Distribution of Aeration and Pulmonary Blood Volume in Healthy, ARDS and COVID-19 Lungs: A Dual-Energy Computed Tomography Retrospective Cohort Study.

RATIONALE AND OBJECTIVES: Few reports have studied lung aeration and perfusion in normal lungs, COVID-19, and ARDS from other causes (NC-ARDS) using dual-energy computed tomography pulmonary angiograms (DE-CTPA). To describe lung aeration and blood-volume distribution using DE-CTPAs of patients with NC-ARDS, COVID-19, and controls with a normal DE-CTPA ("healthy lungs"). We hypothesized that each of these conditions has unique ranges of aeration and pulmonary blood volumes. MATERIALS AND METHODS: This retrospective, single-center study of DE-CTPAs included patients with COVID-19, NC-ARDS (Berlin criteria), and controls. Patients with macroscopic pulmonary embolisms were excluded. The outcomes studied were the (1) lung blood-volume in areas with different aeration levels (normal, ground glass opacities [GGO], consolidated lung) and (2) aeration/blood-volume ratios. RESULTS: Included were 20 patients with COVID-19 (10 milds, 10 moderate-severe), six with NC-ARDS, and 12 healthy-controls. Lung aeration was lowest in patients with severe COVID-19 24% (IQR13%-31%) followed by those with NC-ARDS 40%(IQR21%-46%). Blood-volume in GGO was lowest in patients with COVID-19 [moderate-severe:-28.6 (IQR-33.1-23.2); mild: -30.1 (IQR-33.3-23.4)] and highest in normally aerated areas in NC-ARDS -37.4 (IQR-52.5-30.2-) and moderate-severe COVID-19 -33.5(IQR-44.2-28.5). The median aeration/blood-volume ratio was lowest in severe COVID-19 but some values overlapped with those observed among patients with NC-ARDS. CONCLUSION: Severe COVID-19 disease is associated with low total aerated lung volume and blood-volume in areas with GGO and overall aeration/blood volume ratios, and with high blood volume in normal lung areas. In this hypothesis-generating study, these findings were most pronounced in severe COVID disease. Larger studies are needed to confirm these preliminary findings.

Understanding Ballistic Injuries.

Understanding the pathophysiology of a disease allows physicians to make a diagnosis, alter its natural course, and develop and implement appropriate preventative and management strategies. With ballistic injuries, an understanding of how the mechanism of injury translates to the injuries observed makes it possible to make sense of what can, at times be a complex imaging appearance and mitigate against the long-term complications of gunshot wounds. In this article, the authors describe the different types of ballistic projectiles, their mechanism of injury as well as the injury patterns they cause. In addition, both lead arthropathy and MR imaging safety in patients with retained ballistic debris are discussed.

Bilateral Adrenal Hemorrhage in Coronavirus Disease 2019 Patient: A Case Report.

CONTEXT: Bilateral adrenal hemorrhage is a rare condition with potentially life-threatening consequences such as acute adrenal insufficiency. Early adrenal axis testing, as well as directed imaging, is crucial for immediate diagnosis and treatment. Coronavirus disease 2019 (COVID-19) has been associated with coagulopathy and thromboembolic events. CASE DESCRIPTION: A 66-year-old woman presented with acute COVID-19 infection and primary adrenal insufficiency due to bilateral adrenal hemorrhage (BAH). She also had a renal vein thrombosis. Her past medical history revealed primary antiphospholipid syndrome (APLS). Four weeks after discharge she had no signs of COVID-19 infection and her polymerase chain reaction test for COVID-19 was negative, but she still needed glucocorticoid and mineralocorticoid replacement therapy. The combination of APLS and COVID-19 was probably responsible of the adrenal event as a "two-hit" mechanism. CONCLUSIONS: COVID-19 infection is associated with coagulopathy and thromboembolic events, including BAH. Adrenal insufficiency is life threatening; therefore, we suggest that early adrenal axis testing for COVID-19 patients with clinical suspicion of adrenal insufficiency should be carried out.

Semi-automatic volumetric measurement of response to chemotherapy in lung cancer patients: How wrong are we using RECIST?

OBJECTIVES: Lung cancer typically starts as a near-spherical lesion, but as it grows it may acquire an irregular radiologic formation. RECIST is based on the assumption that tumors are spherical, and consequently, proportional changes of tumor volume and parallel changes in tumor diameter, and vice versa. Hence, a 30% decrease in diameter (2r) implies a 65% decrease of volume, and a 20% increase in diameter implies a 73% increase of volume. MATERIALS AND METHODS: We compared volumetric measurement based on multi-detector CT technology with calculated volume (CV) according to RECIST in a cohort of 43 patients with advanced, non-squamous cell type, lung cancer treated with a combination of platinum and pemetrexed. RESULTS: CV was larger than SMV in most patients both at baseline and at best overall response (BOR). The difference between the sum of volumes based on volumetric measurement (SMV) and CV was larger for higher sum of diameters. The Lin's concordance correlation coefficient between the percent changes in SMV and CV at BOR was 0.757. Of note, four patients (4/43, 9.5%) were categorized as PD according to the method of CV, but SD according to the method of SMV. CONCLUSION: Our study highlights the importance of volumetric measurement for assessing response to treatment in lung cancer patients particularly showing large, irregular lesions.

[Incidence of hospitalizations among chronic obstructive pulmonary disease (COPD) patients with anemia].

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterized by progressive exertional and resting dyspnea and is associated with major co-morbidities. Hemoglobin level disorders (anemia and polycythemia) prevalence among patients and the relationship between them and the clinical expression are still not characterized unequivocally. The main purpose of this work is to test the association between anemia and hospitalizations. The presence of such a link may promote the diagnosis and treatment aimed at the patient's hemoglobin levels. HYPOTHESIS: Anemia in patients with COPD is associated with an increased number of hospitalizations. METHODS: A retrospective cohort study analysis, conducted on a group of COPD patients (n = 333) followed in the Pulmonology Institute of the Soroka University Medical Center in the years 2003-2009. Demographic physiological and clinical characteristics were compared between anemic, polycythemic and normal hemoglobin patients. Using statistical models, we examined the relationship between the presence of anemia and clinical outcome. RESULTS: Anemia was found in 79 patients (24%) and polycythemia among seven patients (2%). No difference was found between the groups in terms of number of hospitalizations, number of hospitalization days and ventilator events. There was a higher rate of co-morbidities (such as heart failure, chronic kidney disease) among anemic patients. There were also lower values of BMI and lung function and a higher proportion of men among anemic patients. CONCLUSIONS: Anemia in patients with COPD was not associated with an increase in the number of severe exacerbations. More studies are needed to clarify the threshold of a hemoglobin level below which there is an increase in the rate of hospitalizations.