Skeletal Muscle Adiposity and Lung Function Trajectory in the Severe Asthma Research Program.

Rationale: Extrapulmonary manifestations of asthma, including fatty infiltration in tissues, may reflect systemic inflammation and influence lung function and disease severity. Objectives: To determine if skeletal muscle adiposity predicts lung function trajectory in asthma. Methods: Adult SARP III (Severe Asthma Research Program III) participants with baseline computed tomography imaging and longitudinal postbronchodilator FEV1% predicted (median follow-up 5 years [1,132 person-years]) were evaluated. The mean of left and right paraspinous muscle density (PSMD) at the 12th thoracic vertebral body was calculated (Hounsfield units [HU]). Lower PSMD reflects higher muscle adiposity. We derived PSMD reference ranges from healthy control subjects without asthma. A linear multivariable mixed-effects model was constructed to evaluate associations of baseline PSMD and lung function trajectory stratified by sex. Measurements and Main Results: Participants included 219 with asthma (67% women; mean [SD] body mass index, 32.3 [8.8] kg/m2) and 37 control subjects (51% women; mean [SD] body mass index, 26.3 [4.7] kg/m2). Participants with asthma had lower adjusted PSMD than control subjects (42.2 vs. 55.8 HU; P < 0.001). In adjusted models, PSMD predicted lung function trajectory in women with asthma (ß = -0.47 Δ slope per 10-HU decrease; P = 0.03) but not men (ß = 0.11 Δ slope per 10-HU decrease; P = 0.77). The highest PSMD tertile predicted a 2.9% improvement whereas the lowest tertile predicted a 1.8% decline in FEV1% predicted among women with asthma over 5 years. Conclusions: Participants with asthma have lower PSMD, reflecting greater muscle fat infiltration. Baseline PSMD predicted lung function decline among women with asthma but not men. These data support an important role of metabolic dysfunction in lung function decline.

Clinical Characteristics and Transplant-Free Survival Across the Spectrum of Pulmonary Vascular Disease.

BACKGROUND: PVDOMICS (Pulmonary Vascular Disease Phenomics) is a precision medicine initiative to characterize pulmonary vascular disease (PVD) using deep phenotyping. PVDOMICS tests the hypothesis that integration of clinical metrics with omic measures will enhance understanding of PVD and facilitate an updated PVD classification. OBJECTIVES: The purpose of this study was to describe clinical characteristics and transplant-free survival in the PVDOMICS cohort. METHODS: Subjects with World Symposium Pulmonary Hypertension (WSPH) group 1-5 PH, disease comparators with similar underlying diseases and mild or no PH and healthy control subjects enrolled in a cross-sectional study. PH groups, comparators were compared using standard statistical tests including log-rank tests for comparing time to transplant or death. RESULTS: A total of 1,193 subjects were included. Multiple WSPH groups were identified in 38.9% of PH subjects. Nocturnal desaturation was more frequently observed in groups 1, 3, and 4 PH vs comparators. A total of 50.2% of group 1 PH subjects had ground glass opacities on chest computed tomography. Diffusing capacity for carbon monoxide was significantly lower in groups 1-3 PH than their respective comparators. Right atrial volume index was higher in WSPH groups 1-4 than comparators. A total of 110 participants had a mean pulmonary artery pressure of 21-24 mm Hg. Transplant-free survival was poorest in group 3 PH. CONCLUSIONS: PVDOMICS enrolled subjects across the spectrum of PVD, including mild and mixed etiology PH. Novel findings include low diffusing capacity for carbon monoxide and enlarged right atrial volume index as shared features of groups 1-3 and 1-4 PH, respectively; unexpected, frequent presence of ground glass opacities on computed tomography; and sleep alterations in group 1 PH, and poorest survival in group 3 PH. PVDOMICS will facilitate a new understanding of PVD and refine the current PVD classification. (Pulmonary Vascular Disease Phenomics Program PVDOMICS [PVDOMICS]; NCT02980887).

Estimated Ventricular Size, Asthma Severity, and Exacerbations: The Severe Asthma Research Program III Cohort.

BACKGROUND: Relative enlargement of the pulmonary artery (PA) on chest CT imaging is associated with respiratory exacerbations in patients with COPD or cystic fibrosis. We sought to determine whether similar findings were present in patients with asthma and whether these findings were explained by differences in ventricular size. METHODS: We measured the PA and aorta diameters in 233 individuals from the Severe Asthma Research Program III cohort. We also estimated right, left, and total epicardial cardiac ventricular volume indices (eERVVI, eELVVI, and eETVVI, respectively). Associations between the cardiac and PA measures (PA-to-aorta [PA/A] ratio, eERVVI-to-eELVVI [eRV/eLV] ratio, eERVVI, eELVVI, eETVVI) and clinical measures of asthma severity were assessed by Pearson correlation, and associations with asthma severity and exacerbation rate were evaluated by multivariable linear and zero-inflated negative binomial regression. RESULTS: Asthma severity was associated with smaller ventricular volumes. For example, those with severe asthma had 36.1 mL/m2 smaller eETVVI than healthy control subjects (P = .003) and 14.1 mL/m2 smaller eETVVI than those with mild/moderate disease (P = .011). Smaller ventricular volumes were also associated with a higher rate of asthma exacerbations, both retrospectively and prospectively. For example, those with an eETVVI less than the median had a 57% higher rate of exacerbations during follow-up than those with eETVVI greater than the median (P = .020). Neither PA/A nor eRV/eLV was associated with asthma severity or exacerbations. CONCLUSIONS: In patients with asthma, smaller cardiac ventricular size may be associated with more severe disease and a higher rate of asthma exacerbations. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT01761630; URL: www.clinicaltrials.gov.

Intraoperative Percutaneous Microcoil Localization of Small Peripheral Pulmonary Nodules Using Cone-Beam CT in a Hybrid Operating Room.

OBJECTIVE. Thoracoscopic surgical resection of small peripheral pulmonary nodules can be challenging, and often preoperative localization techniques are needed to avoid conversion to open thoracotomy. In this article, we show the feasibility and benefits of performing intraoperative percutaneous microcoil localization with C-arm cone-beam CT in a hybrid operating room immediately before video-assisted thoracoscopic surgery for wedge resection of a small pulmonary nodule. CONCLUSION. This technique can provide safe and accurate localization while minimizing patient discomfort and thus enhancing the patient's experience.

Video-Assisted Thoracic Surgery Resection without Intraoperative Fluoroscopy after CT-Guided Microcoil Localization of Peripheral Pulmonary Nodules.

The aim of this brief report is to determine the safety and reliability of minimally invasive video-assisted thoracic surgery (VATS) resection without the aid of intraoperative fluoroscopy after computed tomography (CT)-guided microcoil localization of small peripheral pulmonary nodules. Twenty patients with peripheral lung nodules underwent percutaneous needle localization with a microcoil that was tagged back to the visceral pleural surface. Same-day VATS resection was performed without the use of intraoperative fluoroscopy. All 20 nodules were successfully localized in the CT procedure room, and all 20 nodules were resected with negative margins and no major complications.

Electromagnetic Navigational Bronchoscopy versus CT-guided Percutaneous Sampling of Peripheral Indeterminate Pulmonary Nodules: A Cohort Study.

Purpose To compare the diagnostic yield and complication rates of electromagnetic navigational bronchoscopic (ENB)-guided and computed tomography (CT)-guided percutaneous tissue sampling of lung nodules. Materials and Methods Retrospectively identified were 149 patients sampled percutaneously with CT guidance and 146 patients who underwent ENB with transbronchial biopsy of a lung lesion between 2013 and 2015. Clinical data, incidence of complications, and nodule pathologic analyses were assessed through electronic medical record review. Lung nodule characteristics were reviewed through direct image analysis. Molecular marker studies and pathologic analyses from surgical excision were reviewed when available. Multiple-variable logistic regression models were built to compare the diagnostic yield and complication rates for each method and for different patient and disease characteristics. Results CT-guided sampling was more likely to be diagnostic than ENB-guided biopsy (86.0% [129 of 150] vs 66.0% [99 of 150], respectively), and this difference remained significant even after adjustments were made for patient and nodule characteristics (P < .001). Age, American Society of Anesthesiologists class, emphysema grade, nodule size, and distance from pleura were not significant predictors of increased diagnostic yield. Intraprocedural time for physicians was significantly lower with CT-guided sampling (P < .001). Similar yield for molecular analyses was noted with the two approaches (ENB-guided sampling, 88.9% [32 of 36]; CT-guided sampling, 82.0% [41 of 50]). The two groups had similar rates of major complications (symptomatic hemorrhage, P > .999; pneumothorax requiring chest tube and/or admission, P = .417). Conclusion CT-guided transthoracic biopsy provided higher diagnostic yield in the assessment of peripheral pulmonary nodules than navigational bronchoscopy with a similar rate of clinically relevant complications. © RSNA, 2017 Online supplemental material is available for this article.

Attenuation-based kV pair selection in dual source dual energy computed tomography angiography of the chest: impact on radiation dose and image quality.

OBJECTIVES: The purpose of this study was to evaluate the impact of attenuation-based kilovoltage (kV) pair selection in dual source dual energy (DSDE)-pulmonary embolism (PE) protocol examinations on radiation dose savings and image quality. METHODS: A prospective study was carried out on 118 patients with suspected PE. In patients in whom attenuation-based kV pair selection selected the 80/140Sn kV pair, the pre-scan 100/140Sn CTDIvol (computed tomography dose index volume) values were compared with the pre-scan 80/140Sn CTDIvol values. Subjective and objective image quality parameters were assessed. RESULTS: Attenuation-based kV pair selection switched to the 80/140Sn kV pair ("switched" cohort) in 63 out of 118 patients (53%). The mean 100/140Sn pre-scan CTDIvol was 8.8 mGy, while the mean 80/140Sn pre-scan CTDIvol was 7.5 mGy. The average estimated dose reduction for the "switched" cohort was 1.3 mGy (95% CI 1.2, 1.4; p < 0.001), representing a 15% reduction in dose. After adjusting for patient weight, mean attenuation was significantly higher in the "switched" vs. "non-switched" cohorts in all five pulmonary arteries and in all lobes on iodine maps. CONCLUSIONS: This study demonstrates that attenuation-based kV pair selection in DSDE examination is feasible and can offer radiation dose reduction without compromising image quality. KEY POINTS: • Attenuation-based kV pair selection in dual energy examination is feasible. • It can offer radiation dose reduction to approximately 50% of patients. • Approximate 15% reduction in radiation dose was achieved using this technique. • The image quality is not compromised by use of attenuation-based kV pair selection.

Spectrum of Imaging Findings Following Bronchoscopic Intervention.

Interventional pulmonology (IP) is a relatively new field that uses endoscopy and other technologies for both the diagnosis and treatment of pulmonary and thoracic conditions. IP is a continually developing field driven by clinical need as well as technological and therapeutic innovation. Developments in IP have increased both the efficacy and breadth of procedures that may be encountered by radiologists on periprocedural and postprocedural imaging. In this article, we will describe commonly performed IP procedures, with a focus on relevant imaging implications for radiologists.

Pulmonary Vasculitis: Spectrum of Imaging Appearances.

Pulmonary vasculitis is a relatively uncommon disorder, usually manifesting as part of systemic vasculitis. Imaging, specifically computed tomography, is often performed in the initial diagnostic workup. Although the findings in vasculitis can be nonspecific, they can provide important clues in the diagnosis, and guide the clinical team toward the right diagnosis. Radiologists must have knowledge of common and uncommon imaging findings in various vasculitides. Also, radiologists should be able to integrate the clinical presentation and laboratory test findings together with imaging features, so as to provide a meaningful differential diagnosis.

Radiographic Evaluation of Valvular Heart Disease With Computed Tomography and Magnetic Resonance Correlation.

Valvular heart disease is a group of complex entities with varying etiologies and clinical presentations. There are a number of imaging tools available to supplement clinical evaluation of suspected valvular heart disease, with echocardiography being the most common and clinically established, and more recent emergence of computed tomography and magnetic resonance imaging as additional supportive techniques. Yet even with these newer and more sophisticated modalities, chest radiography remains one of the earliest and most common diagnostic examinations performed during the triage of patients with suspected cardiac dysfunction. Recognizing the anatomic and pathologic features of cardiac radiography including the heart's adaptation to varying hemodynamic changes can provide clues to the radiologist regarding the underlying etiology. In this article, we will elucidate several principles relating to chamber modifications in response to pressure and volume overload as well as radiographic appearances associated with pulmonary fluid status and cardiac dysfunction. We will also present a pattern approach to optimize analysis of the chest radiograph for valvular heart disease, which will help guide the radiologist down a differential diagnostic pathway and create a more meaningful clinical report.

Historical Evolution of Imaging Techniques for the Evaluation of Pulmonary Embolism.

As we celebrate the 100th anniversary of the founding of the Radiological Society of North America (RSNA), it seems fitting to look back at the major accomplishments of the radiology community in the diagnosis of pulmonary embolism. Few diseases have so consistently captured the attention of the medical community. Since the first description of pulmonary embolism by Virchow in the 1850s, clinicians have struggled to reach a timely diagnosis of this common condition because of its nonspecific and often confusing clinical picture. As imaging tests started to gain importance in the 1900s, the approach to diagnosing pulmonary embolism also began to change. Rapid improvements in angiography, ventilation-perfusion imaging, and cross-sectional imaging modalities such as computed tomography (CT) and magnetic resonance imaging have constantly forced health care professionals to rethink how they diagnose pulmonary embolism. Needless to say, the way pulmonary embolism is diagnosed today is distinctly different from how it was diagnosed in Virchow's era; and imaging, particularly CT, now forms the cornerstone of diagnostic evaluation. Currently, radiology offers a variety of tests that are fast and accurate and can provide anatomic and functional information, thus allowing early diagnosis and triage of cases. This review provides a historical journey into the evolution of these imaging tests and highlights some of the major breakthroughs achieved by the radiology community and RSNA in this process. Also highlighted are areas of ongoing research and development in this field of imaging as radiologists seek to combat some of the newer challenges faced by modern medicine, such as rising health care costs and radiation dose hazards.

Pleurodesis: indications and radiologic appearance.

Pleurodesis is frequently performed to prevent recurrence of pneumothorax or recurrent pleural effusion in benign or malignant conditions. In essence, it involves producing an area of adhesion between the parietal and the visceral layers of the pleura. The approach to this procedure can be divided into chemical and mechanical methods. Chemical pleurodesis is performed by introducing various substances such as talc, bleomycin, povidone iodine or other chemicals into the pleural space typically using a pleural catheter. The instilled substances cause inflammation of the parietal and the visceral layers of the pleura and leads to adhesion of the pleural surfaces, preventing further fluid or air accumulation. Mechanical pleurodesis, which is performed with thoracotomy or thoracoscopy, involves mechanical irritation of the pleura or removal of parietal pleura. It is important for the radiologist to develop an understanding of the clinical indications for pleurodesis, methods for the procedure and post-procedure imaging appearance so the radiologist can provide a correct interpretation and avoid misdiagnosis of the radiologic appearance as chronic infection, tumor or other entities with a similar appearance. Thus, the aim of this article is to review the indications, techniques and post-procedural appearances of pleurodesis from an imaging perspective.

Aortic arch dissection: a controversy of classification.

Aortic dissections originating in the ascending aorta and descending aorta have been classified as type A and type B dissections, respectively. However, dissections with intimal flap extension into the aortic arch between the innominate and left subclavian arteries are not accounted for adequately in the widely used Stanford classification. This gap has been the subject of controversy in the medical and surgical literature, and there is a tendency among many radiologists to categorize such arch dissections as type A lesions, thus making them an indication for surgery. However, the radiologic perspective is not supported by either standard dissection classification or current clinical management. In this special report, the origin of dissection classification and its evolution into current radiologic interpretation and surgical practice are reviewed. The cause for the widespread misconception about classification and treatment algorithms is identified. Institutional review board approval and waiver of informed consent were obtained as part of this HIPAA-compliant retrospective study to assess all aortic dissection studies performed at the University of Maryland Medical Center, Baltimore between 2010 and 2012 to determine the prevalence of arch dissections. Finally, a unified classification system that reconciles imaging interpretation and management implementation is proposed.

Treatment of single peripheral pulmonary emboli: patient outcomes and factors associated with decision to treat.

BACKGROUND: Increasing use of computed tomography pulmonary angiography together with higher-resolution scanners has increased the detection of peripheral filling defects. Physicians face the dilemma of whether to treat patients with these findings, especially single defects. The aims of this study were to compare the outcomes of treated and untreated patients with single peripheral filling defects (SPFD) and identify factors associated with treatment. METHODS: All cases with SPFDs over 66 months in a single institution were identified. Patient and treatment information were abstracted and data on 90-day mortality and postdischarge venous thromboembolism (VTE) were collected. RESULTS: A total of 4906 computed tomography pulmonary angiograms were reviewed. A SPFD was identified in 3.1% (n = 153). Of the 153 patients, 134 met criteria for study inclusion. In 99 of 134 (73.9%) studies, the defect was called a pulmonary embolus (PE) by the initial radiologist. Treatment was administered to 61 of 134 (45.5%) patients; 5 patients died in each group. Postdischarge VTE occurred in 3 treated and 2 untreated patients. In 52 of 153 cases, an additional study was performed. None of the patients with normal ventilation perfusion scan and compression ultrasound received treatment. Immobility (odds ratio [OR]: 3.90, 95% confidence interval [CI]: 1.45-10.60), previous VTE (OR: 3.72, 95% CI: 1.18-11.70), and determination of PE by the radiologist (OR: 24.68, 95% CI: 5.40-112.90) were associated with treatment. CONCLUSIONS: There was no difference in 90-day mortality or recurrence between treated and untreated patients. The most influential factor associated with treatment was the radiologist's interpretation. When secondary lung imaging studies were negative, no patient received treatment.

Aortopulmonary fistula in acute dissection: findings at unenhanced and enhanced computed tomographic imaging.

Acquired aortopulmonary fistulas are a rare complication of acute aortic dissections. We present a case of an aortopulmonary fistula after a Stanford type A dissection, focusing on the imaging findings and etiology of this entity. Early recognition can lead to proper surgical planning and increase the chance of survival.