CT course of round atelectasis (RA). MATERIALS AND METHODS: We retrospectively reviewed CT reports for "round" or "rounded atelectasis" over a 5-year time frame. Patients with at least 2 CT scans a minimum of 6 months apart were included. Electronic medical records and clinical and imaging follow-up was reviewed for all cases. RESULTS: Study population included 50 individuals with mean age of 63 years, and 59 unique instances of RA. The most commonly associated etiologies were hepatic hydrothorax (26%, n = 13) and asbestos exposure (26%), followed by post-infectious pleural inflammation (22%), congestive heart failure (12%), and end stage renal disease (8%). RA was found in the right lower lobe in over half of cases (n = 30). Association with one or more pleural abnormality was identified in all cases, including thickening (88%), fluid (60%), or calcification (40%). Nearly one third (n = 19) demonstrated intra-lesional calcification. In those who underwent PET/CT (20%), lesions demonstrated an average SUV of 2.2 (range 0-7.8). CT course over mean follow up of 32 months (range 6-126 months), demonstrated RA to remain stable (n = 26) or decrease (n = 26) in size in the majority (88%) of cases. CONCLUSION: Round atelectasis may arise from diverse etiologies beyond asbestos, and will most often decrease or remain stable in size over serial exams. Accurate identification may obviate the need for added diagnostic interventions.

Correction to: Baseline and annual repeat rounds of screening: implications for optimal regimens of screening.

The original version of this article unfortunately contained a mistake. The conflict of interest was incorrect.

Baseline and annual repeat rounds of screening: implications for optimal regimens of screening.

OBJECTIVES: Differences in results of baseline and subsequent annual repeat rounds provide important information for optimising the regimen of screening. METHODS: A prospective cohort study of 65,374 was reviewed to examine the frequency/percentages of the largest noncalcified nodule (NCN), lung cancer cell types and Kaplan-Meier (K-M) survival rates, separately for baseline and annual rounds. RESULTS: Of 65,374 baseline screenings, NCNs were identified in 28,279 (43.3%); lung cancer in 737 (1.1%). Of 74,482 annual repeat screenings, new NCNs were identified in 4959 (7%); lung cancer in 179 (0.24%). Only adenocarcinoma was diagnosed in subsolid NCNs. Percentages of lung cancers by cell type were significantly different (p < 0.0001) in the baseline round compared with annual rounds, reflecting length bias, as were the ratios, reflecting lead times. Long-term K-M survival rate was 100% for typical carcinoids and for adenocarcinomas manifesting as subsolid NCNs; 85% (95% CI 81-89%) for adenocarcinoma, 74% (95% CI 63-85%) for squamous cell, 48% (95% CI 34-62%) for small cell. The rank ordering by lead time was the same as the rank ordering by survival rates. CONCLUSIONS: The significant differences in the frequency of NCNs and frequency and aggressiveness of diagnosed cancers in baseline and annual repeat need to be recognised for an optimal regimen of screening. KEY POINTS: • Lung cancer aggressiveness varies considerably by cell type and nodule consistency. • Kaplan-Meier survival rates varied by cell type between 100% and 48%. • The percentages of lung cancers by cell type in screening rounds reflect screening biases. • Rank ordering by cell type survival is consistent with that by lead times. • Empirical evidence provides critical information for the regimen of screening.

Estimation of cardiovascular risk on routine chest CT: Ordinal coronary artery calcium scoring as an accurate predictor of Agatston score ranges.

BACKGROUND: Coronary artery calcium (CAC) is often identified on routine chest computed tomography (CT). The purpose of our study was to evaluate whether ordinal scoring of CAC on non-gated, routine chest CT is an accurate predictor of Agatston score ranges in a community-based population, and in particular to determine the accuracy of an ordinal score of zero on routine chest CT. METHODS: Two thoracic radiologists reviewed consecutive same-day ECG-gated and routine non-gated chest CT scans of 222 individuals. CAC was quantified using the Agatston scoring on the ECG-gated scans, and using an ordinal method on routine scans, with a score from 0 to 12. The pattern and distribution of CAC was assessed. The correlation between routine exam ordinal scores and Agatston scores in ECG-gated exams, as well as the accuracy of assigning a zero calcium score on routine chest CT was determined. RESULTS: CAC was most prevalent in the left anterior descending coronary artery in both single and multi-vessel coronary artery disease. There was a strong correlation between the non-gated ordinal and ECG-gated Agatston scores (r = 0.811, p < 0.01). Excellent inter-reader agreement (k = 0.95) was shown for the presence (total ordinal score ≥1) or absence (total ordinal score = 0) of CAC on routine chest CT. The negative predictive value for a total ordinal score of zero on routine CT was 91.6% (95% CI, 85.1-95.9). Total ordinal scores of 0, 1-3, 4-5, and ≥6 corresponded to average Agatston scores of 0.52 (0.3-0.8), 98.7 (78.2-117.1), 350.6 (264.9-436.3) and 1925.4 (1526.9-2323.9). CONCLUSION: Visual assessment of CAC on non-gated routine chest CT accurately predicts Agatston score ranges, including the zero score, in ECG-gated CT. Inclusion of this information in radiology reports may be useful to convey important information on cardiovascular risk, particularly premature atherosclerosis in younger patients.

JOURNAL CLUB: Evidence of Interstitial Lung Disease on Low-Dose Chest CT Images: Prevalence, Patterns, and Progression.

OBJECTIVE: The purposes of this study were to determine the prevalence of interstitial lung disease (ILD) in a cohort undergoing low-dose CT screening for lung cancer, to identify the CT patterns of fibrosis, and to determine prognostic factors of disease progression. MATERIALS AND METHODS: The study drew from a database of 951 participants in a lung cancer screening program between 2010 and 2014. Three thoracic radiologists reviewed CT scans to identify the ILD findings, defined as traction bronchiectasis, ground-glass opacities with traction bronchiectasis, reticulations with traction bronchiectasis, and honeycombing. Evidence of ILD was considered present if at least two of three reviewing radiologists agreed. Age, smoking history, and CT evidence of emphysema were also documented. RESULTS: Of the 951 participants, 63 (6.6%) had CT evidence of ILD, and 16 of the 63 (1.7% of the total cohort) had honeycombing. Significant univariate predictors of ILD were male sex (p = 0.003), older age (p < 0.0001), higher number of pack-years of cigarette smoking (p = 0.0003), and greater severity of emphysema (p = 0.004), but only age and male sex remained significant in the multivariate analysis. The most common pattern of ILD was peripheral fibrosis without honeycombing involving multiple lobes. The presence of honeycombing was significantly associated with progression of fibrosis score (p = 0.0001) and extent of fibrosis (p = 0.005). CONCLUSION: A potential added benefit of CT screening is earlier diagnosis of ILD in older smokers, who are at increased risk. Radiologists should recognize the earliest findings of ILD and understand the importance of early recognition.

The general radiologist's role in breast cancer risk assessment: breast density measurement on chest CT.

To determine if general radiologists can accurately measure breast density on low-dose chest computed tomographic (CT) scans, two board-certified radiologists with expertise in mammography and CT scan interpretation, and seven general radiologists performed retrospective review of 100 women's low-dose chest CT scans. CT breast density grade based on Breast Imaging Reporting and Data System grades was independently assigned for each case. Kappa statistic was used to compare agreement between the expert consensus grading and those of the general radiologists. Kappa statistics were 0.61-0.88 for the seven radiologists, showing substantial to excellent agreement and leading to the conclusion that general radiologists can be trained to determine breast density on chest CT.

Idiopathic interstitial pneumonias: a radiology-pathology correlation based on the revised 2013 American Thoracic Society-European Respiratory Society classification system.

The idiopathic interstitial pneumonias (IIPs) are a group of diffuse lung diseases that share many similar radiologic and pathologic features. According to the revised 2013 American Thoracic Society-European Respiratory Society classification system, these entities are now divided into major IIPs (idiopathic pulmonary fibrosis, idiopathic nonspecific interstitial pneumonia, respiratory bronchiolitis-associated interstitial lung disease, desquamative interstitial pneumonia, cryptogenic organizing pneumonia, and acute interstitial pneumonia), rare IIPs (idiopathic lymphoid interstitial pneumonia, idiopathic pleuroparenchymal fibroelastosis), and unclassifiable idiopathic interstitial pneumonias. Some of the encountered radiologic and histologic patterns can also be seen in the setting of other disorders, which makes them a diagnostic challenge. As such, the accurate classification of IIPs remains complex and is best approached through a collaboration among clinicians, radiologists, and pathologists, as the treatment and prognosis of these conditions vary greatly.