Contrast-enhanced Chest Computed Tomography Scan Research Articles

Contrast-Enhanced Chest Computed Tomography (CT) Scan with Low Radiation and Total Iodine Dose for Lung Cancer Detection Using Adaptive Statistical Iterative Reconstruction

Background: Contrast-enhanced chest computed tomography (CT) is useful for the detection and follow-up of patients with lung cancer. However, reaching balance between diagnostic image quality, radiation dose, and iodixanol dose is a cause of concern. Objectives: To investigate the clinical value of adaptive statistical iterative reconstruction (ASIR) in reducing the iodixanol content and radiation dose during contrast-enhanced chest CT scan for patients diagnosed with lung masses/nodules based on the analysis of image quality. Patients and Methods: This prospective study was conducted on 80 patients diagnosed with nodules or masses, who required contrast-enhanced chest CT scans. The experimental group (n = 40) was subjected to iohexol at a high concentration (350 mgI/L) with a tube voltage of 120 kVp and a filter back projection (FBP) reconstruction algorithm. The comparison group (n = 40) was subject to iodixanol at a lower concentration (270 mgI/L) with a tube voltage of 100 kVp and ASIR (blending ratio, 40%). The radiation dose and total iodixanol content, as well as subjective and objective evaluations of image quality, were analyzed and compared. Results: The two groups obtained non-significantly different subjective scores for five structures detected in the lung window and five structures detected in the mediastinal window, as well as the overall image (P > 0.05 for all). Both the two-group images obtained diagnosis-acceptable scores (≥ 3 points) on displays of 10 structures and overall image quality. The mean CT value of vessels (100 kVp vs. 120 kVp: 314.90 ± 23.42 vs. 308.93 ± 21.40; P > 0.05), standard deviation (13.03 ± 0.88 vs. 12.83 ± 0.90; P > 0.05), and contrast-to-noise ratio (20.77 ± 2.20 vs. 20.36 ± 1.94; P > 0.05) were not significantly different between two groups. However, the CT dose index, dose-length product, effective dose, and total iodine dose were reduced by 27.58%, 36.65%, 36.59%, and 22.86% in the 100-kVp group compared to the 120-kVp group. Conclusion: The ASIR showed great potential in reducing the radiation dose and iodine contrast dose, while maintaining good image quality and providing strong confidence for the diagnosis of lung cancer.

Using Routine Chest Computed Tomography to Diagnose Pulmonary Embolism.

This study investigated the use of routine contrast-enhanced chest computed tomography (CT) to diagnose unsuspected pulmonary embolism (PE). All adult routine contrast-enhanced chest CTs performed at Montefiore in 2018 were included. Pulmonary artery enhancement was measured by placing regions of interest in the pulmonary vasculature. Adequate enhancement was defined as 200 Hounsfield units (HU) or greater. Presence or absence of PE was noted. Descriptive statistics and logistic regression analysis were performed. A total of 3164 CTs were evaluated (55.8% women; mean age, 63.2 years). Main pulmonary enhancement was highly correlated with peripheral enhancement. Of all cases, 28.7% (907 of 3164) reached the 200 HU threshold. Greater enhancement was associated with female sex, older age, outpatients, and contrast amount administered. Pulmonary embolism-positive cases comprised 1.8% (58 of 3164) of total cases. Furthermore, 39.7% (23 of 58) of PE-positive cases reached the 200 HU threshold. Over one quarter of routine contrast-enhanced chest CT scans met the 200 HU threshold indicative of adequate pulmonary artery enhancement, including nearly half of the 2% of examinations positive for PE.

Hereditary hemorrhagic telangiectasia with bilateral pulmonary vascular malformations and a cerebral abscess as a complication: A case report

Introduction: Hereditary hemorrhagic telangiectasia (HHT) also known as Osler–Weber–Rendu syndrome is a relatively common, under-recognized autosomal-dominant disorder that results from multisystem vascular dysplasia. It is characterized by telangiectasis and arteriovenous malformations of skin, mucosa, and viscera. Case Report: A 26-year-old man presented with an 8-day history of headache, fever, cough, right hemiparesis, motor dysphasia, and dysgraphia. The urgent brain computed tomography (CT) scan revealed a bulky rounded left frontal lobe lesion, with peripheral contrast enhancement and marked perilesional edema, indicating a brain abscess or metastasis. A brain magnetic resonance imaging showed an intra-axial hypovascular round enhancing left frontal lobe lesion, with pronounced perilesional edema. Laboratory findings discovered severe polycythemia with normal level of erythropoietin and gas analysis of blood revealed hypoxemia of secondary cause. Computed tomography of the lungs suggested pulmonary arteriovenous malformations (AVMs) in the right and left lung. Contrast-enhanced chest CT scan confirmed AVM of the lungs, while abdominal CT scan ruled out AVM of the liver. The brain abscess was treated neurosurgically. The patient reported positive family history of epistaxis. Conclusion: Brain abscess may be the first manifestation of HHT and early clinical recognition of HHT in patients with positive family history of epistaxis may help to prevent complications. Keywords: Arteriovenous malformations, Brain abscess, Hereditary hemorrhagic telangiectasia, Hypoxemia, Polycythemia

Mediastinal Mass with Unusual Etiology.

Mediastinal Mass with Unusual Etiology.

Prediction of Inflammatory Breast Cancer Survival Outcomes Using Computed Tomography-Based Texture Analysis

Background: Although inflammatory breast cancer (IBC) has poor overall survival (OS), there is little information about using imaging features for predicting the prognosis. Computed tomography (CT)-based texture analysis, a non-invasive technique to quantify tumor heterogeneity, could be a potentially useful imaging biomarker. The aim of the article was to investigate the usefulness of chest CT-based texture analysis to predict OS in IBC patients.Methods: Of the 3,130 patients with primary breast cancers between 2006 and 2016, 104 patients (3.3%) with IBC were identified. Among them, 98 patients who underwent pre-treatment contrast-enhanced chest CT scans, got treatment in our institution, and had a follow-up period of more than 2 years were finally included for CT-based texture analysis. Texture analysis was performed on CT images of 98 patients, using commercially available software by two breast radiologists. Histogram-based textural features, such as quantification of variation in CT attenuation (mean, standard deviation, mean of positive pixels [MPP], entropy, skewness, and kurtosis), were recorded. To dichotomize textural features for survival analysis, receiver operating characteristic curve analysis was used to determine cutoff points. Clinicopathologic variables, such as age, node stage, metastasis stage at the time of diagnosis, hormonal receptor positivity, human epidermal growth factor receptor 2 positivity, and molecular subtype, were assessed. A Cox proportional hazards model was used to determine the association of textural features and clinicopathologic variables with OS.Results: During a mean follow-up period of 47.9 months, 41 of 98 patients (41.8%) died, with a median OS of 20.0 months. The textural features of lower mean attenuation, standard deviation, MPP, and entropy on CT images were significantly associated with worse OS, as was the M1 stage among clinicopathologic variables (all P-values < 0.05). In multivariate analysis, lower mean attenuation (hazard ratio [HR], 3.26; P = 0.003), lower MPP (HR, 3.03; P = 0.002), and lower entropy (HR, 2.70; P = 0.009) on chest CT images were significant factors independent from the M1 stage for predicting worse OS.Conclusions: Lower mean attenuation, MPP, and entropy on chest CT images predicted worse OS in patients with IBC, suggesting that CT-based texture analysis provides additional predictors for OS.

Surgical resection of a middle mediastinal paraganglioma that caused diabetes

BackgroundParagangliomas are rare neuroendocrine tumors originating from chromaffin cells of extra-adrenal origin. Ninety percent of adrenergic tumors originate in the adrenal medulla and are known as pheochromocytomas; the remaining 10% are extra-adrenal and are called paragangliomas. Mediastinum paragangliomas is rare and commonly originate from the posterior mediastinum, while those originating from the middle posterior are quite rare. Some paragangliomas secrete catecholamines, leading to symptoms such as hypertension, tachycardia, and diabetes.Case presentationA 76-year-old woman visited our hospital for the treatment and further evaluation of diabetes. Her hemoglobin A1c levels had risen to 11.0%. To investigate the cause of her diabetes, a contrast-enhanced chest computed tomography scan was performed, revealing a ring-enhancing tumor (30 × 30 mm) in the middle mediastinum. The surgical resection was performed via video-assisted thoracic surgery. Surgery was performed using a vessel-sealing device; however, bleeding was persistent from the surrounding tissue. Total bleeding was 400 g. Blood pressure fluctuations and arrhythmia did not occur during the operation. The patient’s uncontrolled diabetes was cured after the surgery, and the tumor was diagnosed as a functional paraganglioma.ConclusionsWe encountered a rare case of functional paraganglioma located in the middle mediastinum. Functional paragangliomas should be considered as a potential cause of uncontrolled diabetes, and a whole-body CT scan should be performed to investigate this possible cause.

A Rare Case of Haemoptysis Revealing Aortic Coarctation in an Adult.

Adult patients with congenital cardiovascular abnormalities such as aortic coarctation may rarely, due to the high pressure and dilation in the bronchial arteries, present with recurrent haemoptysis as the sole clinical sign.A multidetector computed tomography scan contributes significantly to the aetiological diagnosis of haemoptysis in cases of congenital cardiovascular abnormalities.Interventional procedures such as stenting are currently the preferred approach for the treatment of aortic coarctation in adults, with good outcomes.

Mucosa-associated lymphoid tissue (MALT) lymphoma developing in ectopic mediastinal thyroid tissue: a case report

BackgroundNormally located in the neck, ectopic mediastinal thyroid tissue consists of very rare ectopic thyroid tissue that does not connect to the thyroid gland. A patient with mucosa-associated lymphoid tissue (MALT) lymphoma that has developed in mediastinal thyroid tissue, to our best knowledge, has not been previously reported.Case presentationA 67-year-old woman presented with a superior mediastinal mass that was revealed by chest computed tomography (CT), an optional examination she hoped, during a medical checkup. Contrast-enhanced CT scan performed in our hospital for close examination confirmed the presence of a 2 × 1.3 cm poorly enhanced mass anterior to the trachea during the arterial phase. Magnetic resonance imaging depicted low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. I-131 meta-iodobenzylguanidine did not accumulate in the mass. Serum levels of interleukin-2 receptor, catecholamine, and anti-acetylcholine receptor antibody were within the normal range. The mass was resected through a transverse neck incision for the diagnosis and treatment. The histopathological diagnosis of the specimen was ectopic mediastinal thyroid tissue associated with MALT lymphoma and chronic thyroiditis. Immunoglobulin heavy chain class switch recombination was identified. Fine-needle aspiration biopsy of the cervical thyroid showed chronic thyroiditis but not lymphoma. The patient’s postoperative thyroid function was normal. To date, the patient’s recovery has been uneventful, and she is being monitored without further treatment.ConclusionWe treated the patient with MALT lymphoma that developed in ectopic mediastinal thyroid tissue. This novel case illustrates a new differential diagnosis associated with ectopic mediastinal thyroid tissue.

Bronchopulmonary and vascular anomalies are frequent in children with oesophageal atresia.

Oesophageal atresia is frequently associated with other malformations, and our aim was to use computed tomography (CT) to explore intrathoracic malformations in patients with this condition. This was retrospective study of children aged 0-16 with oesophageal atresia who were born in 1996-2013 and followed up at the French reference centre for rare oesophageal diseases at the University of Lille. Computed tomography scans were available for 48 of the 234 patients during follow-up visits, and these were reviewed by a thoracic radiologist. More than two-thirds of the scans were performed to explore persistent respiratory symptoms. We found that six patients had a pulmonary malformations: four lobar agenesis, one right pulmonary aplasia and one congenital cystic adenomatoid malformation. Computed tomography enabled us to diagnose unexpected thoracic malformations in 16 patients: four lobar agenesis, six arteria lusoria, five persistent left superior vena cava and one partial anomalous pulmonary venous return. It also confirmed the diagnoses of suspected malformations in five patients: one congenital cystic adenomatoid malformation, one pulmonary hypoplasia, two right-sided aortic arches and one communicating bronchopulmonary foregut malformation. Intrathoracic anomalies were frequently associated with oesophageal atresia, and contrast-enhanced chest CT scans should be performed on patients with persistent respiratory symptoms.

"White Thyroid" on Unenhanced Computed Tomography in Amiodarone-Induced Thyrotoxicosis Type 2.

Amiodarone-induced thyrotoxicosis is a common complication of long-term amiodarone treatment. In a patient with amiodarone-induced lung toxicity and amiodarone-induced thyrotoxicosis type 2 (AIT2), a "white thyroid" was incidentally observed on an unenhanced chest computed tomography (CT) scan. This "white thyroid" resembled a thyroid image on a contrast-enhanced CT scan. Therefore, the thyroid density was prospectively evaluated on unenhanced CT scans in cases of AIT2, in euthyroid patients on amiodarone (AEuth), and in unexposed controls. The aim was to test the hypothesis of a higher thyroid density in AIT2 compared to AEuth. The thyroid density, as measured in Hounsfield Units on unenhanced CT scans, is higher in AIT2 compared to AEuth and much higher than in controls. The causality of this association and its potential diagnostic use require further study.

Pulmonary Artery-Vein Classification in CT Images Using Deep Learning.

Recent studies show that pulmonary vascular diseases may specifically affect arteries or veins through different physiologic mechanisms. To detect changes in the two vascular trees, physicians manually analyze the chest computed tomography (CT) image of the patients in search of abnormalities. This process is time consuming, difficult to standardize, and thus not feasible for large clinical studies or useful in real-world clinical decision making. Therefore, automatic separation of arteries and veins in CT images is becoming of great interest, as it may help physicians to accurately diagnose pathological conditions. In this paper, we present a novel, fully automatic approach to classify vessels from chest CT images into arteries and veins. The algorithm follows three main steps: first, a scale-space particles segmentation to isolate vessels; then a 3-D convolutional neural network (CNN) to obtain a first classification of vessels; finally, graph-cuts' optimization to refine the results. To justify the usage of the proposed CNN architecture, we compared different 2-D and 3-D CNNs that may use local information from bronchus- and vessel-enhanced images provided to the network with different strategies. We also compared the proposed CNN approach with a random forests (RFs) classifier. The methodology was trained and evaluated on the superior and inferior lobes of the right lung of 18 clinical cases with noncontrast chest CT scans, in comparison with manual classification. The proposed algorithm achieves an overall accuracy of 94%, which is higher than the accuracy obtained using other CNN architectures and RF. Our method was also validated with contrast-enhanced CT scans of patients with chronic thromboembolic pulmonary hypertension to demonstrate that our model generalizes well to contrast-enhanced modalities. The proposed method outperforms state-of-the-art methods, paving the way for future use of 3-D CNN for artery/vein classification in CT images.

心窩部痛にて発症した気管支動脈蔓状血管腫の1例(A case of racemose hemangioma of the bronchial artery presenting with epigastriac pain)

要旨67歳の男性が突然発症の心窩部痛で救急搬送された。造影CT検査で下行大動脈から分岐する蛇行した異常血管，左血胸，後腹膜血腫を認めた。気管支動脈蔓状血管腫の破裂と診断した。喀血や呼吸困難，胸痛など呼吸器疾患を疑わせる症状は認められなかった。来院後ショック状態となり，緊急で気管支動脈塞栓術を行った。塞栓術後速やかにショックから離脱した。フォローアップ造影CT検査と冠動脈造影で右冠動脈と蔓状血管腫の交通および左冠動脈と肺動脈の交通が認められたが治療適応にはならない血流量であった。経過は良好であり自宅退院し，現在まで再出血は起きていない。気管支動脈蔓状血管腫は腫瘍性病変ではなく血管の形態異常である。主訴は喀血が多く，心窩部痛は稀である。本症例の心窩部痛は血腫が後腹膜に及んだことで起きたと考えられた。突然の心窩部痛を訴える患者では常に胸部臓器疾患の可能性を考慮する必要がある。

(F)utility of computed tomography of the chest in the presence of pleural effusion.

Pleural effusion is common and can cause significant morbidity. The chest X-ray is often the initial radiological test, but additional tests may be required to reduce uncertainty and to provide additional diagnostic information. However, additional exposure and unnecessary costs should be prevented. The objective of the study was to assess the clinical benefit of an additional chest computed tomography (CT) scan over plain chest X-ray alone in the management of patients with pleural effusion. Retrospective analysis in 94 consecutive patients with pleural effusion who underwent chest X-ray and CT scan over an 18-month period in a single institution. All chest X-ray and CT scan reports were compared and correlated with clinical parameters in order to assess their utility in the clinical management. No blinding was applied. In 75 chest CT scan reports (80 %), information provided by the radiologist did not change clinical management when compared to plain chest X-ray alone and did not provide any additional information over chest X-ray. Only 2/49 (4 %) of the native chest CT scan reports provided clinically relevant information as compared to 17/45 (38 %) contrast-enhanced chest CT scan reports (p<0.001). In this retrospective cohort of patients with pleural effusion, an additional chest CT scan was not useful in the majority of patients. However, if a chest CT scan is required, then a contrast-enhanced study after pleural aspiration should be performed. Further prospective studies are required to confirm these findings.

Plain and contrast-enhanced chest computed tomography scan findings of pulmonary cryptococcosis in immunocompetent patients.

Pulmonary cryptococcosis is most commonly reported in immunocompromised patients, whereas immunocompetent hosts are rarely affected and may be asymptomatic, resulting in reduced diagnostic performance of computed tomography (CT) imaging. Thus, the aim of the present study was to review the plain and contrast-enhanced chest CT scan findings of primary pulmonary cryptococcosis in immunocompetent patients, with the aim of improving the diagnosis of this type of pulmonary disease. In the present study, a total of 27 immunocompetent patients of clinically confirmed pulmonary cryptococcosis were analyzed retrospectively. Of the 27 patients, 14 patients underwent plain and contrast-enhanced chest CT scans, while 13 patients only underwent plain chest CT scanning. The clinical and imaging characteristics, including the location, shape, size, number, edge and attenuation or intensity of each lesion, in unenhanced and contrast-enhanced CT scans were reviewed. The results indicated that the most common CT finding was pulmonary nodules (40.74%), with multiple nodules (25.93%) being more common compared with solitary nodules (14.81%). The majority of the nodules were poorly defined and inhomogeneous with observed air-bubble sign. Other findings included consolidation (25.93%), ground-glass opacities (GGO; 22.22%) and a mass (11.11%). The halo, air bronchogram and cavity signs were observed more frequently (22.22, 18.52 and 14.81%, respectively). The pulmonary lesions presented a predominant distribution in the lower lung lobes and peripheral area in 55.55 and 74.07% of the cases, respectively. On the contrast-enhanced CT images, the majority of nodules presented ring enhancement with the mean maximal enhancement value of 20.92±5.67 Hu, and masses demonstrated inhomogeneous enhancement with a mean maximal enhancement value of 35.61±8.32 Hu. In conclusion, familiarity with the CT findings and occupational environment exposure history will assist in earlier and easier diagnosis of pulmonary cryptococcosis in immunocompetent patients.

Mediastinal Mature Teratoma With Rupture Into Pleural Cavity Due to Blunt Trauma

We report a rare case of mediastinal mature teratoma with rupture due to blunt trauma. A 15-year-old boy had received a strong head-butt in the left upper chest wall and was admitted with the sudden onset of left-sided severe chest pain and dyspnea. Chest computed tomography (CT) scan on admission revealed a heterogeneous mass lesion in the anterior mediastinum. The contrast-enhanced CT scans obtained 2 days after admission showed not only mediastinal mass lesion but also left pleural effusion. On the radiologic finding at 5 months later, the lesion became larger and was thought to be a typical mediastinal mature teratoma. The patient underwent extirpation of the tumor. Microscopically, the tumor was typically composed of adult-type tissues and was confirmed to be mature teratoma.

Tracheo-brachiocephalic artery fistula after tracheostomy associated with thoracic deformity: a case report

IntroductionTracheo-brachiocephalic artery fistulae are critical long-term complications after tracheostomy, reported in 0.6% of patients within three to four weeks after the procedure. In 30% to 50% of cases there is some bleeding prior to onset. Since the onset involves sudden massive bleeding, the prognosis is poor; the reported survival rate is 10% to 30%. The direct cause of bleeding is the formation of a fistula with the trachea subsequent to arterial injury by the tracheostomy tube. Endo-tracheal factors are movement of the tracheostomy tube due to body movement and seizures, pressure exerted by the cuff of the tracheostomy tube, tracheostomy at lower levels, and the fragility of blood vessels and the trachea due to steroid or radiation therapy, and malnutrition. Extra-tracheal factors include prior surgery and deformity and shifting of the trachea and major blood vessels due to congenital kyphoscoliosis or thoracic deformity. There has been no report of the usefulness of contrast-enhanced computed tomography studies to identify the anatomical relationship between the trachea and brachiocephalic artery.Case presentationA 27-year-old Mongolian woman with congenital muscular dystrophy who underwent tracheal intubation for airway management due to pneumonia and granulation development developed a tracheo-brachiocephalic artery fistula during the placement of the tracheostomy tube. It was diagnosed by contrast-enhanced chest computed tomography and repaired. About a month later she developed massive airway bleeding during replacement of the tracheostomy tube. Temporary hemostasis was achieved by compression via cuff inflation. A contrast-enhanced chest computed tomography scan demonstrated a narrowed brachiocephalic artery running along and ventral to the tube and a tracheo-brachiocephalic artery fistula was suspected. She underwent brachiocephalic artery resection and aorta, right common carotid artery, and subclavian artery bypass surgery with an innominate vein, tracheoplasty, and partial sternectomy. We noted marked thoracic deformity; the brachiocephalic artery was compressed by the trachea and chest wall resulting in localized wall necrosis and the development of a tracheo-brachiocephalic artery fistula, a fatal complication whose prevention is important.ConclusionsWe suggest that before tracheostomy, the anatomic relationship between the trachea and brachiocephalic artery must be confirmed by contrast-enhanced chest computed tomography scan.

FDG-PET in diagnostic work-up of pulmonary artery sarcomas

To the Editors: Pulmonary artery sarcomas (PAS) represent a group of rare tumours with a poor prognosis. In a recent review, the mean±sd survival of patients with this disease was 11±3 months when no curative resection was attempted, whereas patients undergoing curative resection had a survival of 36.5±20.2 months 1. Appropriate application and interpretation of different imaging modalities facilitates differentiation of PAS from chronic thromboembolism. Findings in chest computed tomography (CT) could be inhomogeneous attenuation, vascular distension or filling defects of the entire luminal diameter of a proximal or main pulmonary artery 2, 3. Extraluminal extension of the tumour can be a specific finding of PAS. Magnetic resonance imaging (MRI) aids the determination of the extent of masses and the relationship to adjacent structures, and during postoperative follow-up 4. The degree of contrast enhancement in MRI was shown to correlate with the degree of tumour differentiation, and contrast enhancement might be used to differentiate neoplasm from central pulmonary embolism 5. Single case reports have shown that fluorodeoxyglucose-positron emission tomography (FDG-PET) might be helpful in differentiating PAS from pulmonary thromboembolic disease, and helps decision-making when it is not possible to perform intraoperative biopsies for histological confirmation of PAS before attempting curative pneumonectomy 6, 7. In the current study, we present three cases of patients with PAS, in whom a presumptive diagnosis of PAS was made preoperatively based on clinical, CT and MRI findings and a positive FDG-PET scan. Case 1 was a 48-yr-old male nonsmoker with absence of previous medical history who presented with progressive dyspnoea. On spiral contrast-enhanced CT scan taken 4 months prior to presentation, a left-sided paracentral pulmonary embolism was suspected. No …

A 61-year-old female patient with right-sided pleuritic chest pain and fatigue

A 61-yr-old Caucasian female patient was investigated because of right-sided pleuritic chest pain. The patient had a 2-month history of chronic, nonproductive cough, extreme fatigue, night sweats and reduced exercise tolerance. Initially, the patient was treated with antibiotics for presumed pneumonia. She had smoked for >20 pack-yrs and her medical history included parotidectomy for Warthin tumour, resection of a benign cyst in the left breast and varicectomy. Physical examination showed no clinical signs of respiratory distress. Sinus rhythm was present with a heart rate of 88 bpm and blood pressure of 135/80 mmHg. Cardiopulmonary auscultation revealed no significant abnormalities and there was no hepatomegaly or limb oedema. No lymphadenopathy was found in the neck, supraclavicular, axillary or inguinal regions. The laboratory results showed an elevated C-reactive protein of 5.02 mg·dL−1. Low haemoglobin and haematocrit values were in keeping with anaemia. Studies of coagulability were all within normal ranges. Arterial blood gas analysis while breathing ambient air showed an arterial oxygen tension of 66 mm Hg, carbon dioxide arterial tension of 40 mmHg, pH of 7.43 and arterial oxygen saturation of 94%. Pulmonary function tests revealed a mild restrictive defect with a reduced diffusing capacity. A chest radiograph (fig. 1⇓) and computed tomography (CT) scans (figs 2⇓ and 3⇓) were performed and the patient underwent bronchoscopy and mediastinoscopy. Bronchoscopy revealed no endobronchial involvement. Subsequent biopsies were all found to be negative. Fig. 1— Chest radiograph. Fig. 2— Axial contrast-enhanced chest computed tomography scan. Extensive soft tissue mass in the right pulmonary artery, extending in different side branches, is indicated by the arrows. Fig. 3— Axial contrast-enhanced chest computed tomography scan. a) Mediastinal window and b) lung window. Two peripherally located wedge-shaped focal consolidations areas at the right lung base are indicated by the arrows. All accessible lymph nodes in the superior mediastinum and the region of the right mainstem bronchus …