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.

Imaging of Pulmonary Fibrosis: An Update, From the AJR Special Series on Imaging of Fibrosis.

Pulmonary fibrosis is recognized as occurring in association with a wide and increasing array of conditions, and it presents with a spectrum of chest CT appearances. Idiopathic pulmonary fibrosis (IPF), which corresponds histologically with usual interstitial pneumonia and represents the most common idiopathic interstitial pneumonia, is a chronic progressive fibrotic interstitial lung disease (ILD) of unknown cause. Progressive pulmonary fibrosis (PPF) describes the radiologic development of pulmonary fibrosis in patients with ILD of a known or unknown cause other than IPF. The recognition of PPF impacts management of patients with ILD-for example, in guiding initiation of antifibrotic therapy. Interstitial lung abnormalities are an incidental CT finding in patients without suspected ILD and may represent an early intervenable form of pulmonary fibrosis. Traction bronchiectasis and/or bronchiolectasis, when detected in the setting of chronic fibrosis, is generally considered evidence of irreversible disease, and progression predicts worsening mortality risk. Awareness of the association between pulmonary fibrosis and connective tissue diseases, particularly rheumatoid arthritis, is increasing. This review provides an update on the imaging of pulmonary fibrosis, with attention given to recent advances in disease understanding with relevance to radiologic practice. The essential role of a multidisciplinary approach to clinical and radiologic data is highlighted.

Impact of interstitial lung abnormalities on postoperative pulmonary complications and survival of lung cancer.

BACKGROUND: Interstitial lung abnormalities (ILAs) are associated with the risk of lung cancer and its mortality. However, the impact of ILA on treatment-related complications and survival in patients who underwent curative surgery is still unknown. RESEARCH QUESTION: This study aimed to evaluate the significance of the presence of computed tomography-diagnosed ILA and histopathologically matched interstitial abnormalities on postoperative pulmonary complications (PPCs) and the long-term survival of patients who underwent surgical treatment for lung cancer. STUDY DESIGN AND METHODS: A matched case-control study was designed to compare PPCs and mortality among 50 patients with ILA, 50 patients with idiopathic pulmonary fibrosis (IPF) and 200 controls. Cases and controls were matched by sex, age, smoking history, tumour location, the extent of surgery, tumour histology and pathological TNM stage. RESULTS: Compared with the control group, the OR of the prevalence of PPCs increased to 9.56 (95% CI 2.85 to 32.1, p<0.001) in the ILA group and 56.50 (95% CI 17.92 to 178.1, p<0.001) in the IPF group. The 5-year overall survival (OS) rates of the control, ILA and IPF groups were 76% (95% CI 71% to 83%), 52% (95% CI 37% to 74%) and 32% (95% CI 19% to 53%), respectively (log-rank p<0.001). Patients with ILA had better 5-year OS than those with IPF (log-rank p=0.046) but had worse 5-year OS than those in the control group (log-rank p=0.002). CONCLUSIONS: The presence of radiological and pathological features of ILA in patients with lung cancer undergoing curative surgery was associated with frequent complications and decreased survival.

Current and Emerging Knowledge in COVID-19.

COVID-19 has emerged as a pandemic leading to a global public health crisis of unprecedented morbidity. A comprehensive insight into the imaging of COVID-19 has enabled early diagnosis, stratification of disease severity, and identification of potential sequelae. The evolution of COVID-19 can be divided into early infectious, pulmonary, and hyperinflammatory phases. Clinical features, imaging features, and management are different among the three phases. In the early stage, peripheral ground-glass opacities are predominant CT findings, and therapy directly targeting SARS-CoV-2 is effective. In the later stage, organizing pneumonia or diffuse alveolar damage pattern are predominant CT findings and anti-inflammatory therapies are more beneficial. The risk of severe disease or hospitalization is lower in breakthrough or Omicron variant infection compared with nonimmunized or Delta variant infections. The protection rates of the fourth dose of mRNA vaccination were 34% and 67% against overall infection and hospitalizations for severe illness, respectively. After acute COVID-19 pneumonia, most residual CT abnormalities gradually decreased in extent, but they may remain as linear or multifocal reticular or cystic lesions. Advanced insights into the pathophysiologic and imaging features of COVID-19 along with vaccine benefits have improved patient care, but emerging knowledge of post-COVID-19 condition, or long COVID, also presents radiology with new challenges.

Chronic cavitary pulmonary aspergillosis: Serial clinical and CT findings correlated with antifungal treatment and patient response.

BACKGROUND: Chronic cavitary pulmonary aspergillosis (CCPA) is the most common form of chronic pulmonary aspergillosis. OBJECTIVE: We hypothesise that by observing serial clinical and CT findings of CCPA patients with antifungal therapy, factors helping predict responses to antifungal therapy could be withdrawn. METHODS: A total of 31 patients with CCPA who received antifungal therapy for greater than six months and who had serial CT studies were included. Clinical finding analyses were performed at initial and last follow-up CT acquisition dates. Clinical characteristics and CT features were compared between clinically improving or stable and deteriorating groups. RESULTS: With antifungal therapy, neutrophil-to-lymphocyte ratio (2.66 vs. 5.12, p = .038) and serum albumin (4.40 vs. 3.85 g/dl, p = .013) and CRP (1.10 vs. 42.80 mg/L, p = .007) were different between two groups. With antifungal therapy, meaningful CT change, regardless of clinical response grouping, was decrease in cavity wall thickness (from 13.70 mm to 8.28 mm, p < .001). But baseline (p = .668) and follow-up (p = .278) cavity wall thickness was not different between two groups. In univariate analysis, initial maximum diameter of cavity (p = .028; HR [0.983], 95% CI [0.967-0.998]) and concurrent NTM infection (p = .030; HR [0.20], 95% CI [0.05-0.86]) were related factors for poor clinical response. CONCLUSIONS: With antifungal therapy, cavities demonstrate wall thinning. Of all clinical and radiological findings and their changes, initial large cavity size and concurrent presence of NTM infection are related factors to poor response to antifungal therapy.

Trimodality therapy for locally advanced esophageal squamous cell carcinoma: the role of volume-based PET/CT in patient management and prognostication.

PURPOSE: To evaluate the role of positron emission tomography/computed tomography (PET/CT) in predicting pathologic complete response (pCR) and identify relevant prognostic factors from clinico-imaging-pathologic features of locally advanced esophageal squamous cell carcinoma (eSCC) patients undergoing trimodality therapy. METHODS: We evaluated 275 patients with eSCCs of T3-T4aN0M0 and T1-T4aN1-N3M0 who received trimodality therapy. We correlated volume-based PET/CT parameters before and after concurrent chemoradiation therapy with pCR after surgery, clinico-imaging-pathologic features, and patient survival. RESULTS: pCR occurred in 75 (27.3%) of 275 patients, of whom 61 (80.9%) showed 5-year survival. Pre-total lesion glycolysis (pre-TLG, OR = 0.318, 95% CI 0.169 to 0.600), post-metabolic tumor volume (post-MTV, OR = 0.572, 95% CI 0.327 to 0.999), and % decrease of average standardized uptake value (% SUVavg decrease, OR = 2.976, 95% CI = 1.608 to 5.507) were significant predictors for pCR. Among them, best predictor for pCR was pre-TLG with best cutoff value of 205.67 and with AUC value of 0.591. Performance status (HR = 5.171, 95% CI 1.737 to 15.397), pathologic tumor size (HR = 1.645, 95% CI 1.351 to 2.002), pathologic N status (N1, HR = 1.572, 95% CI 1.010 to 2.446; N2, HR = 3.088, 95% CI 1.845 to 5.166), and post-metabolic tumor volume (HR = 1.506, 95% CI 1.033 to 2.195) were significant predictors of overall survival. CONCLUSION: Pre-TLG, post-MTV, and % SUVavg decrease are predictive of pCR. Additionally, several clinico-imaging-pathologic factors are significant survival predictors in locally advanced eSCC patients undergoing trimodality therapy.

Human Oncoviruses and Thoracic Tumors: Understanding the Imaging Findings.

Approximately 1.4 million virus-induced cancers occur annually, representing roughly 10% of the cancer burden worldwide. Seven oncogenic DNA and RNA viruses (ie, oncoviruses) are implicated in approximately 12%-25% of all human cancers owing to a variety of mechanisms as uncommon consequences of the normal viral life cycle. These seven well-recognized human oncoviruses are Epstein-Barr virus (EBV), human T-lymphotropic virus 1, hepatitis B virus, hepatitis C virus, HIV, human papilloma virus (HPV), and human herpesvirus 8 (HHV-8). Several viruses-namely, EBV, HPV, and Kaposi sarcoma herpesvirus or HHV-8-are increasingly being recognized as being related to HIV and/or AIDS, the growing number of transplant cases, and the use of immunosuppressive therapies. Infectious and inflammatory processes, and the accompanying lymphadenopathy, are great mimickers of human oncovirus-related tumors. Although it is often difficult to differentiate these entities, the associated clinical setting and radiologic findings may provide clues for an accurate diagnosis and appropriate management. Malignant lymphoid lesions are best evaluated with multidetector chest CT. The radiologic findings of these lesions are often nonspecific and are best interpreted in correlation with clinical data and histopathologic findings. ©RSNA, 2022.

Preoperative Helical Dynamic Enhanced Multidetector Row Computed Tomography: Can It Be a Prognostic Indicator in Early-Stage Non-small Cell Lung Cancer?

OBJECTIVE: This study aimed to investigate the prognostic significance of dynamic contrast-enhanced computed tomography in patients with stage IA non-small cell lung cancer (NSCLC). METHODS: We retrospectively enrolled 139 patients (77 men, 62 women; mean age, 59 years) with stage IA NSCLC who underwent dynamic contrast-enhanced computed tomography. Data on age, pathologic subtype, peak enhancement, and net enhancement of primary lung cancer were collected and correlated with 5-year survival. RESULTS: Peak enhancement had a significant correlation with overall survival in the univariable analysis (hazard ratio [HR], 1.18, confidence interval [CI], 1.01-1.38; P = 0.04) and in the multivariable analysis (HR, 1.19; CI, 1.01-1.39; P = 0.04). Patients with peak enhancement of 90 Hounsfield unit or higher had a significantly increased risk of death compared with patients with less enhancement after curative surgery (HR, 4.15; CI, 1.23-13.95; P = 0.02). CONCLUSIONS: Our study confirmed the prognostic significance of peak enhancement as an indicator for the overall survival of stage IA NSCLC.

Acute Pulmonary Embolism and Chronic Thromboembolic Pulmonary Hypertension: Clinical and Serial CT Pulmonary Angiographic Features.

In acute pulmonary embolism (PE), circulatory failure and systemic hypotension are important clinically for predicting poor prognosis. While pulmonary artery (PA) clot loads can be an indicator of the severity of current episode of PE or treatment effectiveness, they may not be used directly as an indicator of right ventricular (RV) failure or patient death. In other words, pulmonary vascular resistance or patient prognosis may not be determined only with mechanical obstruction of PAs and their branches by intravascular clot loads on computed tomography pulmonary angiography (CTPA), but determined also with vasoactive amines, reflex PA vasoconstriction, and systemic arterial hypoxemia occurring during acute PE. Large RV diameter with RV/left ventricle (LV) ratio > 1.0 and/or the presence of occlusive clot and pulmonary infarction on initial CTPA, and clinically determined high baseline PA pressure and RV dysfunction are independent predictors of oncoming chronic thromboembolic pulmonary hypertension (CTEPH). In this pictorial review, authors aimed to demonstrate clinical and serial CTPA features in patients with acute massive and submassive PE and to disclose acute CTPA and clinical features that are related to the prediction of oncoming CTEPH.

Pulmonary Functional Imaging: Part 1-State-of-the-Art Technical and Physiologic Underpinnings.

Over the past few decades, pulmonary imaging technologies have advanced from chest radiography and nuclear medicine methods to high-spatial-resolution or low-dose chest CT and MRI. It is currently possible to identify and measure pulmonary pathologic changes before these are obvious even to patients or depicted on conventional morphologic images. Here, key technological advances are described, including multiparametric CT image processing methods, inhaled hyperpolarized and fluorinated gas MRI, and four-dimensional free-breathing CT and MRI methods to measure regional ventilation, perfusion, gas exchange, and biomechanics. The basic anatomic and physiologic underpinnings of these pulmonary functional imaging techniques are explained. In addition, advances in image analysis and computational and artificial intelligence (machine learning) methods pertinent to functional lung imaging are discussed. The clinical applications of pulmonary functional imaging, including both the opportunities and challenges for clinical translation and deployment, will be discussed in part 2 of this review. Given the technical advances in these sophisticated imaging methods and the wealth of information they can provide, it is anticipated that pulmonary functional imaging will be increasingly used in the care of patients with lung disease. © RSNA, 2021 Online supplemental material is available for this article.

Pulmonary Functional Imaging: Part 2-State-of-the-Art Clinical Applications and Opportunities for Improved Patient Care.

Pulmonary functional imaging may be defined as the regional quantification of lung function by using primarily CT, MRI, and nuclear medicine techniques. The distribution of pulmonary physiologic parameters, including ventilation, perfusion, gas exchange, and biomechanics, can be noninvasively mapped and measured throughout the lungs. This information is not accessible by using conventional pulmonary function tests, which measure total lung function without viewing the regional distribution. The latter is important because of the heterogeneous distribution of virtually all lung disorders. Moreover, techniques such as hyperpolarized xenon 129 and helium 3 MRI can probe lung physiologic structure and microstructure at the level of the alveolar-air and alveolar-red blood cell interface, which is well beyond the spatial resolution of other clinical methods. The opportunities, challenges, and current stage of clinical deployment of pulmonary functional imaging are reviewed, including applications to chronic obstructive pulmonary disease, asthma, interstitial lung disease, pulmonary embolism, and pulmonary hypertension. Among the challenges to the deployment of pulmonary functional imaging in routine clinical practice are the need for further validation, establishment of normal values, standardization of imaging acquisition and analysis, and evidence of patient outcomes benefit. When these challenges are addressed, it is anticipated that pulmonary functional imaging will have an expanding role in the evaluation and management of patients with lung disease.

Chest CT Diagnosis and Clinical Management of Drug-related Pneumonitis in Patients Receiving Molecular Targeting Agents and Immune Checkpoint Inhibitors: A Position Paper from the Fleischner Society.

Use of molecular targeting agents and immune checkpoint inhibitors (ICIs) has increased the frequency and broadened the spectrum of lung toxicity, particularly in patients with cancer. The diagnosis of drug-related pneumonitis (DRP) is usually achieved by excluding other potential known causes. Awareness of the incidence and risk factors for DRP is becoming increasingly important. The severity of symptoms associated with DRP may range from mild or none to life-threatening with rapid progression to death. Imaging features of DRP should be assessed in consideration of the distribution of lung parenchymal abnormalities (radiologic pattern approach). The CT patterns reflect acute (diffuse alveolar damage) interstitial pneumonia and transient (simple pulmonary eosinophilia) lung abnormality, subacute interstitial disease (organizing pneumonia and hypersensitivity pneumonitis), and chronic interstitial disease (nonspecific interstitial pneumonia). A single drug can be associated with multiple radiologic patterns. Treatment of a patient suspected of having DRP generally consists of drug discontinuation, immunosuppressive therapy, or both, along with supportive measures eventually including supplemental oxygen and intensive care. In this position paper, the authors provide diagnostic criteria and management recommendations for DRP that should be of interest to radiologists, clinicians, clinical trialists, and trial sponsors, among others. This article is a simultaneous joint publication in Radiology and CHEST. The articles are identical except for stylistic changes in keeping with each journal's style. Either version may be used in citing this article. Published under a CC BY 4.0 license. Online supplemental material is available for this article.

Exosomes released from Shiga toxin 2a-treated human macrophages modulate inflammatory responses and induce cell death in toxin receptor expressing human cells.

Shiga toxins (Stxs) produced by Stx-producing Escherichia coli are the primarily virulence factors of hemolytic uremic syndrome and central nervous system (CNS) impairment. Although the precise mechanisms of toxin dissemination remain unclear, Stxs bind to extracellular vesicles (EVs). Exosomes, a subset of EVs, may play a key role in Stx-mediated renal injury. To test this hypothesis, we isolated exosomes from monocyte-derived macrophages in the presence of Stx2a or Stx2 toxoids. Macrophage-like differentiated THP-1 cells treated with Stxs secreted Stx-associated exosomes (Stx-Exo) of 90-130 nm in diameter, which induced cytotoxicity in recipient cells in a toxin receptor globotriaosylceramide (Gb3 )-dependent manner. Stx2-Exo engulfed by Gb3 -positive cells were translocated to the endoplasmic reticulum in the human proximal tubule epithelial cell line HK-2. Stx2-Exo contained pro-inflammatory cytokine mRNAs and proteins and induced more severe inflammation than purified Stx2a accompanied by greater death of target cells such as human renal or retinal pigment epithelial cells. Blockade of exosome biogenesis using the pharmacological inhibitor GW4869 reduced Stx2-Exo-mediated human renal cell death. Stx2-Exo isolated from human primary monocyte-derived macrophages activated caspase 3/7 and resulted in significant cell death in primary human renal cortical epithelial cells. Based on these results, we speculate that Stx-containing exosomes derived from macrophages may exacerbate cytotoxicity and inflammation and trigger cell death in toxin-sensitive cells. Therapeutic interventions targeting Stx-containing exosomes may prevent or ameliorate Stx-mediated acute vascular dysfunction.

Prognostic Implications of CT Feature Analysis in Patients with COVID-19: a Nationwide Cohort Study.

BACKGROUND: Few studies have classified chest computed tomography (CT) findings of coronavirus disease 2019 (COVID-19) and analyzed their correlations with prognosis. The present study aimed to evaluate retrospectively the clinical and chest CT findings of COVID-19 and to analyze CT findings and determine their relationships with clinical severity. METHODS: Chest CT and clinical features of 271 COVID-19 patients were assessed. The presence of CT findings and distribution of parenchymal abnormalities were evaluated, and CT patterns were classified as bronchopneumonia, organizing pneumonia (OP), or diffuse alveolar damage (DAD). Total extents were assessed using a visual scoring system and artificial intelligence software. Patients were allocated to two groups based on clinical outcomes, that is, to a severe group (requiring O2 therapy or mechanical ventilation, n = 55) or a mild group (not requiring O2 therapy or mechanical ventilation, n = 216). Clinical and CT features of these two groups were compared and univariate and multivariate logistic regression analyses were performed to identify independent prognostic factors. RESULTS: Age, lymphocyte count, levels of C-reactive protein, and procalcitonin were significantly different in the two groups. Forty-five of the 271 patients had normal chest CT findings. The most common CT findings among the remaining 226 patients were ground-glass opacity (98%), followed by consolidation (53%). CT findings were classified as OP (93%), DAD (4%), or bronchopneumonia (3%) and all nine patients with DAD pattern were included in the severe group. Uivariate and multivariate analyses showed an elevated procalcitonin (odds ratio [OR], 2.521; 95% confidence interval [CI], 1.001-6.303, P = 0.048), and higher visual CT scores (OR, 1.137; 95% CI, 1.042-1.236; P = 0.003) or higher total extent by AI measurement (OR, 1.048; 95% CI, 1.020-1.076; P < 0.001) were significantly associated with a severe clinical course. CONCLUSION: CT findings of COVID-19 pneumonia can be classified into OP, DAD, or bronchopneumonia patterns and all patients with DAD pattern were included in severe group. Elevated inflammatory markers and higher CT scores were found to be significant predictors of poor prognosis in patients with COVID-19 pneumonia.

Expanding Applications of Pulmonary MRI in the Clinical Evaluation of Lung Disorders: Fleischner Society Position Paper.

Pulmonary MRI provides structural and quantitative functional images of the lungs without ionizing radiation, but it has had limited clinical use due to low signal intensity from the lung parenchyma. The lack of radiation makes pulmonary MRI an ideal modality for pediatric examinations, pregnant women, and patients requiring serial and longitudinal follow-up. Fortunately, recent MRI techniques, including ultrashort echo time and zero echo time, are expanding clinical opportunities for pulmonary MRI. With the use of multicoil parallel acquisitions and acceleration methods, these techniques make pulmonary MRI practical for evaluating lung parenchymal and pulmonary vascular diseases. The purpose of this Fleischner Society position paper is to familiarize radiologists and other interested clinicians with these advances in pulmonary MRI and to stratify the Society recommendations for the clinical use of pulmonary MRI into three categories: (a) suggested for current clinical use, (b) promising but requiring further validation or regulatory approval, and (c) appropriate for research investigations. This position paper also provides recommendations for vendors and infrastructure, identifies methods for hypothesis-driven research, and suggests opportunities for prospective, randomized multicenter trials to investigate and validate lung MRI methods.

Which definition of a central tumour is more predictive of occult mediastinal metastasis in nonsmall cell lung cancer patients with radiological N0 disease?

BACKGROUND: Guidelines recommend invasive mediastinal staging for centrally located tumours, even in radiological N0 nonsmall cell lung cancer (NSCLC). However, there is no uniform definition of a central tumour that is more predictive of occult mediastinal metastasis. METHODS: A total of 1337 consecutive patients with radiological N0 disease underwent invasive mediastinal staging. Tumours were categorised into central and peripheral by seven different definitions. RESULTS: About 7% (93 out of 1337) of patients had occult N2 disease, and they had significantly larger tumour size and more solid tumours on computed tomography. After adjustment for patient- and tumour-related characteristics, only the central tumour definition of the inner one-third of the hemithorax adopted by drawing concentric lines arising from the midline significantly predicted occult N2 disease (adjusted OR 2.13, 95% CI 1.17-3.87; p=0.013). This association was maintained after excluding patients with pure ground-glass nodules (adjusted OR 2.54, 95% CI 1.37-4.71; p=0.003) or only including those with solid tumours (adjusted OR 2.30, 95% CI 1.08-4.88; p=0.030). CONCLUSIONS: We suggest that a central tumour should be defined using the inner one-third of the hemithorax adopted by drawing concentric lines from the midline. This is particularly useful for predicting occult N2 disease in patients with NSCLC.

Diagnostic value of surveillance 18F-fluorodeoxyglucose PET/CT for detecting recurrent esophageal carcinoma after curative treatment.

PURPOSE: Esophageal carcinoma recurs within two years in approximately half of patients who receive curative treatment and is associated with poor survival. While 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is a reliable method of detecting recurrent esophageal carcinoma, in most previous studies FDG PET/CT scans were performed when recurrence was suspected. The aim of this study was to evaluate FDG PET/CT as a surveillance modality to detect recurrence of esophageal carcinoma after curative treatment where clinical indications of recurrent disease are absent. METHODS: A total of 782 consecutive FDG PET/CT studies from 375 patients with esophageal carcinoma after definitive treatment were reviewed. Abnormal lesions suggestive of recurrence on PET/CT scans were then evaluated. Recurrence was determined by pathologic confirmation or other clinical evidence within two months of the scan. If no clinical evidence for recurrence was found at least 6 months after the scan, the case was considered a true negative for recurrence. RESULTS: The diagnostic sensitivity and specificity of PET/CT for detecting recurrent esophageal carcinomas were 100% (64/64) and 94.0% (675/718), respectively. There were no significant differences in the diagnostic performance of PET/CT for detecting recurrence according to initial stage or time between PET/CT and curative treatments. Unexpected second primary cancers were detected by FDG PET/CT in seven patients. CONCLUSIONS: Surveillance FDG PET/CT is a useful imaging tool for detection of early recurrence or clinically unsuspected early second primary cancer in patients with curatively treated esophageal carcinoma but without clinical suspicion of recurrence.

Unilateral Lung Involvement of Nodular Bronchiectatic Mycobacterium Avium Complex Pulmonary Diseases: Proportion and Evolution on Serial CT Studies.

OBJECTIVE. We aimed to explore proportion, involved organisms, and serial CT features of nodular bronchiectatic (NB) Mycobacterium avium complex (MAC) pulmonary diseases that manifested as unilateral lung disease. MATERIALS AND METHODS. We retrospectively identified 674 patients with NB MAC pulmonary disease (PD) who underwent serial CT studies from January 2005 through December 2012. We selected patients with unilateral lung involvement as its initial manifestation. Retrospective analyses on serial CT findings in terms of presence and extent of lung abnormalities were performed. The organism identified (M. avium vs M. intracellulare) and treatment status were reviewed. To find the factors related to progression to involve both lungs, Cox regression analysis was performed. RESULTS. Unilateral MAC PD on initial CT was found in 47 patients (7%). Among them, 10 (21%) showed disease progression on follow-up CT to involve both lungs (mean evolving time, 1536 days). All 10 of these cases initially involved the right lung. Of these 10 patients, eight needed antibiotic treatment because of deteriorating imaging findings (4/8, 50%) or worsening symptoms (4/8, 50%). Initial total CT score (hazard ratio [HR], 1.414; 95% CI, 1.092-1.831; p < 0.01) and age (HR, 1.076; 95% CI, 1.004-1.154; p < 0.05) were related factors for disease progression in simple Cox regression test. CONCLUSION. Unilateral lung involvement of NB MAC PD is an occasional (7%) manifestation, and disease progressed in approximately 20% of patients in our study to involve both lungs. The imaging factor most related to disease progression appears to disease extent on initial CT.

Resected Pure Small Cell Lung Carcinomas and Combined Small Cell Lung Carcinomas: Histopathology Features, Imaging Features, and Prognoses.

OBJECTIVE: The objective of our study was to investigate histopathology features, imaging features, and prognoses of surgically resected pure small cell lung carcinomas (SCLCs) and combined SCLCs. MATERIALS AND METHODS: Forty-one patients with a pure SCLC or a combined SCLC underwent preoperative chest CT and 18F-FDG PET/CT and subsequent surgical resection. The clinicopathologic findings were noted by reviewing the electronic medical records. The imaging features of individual tumors were analyzed on chest CT and PET/CT scans. Each tumor was classified as being located centrally (at or in the segmental bronchus or proximal to the segmental bronchus) or peripherally (distal to the segmental bronchus). The maximum standardized uptake value (SUVmax) of each tumor was measured at PET. The 7th edition of the TNM staging system was adopted for staging. RESULTS: The study group was composed of 34 men and seven women with a mean age of 62.0 ± 10.2 (SD) years. Sixteen of 41 (39%) patients had pure SCLC, and the remaining patients had combined SCLC. The most common combined SCLC histologic subgroup was combined SCLC and large cell neuroendocrine carcinoma in 17 (41%) patients. The mean SUVmax of pure SCLCs was 5.6 ± 2.2 and was significantly lower than that of combined SCLCs (p < 0.01). Thirty-one patients (76%) had a peripheral tumor, and 10 (24%) had a central tumor. The overall survival (OS) of the 10 patients with a central tumor was 44.6 months, significantly shorter than the OS of the 31 patients with a peripheral tumor (179.2 months) (p = 0.017). The OS of 21 patients with stage I disease was significantly longer than the OS of patients with higher-stage cancer (p = 0.004). CONCLUSION: In our study group of patients with surgically resected SCLC, patients with a peripheral tumor (including a purely endobronchial tumor) or stage I disease showed a better prognosis than those with a central tumor or higher-stage disease.

Risk factors and clinical characteristics of lung cancer in idiopathic pulmonary fibrosis: a retrospective cohort study.

BACKGROUND: Lung cancer is a common comorbidity of idiopathic pulmonary fibrosis (IPF) and has poor outcomes. The incidence and clinical factors related to development of lung cancer in idiopathic pulmonary fibrosis (IPF) are unclear. The aim of this study was to elucidate the cumulative incidence, risk factors, and clinical characteristics of lung cancer in IPF. METHODS: In this retrospective study, we analyzed clinical data for 938 patients who were diagnosed with IPF without lung cancer between 1998 and 2013. Demographic, physiologic, radiographic, and histologic characteristics were reviewed. Cumulative incidence of lung cancer and survival were estimated by the Kaplan-Meier method. Risk factors of lung cancer development were determined by Cox proportional hazard analysis. RESULTS: Among 938 IPF patients without lung cancer at initial diagnosis, lung cancer developed in 135 (14.5%) during the follow-up period. The cumulative incidences of lung cancer were 1.1% at 1 year, 8.7% at 3, 15.9% at 5, and 31.1% at 10 years. Risk factors of lung cancer were male gender, current smoking at IPF diagnosis, and rapid annual decline of 10% or more in forced vital capacity (FVC). Patients who developed lung cancer were mostly elderly men with smoking history. Squamous cell carcinoma followed by adenocarcinoma was the most common histologic type. Lung cancer was frequently located in areas abutting or within fibrosis. Survival was significantly worse in patients with lung cancer compared to patients with IPF alone. CONCLUSION: Lung cancer frequently developed in patients with IPF and was common in current-smoking men with rapid decline of FVC.