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.

Rhabdomyolysis as a manifestation of a severe case of COVID-19: A case report.

Since the outbreak of the ongoing pandemic of the novel coronavirus disease (COVID-19) in Wuhan, China, from December 2019, we have learned that multiple organs can be affected with the potential for various complications. Although myalgia is a frequent symptom in COVID-19 patients, no imaging findings of rhabdomyolysis have been featured in the literature. We report a case of presumed rhabdomyolysis in a 38-year-old male with COVID-19 based on the clinical presentation, laboratory results and radiological findings. By discussing the diagnostic rationale and reviewing the relevant literature we hope to advance the existing understanding of this disease and its effects on the musculoskeletal system.

Congenital Coronary Artery Anomalies and Implications.

This pictorial essay presents cases of congenital coronary artery anomalies, including congenital anomalies of origin, course, and termination. Familiarity with atypical coronary anatomy and clinical presentation may facilitate appropriate diagnosis and management, particularly as cardiac and thoracic computed tomographic utilization increases.

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.

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.

Subsolid pulmonary nodules: CT-pathologic correlation using the 2011 IASLC/ATS/ERS classification.

Adenocarcinoma is the most common histologic subtype of lung cancer. Recent advances in oncology, molecular biology, pathology, imaging, and treatment have led to an increased understanding of this disease. In 2011, the International Association for the Study of Lung Cancer, the American Thoracic Society, and the European Respiratory Society published a new international multidisciplinary classification. Using this taxonomy, we review the spectrum of subsolid pulmonary nodules seen on computed tomography together with their histopathologic correlates and current management guidelines.

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.

Magnetic resonance imaging of benign cardiac masses: a pictorial essay.

The differential diagnosis for a cardiac mass includes primary and metastatic neoplasms. While primary cardiac tumors are rare, metastatic disease to the heart is a common finding in cancer patients. Several "tumor-like" processes can mimic a true cardiac neoplasm with accurate diagnosis critical at guiding appropriate management. We present a pictorial essay of the most common benign cardiac masses and "mass-like" lesions with an emphasis on magnetic resonance imaging features.

Normal myocardial perfusion on 64-detector resting cardiac CT.

BACKGROUND: Computed tomography (CT) of the heart is increasingly used to characterize not only the coronary arteries but also cardiac structure and function. The performance of CT in depicting myocardial perfusion is under active investigation. OBJECTIVE: We describe the pattern of normal myocardial perfusion on resting 64-detector cardiac CT. METHODS: Patients (n = 33; 20 women, 13 men; mean age, 52 years) with normal radionuclide myocardial perfusion imaging and normal coronary arteries on CT angiography (120 kVp) comprised the study population. Segmental myocardial perfusion on CT was measured in Hounsfield units (HU) with manual and semiautomated methods for the 17-segment American Heart Association model in both systole and diastole. Segments were aggregated into coronary artery territories, from apex to base and by myocardial wall. The relationships between myocardial perfusion and various patient factors were evaluated. RESULTS: Overall mean myocardial perfusion was 98 HU in systole and 94 HU in diastole with the manual method (P = .011) and 92 HU in systole and 95 HU in diastole with the automated method (P = .001). The septum showed significantly higher mean attenuation values than the other walls in systole and diastole with both methods. Generally, attenuation values were lower in the left circumflex artery territory and in the apex. Bivariate analysis showed higher mean myocardial attenuation values for women than men, although this difference did not persist on multivariate analysis adjusted for patient size. CONCLUSION: Normal mean resting myocardial perfusion correlates with CT attenuation values of approximately 92-98 HU on CT angiography in the coronary arterial phase. The septum consistently shows greater attenuation values than the other walls.

Ventricular myocardial fat: CT findings and clinical correlates.

OBJECTIVES: Replacement of the myocardium by fat is a feature of arrythmogenic right ventricular dysplasia (ARVD). Pathology literature describes ventricular myocardial fat to be present not only in ARVD, but much more frequently related to aging, prior myocardial infarction (MI), and chronic ischemia. We noted focal ventricular myocardial fat in a group of patients who underwent chest computed tomography (CT) for varied indications. The aim of this study is to describe the noncontrast CT findings and clinical correlates of ventricular myocardial fat in this population. MATERIALS AND METHODS: We prospectively identified 26 patients whose noncontrast chest CT (5/03 to 6/04) demonstrated ventricular myocardial fat and whose clinical charts were available. There were 14 men and 12 women with a mean age of 70 years. Twenty-three percent (6/26) had prior CTs. Each CT was reviewed by 3 radiologists in consensus. The site of the ventricular fat was noted. Each patient was categorized based on the location of the fat as follows: group 1-right ventricle (RV) only, group 2-left ventricle (LV) only, group 3-biventricular. Results of cardiac history, laboratory tests, and cardiac imaging were noted. RESULTS: The distribution of ventricular myocardial fat was: group 1 RV-27% (7/26), group 2 LV-46% (12/26), and group 3 biventricular-27% (7/26). Echocardiographic, nuclear cardiology, or electrocardiographic data localizing a prior MI to a specific site were available in 35% (9/26) of patients: 14% (1/7) of group 1, 50% (6/12) of group 2, and 29% (2/7) of group 3. Myocardial fat corresponded to the site of MI in 89% (8/9). The presence and distribution of ventricular fat on CT was unchanged from prior CT in 100% (6/6). When comparing group 1 and group 2, group 1 was older (77 vs. 64 y, P=0.005), more often female (57% vs. 17%, P=0.13) and had fewer prior MI (14% vs. 50%, P=0.17) than group 2. Only 1 patient in this series had ARVD. He was in group 3. CONCLUSIONS: The significance of ventricular myocardial fat varies by location. Fat in the RV is most often related to aging. Prior RV MI and ARVD are less common etiologies. Fat in the LV is frequently related to prior MI. Recognition of myocardial fat on a noncontrast chest CT may be the first opportunity to diagnose a silent MI.