With lung cancer being the most common malignancy diagnosed worldwide, lung nodule assessment has proved to be one of big challenges of modern medicine. The aim of this study was to examine the usefulness of Dual Energy Computed Tomography (DECT) in solitary pulmonary nodule (SPN) assessment. Between January 2017 and June 2018; 65 patients (42 males and 23 females) underwent DECT scans in the late arterial phase (AP) and venous phase (VP). We concluded that imaging at an energy level of 65 keV was the most accurate in detecting malignancy in solitary pulmonary nodules (SPNs) measuring ≤30 mm in diameter on virtual monochromatic maps. Both virtual monochromatic images and iodine concentration maps prove to be highly useful in differentiating benign and malignant pulmonary nodules. As for iodine concentration maps, the analysis of venous phase images resulted in the highest clinical usefulness. To summarize, DECT may be a useful tool in the differentiation of benign and malignant SPNs. A single-phase DECT examination with scans acquired 90 s after contrast media injection is recommended.

The role of the adaptive microenvironment components in severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) infection is widely researched, but remains unclear. Studying the common dynamics of adaptive immune response changes can help understand the pathogenesis of coronavirus disease 2019 (COVID-19), especially in critical patients. The aim of the present study was to determine the cytokines concentration and leukocyte subpopulations profiles in the severe COVID-19 (n = 23) and critical (n = 18) COVID-19 group distinguished by the computed tomography (CT) severity score. We observed lower percentage of lymphocyte subpopulation, higher neutrophils to lymphocytes ratio (NLR) and higher IL-6 concentration in critical COVID-19 group than in severe group. CT severity score was negative correlated with proportion of lymphocytes, lymphocytes T, CD4+ cells, Treg cells and NK cells and positive correlated with neutrophils, NLR, and IL-6. In critical group more correlations between cytokines and lymphocytes were observed, mainly between TNF-α, IL-1β and lymphocyte subpopulations. The collective assessment of the cytokine profile, leukocyte subpopulations and the CT severity score can help to characterize and differentiate patient in advanced COVID-19 than the study of single parameters. We have shown that the interconnection of elements of the adaptive microenvironment can play an important role in critical COVID-19 cases.

Background/Objectives: Coronavirus disease 2019 (COVID-19) course may differ among individuals—in particular, those with comorbidities may have severe pneumonia, requiring oxygen supplementation or mechanical ventilation. Post-COVID-19 long-term structural changes in imaging studies can contribute to persistent respiratory disturbance. This study aimed to investigate COVID-19 sequels affecting the possibility of persistent structural lung tissue abnormalities and their influence on the respiratory function of peripheral airways and gas transfer. Methods: Patients were divided into two groups according to severity grades described by the World Health Organization. Among the 176 hospitalized patients were 154 patients with mask oxygen supplementation and 22 patients with high-flow nasal cannula (HFNC) or mechanical ventilation. All tests were performed at 3, 6, and 9 months post-hospitalization. Results: Patients in the severe/critical group had lower lung volumes in FVC, FVC%, FEV1, FEV1%, LC, TLC%, and DLCO% at three months post-hospitalization. At 6 and 9 months, neither group had significant FVC and FEV1 value improvements. The MEF 25–75 values were not significantly higher in the mild/moderate group than in the severe/critical group at three months. There were weak significant correlations between FVC and FEV1, MEF50, MEF 75, plethysmography TLC, disturbances in DLCO, and total CT abnormalities in the severe/critical group at three months. In a mild/moderate group, there was a significant negative correlation between the spirometry, plethysmography parameters, and CT lesions in all periods. Conclusions: Persistent respiratory symptoms post-COVID-19 can result from fibrotic lung parenchyma and post-infectious stenotic small airway changes not visible in CT, probably due to persistent inflammation.

One of the most commonly observed complications after COVID-19 is persistent pulmonary impairment. The aim of this study was to evaluate the impact of individual factors during the acute phase of COVID-19 on subsequent pulmonary function test results. The study involved 46 patients who were admitted to hospital due to respiratory failure caused by SARS-CoV-2 and who were assessed during follow-up visits at 3 and 9 months after discharge. Patients were divided into two subgroups according to the severity of respiratory failure. The severe group included patients requiring mechanical ventilation or HFNOT. The results of the study showed that a severe course of the disease was associated with a lower FVC and a higher FEV1/FVC ratio 3 months after discharge (both p < 0.05). In addition, it has been revealed that the length of hospitalization is a factor that negatively impacts the FEV1, FVC and TLC values measured at follow-up after 3 months. Furthermore, the obtained results identify the presence of cough in the acute phase of the disease as a factor having a positive impact on several PFT parameters (especially the FEV1/FVC ratio) as well as the 6MWT outcome after 3 months. The FVC improved significantly (p < 0.05) between the follow-up visits. The findings may indicate that COVID-19-induced respiratory dysfunction is usually temporary and spontaneously resolves during recovery. Recovery is slower in those who required more intensive oxygenation. The results of this study may be useful in identifying patients who require more intensive and longer rehabilitation after COVID-19.

For some time, dual energy computed tomography (DECT) has been an established method used in a vast array of clinical applications, including lung nodule assessment. The aim of this study was to analyze (using monochromatic DECT images) how the X-ray absorption of solitary pulmonary nodules (SPNs) depends on the iodine contrast agent and when X-ray absorption is no longer dependent on the accumulated contrast agent. Sixty-six patients with diagnosed solid lung tumors underwent DECT scans in the late arterial phase (AP) and venous phase (VP) between January 2017 and June 2018. Statistically significant correlations (p ≤ 0.001) of the iodine contrast concentration were found in the energy range of 40–90 keV in the AP phase and in the range of 40–80 keV in the VP phase. The strongest correlation was found between the concentrations of the contrast agent and the scanning energy of 40 keV. At the higher scanning energy, no significant correlations were found. We concluded that it is most useful to evaluate lung lesions in DECT virtual monochromatic images (VMIs) in the energy range of 40–80 keV. We recommend assessing SPNs in only one phase of contrast enhancement to reduce the absorbed radiation dose.

The consequences of COVID-19 constitute a significant burden to healthcare systems worldwide. Conducting an HRQoL assessment is an important aspect of the evaluation of the impact of the disease. The aim of this study was to investigate the prevalence of persistent symptoms and their impact on HRQoL and health status in COVID-19 convalescents. The study group consists of 46 patients who required hospitalization due to respiratory failure and who were subsequently evaluated 3 and 9 months after hospital discharge. At the follow-up visits, the patients were asked to assess their HRQoL using the EQ-5D-5L questionnaire. The results of chest CT, 6MWT, as well as the severity of the course of COVID-19 were also considered in the analysis. The obtained results have identified fatigue as the most common persistent symptom. The majority of the convalescents reported an impairment of HRQoL in at least one domain (80% and 82% after 3 and 9 months, respectively), of which the most common was that of pain/discomfort. The presence of ongoing symptoms may affect HRQoL in particular domains. The 6MWT outcome correlates with HRQoL 3 months after hospital discharge. Therefore, it may be useful in identifying patients with reduced HRQoL, allowing early interventions aimed at its improvement.