NUT carcinoma of the lung.

NUT carcinoma of the thorax is a rare and very aggressive tumor, whose definition is based on the demonstration of a nuclear protein in testis (NUTM1; also known as NUT) gene fusion on 15q14 with different partners from the bromodomain-containing proteins gene family. This fusion results in an activation of MYC oncoprotein responsible for the tumor's aggressivity. NUT carcinoma arises preferentially in young adults, presenting a large thoracic mass frequently associated with lymph nodes, bone or pleural metastases. At histology, this tumor is often poorly differentiated, mainly composed of sheets of small cells with scant cytoplasm, a round nucleus with a central nucleolus. Focal areas of squamous differentiation can be observed. Mitoses and necrosis are frequent, as well as neutrophilic infiltrate. The diagnosis is based on the detection of NUT protein expression by immunohistochemistry using the rabbit monoclonal antibody C52B1 in more than 50% of the tumor nuclei. This technique offers 87% sensitivity and nearly 100% specificity with reference to FISH or RT-PCR, which confirm the NUTM1 rearrangement. The differential diagnoses include basaloid carcinoma of the lung, small cell carcinoma, thymic carcinoma (basaloid variant), SMARCA4_deficient thoracic sarcoma, other NUTM1 rearranged undifferentiated tumors, small round cell tumors, non-Hodgkin lymphoma/leukemia, and melanoma. The prognosis of NUT carcinoma remains very poor, with a median survival of 6.7 months, and 1- and 2-year overall survival rates of 30% and 19%, respectively. NUT carcinoma is often refractory to conventional chemotherapy, but ifosfamide-based regimens or BET inhibitors could represent promising therapies.

Comparison of the effects of model-based iterative reconstruction and filtered back projection algorithms on software measurements in pulmonary subsolid nodules.

OBJECTIVES: To evaluate the differences between filtered back projection (FBP) and model-based iterative reconstruction (MBIR) algorithms on semi-automatic measurements in subsolid nodules (SSNs). METHODS: Unenhanced CT scans of 73 SSNs obtained using the same protocol and reconstructed with both FBP and MBIR algorithms were evaluated by two radiologists. Diameter, mean attenuation, mass and volume of whole nodules and their solid components were measured. Intra- and interobserver variability and differences between FBP and MBIR were then evaluated using Bland-Altman method and Wilcoxon tests. RESULTS: Longest diameter, volume and mass of nodules and those of their solid components were significantly higher using MBIR (p < 0.05) with mean differences of 1.1% (limits of agreement, -6.4 to 8.5%), 3.2% (-20.9 to 27.3%) and 2.9% (-16.9 to 22.7%) and 3.2% (-20.5 to 27%), 6.3% (-51.9 to 64.6%), 6.6% (-50.1 to 63.3%), respectively. The limits of agreement between FBP and MBIR were within the range of intra- and interobserver variability for both algorithms with respect to the diameter, volume and mass of nodules and their solid components. There were no significant differences in intra- or interobserver variability between FBP and MBIR (p > 0.05). CONCLUSION: Semi-automatic measurements of SSNs significantly differed between FBP and MBIR; however, the differences were within the range of measurement variability. KEY POINTS: • Intra- and interobserver reproducibility of measurements did not differ between FBP and MBIR. • Differences in SSNs' semi-automatic measurement induced by reconstruction algorithms were not clinically significant. • Semi-automatic measurement may be conducted regardless of reconstruction algorithm. • SSNs' semi-automated classification agreement (pure vs. part-solid) did not significantly differ between algorithms.

Serum potassium concentration predicts brain hypoxia on CT after avalanche-induced cardiac arrest.

BACKGROUND: Brain anoxia after complete avalanche burial and cardiac arrest (CA) may occur despite adequate on-site triage. PURPOSE: To investigate clinical and biological parameters associated with brain hypoxia in a cohort of avalanche victims with whole body computed tomographic (CT) scan. METHODS: Retrospective study of patients with CA and whole body CT scan following complete avalanche burial admitted in a level-I trauma center. MAIN FINDINGS: Out of 19 buried patients with whole body CT scan, eight patients had refractory CA and 11 patients had pre-hospital return of spontaneous circulation. Six patients survived at hospital discharge and only two had good neurologic outcome. Twelve patients had signs of brain hypoxia on initial CT scan, defined as brain edema, loss of gray/white matter differentiation and/or hypodensity of basal ganglia. No clinical pre-hospital parameter was associated with brain anoxia. Serum potassium concentration at admission was higher in patients with brain anoxia as compared to patients with normal CT scan: 5.5 (4.1-7.2) mmol/L versus 3.3 (3.0-4.2) mmol/L, respectively (P<.01). A threshold of 4.35 mmol/L serum potassium had 100% specificity to predict brain anoxia on brain CT scan. CONCLUSIONS: Serum potassium concentration had good predictive value for brain anoxia after complete avalanche burial. This finding further supports the use of serum potassium concentration for extracorporeal life support insertion at hospital admission in this context.

Usual interstitial pneumonia end-stage features from explants with radiologic and pathological correlations.

Idiopathic pulmonary fibrosis (IPF) is the most frequent and severe idiopathic interstitial pneumonia, with typical high-resolution computed tomography (HRCT) features and histologic pattern of usual interstitial pneumonia (UIP); its main differential diagnosis is fibrotic nonspecific interstitial pneumonia (F-NSIP). Usual interstitial pneumonia was mainly described from lung biopsies, and little is known on explants. Twenty-two UIP/IPF explants were analyzed histologically and compared with previous open lung biopsies (OLBs; n = 11) and HRCT (n = 19), when available. Temporospatial heterogeneity and subpleural and paraseptal fibrosis were similarly found in UIP/IPF explants and OLB (91%-95%). Fibroblastic foci were found in 82% of OLBs and 100% of explants, with a higher mean score in explants (P = .023). Honeycombing was present in 64% of OLBs and 95% of explants, with a higher mean score in explants (P = .005). Almost 60% of UIP/IPF explants showed NSIP areas and 41% peribronchiolar fibrosis; inflammation, bronchiolar metaplasia, and vascular changes were more frequent in UIP/IPF explants; and Desquamative Interstitial Pneumonia (DIP)-like areas were not common (18%-27%). Numerous large airspace enlargements with fibrosis were frequent in UIP/IPF explants (59%). On HRCT, honeycombing was observed in 95% of the cases and ground-glass opacities in 53%, correlating with NSIP areas or acute exacerbation at histology. Six patients had combined IPF and emphysema. Lesions were more severe in UIP/IPF explants, reflecting the worsening of the disease. Usual interstitial pneumonia/IPF explants more frequently presented with confounding lesions such as NSIP areas, peribronchiolar fibrosis, and airspace enlargements with fibrosis sometimes associated with emphysema.

Evaluation of RECIST in chemotherapy-treated lung cancer: the Pharmacogenoscan Study.

BACKGROUND: Response Evaluation Criteria in Solid Tumors (RECIST) are widely used to assess the effect of chemotherapy in patients with cancer. We hypothesised that the change in unidimensional tumour size handled as a continuous variable was more reliable than RECIST in predicting overall survival (OS). METHODS: The prospective Pharmacogenoscan study enrolled consecutive patients with non-small-cell lung cancer (NSCLC) at any stage seen between 2005 and 2010 at six hospitals in France, given chemotherapy. After exclusion of patients without RECIST or continuous-scale tumour size data and of those with early death, 464 patients were left for the survival analyses. Cox models were built to assess relationships between RECIST 1.1 categories or change in continuous-scale tumour size and OS. The best model was defined as the model minimising the Akaike Information Criterion (AIC). RESULTS: OS was 14.2 months (IQR, 7.3-28.9 months). According to RECIST 1.1, 146 (31%) patients had a partial or complete response, 245 (53%) stable disease, and 73 (16%) disease progression. RECIST 1.1 predicted better OS than continuous-scale tumour in early (<6 months) predicted survival analyses (p = 0.03) but the accuracy of the two response evaluation methods was similar in late (≥6 months) predicted survival analyses (p = 0.15). CONCLUSION: In this large observational study, change in continuous-scale tumour size did not perform better than RECIST 1.1 in predicting survival of patients given chemotherapy to treat NSCLC. TRIAL REGISTRATION: NCT00222404.

Inter-reader agreement in HRCT detection of pleural plaques and asbestosis in participants with previous occupational exposure to asbestos.

OBJECTIVES: To investigate inter-reader agreement for the detection of pleural and parenchymal abnormalities using CT in a large cross-sectional study comprising information on individual cumulative exposure to asbestos. METHODS: The project was approved by the hospital ethics committee, and all patients received information on the study and gave their written informed consent. In 5511 CT scans performed in a cohort of retired workers previously exposed to asbestos and volunteering to participate in a multiregional survey programme (Asbestos Related Diseases Cohort, ARDCO), double randomised standardised readings, triple in case of disagreement, were performed by seven trained expert radiologists specialised in thoracic imaging and blind to the initial interpretation. Inter-reader agreement was evaluated by calculating the κ-weighted coefficient between pairs of expert readers and results of routine practice and final diagnosis after expert reading. RESULTS: κ-Weighted coefficients between trained experts ranged from 0.28 to 0.52 (fair to good), 0.59 to 0.86 (good to excellent) and 0.11 to 0.66 (poor to good) for the diagnosis of asbestosis, pleural plaques and fibrosis of the visceral pleura, respectively. κ-Weighted coefficients between results of routine practice and final diagnosis after expert reading were 0.13 (poor), 0.53 (moderate) and 0.11 (poor) for the diagnosis of asbestosis, pleural plaques and fibrosis of the visceral pleura, respectively. CONCLUSIONS: Interpretation of benign asbestos-related thoracic abnormalities requires standardisation of the reading and trained readers, particularly for participants asking for compensation, and with a view to the longitudinal survey of asbestos-exposed workers.

Different pathways to lung cancer diagnosis in a real-life setting.

BACKGROUND: Most lung cancers are diagnosed at an advanced stage and therefore have a poor prognosis. One major challenge is to choose the most adapted sampling technique to obtain a rapid pathological diagnosis so as to start treatment as early as possible. A growing number of techniques have been developed in recent years. This study sought to assess the diagnostic efficiency of each, along with the respective duration of the diagnostic pathways. METHODS: This retrospective, bicentric, observational study enrolled patients with inoperable lung cancer (stage III or IV) diagnosed in 2018-2019. Diagnostic efficiency was assessed based on the different examinations performed to achieve a precise diagnosis (pathology, immunohistochemistry, and/or molecular biology). The time between the first medical contact and treatment initiation was also assessed. RESULTS: Overall, 625 patients were included (median age 67 years; men 67 %; adenocarcinoma 55 %). The most frequent examinations were bronchial endoscopy (n = 469, 75 %), followed by metastasis biopsy (n = 137, 21.9 %) and guided transthoracic core-needle biopsy (TCNB) (n = 116, 18.6 %). 372 patients had only one procedure (59.5 %), mainly bronchial endoscopy (n = 217, 34.7 %) and metastasis biopsy (n = 71, 11 %). The most efficient examination was thoracic surgery (surgical pleural biopsy, (n = 32, 100 %); mediastinoscopy (n = 26, 96.3 %); surgical pulmonary biopsy (n = 14, 93.3 %). The second most efficient examination was metastasis biopsy (n = 126, 94 %) followed by guided TCNB (n = 108, 93.1 %). The median time from first medical contact to first examination was 4 days (interquartile range 25 %-75 % 1-8). The median time from first medical contact to pathological result was 17 days (10-34). The median time from first medical contact to treatment start was 48 days (30-69). CONCLUSIONS: In order to make an accurate and rapid diagnosis of lung cancer, it is crucial to choose the most appropriate technique. Bronchial endoscopy remains the first-line examination for central lesions, as it is efficient and easily accessible. Guided TCNB and metastasis biopsy are the preferred techniques for peripheral lesions. The choice of the diagnostic technique should be part of a multidisciplinary approach and a dedicated pathway to optimize initial management.

ECG-gated computed tomography to assess pulmonary capillary wedge pressure in pulmonary hypertension.

OBJECTIVE: We propose a non-invasive method for diagnosing post-capillary pulmonary hypertension (PH group 2). We evaluated pulmonary capillary wedge pressure (PCWP) by studying the left atrium (LA) on thoracic ECG-gated CT compared with right heart catheterisation (RHC). METHODS: We retrospectively studied 54 patients with suspected PH or followed for PH who underwent thoracic ECG-gated CT and RHC within 15 days. The diagnostic accuracy of CT morphological and functional data of the LA for the detection of PCWP >15 mmHg, evaluated by two independent readers, was assessed using correlation and receiver-operating characteristic (ROC) analysis. RESULTS: Interobserver agreement was high (r = 0.97-0.99). Correlations were found between PCWP and the morphological criteria of the LA such as anteroposterior diameter at 0 % of the R-R interval (r = 0.70, P ≤ 0.001) as well as at 40 % (r = 0.69, P ≤ 0.001). ROC curves constructed with a threshold value of PCWP > 15 mmHg showed an area under the curve between 0.88 and 0.91. Significant correlations were found between PCWP and functional criteria of the LA, including distensibility (r = -0.49, P ≤ 0.001) and ejection fraction (r = -0.58, P ≤ 0.001). CONCLUSION: Thoracic ECG-gated CT in a PH workup helps distinguish between pre- and post-capillary PH. KEY POINTS: • Computed tomography may help differentiate the various types of pulmonary hypertension (PH). • Post-capillary PH group 2 is due to left heart disease. • Right heart catheterisation is used to separate pre- and post-capillary PH. • Left atrium anteroposterior diameter measured on CT is of value. • ECG-gated CT helps clinicians to assess patients with PH non-invasively.

Prediction of lobar collateral ventilation in 25 patients with severe emphysema by fissure analysis with CT.

OBJECTIVE: Reducing pulmonary volume through implantation of endobronchial valves is a major interest to improve exercise tolerance and survival in patients with severe emphysema. The primary aim of this study was to evaluate how well CT-determined fissure integrity predicts interlobar collateral ventilation. The secondary objective was to show whether there is a relationship between the size of fissural defects and the presence of collateral ventilation. MATERIALS AND METHODS: Thirty patients with heterogeneous emphysema (postbronchodilator forced expiratory volume in 1 second [FEV1] = 20-50% predicted and > 50% of emphysema in a lobe) underwent collateral ventilation measurements with a catheter through an occlusive balloon within this target lobe during flexible endoscopy. Two senior thoracic radiologists studied the fissures on thoracic high-resolution CT. RESULTS: Collateral ventilation was successfully measured in 37 target lobes in 25 patients. The fissures surrounding the 37 target lobes were evaluated on CT. For the detection of collateral ventilation, the presence of a fissural defect on CT has a sensitivity, specificity, positive predictive value, and negative predictive value of 95%, 44%, 69%, and 88%, respectively. There was a statistically significant difference in the area of the defect between patients with collateral ventilation and those without collateral ventilation (p = 0.04). CONCLUSION: Analysis of pulmonary fissures using CT is useful before endoscopic volume reduction because results are well correlated to endoscopic measurements of collateral ventilation. Further study with clinical outcomes is mandatory to determine if and when one test or the other or both should be used in patient selection.

A comparative study of two automated solutions for cross-sectional skeletal muscle measurement from abdominal computed tomography images.

BACKGROUND: Measurement of cross-sectional muscle area (CSMA) at the mid third lumbar vertebra (L3) level from computed tomography (CT) images is becoming one of the reference methods for sarcopenia diagnosis. However, manual skeletal muscle segmentation is tedious and is thus restricted to research. Automated solutions are required for use in clinical practice. PURPOSE: The aim of this study was to compare the reliability of two automated solutions for the measurement of CSMA. METHODS: We conducted a retrospective analysis of CT images in our hospital database. We included consecutive individuals hospitalized at the Grenoble University Hospital in France between January and May 2018 with abdominal CT images and sagittal reconstruction. We used two types of software to automatically segment skeletal muscle: ABACS, a module of the SliceOmatic software solution "ABACS-SliceOmatic," and a deep learning-based solution called "AutoMATiCA." Manual segmentation was performed by a medical expert to generate reference data using "SliceOmatic." The Dice similarity coefficient (DSC) was used to measure overlap between the results of the manual and the automated segmentations. The DSC value for each method was compared with the Mann-Whitney U test. RESULTS: A total of 676 hospitalized individuals was retrospectively included (365 males [53.8%] and 312 females [46.2%]). The median DSC for SliceOmatic vs AutoMATiCA (0.969 [5th percentile: 0.909]) was greater than the median DSC for SliceOmatic vs. ABACS-SliceOmatic (0.949 [5th percentile: 0.836]) (p < 0.001). CONCLUSIONS: AutoMATiCA, which used artificial intelligence, was more reliable than ABACS-SliceOmatic for skeletal muscle segmentation at the L3 level in a cohort of hospitalized individuals. The next step is to develop and validate a neural network that can identify L3 slices, which is currently a fastidious process.

Pulmonary embolism in mechanically ventilated patients requiring computed tomography: Prevalence, risk factors, and outcome.

OBJECTIVE: To estimate the rate of pulmonary embolism among mechanically ventilated patients and its association with deep venous thrombosis. DESIGN: Prospective cohort study. SETTING: Medical intensive care unit of a university-affiliated teaching hospital. INCLUSION CRITERIA: mechanically ventilated patients requiring a thoracic contrast-enhanced computed tomography scan for any medical reason. EXCLUSION CRITERIA: a diagnosis of pulmonary embolism before intensive care unit admission, an allergy to contrast agents, and age younger than 18 yrs. INTERVENTIONS: All the mechanically ventilated patients requiring a thoracic computed tomography underwent the standard imaging protocol for pulmonary embolism detection. Therapeutic anticoagulation was given immediately after pulmonary embolism diagnosis. All the included patients underwent a compression ultrasound of the four limbs within 48 hrs after the computed tomography scan to detect deep venous thrombosis. RESULTS: Of 176 included patients, 33 (18.7%) had pulmonary embolism diagnosed by computed tomography, including 20 (61%) with no clinical suspicion of pulmonary embolism. By multiple logistic regression, independent risk factors for pulmonary embolism were male gender, high body mass index, history of cancer, past medical history of deep venous thrombosis, coma, and high platelet count. Previous prophylactic anticoagulant use was not a risk factor for pulmonary embolism. Of the 176 patients, 35 (19.9%) had deep venous thrombosis by compression ultrasonography, including 20 (57.1%) in the lower limbs and 24 (68.6%) related to central venous catheters. Of the 33 pulmonary embolisms, 11 (33.3%) were associated with deep venous thrombosis. The pulmonary embolism risk was increased by lower-limb deep venous thrombosis (odds ratio 4.0; 95% confidence interval 1.6-10) but not upper-limb deep venous thrombosis (odds ratio 0.6; 95% confidence interval 0.1-2.9). Crude comparison of patients with and without pulmonary embolism shows no difference in length of stay or mortality. CONCLUSIONS: In mechanically ventilated patients who needed a computed tomography, pulmonary embolism was more common than expected. Patients diagnosed with pulmonary embolism were all treated with therapeutic anticoagulation, and their intensive care unit or hospital mortality was not impacted by the pulmonary embolism occurrence. These results invite further research into early screening and therapeutic anticoagulation of pulmonary embolism in critically ill patients.

Case reports: iatrogenic bronchial rupture following the use of endotracheal tube introducers.

PURPOSE: Endotracheal tube introducers are often used in difficult tracheal intubations, but they are rarely deemed responsible for airway injuries. There have been only a few reports of severe complications, such as pharyngeal perforation, mainstem bronchus bleeding, perforation of the tracheal mucosa, and tracheal abrasion associated with hemopneumothorax. Using a computed tomography (CT) scan, we illustrate two cases of non-severe airway injuries related to endotracheal tube introducers. CLINICAL FEATURES: We present two cases of distal bronchial lacerations caused by introducers. The first occurrence was caused by a Muallem ET Tube Stylet (METTS) in a patient who underwent surgery for a total thyroidectomy and presented hemoptysis at suction after tracheal intubation. The second occurrence was caused by an Eschmann® Tracheal Tube Introducer (gum elastic bougie) in a patient whose trachea was intubated before a radiofrequency ablation of a single lung metastasis. There was evidence of blood on the tip of the bougie after withdrawal. In both cases, a CT scan showed a post-traumatic bronchial laceration with an acquired bronchial ectasia surrounded by ground-glass opacity due to alveolar hemorrhage. The patients had no other clinical complications, and bronchial lesions resolved spontaneously at control CT scan. CONCLUSION: These two cases show that airway damage related to endotracheal tube introducers may not be exceptional. It is not unusual to have some blood on an airway management device, and the rate and severity of these lesions are unknown. However, damage to the airway can be avoided by adapting preventive techniques during tracheal intubation.

Pulmonary artery and right ventricle assessment in pulmonary hypertension: correlation between functional parameters of ECG-gated CT and right-side heart catheterization.

BACKGROUND: Right ventricular function predicts outcome in patients with pulmonary hypertension (PH). Therefore accurate assessment of right ventricular function is essential to graduate severity, assess follow-up, and response to therapy. PURPOSE: To evaluate whether PH severity could be assessed using electrocardiography-gated CT (ECG-gated CT) functional parameters. A further objective was to evaluate cardiac output (CO) using two ECG-gated CT methods: the reference Simpson technique and the fully automatic technique generated by commercially available cardiac software. MATERIAL AND METHODS: Our institutional review board approved this study; patient consent was not required. Twenty-seven patients who had undergone ECG-gated CT and right heart catheterization (RHC) were included. Two independent observers measured pulmonary artery (PA) diameter, PA distensibility, aorta diameter, right ventricular cardiac output (CT-RVCO) and right ventricular ejection fraction (CT-RVEF) with automatic and Simpson techniques on ECG-gated CT. RHC-CO and mean pulmonary arterial pressure (mPAP) were measured on RHC. Relationship between ECG-gated CT and RHC measurements was tested with linear regression analysis. RESULTS: Inter-observer agreement was good for all measurements (r > 0.7) except for CT-RVCO calculated with Simpson's technique (r = 0.63). Pulmonary artery (PA) distensibility was significantly correlated to mPAP (r = -0.426, P = 0.027). CT-RVEF was correlated with mPAP only when issued from Simpson technique (r = -0.417, P = 0.034). CT-RVEF was not significantly correlated to RHC-CO (P > 0.2). CT-RVCO measured with Simpson technique (r = 0.487, P = 0.010) and automatic segmentation (r = 0.549, P = 0.005) correlated equally with RHC-CO. CONCLUSION: CT-RVEF and CT-RVCO measured on ECG-gated CT are significantly correlated, respectively, to mPAP and RHC-CO in this population with severe reduction of the right ventricular ejection fraction and could be useful for evaluating and following patients with PH.

Computed Tomography Registration-Derived Regional Ventilation Indices Compared to Global Lung Function Parameters in Patients With COPD.

CT registration-derived indices provide data on regional lung functional changes in COPD. However, because unlike spirometry which involves dynamic maximal breathing maneuvers, CT-based functional parameters are assessed between two static breath-holds, it is not clear how regional and global lung function parameters relate to each other. We assessed the relationship between CT-density change (dHU), specific volume change (dsV), and regional lung tissue deformation (J) with global spirometric and plethysmographic parameters, gas exchange, exercise capacity, dyspnoea, and disease stage in a prospective cohort study in 102 COPD patients. There were positive correlations of dHU, dsV, and J with spirometric variables, DLCO and gas exchange, 6-min walking distance, and negative correlations with plethysmographic lung volumes and indices of trapping and lung distension as well as GOLD stage. Stepwise regression identified FEV1/FVC (standardized ß = 0.429, p < 0.0001), RV/TLC (ß = -0.37, p < 0.0001), and BMI (ß = 0.27, p=<0.001) as the strongest predictors of CT intensity-based metrics dHU, with similar findings for dsV, while FEV1/FVC (ß = 0.32, p=<0.001) and RV/TLC (ß = -0.48, p=<0.0001) were identified as those for J. These data suggest that regional lung function is related to two major pathophysiological processes involved in global lung function deterioration in COPD: chronic airflow obstruction and gas trapping, with an additional contribution of nutritional status, which in turn determines respiratory muscle strength. Our data confirm previous findings in the literature, suggesting the potential of CT image-based regional lung function metrics as the biomarkers of disease severity and provide mechanistic insight into the interpretation of regional lung function indices in patients with COPD.

Nasal High Flow at 25 L/min or Expiratory Resistive Load Do Not Improve Regional Lung Function in Patients With COPD: A Functional CT Imaging Study.

BACKGROUND: Nasal high flow (NHF) is a non-invasive breathing therapy that is based on the delivery via a large-caliber nasal cannula of heated and humidified air at flow rates that exceed peak inspiratory flow. It is thought that positive airway pressure generated by NHF can help reduce gas trapping and improve regional lung ventilation. There are no data to confirm this hypothesis at flow rates applicable in stable chronic obstructive pulmonary disease (COPD) patients. METHODS: In this study, we used non-rigid registration of computed tomography (CT) images acquired at maximal expiration and inspiration to compute regional lung attenuation changes (ΔHU), and lung displacement (LD), indices of regional lung ventilation. Parametric response maps (Galban et al., 2012) were also computed in each experimental condition. Eight COPD patients were assessed at baseline (BL) and after 5 min of NHF and expiratory resistive loading (ERL). RESULTS: ΔHU was: BL (median, IQR): 85 (67.2, 102.8); NHF: 90.7 (57.4, 97.6); ERL: 74.6 (46.4, 89.6) HU (p = 0.531); and LD: 27.8 (22.3, 39.3); 17.6 (15.4, 27.9); and 20.4 (16.6, 23.6) mm (p = 0.120) in the 3 conditions, respectively. No significant difference in trapping was observed. Respiratory rate significantly decreased with both treatments [BL: 17.3 (16.4, 18.9); NHF: 13.7; ERL: 11.4 (9.6, 13.2) bpm; and p < 0.001]. CONCLUSION: Neither NHF at 25 L/min nor ERL significantly improved the regional lung ventilation of stable COPD patients with gas trapping, based on functional lung CT imaging. Further study including more subjects is needed to assess the potential effect of NHF on regional lung function at higher flow rates. CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov/under, identifier NCT03821311.

Collagenase-Induced Patellar Tendinopathy with Neovascularization: First Results towards a Piglet Model of Musculoskeletal Embolization.

BACKGROUND: Therapeutic strategies targeting neovessels responsible for musculoskeletal chronic pain have emerged, including neovessels embolization. Our study aimed to develop a large animal model of patellar tendinopathy with neovascularization. METHODS: Nine 3-month-old male piglets (18 patellar tendons) received percutaneous injections of increasing doses of collagenase (0 to 50 mg) at day 0 (D0). Tendinopathy was evaluated by ultrasound (D7 and D14). Neovascularization was evaluated visually and on angiographies. Bonar score was used for histological analysis (D14). Correlations were evaluated using Spearman's rank (Rs) test. RESULTS: Research protocol was well tolerated. All tendons were enlarged with a median increase of 31.58% [25-40.28] at D7 (p = 0.244) at D7 and 57.52% [48.41-91.45] at D14 (p = 0.065). Tendons with collagenase injection had more hypoechoic changes, with one tendon rupture (p = 0.012). Neovascularization was reported above 5 mg collagenase (p < 0.01) at D7 and D14 with dose-related neovessels induction (Rs = 0.8, p < 0.001). The Bonar score increased above 5 mg collagenase, correlated with the dose (Rs = 0.666, p = 0.003). CONCLUSIONS: The study shows the feasibility, safety and reproducibility of this new large animal model of patellar tendinopathy with neovascularization after collagenase injection. It will allow studying new treatments on direct embolization of neovessels by endovascular approach.

Imaging features and differential diagnoses of non-neoplastic diffuse mediastinal diseases.

Acute or chronic non-neoplastic diffuse mediastinal diseases have multiple causes, degrees of severity, and a wide range of management. Some situations require emergency care while others do not need specific treatment. Although the diagnosis may be suspected on chest X-ray, it is mainly based on CT. A delayed recognition is not uncommonly observed. Some findings may prompt the radiologist to look for specific associated injuries or lesions.This pictorial review will successively describe the various non-neoplastic causes of diffuse mediastinal diseases with their typical findings and major differentials.First, pneumomediastinum that can be provoked by extra- or intra-thoracic triggers requires the knowledge of patient's history or recent occurrences. Absence of any usual etiological factor should raise suspicion of cocaine inhalation in young individuals.Next, acute mediastinitis may be related to post-operative complications, esophageal perforation, or contiguous spread of odontogenic or retropharyngeal infections. The former diagnosis is not an easy task in the early stage, owing to the similarities of imaging findings with those of normal post-operative appearance during the first 2-3 weeks.Finally, fibrosing mediastinitis that is linked to an excessive fibrotic reaction in the mediastinum with variable compromise of mediastinal structures, in particular vascular and airway ones. Differential diagnosis includes tumoral and inflammatory infiltrations of the mediastinum.

Percutaneous CT-guided biopsy of lytic bone lesions in patients clinically suspected of lung cancer: Diagnostic performances for pathological diagnosis and molecular testing.

OBJECTIVES: Bone is a common location for lung cancer metastasis. Clinicians are often reluctant to biopsy bone metastases, as they are known to require a decalcification process that damages nucleic acids, which makes it incompatible with molecular testing. We performed this study to assess the diagnostic performance of histopathology and molecular testing of computed tomography (CT)-guided percutaneous bone biopsies of lytic bone lesions during the initial assessment or during the progression of lung cancer. MATERIALS AND METHODS: This retrospective study included all patients suspected of having or known to have primary lung cancer and CT-guided percutaneous bone biopsies of lytic bone from January 2010 to June 2017. The main judgment criterion was the diagnostic performance of the pathological analysis. Secondary endpoints were the diagnostic performance of molecular testing and incidence of complications. RESULTS: Fifty patients were included. The yield of CT-guided percutaneous bone biopsies for pathological analysis was 100 %, allowing for a diagnosis of certainty in all cases. The percentage of tumor cells in samples was higher than the 20 % threshold in 83.9 % of cases. The yield of molecular analysis was 94.6 %. A mutation was found in 60 % of cases; most frequently in KRAS (Kirsten rat sarcoma viral oncogene homolog) (28.6 %) and EGFR (epidermal growth factor receptor) (14.3 %). The complication rate was 2 %, i.e. a minor undrained pneumothorax. CONCLUSION: CT-guided percutaneous biopsies of lytic bone is associated with a very low complication rate and high diagnostic performance for histopathology and mutation testing.

Development and Validation of a Deep Learning-Based Automated Detection Algorithm for Major Thoracic Diseases on Chest Radiographs.

Importance: Interpretation of chest radiographs is a challenging task prone to errors, requiring expert readers. An automated system that can accurately classify chest radiographs may help streamline the clinical workflow. Objectives: To develop a deep learning-based algorithm that can classify normal and abnormal results from chest radiographs with major thoracic diseases including pulmonary malignant neoplasm, active tuberculosis, pneumonia, and pneumothorax and to validate the algorithm's performance using independent data sets. Design, Setting, and Participants: This diagnostic study developed a deep learning-based algorithm using single-center data collected between November 1, 2016, and January 31, 2017. The algorithm was externally validated with multicenter data collected between May 1 and July 31, 2018. A total of 54 221 chest radiographs with normal findings from 47 917 individuals (21 556 men and 26 361 women; mean [SD] age, 51 [16] years) and 35 613 chest radiographs with abnormal findings from 14 102 individuals (8373 men and 5729 women; mean [SD] age, 62 [15] years) were used to develop the algorithm. A total of 486 chest radiographs with normal results and 529 with abnormal results (1 from each participant; 628 men and 387 women; mean [SD] age, 53 [18] years) from 5 institutions were used for external validation. Fifteen physicians, including nonradiology physicians, board-certified radiologists, and thoracic radiologists, participated in observer performance testing. Data were analyzed in August 2018. Exposures: Deep learning-based algorithm. Main Outcomes and Measures: Image-wise classification performances measured by area under the receiver operating characteristic curve; lesion-wise localization performances measured by area under the alternative free-response receiver operating characteristic curve. Results: The algorithm demonstrated a median (range) area under the curve of 0.979 (0.973-1.000) for image-wise classification and 0.972 (0.923-0.985) for lesion-wise localization; the algorithm demonstrated significantly higher performance than all 3 physician groups in both image-wise classification (0.983 vs 0.814-0.932; all P < .005) and lesion-wise localization (0.985 vs 0.781-0.907; all P < .001). Significant improvements in both image-wise classification (0.814-0.932 to 0.904-0.958; all P < .005) and lesion-wise localization (0.781-0.907 to 0.873-0.938; all P < .001) were observed in all 3 physician groups with assistance of the algorithm. Conclusions and Relevance: The algorithm consistently outperformed physicians, including thoracic radiologists, in the discrimination of chest radiographs with major thoracic diseases, demonstrating its potential to improve the quality and efficiency of clinical practice.

Multi-detector CT evaluation in patients suspected of tracheobronchomalacia: comparison of end-expiratory with dynamic expiratory volumetric acquisitions.

PURPOSE: The aim of this study was to compare dynamic expiratory imaging and end-expiratory imaging using multi-detector CT (MDCT) of the central airways in patients suspected of tracheobronchomalacia (TBM). METHODS: This study had local ethical committee approval. Seventy patients suspected of TBM were prospectively included. All patients underwent evaluation of central airways by three different low-dose MDCT acquisitions: end inspiration, end expiration, and dynamic expiration. Degree of airway collapse was measured by calculating the percentage change in the area and diameter of the airways between inspiratory and the two expiratory techniques at three levels of the trachea and in the sagittal diameter of the right and left main bronchi. Three threshold levels of percentage reduction in diameter or area (30%, 50%, and 70%) for defining TBM were evaluated. RESULTS: In the entire population, the mean percentage of airway collapse was significantly greater with dynamic expiratory imaging than with the end-expiratory imaging at three different levels: lower thoracic trachea (26% vs. 16.6%, p<0.009), right (25.2% vs. 14%, p<0.01) and left main (24.7% vs. 13.3%, p<0.01) bronchus. Whatever the threshold value for defining TBM, dynamic expiratory imaging always resulted in diagnosing TBM in more patients than end-expiratory imaging. CONCLUSIONS: Dynamic expiratory imaging shows a significantly greater degree and a significantly greater extent of airway collapse than standard end-expiratory imaging in patients suspected of TBM. Further evaluation of the clinical relevance of such findings is warranted.