Mucus plugs in the airways of asthmatic subjects and smoking status.

BACKGROUND: Mucus plugs have been described in the airways of asthmatic subjects, particularly those with associated with type 2 inflammation and sputum eosinophilia. In the current study we addressed the question of whether smoking, neutrophilic inflammation and airway dimensions affected the prevalence of mucus plugs. METHODS: In a cohort of moderate to severe asthmatics (n = 50), including a group of ex-smokers and current smokers, the prevalence of mucus plugs was quantified using a semi-quantitative score based on thoracic computerized tomography. The relationships between mucus score, sputum inflammatory profile and airway architecture were tested according to patient's smoking status. RESULTS: Among the asthmatics (37% former or active smokers), 74% had at least one mucus plug. The median score was 3 and was unrelated to smoking status. A significant but weak correlation was found between mucus score, FEV1 and FEV1/FVC. Mucus score was significantly correlated with sputum eosinophils. Among former and active smokers, mucus score was correlated with sputum neutrophils. Mucus score was positively associated with FeNO in non-smoking subjects. The lumen dimensions of the main and lobar bronchi were significantly inversely correlated with mucus score. CONCLUSION: Airway mucus plugs could define an asthma phenotype with altered airway architecture and can occur in asthmatic subjects with either neutrophilic or eosinophilic sputum according to their smoking status.

Unilateral metastatic pulmonary calcification in context of ipsilateral central pulmonary embolism.

We report a case of unilateral left metastatic pulmonary calcification (MPC) in a 30-year-old woman with systemic lupus erythematosus, acute nephritis, and left main pulmonary artery pulmonary embolism. Unilateral MPC is rare and is mostly seen in the context of ipsilateral pulmonary embolism. The proposed mechanism is the promotion of calcium salts precipitation by focal alkalosis resulting from reduced blood flow to the lung affected by the pulmonary arterial obstruction.

Cor triatriatum simulating a left atrial mass in adult patient.

We report a case of non-thrombosed cor triatriatum sinister simulating a cardiac mass on thoracic CT angiogram in a 58-year-old man presenting with acute chest pain. Following additional imaging with cardiac CT and MRI, and otherwise unremarkable cardio-pulmonary work-up, diagnosis of presumably coincidental cor triatriatum was established.

Diagnostic pitfalls in computed tomography of the chest.

Anatomical variants and imaging artifacts on thoracic computed tomography (CT), when unrecognized as such, can lead to radiological misinterpretation and erroneous diagnosis. This is a concise review of 15 common CT diagnostic pitfalls due to anatomical variants and imaging artifacts which have potential to be misinterpreted as significant pathology, such as neoplasia, infection, traumatic injury, interstitial lung disease, pleural disease, or vascular lesions.

Coronary bioresorbable stents: Non-invasive quantitative evaluation of intra- and juxta-stent plaque composition-A computed tomography longitudinal study.

PURPOSE: Coronary bioresorbable stents (BRS) do not produce blooming artifacts on computed tomography (CT), in contrast to metallic stents, as they are made of a bioresorbable polymer and are radiolucent. They allow to evaluate the coronary plaque beneath. The low-attenuation plaque (LAP) suggests plaque vulnerability and is CT assessable. The aim of our study was to show the possibility of a non-invasive CT evaluation of the volume and the LAP composition of the intra- and juxta-stent plaque. METHODOLOGY: In our prospective longitudinal study, we recruited 27 consecutive patients (35 BRS stents total; mean age 60 +/- 9 years) with bioresorbable stents for a 256-slice ECG-synchronized CT evaluation at 1- and 12-months post stent implantation. Total plaque volume (mm3), absolute and relative (%) LAP volume per block in the pre- intra- and post-stent zones were analyzed; comparison 1- and 12-months post-implantation of BRS. Changes in the previously mentioned variables were assessed by the mixed effects models with and without spline, which also accounted for the correlation between repeated measurements. RESULTS: Our block or spline model analysis has shown no significant difference in plaque or absolute LAP volumes in pre- intra- and post-stent zones between 1 and 12 months. Interestingly, % LAP volume increases near-significantly in the distal block of the intrastent at 12-mo follow-up (from 23.38 ± 1.80% to 26.90 ± 2.22% (increase of 15%), p = 0.052). CONCLUSION: Our study demonstrates the feasibility of the repeated non-invasive quantitative analysis of the intrastent coronary plaque and of the in-stent lumen by CT scan.

Horseshoe adrenal gland associated with retro-aortic right diaphragmatic crus and several vascular variants: Report of two cases.

Horseshoe adrenal gland (HA) refers to congenital fusion of the adrenal glands across the midline - a rare anatomical variant often found in association with other congenital anomalies. Here we report 2 cases of HA associated with retro-aortic course of the right diaphragmatic crus, yet another rare anatomical variant, in a 61 your-old male and a 69-year-old female, who underwent CT examinations for unrelated reasons. Both patients also had additional vascular and vertebral anomalies. To the best of our knowledge, this is the first report to document association of 2 rare congenital anomalies: HA and retro-aortic right diaphragmatic crus.

Improved Detection of Chronic Obstructive Pulmonary Disease at Chest CT Using the Mean Curvature of Isophotes.

PURPOSE: To determine if the mean curvature of isophotes (MCI), a standard computer vision technique, can be used to improve detection of chronic obstructive pulmonary disease (COPD) at chest CT. MATERIALS AND METHODS: In this retrospective study, chest CT scans were obtained in 243 patients with COPD and 31 controls (among all 274: 151 women [mean age, 70 years; range, 44-90 years] and 123 men [mean age, 71 years; range, 29-90 years]) from two community practices between 2006 and 2019. A convolutional neural network (CNN) architecture was trained on either CT images or CT images transformed through the MCI algorithm. Separately, a linear classification based on a single feature derived from the MCI computation (called hMCI1) was also evaluated. All three models were evaluated with cross-validation, using precision-macro and recall-macro metrics, that is, the mean of per-class precision and recall values, respectively (the latter being equivalent to balanced accuracy). RESULTS: Linear classification based on hMCI1 resulted in a higher recall-macro relative to the CNN trained and applied on CT images (0.85 [95% CI: 0.84, 0.86] vs 0.77 [95% CI: 0.75, 0.79]) but with a similar reduction in precision-macro (0.66 [95% CI: 0.65, 0.67] vs 0.77 [95% CI: 0.75, 0.79]). The CNN model trained and applied on MCI-transformed images had a higher recall-macro (0.85 [95% CI: 0.83, 0.87] vs 0.77 [95% CI: 0.75, 0.79]) and precision-macro (0.85 [95% CI: 0.83, 0.87] vs 0.77 [95% CI: 0.75, 0.79]) relative to the CNN trained and applied on CT images. CONCLUSION: The MCI algorithm may be valuable toward the automated detection and diagnosis of COPD on chest CT scans as part of a CNN-based pipeline or with stand-alone features.Keywords: Chronic Obstructive Pulmonary Disease, Quantification, Lung, CT Supplemental material is available for this article. See also the invited commentary by Vannier in this issue.© RSNA, 2021.

Outcomes of Multidetector Computed Tomography Pulmonary Angiography in Pregnant and Postpartum Women With Suspected Pulmonary Embolism.

PURPOSE: Verify whether there is a difference in likelihood of developing pulmonary embolism (PE) between pregnant women, nonpregnant women of reproductive age, and postpartum (up to 6 weeks) women, by comparing their outcomes on computed tomography pulmonary angiography (CTPA) done for suspicion of PE. MATERIALS AND METHODS: Retrospective cohort study of 1463 CTPA done for suspicion of PE in females of reproductive age (18-40 years), nonpregnant, pregnant (antepartum), and postpartum, from 2 tertiary-care academic hospitals between October 2006 and September 2015. Primary outcome was diagnosis of PE on imaging. Additional assessment was made of technical adequacy of the studies and method of delivery for the postpartum cohort (vaginal vs caesarean birth). Twenty-nine technically nondiagnostic studies were excluded. The effect of any potential variable on PE status was tested using univariate logistic regression. Subgroup analysis was performed after excluding patients with independent risk factors for PE. RESULTS: The rate of CTPA positive for PE was less among pregnant patients compared to early postpartum and nonpregnant women of similar age, 2.9% vs 11.5% and 10.3%, respectively. Pregnancy was associated with statistically significant decreased odds ratio of developing a PE on CTPA, 0.23 (0.09-0.89), P value = .004. After excluding patients with additional independent risk factors for PE, there was no statistically significant odds ratio association between presence of PE on CTPA and pregnancy 0.41 (0.13-1.34), P value = .14. CONCLUSION: Rate of CTPA positive for PE in pregnant women was lower than in nonpregnant and early postpartum women. Pregnancy was statistically significantly less likely to be associated with positive PE on a CTPA study. The common perception that pregnancy (antepartum state) is associated with an increased risk of PE may require a thorough critical reappraisal.

Multiple pulmonary myofibromas mimicking metastatic disease in an adult patient.

We report a case of multiple bilateral pulmonary myofibromas in an asymptomatic 76-year-old man, who was referred to our institution for investiagtion of incidentally discovered pulmonary nodules, orginially suspected to represent pulmonary metastases. Myofibromas are unusual benign neoplasms, infrequent in adults, and rarely affecting the lungs. Pulmonary neurofibromas can mimic lung metastases and their diagnosis requires histopathological assessment.

Pulmonary air embolism associated with proximal bland thrombus.

We report a case of pulmonary air embolism associated with proximal bland thrombus seen on computed tomography pulmonary angiography in a 49-year-old man, who developed acute hypoxia following removal of central venous catheter.

Imaging-Based Surrogate Markers of Epidermal Growth Factor Receptor Mutation in Lung Adenocarcinoma: A Local Perspective.

PURPOSE: To identify computed tomography (CT) features of epidermal growth factor receptor (EGFR) mutation-positive lung adenocarcinoma in Canadian population and whether imaging-based surrogate markers of EGFR mutation in our population were similar to those found in the Asian population. MATERIALS AND METHODS: Pretreatment CT scans of 223 patients with adenocarcinoma of the lung (112 with EGFR mutation and 111 without mutation) were retrospectively assessed for 20 specific CT features by 2 radiologists, who were blinded to the status of EGFR mutation. Univariate and multivariate logistic regression analyses as well as areas under the receiver operating characteristic curve were performed to discriminate characteristics of EGFR-activating mutation features. RESULTS: Epidermal growth factor receptor mutation-positive adenocarcinomas were more frequently found in female (P < .03), less than 20 pack-year smoking history (P < .001), smaller tumor (P < .01), spiculated margins (P < .05), without centrilobular emphysema (P < .001), and without lymphadenopathy (P < .05), similarly to the Asian population. Multivariate logistic regression analyses of combined clinical and radiological features identified less than 20 pack-year smoking history, smaller tumor diameter, fine or coarse spiculations, noncentral location of the tumor, and lack of centrilobular emphysema and pleural attachment as the strongest independent prognostic factors for the presence of an EGFR mutation. These combined features improved prognostic ability area under the curve to 0.879, compared to 0.788 for clinical features only. CONCLUSION: Several CT findings may help predict the presence of an activating mutation in EGFR in lung adenocarcinomas in our Canadian population. Combining clinical and radiological features improves prognostic ability to determine the EGFR mutation status compared to clinical features alone.

"Distal bright vessel sign" - Novel radiological sign of pulmonary thromboembolism.

We describe a novel radiological sign of pulmonary thromboembolism on computed tomography aortic angiogram. It consists of focal hyperenhancement of pulmonary arteries distal to the pulmonary thrombus, while the thrombus itself remains occult and the rest of pulmonary arteries are hypoattenuating. The sign was observed on computed tomography aortic angiograms in 2 patients assessed for suspected acute aortic syndrome. Pulmonary emboli were subsequently confirmed with computed tomography pulmonary angiography.

Mediastinal epithelioid hemangioendothelioma-Mimicker of mature teratoma.

We report a case of an adult man who underwent surgical resection of a presumed anterior mediastinal teratoma, which upon histopathologic assessment was diagnosed as an epithelioid hemangioendothelioma (EHE). EHE is a rare vascular tumor of variable, but usually low malignant potential. Its occurrence in mediastinum is estimated at 1 in a million. As EHE often contains macroscopic fat and bone, it can be indistinguishable on imaging from mediastinal mature teratoma. Therefore, EHE should be included in differential diagnosis of fat and bone-containing mediastinal masses.

Imaging of Thoracic Wall Abnormalities.

Identification of certain abnormalities of the chest wall can be extremely helpful in correctly diagnosing a number of syndromic conditions and systemic diseases. Additionally, chest wall abnormalities may sometimes constitute diagnoses by themselves. In the present pictorial essay, we review a number of such conditions and provide illustrative cases that were retrospectively identified from our clinical imaging database. These include pentalogy of Cantrell, Klippel-Feil syndrome, cleidocranial dysplasia, Poland syndrome, osteopetrosis, neurofibromatosis type 1, Marfan syndrome, Gardner syndrome, systemic sclerosis, relapsing polychondritis, polymyositis/dermatomyositis, ankylosing spondylitis, hyperparathyroidism, rickets, sickle cell anemia, thalassemia, tuberculosis, septic arthritis of the sternoclavicular joint, elastofibroma dorsi, and sternal dehiscence.

Many Faces of Thoracic Histoplasmosis-Pictorial Essay.

Histoplasmosis is primarily a pulmonary fungal infection with a vast array of radiological manifestations, which can mimic a number of thoracic diseases. This article reviews various presentations of histoplasmosis on chest imaging.

Migration of the azygos vein from the azygos fissure to the mediastinum.

We report a case of migration of the azygos vein from an azygos fissure into the mediastinum following a large right pleural effusion.

Interstitial lung disease as a late complication of pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis is a rare condition characterized by accumulation of intra-alveolar surfactant. Here, we report a case of interstitial lung disease which developed over the years in a patient with pulmonary alveolar proteinosis.

Imaging of Post Transthoracic Needle Biopsy Complications.

When faced with characterization of a suspicious lung lesion, transthoracic needle biopsy (TTNB) is the standard technique used to retrieve a pathological specimen. Usual complications reported for this intervention are pneumothorax, hemorrhage, air embolism, and tumor seeding. This pictorial essay illustrates imaging of these complications.

Giant cell tumor of a rib following denosumab treatment.

Giant cell tumor (GCT) of the bone is an aggressive lytic lesion, commonly treated with surgery. Denosumab is a relatively recently introduced osteoclast activation inhibitor used for neoadjuvant therapy of GCT. Here we report the case of a GCT of a rib undergoing extensive osteosclerosis on computed tomography imaging following treatment with denosumab.

Thoracic Diseases With Musculoskeletal Manifestations and Vice Versa: A Review.

OBJECTIVE: The purpose of this article is to review several thoracic conditions that are associated with certain musculoskeletal radiological abnormalities using imaging of patients with concomitant chest and musculoskeletal manifestations as illustrative examples. CONCLUSION: Radiologic findings of many thoracic diseases are often nonspecific. When standing alone, their interpretation commonly results in long differential diagnosis. However, in certain instances, a reasonably accurate diagnosis can be made based on imaging findings alone.