Distinguishing recurrence from radiation-induced lung injury at the time of RECIST progressive disease on post-SABR CT scans using radiomics.

Stereotactic ablative radiotherapy (SABR) is a highly effective treatment for patients with early-stage lung cancer who are inoperable. However, SABR causes benign radiation-induced lung injury (RILI) which appears as lesion growth on follow-up CT scans. This triggers the standard definition of progressive disease, yet cancer recurrence is not usually present, and distinguishing RILI from recurrence when a lesion appears to grow in size is critical but challenging. In this study, we developed a tool to do this using scans with apparent lesion growth after SABR from 68 patients. We performed bootstrapped experiments using radiomics and explored the use of multiple regions of interest (ROIs). The best model had an area under the receiver operating characteristic curve of 0.66 and used a sphere with a diameter equal to the lesion's longest axial measurement as the ROI. We also investigated the effect of using inter-feature and volume correlation filters and found that the former was detrimental to performance and that the latter had no effect. We also found that the radiomics features ranked as highly important by the model were significantly correlated with outcomes. These findings represent a key step in developing a tool that can help determine who would benefit from follow-up invasive interventions when a SABR-treated lesion increases in size, which could help provide better treatment for patients.

Chronic Lung Injury after COVID-19 Pneumonia: Clinical, Radiologic, and Histopathologic Perspectives.

With the COVID-19 pandemic having lasted more than 3 years, concerns are growing about prolonged symptoms and respiratory complications in COVID-19 survivors, collectively termed post-COVID-19 condition (PCC). Up to 50% of patients have residual symptoms and physiologic impairment, particularly dyspnea and reduced diffusion capacity. Studies have also shown that 24%-54% of patients hospitalized during the 1st year of the pandemic exhibit radiologic abnormalities, such as ground-glass opacity, reticular opacity, bronchial dilatation, and air trapping, when imaged more than 1 year after infection. In patients with persistent respiratory symptoms but normal results at chest CT, dual-energy contrast-enhanced CT, xenon 129 MRI, and low-field-strength MRI were reported to show abnormal ventilation and/or perfusion, suggesting that some lung injury may not be detectable with standard CT. Histologic patterns in post-COVID-19 lung disease include fibrosis, organizing pneumonia, and vascular abnormality, indicating that different pathologic mechanisms may contribute to PCC. Therefore, a comprehensive imaging approach is necessary to evaluate and diagnose patients with persistent post-COVID-19 symptoms. This review will focus on the long-term findings of clinical and radiologic abnormalities and describe histopathologic perspectives. It also addresses advanced imaging techniques and deep learning approaches that can be applied to COVID-19 survivors. This field remains an active area of research, and further follow-up studies are warranted for a better understanding of the chronic stage of the disease and developing a multidisciplinary approach for patient management.

Characterisation of quantitative imaging biomarkers for inflammatory and fibrotic radiation-induced lung injuries using preclinical radiomics.

BACKGROUND AND PURPOSE: Radiomics is a rapidly evolving area of research that uses medical images to develop prognostic and predictive imaging biomarkers. In this study, we aimed to identify radiomics features correlated with longitudinal biomarkers in preclinical models of acute inflammatory and late fibrotic phenotypes following irradiation. MATERIALS AND METHODS: Female C3H/HeN and C57BL6 mice were irradiated with 20 Gy targeting the upper lobe of the right lung under cone-beam computed tomography (CBCT) image-guidance. Blood samples and lung tissue were collected at baseline, weeks 1, 10 & 30 to assess changes in serum cytokines and histological biomarkers. The right lung was segmented on longitudinal CBCT scans using ITK-SNAP. Unfiltered and filtered (wavelet) radiomics features (n = 842) were extracted using PyRadiomics. Longitudinal changes were assessed by delta analysis and principal component analysis (PCA) was used to remove redundancy and identify clustering. Prediction of acute (week 1) and late responses (weeks 20 & 30) was performed through deep learning using the Random Forest Classifier (RFC) model. RESULTS: Radiomics features were identified that correlated with inflammatory and fibrotic phenotypes. Predictive features for fibrosis were detected from PCA at 10 weeks yet overt tissue density was not detectable until 30 weeks. RFC prediction models trained on 5 features were created for inflammation (AUC 0.88), early-detection of fibrosis (AUC 0.79) and established fibrosis (AUC 0.96). CONCLUSIONS: This study demonstrates the application of deep learning radiomics to establish predictive models of acute and late lung injury. This approach supports the wider application of radiomics as a non-invasive tool for detection of radiation-induced lung complications.

Noninvasive Quantification of Radiation-Induced Lung Injury Using a Targeted Molecular Imaging Probe.

PURPOSE: Radiation-induced lung injury (RILI) is a progressive inflammatory process seen after irradiation for lung cancer. The disease can be insidious, often characterized by acute pneumonitis followed by chronic fibrosis with significant associated morbidity. No therapies are approved for RILI, and accurate disease quantification is a major barrier to improved management. Here, we sought to noninvasively quantify RILI using a molecular imaging probe that specifically targets type 1 collagen in mouse models and patients with confirmed RILI. METHODS AND MATERIALS: Using a murine model of lung radiation, mice were imaged with EP-3533, a type 1 collagen probe, to characterize the development of RILI and to assess disease mitigation after losartan treatment. The human analog probe 68Ga-CBP8, targeting type 1 collagen, was tested on excised human lung tissue containing RILI and was quantified via autoradiography. 68Ga-CBP8 positron emission tomography was used to assess RILI in vivo in 6 human subjects. RESULTS: Murine models demonstrated that probe signal correlated with progressive RILI severity over 6 months. The probe was sensitive to mitigation of RILI by losartan. Excised human lung tissue with RILI had increased binding versus unirradiated control tissue, and 68Ga-CBP8 uptake correlated with collagen proportional area. Human imaging revealed significant 68Ga-CBP8 uptake in areas of RILI and minimal background uptake. CONCLUSIONS: These findings support the ability of a molecular imaging probe targeted at type 1 collagen to detect RILI in preclinical models and human disease, suggesting a role for targeted molecular imaging of collagen in the assessment of RILI.

Early, non-invasive detection of radiation-induced lung injury using PET/CT by targeting CXCR4.

PURPOSE: Radiation-induced lung injury (RILI) is a severe side effect of radiotherapy (RT) for thoracic malignancies and we currently lack established methods for the early detection of RILI. In this study, we synthesized a new tracer, [18F]AlF-NOTA-QHY-04, targeting C-X-C-chemokine-receptor-type-4 (CXCR4) and investigated its feasibility to detect RILI. METHODS: An RILI rat model was constructed and scanned with [18F]AlF-NOTA-QHY-04 PET/CT and [18F]FDG PET/CT periodically after RT. Dynamic, blocking, autoradiography, and histopathological studies were performed on the day of peak uptake. Fourteen patients with radiation pneumonia, developed during or after thoracic RT, were subjected to PET scan using [18F]AlF-NOTA-QHY-04. RESULTS: The yield of [18F]AlF-NOTA-QHY-04 was 28.5-43.2%, and the specific activity was 27-33 GBq/µmol. [18F]AlF-NOTA-QHY-04 was mainly excreted through the kidney. Significant increased [18F]AlF-NOTA-QHY-04 uptake in the irradiated lung compared with that in the normal lung in the RILI model was observed on day 6 post-RT and peaked on day 14 post-RT, whereas no apparent uptake of [18F]FDG was shown on days 7 and 15 post-RT. MicroCT imaging did not show pneumonia until 42 days post-RT. Significant intense [18F]AlF-NOTA-QHY-04 uptake was confirmed by autoradiography. Immunofluorescence staining demonstrated expression of CXCR4 was significantly increased in the irradiated lung tissue, which correlated with results obtained from hematoxylin-eosin and Masson's trichrome staining. In 14 patients with radiation pneumonia, maximum standardized uptake values (SUVmax) were significantly higher in the irradiated lung compared with those in the normal lung. SUVmax of patients with grade 2 RILI was significantly higher than that of patients with grade 1 RILI. CONCLUSION: This study indicated that [18F]AlF-NOTA-QHY-04 PET/CT imaging can detect RILI non-invasively and earlier than [18F]FDG PET/CT in a rat model. Clinical studies verified its feasibility, suggesting the clinical potential of [18F]AlF-NOTA-QHY-04 as a PET/CT tracer for early monitoring of RILI.

Blast Lung Injury in Children: Injury Patterns and Associated Organ Injuries.

BACKGROUND: Bombings are the most common cause of civilian deaths in wars, and unfortunately, a large proportion of civilian victims are children. OBJECTIVE: This study aimed to evaluate the frequency of blast lung injury (BLI), to evaluate lung injury patterns on tomographic images, and to document the relationship between blast lung and mortality in children exposed to the blast effect. METHODS: Thirty-six children (25.3% of pediatric patients brought to our hospital with blast injury) with BLI were included in the study. The pediatric trauma score evaluations made in the emergency department in the first admission were recorded. Lung injury findings in the computed tomography images of the patients were examined, and injuries detected in other systems were recorded. RESULTS: The most common lung injury pattern was contusion (right: 69.4%, left: 80.6%). The incidence of brain damage (52.4%) and intra-abdominal injury (76.2%) in children with low pediatric trauma score value was statistically significantly higher ( P = 0.049, P = 0.017, respectively). There was no statistically significant correlation between the presence of lung injury, injury patterns, and mortality. The incidence of brain damage in deceased patients (61.5%) was statistically significantly higher than the incidence of brain damage in surviving patients (26.1%) ( P = 0.036). Low pediatric trauma score was observed in 11 (84.6%) of the deceased children and in 10 (43.5%) of the survivors ( P = 0.016). The mean age of children with hemothorax in the right lung was statistically significantly lower than those without ( P = 0.014). CONCLUSION: Our findings revealed that pediatric BLI is common after a blast, that it is associated with other system injuries, and that a multimodal radiological approach is required in child victims.

Radiological findings based comparison of functional status in patients who have post-covid lung injury or idiopathic pulmonary fibrosis.

BACKGROUND: Following COVID-19 infection, some patients acquired lung injury and fibrosis. Idiopathic pulmonary fibrosis is characterized by lung fibrosis. Both post-COVID lung injury and idiopathic pulmonary fibrosis cause loss of respiratory function and involvement of the lung parenchyma. We aimed to compare respiratory related functional characteristics and radiological involvement between post-COVID lung injury and idiopathic pulmonary fibrosis. METHODS: A single center, cross-sectional study was applied. Patients with post-COVID lung injury and idiopathic pulmonary fibrosis included in the study. All patients underwent the 6-minute walk test, as well as the Borg and MRC scales. Radiological images were evaluated and scored for lung parenchymal involvement. The impact of post-COVID lung injury and idiopathic pulmonary fibrosis on respiratory functions of were compared. The relationship of functional status and radiological involvement, as well as the effect of potential confounding factors were investigated. RESULTS: A total of 71 patients were included in the study. Forty-eight (67.6%) of the patients were male and the mean age was 65.4 ± 10.3 years. Patients with post-COVID lung injury had greater 6-minute walk test distance and duration, as well as higher oxygen saturations. The MRC and Borg dyspnea scores were comparable. At radiologic evaluation, ground glass opacity scores were higher in patients with post-COVID lung injury, whereas pulmonary fibrosis scores were higher in patients with idiopathic pulmonary fibrosis. However, the total severity scores were similar. While pulmonary fibrosis score was found to have a negative correlation with 6-minute walk test distance, test duration, and pre- and post-test oxygen saturation levels, there was a positive correlation with oxygen saturation recovery time and MRC score. There was no relationship between ground glass opacity and the functional parameters. CONCLUSIONS: Despite having equal degrees of radiological involvement and dyspnea symptom severity, PCLI patients exhibited higher levels of functional status. This might be due to different pathophysiological mechanisms and radiological involvement patterns of both diseases.

A 43-Year-Old Brazilian Man with Acute Impairment of Lung Function and Pulmonary Nodules with Features of Electronic Cigarette or Vaping Product Use-Associated Lung Injury (EVALI).

BACKGROUND Electronic smoking devices were created, and their production industrialized, recently. Since their creation, their use has spread widely. This increase in users led to the appearance of a new lung condition. In 2019, the CDC established the criteria for the diagnosis of electronic cigarette or vaping product use-associated lung injury (EVALI) and the eponym EVALI is now widely recognized. The condition results from the inhalation of heated vapor, which damages the large and small airways and alveoli. CASE REPORT This report presents the case of a 43-year-old Brazilian man with acute impairment of lung function, pulmonary nodules on chest computed tomography (CT) and features of EVALI. He was hospitalized after 9 days of respiratory symptoms due to worsening dyspnea, and underwent a bronchoscopy on the same day. His condition evolved into severe hypercapnic respiratory failure that took 3 weeks to improve, and he underwent a surgical lung biopsy that showed an organizing pneumonia pattern. He was discharged after 50 days of hospitalization. Infectious diseases and other lung conditions were ruled out on clinical, laboratory, radiological, epidemiological, and histopathological grounds. CONCLUSIONS In conclusion, we report the unusual presentation of EVALI on chest CT showing nodules instead of a ground-glass pattern, as stated in the CDC definitions of a confirmed case. We also report the progression to a critical clinical state and, after treatment, the evolution to complete recovery. We also draw attention to the difficulties in diagnosing and managing the disease, especially at a time when COVID-19 has emerged.

Biomarkers to Predict Lethal Radiation Injury to the Rat Lung.

Currently, there are no biomarkers to predict lethal lung injury by radiation. Since it is not ethical to irradiate humans, animal models must be used to identify biomarkers. Injury to the female WAG/RijCmcr rat has been well-characterized after exposure to eight doses of whole thorax irradiation: 0-, 5-, 10-, 11-, 12-, 13-, 14- and 15-Gy. End points such as SPECT imaging of the lung using molecular probes, measurement of circulating blood cells and specific miRNA have been shown to change after radiation. Our goal was to use these changes to predict lethal lung injury in the rat model, 2 weeks post-irradiation, before any symptoms manifest and after which a countermeasure can be given to enhance survival. SPECT imaging with 99mTc-MAA identified a decrease in perfusion in the lung after irradiation. A decrease in circulating white blood cells and an increase in five specific miRNAs in whole blood were also tested. Univariate analyses were then conducted on the combined dataset. The results indicated that a combination of percent change in lymphocytes and monocytes, as well as pulmonary perfusion volume could predict survival from radiation to the lungs with 88.5% accuracy (95% confidence intervals of 77.8, 95.3) with a p-value of < 0.0001 versus no information rate. This study is one of the first to report a set of minimally invasive endpoints to predict lethal radiation injury in female rats. Lung-specific injury can be visualized by 99mTc-MAA as early as 2 weeks after radiation.

[Lung contusion after jumping from a 10 meter tower in a swimming pool]. / Lungenkontusion nach Sprung ins Wasser.

BACKGROUND: Lung contusions often occur in the context of polytrauma, but much less frequently in sports injuries. CASE DESCRIPTION: We report on a 22-year-old patient who presented to our emergency room. On the same day he jumped from a 10 meter tower in a swimming pool and hit the surface of the water with his thorax and abdomen. He complained of pain in the right chest and hemoptysis immediately after the jump.The examination findings remained without further abnormalities.In the chest x-ray no abnormalities were found.The CT thorax with contrast medium revealed homogeneous ground-glass opacities in the middle lobe and less in the ventrobasal upper lobe on the right, consistent with the pulmonary contusion with parenchymal bleeding. In addition, there was a minimal pneumothorax border on the paracardial right side.Bronchoscopy performed on the same day showed evidence of blood in the middle lobe bronchus.The hemoptysis stopped spontaneously. On the 3rd day of the hospital stay, the patient was discharged with stable vital parameters and asymptomatic. CONCLUSION: Hemoptysis immediately after a sports chest injury may occur as a result of pulmonary contusion. In contrast to conventional chest x-rays, computed tomography is of great importance in the diagnosis of pulmonary contusion.

Impact of inactivated COVID-19 vaccines on lung injury in B.1.617.2 (Delta) variant-infected patients.

BACKGROUND: Chest computerized tomography (CT) scan is an important strategy that quantifies the severity of COVID-19 pneumonia. To what extent inactivated COVID-19 vaccines could impact the COVID-19 pneumonia on chest CT is not clear. METHODS: This study recruited 357 SARS-COV-2 B.1.617.2 (Delta) variant-infected patients admitted to the Second Hospital of Nanjing from July to August 2021. An artificial intelligence-assisted CT imaging system was used to quantify the severity of COVID-19 pneumonia. We compared the volume of infection (VOI), percentage of infection (POI) and chest CT scores among patients with different vaccination statuses. RESULTS: Of the 357 Delta variant-infected patients included for analysis, 105 were unvaccinated, 72 were partially vaccinated and 180 were fully vaccinated. Fully vaccination had the least lung injuries when quantified by VOI (median VOI of 222.4 cm3, 126.6 cm3 and 39.9 cm3 in unvaccinated, partially vaccinated and fully vaccinated, respectively; p < 0.001), POI (median POI of 7.60%, 3.55% and 1.20% in unvaccinated, partially vaccinated and fully vaccinated, respectively; p < 0.001) and chest CT scores (median CT score of 8.00, 6.00 and 4.00 in unvaccinated, partially vaccinated and fully vaccinated, respectively; p < 0.001). After adjustment for age, sex, comorbidity, time from illness onset to hospitalization and viral load, fully vaccination but not partial vaccination was significantly associated with less lung injuries quantified by VOI {adjust coefficient[95%CI] for "full vaccination": - 106.10(- 167.30,44.89); p < 0.001}, POI {adjust coefficient[95%CI] for "full vaccination": - 3.88(- 5.96, - 1.79); p = 0.001} and chest CT scores {adjust coefficient[95%CI] for "full vaccination": - 1.81(- 2.72, - 0.91); p < 0.001}. The extent of reduction of pulmonary injuries was more profound in fully vaccinated patients with older age, having underlying diseases, and being female sex, as demonstrated by relatively larger absolute values of adjusted coefficients. Finally, even within the non-severe COVID-19 population, fully vaccinated patients were found to have less lung injuries. CONCLUSION: Fully vaccination but not partially vaccination could significantly protect lung injury manifested on chest CT. Our study provides additional evidence to encourage a full course of vaccination.

Acoustic radiation force impulse-induced lung hemorrhage: investigating the relationship with peak rarefactional pressure amplitude and mechanical index in rabbits.

PURPOSE: The safety of acoustic radiation force impulse (ARFI) elastography, which applies higher acoustic power with a longer pulse duration (PD) than conventional diagnostic ultrasound, is yet to be verified. We assessed the ARFI-induced lung injury risk and its relationship with peak rarefactional pressure amplitude (PRPA) and mechanical index (MI). METHODS: Eighteen and two rabbits were included in the ARFI (0.3-ms push pulses) and sham groups, respectively. A 5.2-MHz linear probe was applied to the subcostal area and aimed at both lungs through the liver for 30 ARFI emissions. The derated PRPA varied among the six ARFI groups-0.80 MPa, 1.13 MPa, 1.33 MPa, 1.70 MPa, 1.91 MPa, and 2.00 MPa, respectively. RESULTS: The occurrence of lung hemorrhage and the mean lesion area among all samples in the seven groups were 0/6, 0/6, 1/6 (1.7 mm2), 4/6 (8.0 mm2), 4/6 (11.2 mm2), 5/6 (23.8 mm2), and 0/4 (sham), respectively. Logistic regression analysis showed that derated PRPA was significantly associated with lung injury occurrence (odds ratio: 207, p < 0.01), with the threshold estimated to be 1.1 MPa (MI, 0.5). Spearman's rank correlation showed a positive correlation between derated PRPA and lesion area (r = 0.671, p < 0.01). CONCLUSION: This study demonstrated that the occurrence and severity of ARFI-induced lung hemorrhage increased with a rise in PRPA under clinical conditions in rabbits. This indicates a potential risk of lung injury due to ARFI elastography, especially when ARFI is unintentionally directed to the lungs during liver, heart, or breast examinations.

Pulmonary Barotrauma in a BUD/S Candidate Following Shallow Dives Using the MK 25 Rebreather.

Pulmonary barotrauma of ascent is a well-recognized risk of compressed air diving in the civilian and military diving communities. Chest imaging is a beneficial adjunct to clinical evaluation in screening select individuals for fitness to dive, evaluating dive-related injuries, and safely returning individuals to diving duty. We present a case of a 26-year-old male U.S. Navy Ensign and Basic Underwater Demolition/SEAL (BUD/S) candidate who experienced pulmonary barotrauma following two shallow dives to a maximum depth of 18 feet of seawater using the MK-25 100% oxygen rebreather. A chest radiograph showed a left upper lobe peripheral wedge-shaped opacity abutting the pleural surface. A subsequent computerized tomography (CT) scan of the chest showed multifocal areas of peripheral pulmonary hemorrhage associated with small pneumatoceles. Two months after the diving injury, chest CT showed resolution of the pulmonary hemorrhage and pneumatoceles. Diving-related pulmonary barotrauma occurs most often secondary to breath-holding on ascent by inexperienced divers and is one of the most common diving injuries seen in BUD/S candidates. The risk of pulmonary barotrauma may be decreased through adequate training and thorough medical screening to include assessing for symptoms of infection before every dive. In cases of acute pulmonary barotrauma, chest radiographs may be used to screen for thoracic injury. Chest CT with inspiratory and expiratory sequences should be used to screen dive candidates on a case-by-case basis and to evaluate lung injury and predisposing pulmonary conditions following pulmonary barotrauma.

Bronchoalveolar Lavage (BAL) and Pathologic Assessment of Electronic Cigarette or Vaping Product Use-associated Lung Injury (EVALI): The EVALI-BAL Study, A Multicenter Cohort.

BACKGROUND: E-cigarette or vaping-use related acute lung injury (EVALI) is a spectrum of radiographic and histologic patterns consistent with acute to subacute lung injury. However, limited data exist characterizing bronchoalveolar lavage (BAL) findings. The goal of this study is to further define the pathologic findings from BAL and biopsy samples of subjects with EVALI across 7 institutions. METHODS: A multicentered registry of patients admitted with EVALI who underwent flexible bronchoscopy with BAL+/-transbronchial biopsy from July 2019 to April 2021 was compiled for retrospective evaluation from 7 academic institutions throughout the United States. Radiographic and cytopathologic findings and frequencies were correlated with the substance vaped. RESULTS: Data from 21 subjects (42.9% women) who were predominantly White (76.2%) with a median age of 25 years (range, 16 to 68) with EVALI were included in this study. Sixteen patients (76.2%) reported use of tetrahydrocannabinol; the remainder used nicotine. BAL was performed in 19 of the 21 subjects, and transbronchial lung biopsy was performed in 7 subjects. BAL findings revealed neutrophilic predominance (median, 59.5%, range, 3.1 to 98) in most cases. Ten BAL samples demonstrated pulmonary eosinophilia ranging from 0.2% to 49.1% with one subject suggesting a diagnosis of acute eosinophilic pneumonia associated with the use of e-cigarettes. Lipid-laden macrophages were noted in 10 of 15 reports (66.7%). Transbronchial biopsy most frequently demonstrated patterns of organizing pneumonia (57.1%). CONCLUSION: EVALI-associated BAL findings typically demonstrate a spectrum of nonspecific inflammatory changes, including neutrophilia, lipid-laden macrophages, and in some cases eosinophilia.

Differential diagnosis of infectious diseases, drug-induced lung injury, and pulmonary infiltration due to underlying malignancy in patients with hematological malignancy using HRCT.

PURPOSE: To differentiate among infectious diseases, drug-induced lung injury (DILI) and pulmonary infiltration due to underlying malignancy (PIUM) based on high-resolution computed tomographic (HRCT) findings from patients with hematological malignancies who underwent chemotherapy or hematopoietic stem cell transplantation. MATERIALS AND METHODS: A total of 221 immunocompromised patients with hematological malignancies who had proven chest complications (141 patients with infectious diseases, 24 with DILI and 56 with PIUM) were included. Two chest radiologists evaluated the HRCT findings, including ground-glass opacity, consolidation, nodules, and thickening of bronchovascular bundles (BVBs) and interlobular septa (ILS). After comparing these CT findings among the three groups using the χ2test, multiple logistic regression analyses (infectious vs noninfectious diseases, DILI vs non-DILI, and PIUM vs non-PIUM) were performed to detect useful indicators for differentiation. RESULTS: Significant differences were detected in many HRCT findings by the χ2 test. The results from the multiple logistic regression analyses identified several indicators: nodules without a perilymphatic distribution [p = 0.012, odds ratio (95% confidence interval): 4.464 (1.355-11.904)], nodules with a tree-in-bud pattern [p = 0.011, 8.364 (1.637-42.741)], and the absence of ILS thickening[p = 0.003, 3.621 (1.565-8.381)] for infectious diseases, the presence of ILS thickening [p = 0.001, 7.166 (2.343-21.915)] for DILI, and nodules with a perilymphatic distribution [p = 0.011, 4.256 (1.397-12.961)] and lymph node enlargement (p = 0.008, 3.420 (1.385-8.441)] for PIUM. CONCLUSION: ILS thickening, nodules with a perilymphatic distribution, tree-in-bud pattern, and lymph node enlargement could be useful indicators for differentiating among infectious diseases, DILI, and PIUM in patients with hematological malignancies.

Neumatocele traumático: una presentación inusual del trauma cerrado de tórax en paciente de 21 años / Traumatic pneumatocele: an unusual presentation of blunt chest trauma in a 21-year-old patient

El neumatocele traumático, o pseudoquiste pulmonar traumático, es una complicación infrecuente del trauma cerrado de tórax, caracterizada por lesiones cavitadas únicas o múltiples de paredes fibrosas bien delimitadas, sin revestimiento epitelial. Representa un reto diagnóstico ante la prevalencia de etiologías más frecuentes de cavitación pulmonar, presentación clínica inespecífica y el carácter subreportado de la patología. Se presenta el caso de un paciente de 21 años, con cuadro clínico de fiebre y dolor torácico posterior a traumatismo contuso por accidente en motocicleta, con identificación de una lesión cavitada rodeada de vidrio esmerilado, ubicada en lóbulo superior derecho en tomografía de tórax. Se ofreció tratamiento antibiótico ante la sospecha clínica de sobreinfección. Sin embargo, se atribuyó la alteración pseudoquística pulmonar al antecedente traumático. En ocasiones las cavitaciones pulmonares postrauma no son identificadas en la atención inicial, por ende, es fundamental la evaluación clínica e imagenológica subsecuente.

Traumatic pneumatocele, or traumatic pulmonary pseudocyst, is a rare complication of blunt chest trauma, characterized by multiple or unique cavitary lesions, with well-defined fibrous walls without epithelial lining. It represents a diagnostic challenge due to the higher prevalence of other etiologies of lung cavities, nonspecific clinical features and the under-reported nature of this pathology. We present the case of a 21-year-old male with fever and chest pain after a blunt chest trauma in a motorcycle accident, with identification of a cavity in the right upper lobe, surrounded by ground glass opacities. Antibiotic therapy was administered after clinical suspicion of superinfection, however, the cavitary lesion was attributed to the trauma. Occasionally, traumatic pulmonary pseudocysts are not identified during initial assessment, therefore, clinical and imagenologic follow-up is essential.

Imaging of Smoking and Vaping Related Diffuse Lung Injury.

Lung injury associated with smoking tobacco or other substances results in a variety of clinical presentations and imaging patterns, depending on mechanism of injury and substance inhaled. Patients may present in the acute setting, as in the case of acute eosinophilic pneumonia, e-cigarette or vaping product use-associated lung injury, crack lung, or heroin inhalation. They may present with subacute shortness of breath and demonstrate findings of pulmonary Langerhans cell histiocytosis, respiratory bronchiolitis, or desquamative interstitial pneumonia. Alternatively, they may present with chronic dyspnea and demonstrate findings of emphysema or smoking-related interstitial lung fibrosis.

[Traumatic Lung Injury].

Thoracic injuries are significant causes of morbidity and mortality in trauma patients. Traumatic pulmonary contusion and/or laceration are often observed in patients with chest trauma, explosion injuries or a shock wave associated with penetrating trauma. A pulmonary contusion is an injury to the lung parenchyma without actual structural damage. As a result of damage to alveoli and capillaries, it results in leakage of blood and other interstitial fluids across the alveolar-capillary membrane into lung tissue and alveolar space. Since oxygenated air can not enter into fluid-filled alveoli, hypoventilation and decreased perfusion by reflux vasoconstriction result in hypoxemia and hypercapnia. Pulmonary laceration is a lung injury with disruption of the architecture of the lung, while pulmonary contusion does not. There is almost always concurrent pulmonary contusion, and pneumothorax, hemothorax, or hemopneumothorax. In addition, pulmonary laceration can be a cause of forming a cyst or hematoma, which usually disappears over a period of weeks or months. However, pneumatocele can occur in some cases when lacerations are enlarged with air-filled cavity. It is important for thoracic surgeons to understand pathophysiology of traumatic lung injury, and to know the diagnosis and treatment.

Imaging findings of pulmonary contusions on multidetector CT: A retrospective study comparing adults and children.

To describe imaging findings of pulmonary contusions (PC) in adults and children using multidetector computed tomography (CT) scanners. We conducted a retrospective single center study. All chest multidetector computed tomography (MDCT) scans of victims of blunt trauma admitted to the emergency unit of a reference trauma center of Brazil between January 2015 and December 2016 were reviewed in search of opacities compatible with PC. The CT images were analyzed in conjunction with medical records, that provided demographic and clinical data. The obtained data were analyzed in the overall population and comparing children and adults. Significant P value was defined as <.05. 52.7% of patients presented bilateral opacities. Middle third, posterior and peripheral portions of the lungs were more frequently affected, in the craniocaudal, anteroposterior and axial axes, respectively. A vast majority of patients (80.6%) presented multiple opacities, whereas a minority showed subpleural sparing (26.9%) and fissure crossing (22.6%), with similar frequencies in children and adults. Children, although, more frequently presented consolidation and more diffuse lesions in the anteroposterior axis compared to adults, with statistically significant differences. PC usually are multiple and predominate in middle, posterior and peripheral portions of the lungs. Subpleural sparing and fissure crossing seems to be infrequent and have similar frequencies between children and adults. Although, there are differences between these age groups, as younger people tend to have more consolidation and diffuse opacities in the anteroposterior axis than older ones.