Chest Computed Tomography Scan Research Articles

In situ ascending aortic thrombus in a patient with metastatic lung adenocarcinoma and no aortic atherosclerosis or cisplatin exposure: a case report

BackgroundAn ascending aortic thrombus is exceedingly rare. Two instances have been reported in the setting of lung cancer, but only after cisplatin use, which is associated with hypercoagulability. We present the first case of a patient with lung cancer who developed an ascending aortic thrombus without structural risk factors or chemotherapy use.CaseA 60-year-old white female with significant smoking history presented with several weeks of malaise. A chest computed tomography scan revealed a 2.2-cm right upper lobe mass. As an outpatient, right hilar lymph node immunohistochemistry (IHC) samples via endobronchial ultrasound confirmed thyroid transcription factor-1 adenocarcinoma. After the procedure, the patient endorsed dyspnea and was advised to go to the emergency department. A chest computed tomography angiography identified a new 2.4 × 1.1 × 1.1 cm thrombus within the proximal aortic arch. No pulmonary emboli or intrapulmonary shunts were identified. A hypercoagulable workup was negative. Transthoracic echocardiogram was without left ventricular thrombus, akinesis or hypokinesis, left atrial dilation, or intracardiac shunts. A lower extremity ultrasound was negative for deep vein thrombosis. Given the procedural risk, thrombectomy was deferred. The patient was transitioned to enoxaparin, and a repeat computed tomography for resolution is in process.ConclusionTo our knowledge, this is the only case detailing an in situ ascending aortic thrombus in the setting of lung cancer, without structural risk factors, chemotherapy use, or other hypercoagulable comorbidities. Optimal management for an aortic thrombus and malignant disease is less clear. Clinicians should be vigilant for unusual arterial thromboses in patients with high metastatic burden.

ReDS to detect pulmonary congestion in the emergency department: reproducibility and effect of pulmonary comorbidities

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): This work was supported by the research fund of Bispebjerg University Hospital and Helsefonden. Background Remote Dielectric Sensing (ReDS) is a fast, non-invasive bedside method that estimates lung fluid content observer-independently. We previously described that ReDS has a moderate accuracy to detect acute heart failure in consecutive patients, and we hypothesise that unprecise ReDS estimates may arise from concomitant pulmonary diseases. Still, it is unknown how common comorbidities influence estimates of pulmonary congestion when using ReDS in the emergency department (ED). Purpose To examine the reproducibility of ReDS and the effect of pulmonary comorbidities in dyspnoeic patients in the ED. Method This prospective observational study included consecutive ED patients ≥50 years with acute dyspnoea. Upon admission, all patients were examined with a low-dose chest computed tomography (CT), an echocardiography and a ReDS examination. The default ReDS examination is performed with the ReDS device placed on the right hemithorax in sitting position. However, for reproducibility comparisons, we conducted three ReDS measurements on the right hemithorax after small adjustments, and in supine position (Picture 1: Scenario 1 and 2). Two blinded radiologists evaluated the CT scans for pulmonary congestion and other common pulmonary diseases. Results 97 patients were included and had study examinations conducted within a median of 4.8 hours from admission. Reproducibility comparisons revealed coefficients of variations (CV) of 9.6%, 8.2%, and 8.3% for three ReDS measurements on the right hemithorax (Picture 1: Scenario 1). Similarly, CV was 9.5% for sitting versus supine positions (Picture 1: Scenario 2). For scenario 2, patients with CT verified pulmonary congestion had CV of 5.9%, while those without pulmonary congestion had CV of 10.3%. In multivariate linear regression, we examined the relationship between pulmonary findings on CT and ReDS as a response variable (overall mean ReDS=31.6%, p<0.001). Lower ReDS estimates were observed in patients with pneumonia (-1.81, p=0.215, N=51) and emphysema (-5.44, p=0.001, N=26). Higher ReDS estimates were observed in fibrosis (5.58, p=0.032, N=8) and pulmonary congestion (5.79, p=0.002, N=17). Conclusion ReDS showed good reproducibility for patients with CT verified pulmonary congestion. However, the reproducibility was only moderate for consecutive patients with dyspnoea, who had a high prevalence of CT verified emphysema, lowering the ReDS estimates.Reproducibility comparisons

Clinical thinking and instrumental diagnostics in the late stage of hypersensitive pneumonitis

The existing inertia of clinical thinking in establishing a diagnosis, even in the presence of instrumental and valid diagnostic criteria, does not always allow for a reconsideration of the diagnosis given to the patient, especially several years ago. Existing clinical recommendations for certain nosological forms, which currently play a decisive role in diagnostics, treatment, and quality assessment of medical services, may not be fully applicable to all patients with a specifi c disease. As an illustration of the above, a clinical example of a patient diagnosed with “bronchial asthma” about 15 years ago without diagnostic criteria for this condition is provided. Three years ago, on a hospitalization described in the article, a chest computed tomography scan revealed typical signs of diff use pulmonary pneumonia. However, this did not allow for a change in the stereotypical diagnostic view and the correct diagnosis and appropriate treatment, including in a specialized pulmonology department. As a result, the disease progressed with the development of complications in the form of severe respiratory and heart failure. Only a reassessment of clinical symptoms, including inspiratory crackles, chest CT scan (diffuse opacity reduction resembling ground glass), and restrictive abnormalities in external respiration function without obstructive components, allowed for a reevaluation of the diagnosis and the prescription of pathogenetic therapy with glucocorticoids in combination with treatment for respiratory and heart failure, leading to rapid clinical improvement.

Comparing Visual and Software-Based Quantitative Assessment Scores of Lungs’ Parenchymal Involvement Quantification in COVID-19 Patients

(1) Background: Computed tomography (CT) plays a paramount role in the characterization and follow-up of COVID-19. Several score systems have been implemented to properly assess the lung parenchyma involved in patients suffering from SARS-CoV-2 infection, such as the visual quantitative assessment score (VQAS) and software-based quantitative assessment score (SBQAS) to help in managing patients with SARS-CoV-2 infection. This study aims to investigate and compare the diagnostic accuracy of the VQAS and SBQAS with two different types of software based on artificial intelligence (AI) in patients affected by SARS-CoV-2. (2) Methods: This is a retrospective study; a total of 90 patients were enrolled with the following criteria: patients’ age more than 18 years old, positive test for COVID-19 and unenhanced chest CT scan obtained between March and June 2021. The VQAS was independently assessed, and the SBQAS was performed with two different artificial intelligence-driven software programs (Icolung and CT-COPD). The Intraclass Correlation Coefficient (ICC) statistical index and Bland–Altman Plot were employed. (3) Results: The agreement scores between radiologists (R1 and R2) for the VQAS of the lung parenchyma involved in the CT images were good (ICC = 0.871). The agreement score between the two software types for the SBQAS was moderate (ICC = 0.584). The accordance between Icolung and the median of the visual evaluations (Median R1–R2) was good (ICC = 0.885). The correspondence between CT-COPD and the median of the VQAS (Median R1–R2) was moderate (ICC = 0.622). (4) Conclusions: This study showed moderate and good agreement upon the VQAS and the SBQAS; enhancing this approach as a valuable tool to manage COVID-19 patients and the combination of AI tools with physician expertise can lead to the most accurate diagnosis and treatment plans for patients.

Factors influencing survival and mortality among adult Aboriginal Australians with bronchiectasis—A 10-year retrospective study

BackgroundThe prevalence of bronchiectasis among adult Aboriginal Australians is higher than that of non-Aboriginal Australians. However, despite evidence to suggest higher prevalence of bronchiectasis among Aboriginal people in Australia, there is sparce evidence in the literature assessing clinical parameters that may predict survival or mortality in this population.MethodsAboriginal Australians residing in the Top End Health Service region of the Northern Territory of Australia aged >18 years with chest computed tomography (CT) confirmed bronchiectasis between 2011 and 2020 were included. Demographics, body mass index (BMI), medical co-morbidities, lung function data, sputum microbiology, chest CT scan results, hospital admissions restricted to respiratory conditions and all-cause mortality were assessed.ResultsA total of 459 patients were included, of whom 146 were recorded deceased (median age at death 59 years). Among the deceased cohort, patients were older (median age 52 vs. 45 years, p = 0.023), had a higher prevalence of chronic obstructive pulmonary disease (91 vs. 79%, p = 0.126), lower lung function parameters (median percentage predicted forced expiratory volume in 1 s 29 vs. 40%, p = 0.149), a significantly greater proportion cultured non-Aspergillus fungi (65 vs. 46%, p = 0.007) and pseudomonas (46 vs. 28%, p = 0.007) on sputum microbiology and demonstrated bilateral involvement on radiology. In multivariate models advancing age, prior pseudomonas culture and Intensive care unit (ICU) visits were associated with increased odds of mortality. Higher BMI, better lung function on spirometry, prior positive sputum microbiology for Haemophilus and use of inhaled long-acting beta antagonist/muscarinic agents may have a favourable effect.ConclusionThe results of this study may be of use to stratify high risk adult Aboriginal patients with bronchiectasis and to develop strategies to prevent future mortality.

Determination of pulmonary vessel alteration in Chinese male smokers by quantitative computed tomography measurements: a retrospective study.

The blood volume of intraparenchymal vessels is reported to be increased in smokers. However, the blood volume can be affected by many confounders besides tobacco exposure. This study aimed to investigate the association between cigarette smoking and pulmonary blood volume after adjusting the related factors in a large cohort of Chinese males. In this retrospective study, male participants admitted to the First Affiliated Hospital of Xi'an Jiaotong University for annual health assessment between February 2017 and February 2018 were enrolled. All subjects underwent non-contrast chest computed tomography (CT) scans, and 152 subjects underwent a review CT scan 2-3 years later. A three-dimensional approach was employed to segment the lung and intrapulmonary vessels and quantitative CT (QCT) measurements, including lung volume (LV), intrapulmonary vessel volume (IPVV), low-attenuation area <-950 Hounsfield unit (LAA-950 and LAA-950%), and mean lung density (MLD). Linear regression was used to estimate the association between IPVV and the smoking index (SI). A paired t-test was used to compare the QCT parameters between the initial and follow-up CT scans. A total of 656 male participants were enrolled and classified into three subgroups: non-smokers (n=311), current smokers (n=267), and former smokers (n=78). The IPVV of current smokers (134.62±23.96 vs. 120.76±25.52 mL) and former smokers (130.79±25.13 vs. 120.76±25.52 mL) were significantly larger than that of non-smokers (P<0.05). A higher SI was associated with greater IPVV [non-standardized coefficient: 0.167, 95% confidence interval (CI): 0.086-0.248]. For current smokers, the IPVV of the follow-up scan significantly increased compared to its baseline scan (135.49±28.60 vs. 129.73±29.75 mL, t=-2.326, P=0.02), but for the non-smokers and former smokers, the IPVV of the follow-up scan did not increase or decrease compared to the baseline scan (P>0.05). Pulmonary vascular volumes detectable on non-contrast CT are associated with cigarette exposure, and smoking cessation may prevent pulmonary vasculature remodeling.

Radiographic chest wall abnormalities in primary spontaneous pneumothorax identified by artificial intelligence

Primary spontaneous pneumothorax (PSP) primarily affects slim and tall young males. Exploring the etiological link between chest wall structural characteristics and PSP is crucial for advancing treatment methods. In this case-control study, chest computed tomography (CT) images from patients undergoing thoracic surgery, with or without PSP, were analyzed using Artificial Intelligence. Convolutional Neural Network (CNN) model of EfficientNetB3 and InceptionV3 were used with transfer learning on the Imagenet to compare the images of both groups. A heatmap was created on the chest CT scans to enhance interoperability, and the scale-invariant feature transform (SIFT) was adopted to further compare the image level. A total of 2,312 CT images of 26 non-PSP patients and 1,122 CT images of 26 PSP patients were selected. Chest-wall apex pit (CAP) was found in 25 PSP and three non-PSP patients (p < 0.001). The CNN achieved a testing accuracy of 93.47 % in distinguishing PSP from non-PSP based on chest wall features by identifying the existence of CAP. Heatmap analysis demonstrated CNN's precision in targeting the upper chest wall, accurately identifying CAP without undue influence from similar structures, or inappropriately expanding or minimizing the test area. SIFT results indicated a 10.55 % higher mean similarity within the groups compared to between PSP and non-PSP (p < 0.001). In conclusion, distinctive radiographic chest wall configurations were observed in PSP patients, with CAP potentially serving as an etiological factor linked to PSP. This study accentuates the potential of AI-assisted analysis in refining diagnostic approaches and treatment strategies for PSP.

Renal Embolism Associated with the Atrial Myxoma: A Case Report and Literature Review

Renal embolisms due to cardiac myxomas are extremely rare; the clinical course, treatment, and prognosis of this disease are not established. A 69-year-old Japanese woman who underwent a nephrectomy for renal cell carcinoma 3 years earlier was hospitalized with a right occipital lobe cerebral infarction. Her renal function suddenly worsened 3 days post-admission: her serum creatinine rose from 1.46 mg/dL to 6.57 mg/dL and then to 8.03 mg/dL the next day, and hemodialysis therapy was started. Abdominal computed tomography (CT) scans showed patchy non-contrasted low-density areas in the right kidney, and chest CT scans and transesophageal ultrasonography revealed a left atrial tumor. We diagnosed renal infarction due to a left atrial myxoma. Hemodialysis and anticoagulant therapy (heparin) were continued, followed by the cardiac myxoma’s resection. The patient’s renal function gradually improved post-surgery, and the hemodialysis was discontinued. Considering our patient and 19 other case reports of renal infarction associated with cardiac myxoma, the treatment for such a renal infarction and the outcomes differ depending on the embolus site. The poor outcome of abdominal aortic embolism requires a prompt embolectomy, whereas a branch renal artery embolism requires anticoagulation therapy to prevent thrombosis formation around the myxoma.

Computed Tomography-Based Body Composition is Related to Perioperative Morbidity in Older Lung Transplant Recipients

Abstract Background In older patients, a limited physical reserve is considered a contraindication for lung transplantation (LTx). Herein, we aimed to establish a computed tomography (CT)-based quantification of physical reserve in older patients scheduled for transplantation. Methods This retrospective study included patients older than 60 years who received LTx. Semiautomatic measurements of the mediastinal fat area and the dorsal muscle group area in pretransplantation CT scans were performed, and normalized data were correlated with clinical parameters. Results Patients (n = 108) were assigned into three groups (Musclehighfatlow [n = 25], Musclelowfathigh [n = 24], and other combinations [n = 59]). The Musclelowfathigh group had a significantly increased risk of wound infections (p = 0.002) and tracheostomy (p = 0.001) compared with Musclehighfatlow patients. The median length of intensive care unit stay (25 vs. 3.5 days; p = 0.002) and the median length of hospital stay (44 vs. 22.5 days; p = 0.013) post-LTx were significantly prolonged in the Musclelowfathigh group. Significantly more patients in this group had a prolonged ventilation time (11 vs. 0; p &lt; 0.001). Conclusion Body composition parameters determined in pretransplant chest CT scans in older LTx candidates might aid in identifying high-risk patients with a worse perioperative outcome after LTx.

Radiation exposure of patients from computed tomography for COVID-19 diagnosis

BackgroundDuring the global Coronavirus Disease 2019 (COVID-19) pandemic, numerous computed tomography (CT) scans were conducted to assess pulmonary abnormalities associated with COVID-19. A number of studies have contributed to our current understanding of radiation doses in the context of chest CT scans for COVID-19 diagnosis, but there remains a discernible gap in the literature regarding organ-level dose assessments. Materials and methodsWe estimated organ and effective dose for the COVID-19-related chest CT patients in the following three steps. First, we collected CTDIvol and DLP from the literature published during and after COVID-19 pandemic period. Second, we developed the probability density functions (PDFs) for the CTDIvol and the starting location of CT scans by age groups from which 1000 sets of patient and technique parameters were created. With CT organ dose calculation software, National Cancer Institute dosimetry system for CT (NCICT), we calculated 1000 sets of plausible organ and effective doses and evaluated summary statistics for the patient population. ResultsThe standard dose protocol administered approximately five times higher CTDIvol (5.4 mGy) to patients undergoing COVID-19-related chest CT scans compared to the low dose protocol (1.1 mGy). The median lung dose (11.8 mGy) for the 1-year-old patients was about 1.5 times greater than that (7.8 mGy) of the adult patients. We found that 75% of whole COVID-19-related CT patients would have received effective doses less than 6.4 mSv and 1.5 mSv when scanned by standard dose and low dose protocols, respectively. ConclusionWe evaluated the distribution of organ and effective dose for the COVID-19-related chest CT patients worldwide by collecting comprehensive data of CTDIvol for the COVID-19-related chest CT scans from the literature and combining them with NCICT organ dose calculator. While past studies have predominantly reported basic CT dose descriptors, our work takes it a step further by reporting organ-level doses and effective doses. Subsequent research endeavors could involve enhancing the precision of radiation dose assessment through the collection of a subset of electronic CT records.

Multi-modal Pulmonary Imaging: Using Complementary Information from CT and Hyperpolarized 129Xe MRI to Evaluate Lung Structure-Function.

Hyperpolarized 129Xe gas MRI is an emerging technique to evaluate and measure regional lung function including pulmonary gas distribution and gas exchange. Chest computed tomography (CT) still remains the clinical gold standard for imaging of the lungs, though, in part due to the rapid CT protocols that acquire high-resolution images in seconds and the widespread availability of CT scanners. Quantitative approaches have enabled the extraction of structural lung parenchymal, airway and vascular measurements from chest CT that have been evaluated in many clinical research studies. Together, CT and 129Xe MRI provide complementary information that can be used to evaluate regional lung structure and function, resulting in new insights into lung health and disease. 129Xe MR-CT image registration can be performed to measure regional lung structure-function to better understand lung disease pathophysiology, and to perform image-guided pulmonary interventions. Here, a method for 129Xe MRI-CT registration is outlined to support implementation in research or clinical settings. Registration methods and applications that have been employed to date in the literature are also summarized, and suggestions are provided for future directions that may further overcome technical challenges related to 129Xe MR-CT image registration and facilitate broader implementation of regional lung structure-function evaluation.

Integration of Artificial Intelligence into Chest Computed Tomography

The integration of Artificial Intelligence (AI) in radiology, especially for chest computed tomography (CT) scan analysis, marked a significant advancement in medical diagnostics, aiming to improve patient care and streamline the workflow for radiologists. This review article examined the role of current AI technologies, including machine learning (ML), deep learning (DL), convolutional neural networks (CNN), and radiomics, in enhancing the detection and characterisation of lung diseases. These technologies are instrumental in identifying complex patterns within imaging data and constructing more informed decisions regarding disease severity, progression, and potential treatment options. Deep learning and CNN have demonstrated effectiveness in analysing the intricate details present in chest CT scans, offering a high degree of accuracy. Radiomics complements these methods by extracting quantitative features from medical images, providing deeper insights into disease characteristics that are not visible through standard imaging techniques. The application of AI has shown promise in improving the diagnosis and management of interstitial lung diseases and lung cancers, contributing to the development of personalised treatment plans. However, this review also highlights limitations, such as small sample sizes in studies, which may impact the generalisability of AI applications in this field. Despite these challenges, the ongoing incorporation of AI into radiological practices is anticipated to significantly enhance the accuracy and efficiency of lung disease diagnostics, setting a foundation for future research and improvements in clinical practice.

Opportunistic Screening for Acute Vertebral Fractures on a Routine Abdominal or Chest Computed Tomography Scans Using an Automated Deep Learning Model.

To develop an opportunistic screening model based on a deep learning algorithm to detect recent vertebral fractures in abdominal or chest CTs. A total of 1309 coronal reformatted images (504 with a recent fracture from 119 patients, and 805 without fracture from 115 patients), from torso CTs, performed from September 2018 to April 2022, on patients who also had a spine MRI within two months, were included. Two readers participated in image selection and manually labeled the fractured segment on each selected image with Neuro-T (version 2.3.3; Neurocle Inc.) software. We split the images randomly into the training and internal test set (labeled: unlabeled = 480:700) and the secondary interval validation set (24:105). For the observer study, three radiologists reviewed the CT images in the external test set with and without deep learning assistance and scored the likelihood of an acute fracture in each image independently. For the training and internal test sets, the AI achieved a 99.86% test accuracy, 91.22% precision, and 89.18% F1 score for detection of recent fracture. Then, in the secondary internal validation set, it achieved 99.90%, 74.93%, and 78.30%, respectively. In the observer study, with the assistance of the deep learning algorithm, a significant improvement was observed in the radiology resident's accuracy, from 92.79% to 98.2% (p = 0.04). The model showed a high level of accuracy in the test set and also the internal validation set. If this algorithm is applied opportunistically to daily torso CT evaluation, it will be helpful for the early detection of fractures that require treatment.

Predictive value of CT and 18F-FDG PET/CT features on spread through air space in lung adenocarcinoma

BackgroundLung adenocarcinoma, a leading cause of cancer-related mortality, demands precise prognostic indicators for effective management. The presence of spread through air space (STAS) indicates adverse tumor behavior. However, comparative differences between 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography(PET)/computed tomography(CT) and CT in predicting STAS in lung adenocarcinoma remain inadequately explored. This retrospective study analyzes preoperative CT and 18F-FDG PET/CT features to predict STAS, aiming to identify key predictive factors and enhance clinical decision-making.MethodsBetween February 2022 and April 2023, 100 patients (108 lesions) who underwent surgery for clinical lung adenocarcinoma were enrolled. All these patients underwent 18F-FDG PET/CT, thin-section chest CT scan, and pathological biopsy. Univariate and multivariate logistic regression was used to analyze CT and 18F-FDG PET/CT image characteristics. Receiver operating characteristic curve analysis was performed to identify a cut-off value.ResultsSixty lesions were positive for STAS, and 48 lesions were negative for STAS. The STAS-positive was frequently observed in acinar predominant. However, STAS-negative was frequently observed in minimally invasive adenocarcinoma. Univariable analysis results revealed that CT features (including nodule type, maximum tumor diameter, maximum solid component diameter, consolidation tumor ratio, pleural indentation, lobulation, spiculation) and all 18F-FDG PET/CT characteristics were statistically significant difference in STAS-positive and STAS-negative lesions. And multivariate logistic regression results showed that the maximum tumor diameter and SUVmax were the independent influencing factors of CT and 18F-FDG PET/CT in STAS, respectively. The area under the curve of maximum tumor diameter and SUVmax was 0.68 vs. 0.82. The cut-off value for maximum tumor diameter and SUVmax was 2.35 vs. 5.05 with a sensitivity of 50.0% vs. 68.3% and specificity of 81.2% vs. 87.5%, which showed that SUVmax was superior to the maximum tumor diameter.ConclusionThe radiological features of SUVmax is the best model for predicting STAS in lung adenocarcinoma. These radiological features could predict STAS with excellent specificity but inferior sensitivity.

Rosai-Dorfman disease manifesting as a solitary mass with fat in the thymus a case report

BackgroundSinus histiocytosis with massive lymphadenopathy, also known as Rosai-Dorfman disease, is a rare, self-limiting disease that predominantly affects children and young adults. Moreover, the disease is characterized by painless bilateral cervical lymphadenopathy in 95% of the patients. However, few reports are available on the Rosai-Dorfman disease of the thymus.Case presentationWe report a rare case of thymic Rosai-Dorfman disease detected using computed tomography. During a medical examination, a 50-year-old man underwent a chest computed tomography scan, which revealed an anterior mediastinal single mass with fat in the thymus. A thymectomy was performed to completely remove the tumor using a thoracoscopic technique due to a clinical suspicion of thymoma. Furthermore, Rosai-Dorfman disease was confirmed using histological and immunohistochemical analyses.ConclusionsTo the best of our knowledge, this is the sixth case of thymus-affecting solitary Rosai-Dorfman disease with histological and immunohistochemical evidence. Fat in the thymus, as was present in this case, has never been described in Rosai-Dorfman disease previously. Our results highlight the challenge of diagnosing this uncommon tumor before surgery, and more cases need to be reported to help with the preoperative diagnosis of such a rare tumor.

Residual radiological opacities correlate with disease outcomes in ICU-treated COVID-19.

Few studies consider both radiological and functional outcomes in COVID-19 survivors treated in the intensive care unit (ICU). We investigated clinical findings and pulmonary abnormalities on chest computed tomography (CT) and compared outcomes of severe versus mild-moderate acute respiratory distress syndrome (ARDS) on long-term follow-up. This longitudinal cohort study included 118 COVID-19 patients (median age, 58 years; 79% men). Thoracic CT scans were performed 4, 10, and 22 months after hospital discharge. Two independent blinded radiologists analyzed the 10 months scans and scored the radiology findings semi-quantitatively, as no/minor versus widespread opacities [low-radiology opacity grade (ROG) versus high-ROG]. ARDS severity was based on the PaO2/FiO2 ratio. The 6 min walk test (6MWT) was performed after 3 and 9 months, and lung diffusion capacity for carbon monoxide (DLCO) and lung volume measurement after 9 and 15 months. Dynamic spirometry was done at all time points. Residual symptoms and health-related quality-of-life (HRQL) were evaluated using validated questionnaires. At 10 months, most patients (81/118; 69%) were classified as high-ROG, of which 70% had severe ARDS during hospitalisation; 69% of those with mild-moderate ARDS also had high-ROG. Patients with high-ROG had longer ICU stay and lower PaO2/FiO2 during hospitalisation (p < 0.01). At 9 months follow-up, patients with high-ROG had smaller lung volumes as % of predicted values [mean (±CI): 80 (77-84) vs. 93 (88-98) (p < 0.001)], lower DLCO as % of predicted values [74 (70-78) vs. 87 (82-92) (p < 0.001)], lower oxygen saturation during 6MWT (p = 0.02), and a tendency to more severe dyspnoea (p = 0.07), but no difference was found in HRQL compared with no/minor ROG (p = 0.92). A higher opacity score was related to lower DLCO at follow-up (r = -0.48, p < 0.001, Spearman rank test). Severe ARDS patients had slightly more severe fatigue at 9 months compared to mild-moderate, but no differences in dyspnoea or lung function at follow-up. Fibrotic-like changes were found in 93% of patients examined with CT scans at 2 years (55/118; 47%). Severe ARDS could predict widespread opacities (ROG > 25%) in most patients at follow-up at 10 months (AUC 0.74). Residual radiological abnormalities in ICU-treated COVID-19 patients, evaluated for up to 2 years, relate to persisting symptoms and impaired lung function, demanding careful follow-up regardless of ARDS severity at hospitalisation.

The Histopathologic Features of Early COVID Pneumonia in a Pediatric Patient: New Insight into the Role of Macrophages

A life-threatening complication of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection is acute respiratory distress syndrome. Our understanding of the pathologic changes in coronavirus disease 2019 (COVID-19) is based almost exclusively on post-mortem analyses of adults. These studies established several hallmarks of SARS-CoV-2 lung infection, including diffuse alveolar damage, microvascular thrombi, and acute bronchopneumonia. We describe a fatal example of COVID pneumonia in a 9-year-old girl who presented with fever 10 months following the diagnosis of ALK-positive anaplastic large cell lymphoma (ALCL). A chest computed tomography scan revealed left upper lobe lung consolidation and nodular airspace disease, and an initial SARS-CoV-2 nasopharyngeal swab (RT-PCR) was negative. A subsequent lung biopsy performed due to concern for relapsed ALCL demonstrated sheets of intra-alveolar and interstitial macrophages, and macrophage-rich fibrinous exudates. Immunohistochemical and in-situ hybridization stains confirmed these macrophages as the predominant SARS-CoV-2-infected cell type. Subsequent RT-PCR testing of upper and lower respiratory tract samples was positive for SARS-CoV-2 infection. Whole genome sequencing confirmed the presence of the B.1.617.2 (Delta) variant. This biopsy illustrates the histopathologic features of early COVID pneumonia in antemortem lung tissue from a pediatric patient, and establishes macrophages as a potential source of SARS-CoV-2 amplification.

Correlation Between HIF1-A Expression and Airway Remodeling in COPD.

Airway remodeling is a significant pathological characteristic of chronic obstructive pulmonary disease (COPD). In recent years, hypoxia-inducible factor 1-α (HIF-1α), a member of the hypoxia-inducible factor protein family, has gained attention. However, the potential correlation between HIF-1α and COPD airway remodeling remains unclear. This study explored the expression patterns of HIF-1α in patients with COPD and its association with airway remodelling. This investigation aims to furnish novel insights for the clinical identification of prospective therapeutic targets for ameliorating COPD-related airway remodelling. A total of 88 subjects were included, consisting of 28 controls and 60 COPD patients. Various staining methods were employed to observe the pathological changes in airway tissues. Immunohistochemistry was utilized to detect the expression of HIF-1α and MMP9 (matrix metalloproteinase 9) in airway tissues. Enzyme-linked immunosorbent assay (ELISA) was used to measure the concentration in serum of HIF-1α and MMP9. Computed tomography (CT) airway parameters were measured in all participants to assess airway remodeling. The relationship between serum HIF-1α and MMP9 concentrations and airway parameters was analyzed. Staining of airway structures in COPD patients revealed significant pathological changes associated with airway remodelling, including mixed cilia and subepithelial fibrosis. The expression of HIF-1α and MMP9 was significantly higher in both human airway tissue and serum compared to controls. Chest CT scans exhibited typical imaging features of airway remodeling and increased airway parameters. The findings suggest a correlation between increased HIF-1α expression and COPD airway remodelling. This study provides novel evidence that HIF-1α may be a potential biomarker for airway remodelling in COPD patients.

Hydropneumothorax as a rare manifestation of primary pulmonary hydatid disease

ABSTRACT Echinococcosis, alternatively referred to as hydatid disease, is caused by the larvae of the tapeworm Echinococcus. The primary agents of human infections are Echinococcus granulosus and Echinococcus multilocularis. The present case report pertains to an individual who relocated from an endemic region to the United Arab Emirates and subsequently manifested symptoms of hydropneumothorax. The 44-year-old male patient presented with a 4-day fever and right-sided chest pain, accompanied by cough and breathlessness for 2 weeks. Computed tomography (CT) of the chest revealed right hydropneumothorax and a ruptured hydatid cyst with consolidation. The patient was diagnosed with a ruptured pulmonary hydatid cyst based on a strongly positive hydatid serology and the presence of hydatid tissue on histopathological examination. The patient underwent surgical decortication with cyst removal and received medical treatment with ceftriaxone and albendazole. He was discharged in good condition after a 10-day hospitalisation period. Echinococcosis is a parasitic disease that most often affects the liver and lungs. Although more than half of the patients do not show any symptoms, the main symptoms observed during presentation include dry cough, haemoptysis, and chest pain. Plain radiographs or chest CT scans are used for diagnosis. Surgery is considered the primary treatment for pulmonary hydatid cysts and medical treatment with benzimidazoles (albendazole and mebendazole) is recommended. Complicated pulmonary hydatid disease can manifest in various ways, including hydropneumothorax, as observed in the present case. Early diagnosis, surgical intervention combined with medical treatment, and multidisciplinary teamwork can significantly improve patient outcomes.

Longitudinal long term follow up investigation on the carcinogenic impact of polyhexamethylene guanidine phosphate in rat models

Polyhexamethylene guanidine phosphate (PHMG-p) is a major component in humidifier disinfectants, which cause life-threatening lung injuries. However, to our knowledge, no published studies have investigated associations between PHMG-p dose and lung damage severity with long-term follow-up. Therefore, we evaluated longitudinal dose-dependent changes in lung injuries using repeated chest computed tomography (CT). Rats were exposed to low (0.2 mg/kg, n = 10), intermediate (1.0 mg/kg, n = 10), and high (5.0 mg/kg, n = 10) doses of PHMG-p. All rats underwent repeated CT scans after 10 and 40 weeks following the first exposure. All CT images were quantitatively analyzed using commercial software. Inflammation/fibrosis and tumor counts underwent histopathological evaluation. In both radiological and histopathologic results, the lung damage severity increased as the PHMG-p dose increased. Moreover, the number, size, and malignancy of the lung tumors increased as the dose increased. Bronchiolar–alveolar hyperplasia developed in all groups. During follow-up, there was intergroup variation in bronchiolar–alveolar hyperplasia progression, although bronchiolar–alveolar adenomas or carcinomas usually increase in size over time. Thirty-three carcinomas were detected in the high-dose group in two rats. Overall, lung damage from PHMG-p and the number and malignancy of lung tumors were shown to be dose-dependent in a rat model using repeated chest CT scans during a long-term follow-up.