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Thoracic interventions are frequently performed by radiologists, but guidelines on appropriateness criteria and technical considerations to ensure patient safety regarding such interventions is lacking. These guidelines, developed by the Canadian Association of Radiologists, Canadian Association for Interventional Radiology and Canadian Society of Thoracic Radiology focus on the interventions commonly performed by thoracic radiologists. They provide evidence-based recommendations and expert consensus informed best practices for patient preparation; biopsies of the lung, mediastinum, pleura and chest wall; thoracentesis; pre-operative lung nodule localization; and potential complications and their management.

Background Systemic therapy prolongs overall survival (OS) in advanced non‐small cell lung cancer (NSCLC), but diagnostic tests, staging and molecular profiling take time, and this can delay therapy initiation. OS approximates first‐order kinetics. Methods We used OS of chemo‐naive NSCLC patients on a placebo/best supportive care trial arm to estimate % of patients dying while awaiting therapy. We digitized survival curves from eight studies, calculated OS half‐life, then estimated the proportion surviving after different times of interest (t n) using the formula: X=exp‐tn∗0.693/t1/2, where EXP signifies exponential, * indicates multiplication, 0.693 is the natural log of 2, and t 1/2 is the survival half‐life in weeks. Results Across trials, the OS half‐life for placebo/best supportive care in previously untreated NSCLC was 19.5 weeks. Hence, based on calculations using the formula above, if therapy were delayed by 1, 2, 3, or 4 weeks then 4%, 7%, 10%, and 13% of all patients, respectively, would die while awaiting treatment. Others would become too sick to consider therapy even if still alive. Conclusions This quantifies why rapid baseline testing and prompt therapy initiation are important in advanced NSCLC. It also illustrates why screening procedures for clinical trial inclusion must be faster. Otherwise, it is potentially hazardous for a patient to be considered for a trial due to risk of death or deterioration while awaiting eligibility assessment. It is also important to not delay initiation of systemic therapy for procedures that add relatively little value, such as radiotherapy for small, asymptomatic brain metastases., In patients with metastatic non‐small cell lung cancer, it takes time for diagnostic and staging tests and for initiation of therapy. Based on exponential decay nonlinear regression analysis of overall survival curves from placebo or best supportive care arms of first line studies in metastatic disease, we calculated that an average of 4% of remaining patients will die during each week that passes without initiation of systemic therapy. It is important to initiate therapy as rapidly as possible.

In this chapter, the authors review and discuss the literature on multidisciplinary cancer conferences (MCCs, aka tumor boards), clarifying the terminology, showing the evolution of the field, and providing an evidence-based perspective on positive outcomes, best practices, factors influencing the quality of MCCs, evaluation tools to assess the quality of MCCs, and quality improvement interventions for MCCs. The authors then discuss some perspectives from their MCC and initiatives that they undertook to improve the work of their team and the care that they provide to patients in the area of thoracic oncology.

In this review, the authors describe the imaging characteristics of solid and subsolid nodules as well as their management recommendations including the use of image-guided percutaneous biopsy and preoperative coil localization. Using case presentations, they offer practical management tips for the most commonly encountered nodule nodules in a thoracic surgical practice.

The investigation of acute pulmonary embolism is a common task for radiologists in Canada. Technical image quality and reporting quality must be excellent; pulmonary embolism is a life-threatening disease that should not be missed but overdiagnosis and unnecessary treatment should be avoided. The most frequently performed imaging investigation, computed tomography pulmonary angiogram (CTPA), can be limited by poor pulmonary arterial opacification, technical artifacts and interpretative errors. Image quality can be affected by patient factors (such as body habitus, motion artifact and cardiac output), intravenous (IV) contrast protocols (including the timing, rate and volume of IV contrast administration) and common physics artifacts (including beam hardening). Mimics of acute pulmonary embolism can be seen in normal anatomic structures, disease in non-vascular structures and pulmonary artery filling defects not related to acute pulmonary emboli. Understanding these pitfalls can help mitigate error, improve diagnostic quality and optimize patient outcomes. Dual energy computed tomography holds promise to improve imaging diagnosis, particularly in clinical scenarios where routine CTPA may be problematic, including patients with impaired renal function and patients with altered cardiac anatomy.

Historically thoracic MRI has been limited by the lower proton density of lung parenchyma, cardiac and respiratory motion artifacts and long acquisition times. Recent technological advancements in MR hardware systems and improvement in MR pulse sequences have helped overcome these limitations and expand clinical opportunities for non-vascular thoracic MRI. Non-vascular thoracic MRI has been established as a problem-solving imaging modality for characterization of thymic, mediastinal, pleural chest wall and superior sulcus tumors and for detection of endometriosis. It is increasingly recognized as a powerful imaging tool for detection and characterization of lung nodules and for assessment of lung cancer staging. The lack of ionizing radiation makes thoracic MRI an invaluable imaging modality for young patients, pregnancy and for frequent serial follow-up imaging. Lack of familiarity and exposure to non-vascular thoracic MRI and lack of consistency in existing MRI protocols have called for clinical practice guidance. The purpose of this guide, which was developed by the Canadian Society of Thoracic Radiology and endorsed by the Canadian Association of Radiologists, is to familiarize radiologists, other interested clinicians and MR technologists with common and less common clinical indications for non-vascular thoracic MRI, discuss the fundamental imaging findings and focus on basic and more advanced MRI sequences tailored to specific clinical questions.

BACKGROUND Hypertension (HTN) has the greatest population-attributable risk for aortic dissection and is highly prevalent among patients with thoracic aortic aneurysms (TAAs). Although HTN is diagnosed based on brachial blood pressure (bBP), central HTN (central systolic blood pressure [cSBP] ≥130 mm Hg) is of interest as it better reflects blood pressure (BP) in the aorta. We aimed to (i) evaluate the prevalence of central HTN among TAA patients without a diagnosis of HTN, and (ii) assess associations of bBP vs. central blood pressure (cBP) with aneurysm size and growth. METHODS One hundred and five unoperated subjects with TAAs were recruited. With validated methodology, cBP was assessed with applanation tonometry. Aneurysm size was assessed at baseline and follow-up using imaging modalities. Aneurysm growth rate was calculated in mm/year. Multivariable linear regression adjusted for potential confounders assessed associations of bBP and cBP with aneurysm size and growth. RESULTS Seventy-seven percent of participants were men and 49% carried a diagnosis of HTN. Among participants without diagnosis of HTN, 15% had central HTN despite normal bBP (“occult central HTN”). In these patients, higher central systolic BP (cSBP) and central pulse pressure (cPP) were independently associated with larger aneurysm size (β ± SE = 0.28 ± 0.11, P = 0.014 and cPP = 0.30 ± 0.11, P = 0.010, respectively) and future aneurysm growth (β ± SE = 0.022 ± 0.008, P = 0.013 and 0.024 ± 0.009, P = 0.008, respectively) while bBP was not (P > 0.05). CONCLUSIONS In patients with TAAs without a diagnosis of HTN, central HTN is prevalent, and higher cBP is associated with larger aneurysms and faster aneurysm growth.

BACKGROUND: The extent to which health care systems have adapted to the COVID-19 pandemic to provide necessary cardiac diagnostic services is unknown.OBJECTIVES: The aim of this study was to determine the impact of the pandemic on cardiac testing practices, volumes and types of diagnostic services, and perceived psychological stress to health care providers worldwide.METHODS: The International Atomic Energy Agency conducted a worldwide survey assessing alterations from baseline in cardiovascular diagnostic care at the pandemic's onset and 1 year later. Multivariable regression was used to determine factors associated with procedure volume recovery.RESULTS: Surveys were submitted from 669 centers in 107 countries. Worldwide reduction in cardiac procedure volumes of 64% from March 2019 to April 2020 recovered by April 2021 in high- and upper middle-income countries (recovery rates of 108% and 99%) but remained depressed in lower middle- and low-income countries (46% and 30% recovery). Although stress testing was used 12% less frequently in 2021 than in 2019, coronary computed tomographic angiography was used 14% more, a trend also seen for other advanced cardiac imaging modalities (positron emission tomography and magnetic resonance; 22%-25% increases). Pandemic-related psychological stress was estimated to have affected nearly 40% of staff, impacting patient care at 78% of sites. In multivariable regression, only lower-income status and physicians' psychological stress were significant in predicting recovery of cardiac testing.CONCLUSIONS: Cardiac diagnostic testing has yet to recover to prepandemic levels in lower-income countries. Worldwide, the decrease in standard stress testing is offset by greater use of advanced cardiac imaging modalities. Pandemic-related psychological stress among providers is widespread and associated with poor recovery of cardiac testing.

Thoracic aortic aneurysm (TAA) is associated with high morbidity and mortality, and there is a critical need for improved tools for risk assessment and prognostication. We have previously shown that aortic stiffness, measured from arterial tonometry (carotid-femoral pulse wave velocity [cfPWV]), is independently associated with TAA expansion. To increase clinical applicability, we sought to determine the association of mathematically estimated aortic pulse wave velocity (e-PWV) with TAA expansion.One-hundred and five consecutive unoperated subjects with TAA were recruited. We used arterial tonometry to measure cfPWV and used mean arterial pressure and age to calculate e-PWV according to validated equations. Multivariable linear regression assessed associations of baseline e-PWV with future aneurysm growth. Given sex differences in TAA outcomes, sex-stratified analyses were performed.Seventy-eight percent of subjects were men. Mean ± standard deviation (SD) age, baseline aneurysm size, and follow-up time were 62.6 ± 11.4 years, 46.2 ± 3.8 mm, and 2.9 ± 1.0 years, respectively. Aneurysm growth was 0.43 ± 0.37 mm per year; e-PWV was independently associated with future aneurysm expansion (β ± SE: 0.240 ± 0.085, P = 0.006). In sex-specific analyses, e-PWV was associated with aneurysm growth in both men (β ± standard error (SE) : 0.076 ± 0.022, P = 0.001) and women (β ± SE : 0.145 ± 0.050, P = 0.012), but the strength of association nearly twice as strong in women as in men.Greater aortic stiffness reflects worse aortic health and provides novel insights into disease activity; e-PWV is independently associated with TAA growth. This finding increases clinical applicability, as e-PWV can be estimated simply, quickly, and free of cost without the need for specialized equipment.

Thoracic aortic aneurysm (TAA) is a deadly disease whose current method for risk stratification (aneurysm size) is imperfect. We sought to evaluate whether combining aortic size with hemodynamic measures that reflect the aorta's function was superior to aortic size alone in the assessment of TAA expansion.One hundred thirty-seven nonoperated participants with TAA were followed prospectively. Aortic stiffness and pulsatile hemodynamics were noninvasively assessed at baseline with a combination of arterial tonometry with echocardiography using validated methodology. Aneurysm growth was calculated from standard imaging modalities. Multivariable linear regression models adjusted for potential confounders evaluated the association of aneurysm size and arterial hemodynamics, alone and in combination, with TAA growth.Sixty-nine percent of participants were male. Mean ± SD age, baseline aneurysm size, follow-up, and aneurysm expansion were, respectively, 62.2 ± 11.4 years, 45.9 ± 4.0 mm, 4.5 ± 1.9 years, and 0.41 ± 0.46 mm/year. In the linear regression models, the standardised β (β∗) for the association of aneurysm size with aneurysm expansion was 0.178 (P = 0.044). This was improved by combining aortic size with most measures of aortic function, with β∗ ranging from 0.192 (for aneurysm size combined with central diastolic blood pressure) to 0.484 (for aneurysm size combined with carotid-femoral pulse-wave velocity) (P ≤ 0.05 for each).Combining aneurysm size with measures of arterial function improves assessment of aneurysm growth over TAA size alone, which is the standard for clinical decisions in TAA. Thus, combining aneurysm size with measures of aortic function provides a clinical advantage in the assessment of TAA disease activity.

On March 11, 2020, the World Health Organization declared infection related to a novel coronavirus (SARS-CoV-2) a pandemic. The role and impact of imaging predates this declaration and continues to change rapidly. This article is a consensus statement provided by the Canadian Society of Thoracic Radiology and the Canadian Association of Radiologists outlining the role of imaging in COVID-19 patients. The objectives are to answer key questions related to COVID-19 imaging of the chest and provide guidance for radiologists who are interpreting such studies during this pandemic. The role of chest radiography (CXR), computed tomography (CT), and lung ultrasound is discussed. This document attempts to answer key questions for the imager when dealing with this crisis, such as “When is CXR appropriate in patients with suspected or confirmed COVID-19 infection?” or “How should a radiologist deal with incidental findings of COVID-19 on CT of the chest done for other indications?” This article also provides recommended reporting structure for CXR and CT, breaking diagnostic possibilities for both CXR and CT into 3 categories: typical, nonspecific, and negative based on imaging findings with representative images provided. Proposed reporting language is also outlined based on this structure. As our understanding of this pandemic evolves, our appreciation for how imaging fits into the workup of patients during this unprecedented time evolves as well. Although this consensus statement was written using the most recent literature, it is important to maintain an open mind as new information continues to surface.

BACKGROUND The incidence of pulmonary embolism has been increasing, but its case-fatality rate is decreasing, suggesting a lesser severity of illness. The clinical importance of patients with pulmonary embolism isolated to the subsegmental vessels is unknown. OBJECTIVE To determine the rate of recurrent venous thromboembolism in patients with subsegmental pulmonary embolism managed without anticoagulation. DESIGN Multicenter prospective cohort study. (ClinicalTrials.gov: NCT01455818). SETTING Eighteen sites between February 2011 and February 2021. PATIENTS Patients with isolated subsegmental pulmonary embolism. INTERVENTION At diagnosis, patients underwent bilateral lower-extremity venous ultrasonography, which was repeated 1 week later if results were negative. Patients without deep venous thrombosis did not receive anticoagulant therapy. MEASUREMENTS The primary outcome was recurrent venous thromboembolism during the 90-day follow-up period. RESULTS Recruitment was stopped prematurely because the predefined stopping rule was met after 292 of a projected 300 patients were enrolled. Of the 266 patients included in the primary analysis, the primary outcome occurred in 8 patients, for a cumulative incidence of 3.1% (95% CI, 1.6% to 6.1%) over the 90-day follow-up. The incidence of recurrent venous thromboembolism was 2.1% (CI, 0.8% to 5.5%) and 5.7% (CI, 2.2% to 14.4%) over the 90-day follow-up in patients with single and multiple isolated subsegmental pulmonary embolism, respectively. No patients had a fatal recurrent pulmonary embolism. LIMITATION The study was restricted to patients with low-risk subsegmental pulmonary embolism. CONCLUSION Overall, patients with subsegmental pulmonary embolism who did not have proximal deep venous thrombosis had a higher-than-expected rate of recurrent venous thromboembolism. PRIMARY FUNDING SOURCE Heart and Stroke Foundation of Canada and French Ministry of Health Programme Hospitalier de Recherche Clinique.

Purpose: To assess the diagnostic accuracy of limited chest ultrasound in detecting pneumothorax following percutaneous transthoracic needle interventions using chest X-ray (CXR) as the reference standard. Methods: With IRB approval, after providing consent, asymptomatic patients after percutaneous transthoracic needle interventions were enrolled to undergo limited chest ultrasound in addition to CXR. A chest Radiologist blinded to the patient’s prior imaging performed a bedside ultrasound, scanning only the first 3 anterior intercostal spaces. Pneumothorax diagnosed on CXR was categorized as small or large and on ultrasound as grades 1, 2, or 3 when detected in 1, 2, or 3 intercostal spaces, respectively. Results: 38 patients underwent 36 biopsies (34 lungs, 1 pleura, and 1 mediastinum) and 2 coil localizations. CXR showed pneumothorax in 13 patients. Ultrasound was positive in 10 patients, with 9 true-positives, 1 false-positive, 4 false-negatives, and 24 true-negatives. The false positive results were due to apical subpleural bullae. The false-negative results occurred in 2 small apical and 2 focal pneumothoraces at the needle entry sites. Four pneumothoraces were categorized as large on CXR, all of which were categorized as grade 3 on ultrasound. Sensitivity and specificity of US for detection of pneumothorax of any size were 69.23% (95%CI 38.6%, 90.1%) and 96.0% (95%CI 79.6%, 99.9%), and for detection of large pneumothorax were 100% (95%CI 39.8%, 100%) and 100% (95%CI 89.7%, 100%). Conclusions: Results of this prospective study is promising. Limited chest ultrasound could potentially replace CXR in the management of postpercutaneous transthoracic needle intervention patients.

A 62-year-old woman with a 30 pack-year smoking history undergoes low-dose chest CT (LDCT) for lung cancer screening (LCS). This is her first LCS examination. The CT demonstrates consolidation with...

Acute pulmonary embolism (APE) is a well-recognized cause of circulatory system compromise and even demise which can frequently present a diagnostic challenge for the physician. The diagnostic challenge is primarily due to the frequency of indeterminate presentations as well as several other conditions which can have a similar clinical presentation. This often obliges the physician to establish a firm diagnosis due to the potentially serious outcomes related to this disease. Computed tomography pulmonary angiography (CTPA) has increasingly cemented its role as the primary investigation tool in this clinical context and is widely accepted as the standard of care due to several desired attributes which include great accuracy, accessibility, rapid turn-around time and the ability to suggest an alternate diagnosis when APE is not the culprit. In Part 1 of this guidance document, a series of up-to-date recommendations are provided to the reader pertaining to CTPA protocol optimization (including scan range, radiation and intravenous contrast dose), safety measures including the departure from breast and gonadal shielding, population-specific scenarios (pregnancy and early post-partum) and consideration of alternate diagnostic techniques when clinically deemed appropriate.

Background The respiratory illness caused by SARS‐CoV‐2 infection continues to present diagnostic challenges. Our 2020 edition of this review showed thoracic (chest) imaging to be sensitive and moderately specific in the diagnosis of coronavirus disease 2019 (COVID‐19). In this update, we include new relevant studies, and have removed studies with case‐control designs, and those not intended to be diagnostic test accuracy studies. Objectives To evaluate the diagnostic accuracy of thoracic imaging (computed tomography (CT), X‐ray and ultrasound) in people with suspected COVID‐19. Search methods We searched the COVID‐19 Living Evidence Database from the University of Bern, the Cochrane COVID‐19 Study Register, The Stephen B. Thacker CDC Library, and repositories of COVID‐19 publications through to 30 September 2020. We did not apply any language restrictions. Selection criteria We included studies of all designs, except for case‐control, that recruited participants of any age group suspected to have COVID‐19 and that reported estimates of test accuracy or provided data from which we could compute estimates. Data collection and analysis The review authors independently and in duplicate screened articles, extracted data and assessed risk of bias and applicability concerns using the QUADAS‐2 domain‐list. We presented the results of estimated sensitivity and specificity using paired forest plots, and we summarised pooled estimates in tables. We used a bivariate meta‐analysis model where appropriate. We presented the uncertainty of accuracy estimates using 95% confidence intervals (CIs). Main results We included 51 studies with 19,775 participants suspected of having COVID‐19, of whom 10,155 (51%) had a final diagnosis of COVID‐19. Forty‐seven studies evaluated one imaging modality each, and four studies evaluated two imaging modalities each. All studies used RT‐PCR as the reference standard for the diagnosis of COVID‐19, with 47 studies using only RT‐PCR and four studies using a combination of RT‐PCR and other criteria (such as clinical signs, imaging tests, positive contacts, and follow‐up phone calls) as the reference standard. Studies were conducted in Europe (33), Asia (13), North America (3) and South America (2); including only adults (26), all ages (21), children only (1), adults over 70 years (1), and unclear (2); in inpatients (2), outpatients (32), and setting unclear (17). Risk of bias was high or unclear in thirty‐two (63%) studies with respect to participant selection, 40 (78%) studies with respect to reference standard, 30 (59%) studies with respect to index test, and 24 (47%) studies with respect to participant flow. For chest CT (41 studies, 16,133 participants, 8110 (50%) cases), the sensitivity ranged from 56.3% to 100%, and specificity ranged from 25.4% to 97.4%. The pooled sensitivity of chest CT was 87.9% (95% CI 84.6 to 90.6) and the pooled specificity was 80.0% (95% CI 74.9 to 84.3). There was no statistical evidence indicating that reference standard conduct and definition for index test positivity were sources of heterogeneity for CT studies. Nine chest CT studies (2807 participants, 1139 (41%) cases) used the COVID‐19 Reporting and Data System (CO‐RADS) scoring system, which has five thresholds to define index test positivity. At a CO‐RADS threshold of 5 (7 studies), the sensitivity ranged from 41.5% to 77.9% and the pooled sensitivity was 67.0% (95% CI 56.4 to 76.2); the specificity ranged from 83.5% to 96.2%; and the pooled specificity was 91.3% (95% CI 87.6 to 94.0). At a CO‐RADS threshold of 4 (7 studies), the sensitivity ranged from 56.3% to 92.9% and the pooled sensitivity was 83.5% (95% CI 74.4 to 89.7); the specificity ranged from 77.2% to 90.4% and the pooled specificity was 83.6% (95% CI 80.5 to 86.4). For chest X‐ray (9 studies, 3694 participants, 2111 (57%) cases) the sensitivity ranged from 51.9% to 94.4% and specificity ranged from 40.4% to 88.9%. The pooled sensitivity of chest X‐ray was 80.6% (95% CI 69.1 to 88.6) and the pooled specificity was 71.5% (95% CI 59.8 to 80.8). For ultrasound of the lungs (5 studies, 446 participants, 211 (47%) cases) the sensitivity ranged from 68.2% to 96.8% and specificity ranged from 21.3% to 78.9%. The pooled sensitivity of ultrasound was 86.4% (95% CI 72.7 to 93.9) and the pooled specificity was 54.6% (95% CI 35.3 to 72.6). Based on an indirect comparison using all included studies, chest CT had a higher specificity than ultrasound. For indirect comparisons of chest CT and chest X‐ray, or chest X‐ray and ultrasound, the data did not show differences in specificity or sensitivity. Authors' conclusions Our findings indicate that chest CT is sensitive and moderately specific for the diagnosis of COVID‐19. Chest X‐ray is moderately sensitive and moderately specific for the diagnosis of COVID‐19. Ultrasound is sensitive but not specific for the diagnosis of COVID‐19. Thus, chest CT and ultrasound may have more utility for excluding COVID‐19 than for differentiating SARS‐CoV‐2 infection from other causes of respiratory illness. Future diagnostic accuracy studies should pre‐define positive imaging findings, include direct comparisons of the various modalities of interest in the same participant population, and implement improved reporting practices., Plain language summary How accurate is chest imaging for diagnosing COVID‐19? Why is this question important? People with suspected COVID‐19 need to know quickly whether they are infected, so they can receive appropriate treatment, self‐isolate, and inform close contacts. Currently, a formal diagnosis of COVID‐19 requires a laboratory test (RT‐PCR) of nose and throat samples. RT‐PCR requires specialist equipment and takes at least 24 hours to produce a result. It is not completely accurate, and may require a second RT‐PCR or a different test to confirm diagnosis. COVID‐19 is a respiratory disease. Clinicians may use chest imaging to diagnose people who have COVID‐19 symptoms, while awaiting RT‐PCR results or when RT‐PCR results are negative, and the person has COVID‐19 symptoms. What did we want to find out? We wanted to know whether chest imaging is accurate enough to diagnose COVID‐19 in people with suspected infection. This is the second update of this review; in it, we included studies in people with suspected COVID‐19 only; we excluded studies in people with confirmed COVID‐19. The evidence is up to date to 30 September 2020. What are chest imaging tests? X‐rays or scans produce an image of the organs and structures in the chest. ‐ X‐rays (radiography) use radiation to produce a 2‐D image. Usually done in hospitals, using fixed equipment by a radiographer, they can also be done on portable machines. ‐ Computed tomography (CT) scans use a computer to merge 2‐D X‐ray images and convert them to a 3‐D image. They require highly specialised equipment and are done in hospital by a specialist radiographer. ‐ Ultrasound scans use high‐frequency sound waves to produce an image. They can be done in hospitals or other healthcare settings, such as a doctor’s office. What did we do? We searched for studies that assessed the accuracy of chest imaging to diagnose COVID‐19 in people of any age with suspected COVID‐19. Studies could be of any design, except for case control studies, and could take place anywhere. What did we find? We found 51 studies with 19,775 participants. Of these people, 10,155 (51%) had a final diagnosis of COVID‐19. Forty‐seven studies confirmed COVID‐19 infection using RT‐PCR alone. Four studies used RT‐PCR with another test. Forty‐seven studies evaluated one imaging technique each, and four studies evaluated two imaging techniques each. Chest CT was evaluated by 41 studies (16,133 participants, 8110 (50%) confirmed COVID‐19 cases), chest X‐ray by nine studies (3694 participants, 2111 (57%) confirmed COVID‐19 cases), and ultrasound by five studies (446 participants, 211 (47%) confirmed COVID‐19 cases). Thirty‐three studies were conducted in Europe, 13 in Asia, three in North America and two in South America. Twenty‐six studies included only adults, 21 included both adults and children, one included only children, one included participants aged 70 years and older, and two studies did not report participants' ages. Two studies included hospital inpatients and 32 included hospital outpatients. The setting was unclear in the remaining 17 studies. Where four or more studies evaluated a particular type of chest imaging, we pooled their results and analysed them together. Chest CT Pooled results showed that chest CT correctly diagnosed COVID‐19 in 87.9% of people who had COVID‐19. However, it incorrectly identified COVID‐19 in 20% of people who did not have COVID‐19. Chest X‐ray Pooled results showed that chest X‐ray correctly diagnosed COVID‐19 in 80.6% of people who had COVID‐19. However, it incorrectly identified COVID‐19 in 28.5% of people who did not have COVID‐19. Lung ultrasound Pooled results showed that lung ultrasound correctly diagnosed COVID‐19 in 86.4% of people with COVID‐19. However, it incorrectly diagnosed COVID‐19 in 45% of people who did not have COVID‐19. How reliable are the results? The studies differed from each other and used different methods to report their results. Few studies evaluated chest X‐ray and chest ultrasound; and very few studies directly compared one type of imaging test with another. Therefore, we cannot draw confident conclusions based on results from studies in this review. What does this mean? The evidence suggests that chest CT is better at ruling out COVID‐19 infection than distinguishing it from other respiratory problems. So, its usefulness may be limited to excluding COVID‐19 infection rather than distinguishing it from other causes of lung infection. We plan to update this review as more evidence becomes available. Future studies should predefine what a positive test is, and compare different types of imaging tests on similar groups of people.

Thoracic aortic aneurysm (TAA) is a highly morbid disease. We have previously shown that baseline hemodynamic measures reflecting aortic function are associated with future TAA expansion. However, whether serial arterial hemodynamic assessment further improves TAA growth assessment remains unknown. Therefore, we aimed to compare single vs serial arterial hemodynamic assessments in the evaluation of future TAA growth.Eighty-six unoperated participants with TAA underwent noninvasive arterial hemodynamic assessment using arterial tonometry and echocardiography at baseline and after 1 year. Aortic diameter was measured serially with the use of standard imaging modalities. Stepwise multivariable linear regression was used to assess associations of baseline and 1-year change (Δ) in arterial hemodynamic measures with TAA growth.Mean age was 62.7 ± 11.0 years; 79% were male. Mean aneurysm growth was 0.48 ± 0.54 mm/year after a follow-up of 2.96 ± 1.03 years. Yearly changes in arterial hemodynamic measures ranged from -3.2% to +4.2%. Linear regression results showed that while baseline arterial hemodynamic measures were independently associated with aneurysm growth (carotid-femoral pulse wave velocity: β ± SE = 0.038 ± 0.013; aortic characteristic impedance: β ± SE = 0.002 ± 0.001; proximal aortic compliance: β ± SE = -0.011 ± 0.006; forward pressure wave amplitude: β ± SE 0.009 ± 0.002; reflected pressure wave amplitude: β ± SE = 0.017 ± 0.006; P0.05 for each), the 1-year Δ in these measures did not incrementally add to aneurysm growth assessment (P0.05 for each Δ).Although baseline measures of aortic function independently predict TAA expansion, 1-year changes in these measures do not improve this prediction. Thus, for TAA risk assessment purposes, a baseline assessment of aortic function may suffice, which simplifies its use for potential predictive algorithms.

Thoracic aortic aneurysm is a disease associated with high morbidity and mortality. Clinically useful strategies for medical management of thoracic aortic aneurysm are critically needed. To address this need, we sought to determine the role of aortic stiffness and pulsatile arterial load on future aneurysm expansion. One hundred five consecutive, unoperated subjects with thoracic aortic aneurysm were recruited and prospectively followed. By combining arterial tonometry with echocardiography, we estimated measures of aortic stiffness, central blood pressure, steady, and pulsatile arterial load at baseline. Aneurysm size was measured at baseline and follow-up with imaging; growth was calculated in mm/y. Stepwise multivariable linear regression assessed associations of arterial stiffness and load measures with aneurysm growth after adjusting for potential confounders. Mean±SD age, baseline aneurysm size, and follow-up time were 62.6±11.4 years, 46.24±3.84 mm, and 2.92±1.01 years, respectively. Aneurysm growth rate was 0.43±0.37 mm/y. After correcting for multiple comparisons, higher central systolic (β±SE: 0.026±0.009, P =0.007), and pulse pressures (β±SE: 0.032±0.009, P =0.0002), carotid-femoral pulse wave velocity (β±SE: 0.032±0.011, P =0.005), amplitudes of the forward (β±SE: 0.044±0.012, P =0.0003) and reflected (β±SE: 0.060±0.020, P =0.003) pressure waves, and lower total arterial compliance (β±SE: −0.086±0.032, P =0.009) were independently associated with future aneurysm growth. Measures of aortic stiffness and pulsatile hemodynamics are independently associated with future thoracic aortic aneurysm growth and provide novel insights into disease activity. Our findings highlight the role of central hemodynamic assessment to tailor novel risk assessment and therapeutic strategies to patients with thoracic aortic aneurysm.

La COVID-19 se diagnostique a partir des symptomes cliniques et par l’obtention d’un resultat positif a un test d’amplification en chaine par polymerase couplee a une transcription inverse (RT-PCR)1. La radiographie thoracique a une sensibilite de 25 % a 69 % et une specificite

Background Thoracic aortic aneurysm (TAA) is a deadly disease in critical need of novel strategies for risk assessment and medical management. To address this need, we have previously shown that directly measured carotid-femoral pulse wave velocity (cfPWV), a marker of aortic stiffness and health, independently predicts future TAA expansion. Since aortic pulse wave velocity can be estimated from age and mean arterial pressure (MAP), in the present study we sought to determine whether estimated aortic pulse wave velocity (e-aPWV) also predicts TAA expansion. Methods One hundred and five consecutive, unoperated subjects with TAA were recruited. e-aPWV was estimated from validated equations based on age and MAP. cfPWV was measured with arterial tonometry according to guidelines. TAA size was measured at baseline and at the latest follow-up using available imaging modalities according to guidelines. Stepwise multivariable linear regression (P≤0.25 to enter, P≤0.10 to stay in the model) assessed independent associations of e-aPWV and cfPWV with future TAA growth. Variables considered in the models were: age, sex, BSA, MAP, TAA etiology and location, baseline TAA size, follow-up time, imaging modality, history of hypertension, diabetes and smoking. Results Seventy eight percent of subjects were men. Mean±SD age, baseline aneurysm size and follow-up time were 62.6±11.4 years, 46.2±3.8 mm and 3.0±1.0 years, respectively. e-aPWV and cfPWV were moderately correlated (Pearson's correlation coefficient = 0.61). Results of the linear regression analyses showed that both measured (cfPWV) and estimated (e-aPWV) independently predicted future TAA expansion (β±SE: 0.032±0.011, P=0.048 and 0.240±0.085, P=0.006, respectively). The base model's R-squared value of 0.39 was increased to 0.44 with addition of either cfPWV or e-aPWV to the model, confirming that each parameter of aortic stiffness enhances prediction of TAA growth. Conclusion Aortic stiffness is relevant for assessment of TAA disease activity. Similar to cfPWV, e-aPWV is also independently associated with future TAA expansion. Thus, e-aPWV represents a tool to improve TAA risk stratification that is simple, free of cost, and obviates the need for specialized equipment or dedicating training, which leads to excellent potential for widespread incorporation into clinical practice. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Canadian Institutes of Health Research

OBJECTIVE. The purpose of this study was to assess the use of an electronic consultation platform to connect primary care providers and radiologists and provide opportunities for valuable consultation regarding diagnostic imaging in patients, as well as to identify opportunities for targeted education surrounding high-yield radiology topics. MATERIALS AND METHODS. A retrospective review was performed of consultations conducted using the electronic platform from September 2012 to January 2017. Consultations were classified by subspecialty (neuroradiology, thoracic, abdominal, musculoskeletal, or pediatric radiology), question type (workup, surveillance, education, specialist referral query, discharge, or other), anatomy, and pathology. Feedback surveys were completed by primary care providers after each consultation to evaluate timeliness, value, and impact on patient care. RESULTS. A total of 302 consultations were reviewed. Subspecialty breakdown was as follows: abdominal, 94/302 (31%); neuroradiology, 74/302 (25%); musculoskeletal, 61/302 (20%); thoracic, 56/302 (19%); and pediatric, 17/302 (6%). The majority of consultations pertained to patient workup (112/302 [37%]), surveillance of imaging findings (95/302 [31%]), and provider education (48/302 [16%]). Cystic lesions (38/302 [13%]), pain (24/302 [8%]), and bone lesions (21/302 [7%]) were the most queried conditions. Patient management was altered in 167 cases (55%), and unnecessary testing was avoided in 84 (28%). Providers rated the perceived value of the electronic consultation system as excellent in 227 cases (75%). CONCLUSION. The electronic consultation system allowed primary care providers to easily consult with radiologists, was perceived as high value by primary care providers, resulted in altered patient management, and avoided unnecessary imaging tests. We identified follow-up imaging of cystic lesions and imaging workup of pain in patients as opportunities for continuing medical education for primary care providers.

This is a protocol for a Cochrane Review (diagnostic). The objectives are as follows: The primary objective is to determine the diagnostic accuracy of chest imaging (computed tomography (CT), chest X‐ray and ultrasound) in the evaluation of people suspected to have COVID‐19. This may also refer to specific signs, such as a particular CT finding. SECONDARY OBJECTIVES: 1. To evaluate whether these imaging tests are sufficiently accurate to rule out COVID‐19 (main measure of interest will be the negative predictive value). 2. To evaluate the rate of positive imaging in patients with initial RT‐PCR negative results who have a positive result on a follow‐up RT‐PCR test. 3. To determine if there is an association between number of days after symptom onset, symptom severity and the findings on chest imaging for patients with COVID‐19. 4. To determine the rate of discrepancy or agreement between CT, chest X‐ray and ultrasound findings. 5. To evaluate for ‘threshold’ effects of imaging findings of COVID‐19 and accuracy measures. 6. To determine the rate of alternative diagnoses identified by chest imaging.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is an evolving global pandemic that is predicted to strain healthcare resources at multiple locations throughout North America and the World. As of April 6, 2020, the apex of infection rates is predicted to occur within 1 to 5 weeks at various locations. Widespread reports of personal protective equipment (PPE) shortages, and healthcare worker exposure to disease have become commonplace. To mitigate this crisis, we are suggesting imaging strategies that aim to use the least PPE, require the smallest number of potential staff exposures, and streamlines utilization of imaging. They are broadly organized by (1) substituting a noninvasive diagnostic test in place of a semi-invasive or invasive diagnostic tests, and (2) consolidating diagnostic imaging.

Background: Cardiac magnetic resonance (CMR) is a recommended imaging test for patients with heart failure (HF); however, there is a lack of evidence showing incremental benefit over transthoracic echocardiography. Our primary hypothesis was that routine use of CMR will yield more specific diagnoses in nonischemic HF. Our secondary hypothesis was that routine use of CMR will improve patient outcomes. Methods: Patients with nonischemic HF were randomized to routine versus selective CMR. Patients in the routine strategy underwent echocardiography and CMR, whereas those assigned to selective use underwent echocardiography with or without CMR according to the clinical presentation. HF causes was classified from the imaging data as well as by the treating physician at 3 months (primary outcome). Clinical events were collected for 12 months. Results: A total of 500 patients (344 male) with mean age 59±13 years were randomized. The routine and selective CMR strategies had similar rates of specific HF causes at 3 months clinical follow-up (44% versus 50%, respectively; P =0.22). At image interpretation, rates of specific HF causes were also not different between routine and selective CMR (34% versus 30%, respectively; P =0.34). However, 24% of patients in the selective group underwent a nonprotocol CMR. Patients with specific HF causes had more clinical events than those with nonspecific caused on the basis of imaging classification (19% versus 12%, respectively; P =0.02), but not on clinical assessment (15% versus 14%, respectively; P =0.49). Conclusions: In patients with nonischemic HF, routine CMR does not yield more specific HF causes on clinical assessment. Patients with specific HF causes from imaging had worse outcomes, whereas HF causes defined clinically did not. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01281384.

Essentials Exercise Limitation 1 year after an acute pulmonary embolism is common.Serial imaging after acute pulmonary embolism is not well described and how it affects exercise limitation remains unknown.1 year after an acute pulmonary embolism chronic changes are common, more so on perfusion lung scanning than CT pulmonary angiography, but imaging findings did not predict exercise limitation. Introduction Risk factors for exercise limitation after acute pulmonary embolism (PE) are unknown. As a planned sub‐study of the prospective, multicenter ELOPE (Evaluation of Long‐term Outcomes after PE) Study, we aimed to describe the results of serial imaging by computed tomography pulmonary angiography (CTPA) and perfusion scan during 1 year after a first episode of acute pulmonary embolism, and to assess the association between imaging parameters and exercise limitation at 1 year. Methods In a prospective cohort study, 100 patients were recruited between June 2010 and February 2013 at five Canadian university–affiliated hospitals. CT pulmonary angiography was performed at baseline and 12 months, perfusion scan at 6 and 12 months, and cardio‐pulmonary exercise testing at 1 and 12 months. Imaging parameters included: on CT pulmonary angiography, CT obstruction index (CTO) (% clot burden in the pulmonary vasculature), and on perfusion scan, pulmonary vascular obstruction (PVO) (% perfusion defect). Abnormal cardio‐pulmonary exercise test (primary outcome) was defined as percent of predicted peak oxygen uptake (VO2) 80% on 1‐year cardio‐pulmonary exercise testing (1.4% [0%; 5.7%] vs 1.0% [0%; 2.4%]; P = .70). Mean (SD) pulmonary vascular obstruction at 6 and at 12 months was similar in patients with percent‐predicted VO2 peak 80% (6 months: 5.9% [0%; 10.4%] vs 6.2% [4.5%; 9.0%]; P = .91; 12 months: 5.1% [0%; 10.2%] vs 6.0% [0%; 9.7%]; P = .71). Conclusions Imaging findings after pulmonary embolism did not predict exercise limitation. Residual thrombus does not appear to explain long‐term functional limitation after pulmonary embolism.

Purpose To compare the diagnostic accuracy of different computed tomographic (CT) fractional flow reserve (FFR) algorithms for vessels with intermediate stenosis. Materials and Methods This cross-sectional HIPAA-compliant and human research committee-approved study applied a four-step CT FFR algorithm in 61 patients (mean age, 69 years ± 10; age range, 29-89 years) with a lesion of intermediate-diameter stenosis (25%-69%) at CT angiography who underwent FFR measurement within 90 days. The per-lesion diagnostic performance of CT FFR was tested for three different approaches to estimate blood flow distribution for CT FFR calculation. The first two, the Murray law and the Huo-Kassab rule, used coronary anatomy; the third used contrast material opacification gradients. CT FFR algorithms and CT angiography percentage diameter stenosis (DS) measurements were compared by using the area under the receiver operating characteristic curve (AUC) to detect FFRs of 0.8 or lower. Results Twenty-five lesions (41%) had FFRs of 0.8 or lower. The AUC of CT FFR determination by using contrast material gradients (AUC = 0.953) was significantly higher than that of the Huo-Kassab (AUC = 0.882, P = .043) and Murray law models (AUC = 0.871, P = .033). All three AUCs were higher than that for 50% or greater DS at CT angiography (AUC = 0.596, P < .001). Correlation of CT FFR with FFR was highest for gradients (Spearman ρ = 0.80), followed by the Huo-Kassab rule (ρ = 0.68) and Murray law (ρ = 0.67) models. All CT FFR algorithms had small biases, ranging from -0.015 (Murray) to -0.049 (Huo-Kassab). Limits of agreement were narrowest for gradients (-0.182, 0.147), followed by the Huo-Kassab rule (-0.246, 0.149) and the Murray law (-0.285, 0.256) models. Conclusion Clinicians can perform CT FFR by using a four-step approach on site to accurately detect hemodynamically significant intermediate-stenosis lesions. Estimating blood flow distribution by using coronary contrast opacification variations may improve CT FFR accuracy. © RSNA, 2017 Online supplemental material is available for this article.

Background: The Ottawa Hospital (TOH) defined delay to timely lung cancer care as a system design problem. Recognizing the patient need for an integrated journey and the need for dynamic alignment of providers, TOH used a learning health system (LHS) vision to redesign regional diagnostic processes. A LHS is driven by feedback utilizing operational and clinical information to drive system optimization and innovation. An essential component of a LHS is a collaborative platform that provides connectivity across silos, organizations, and professions. Methods: To operationalize a LHS, we developed the Ottawa Health Transformation Model (OHTM) as a consensus approach that addresses process barriers, resistance to change, and conflicting priorities. A regional Community of Practice (COP) was established to engage stakeholders, and a dedicated transformation team supported process improvements and implementation. Results: The project operationalized the lung cancer diagnostic pathway and optimized patient flow from referral to initiation of treatment. Twelve major processes in referral, review, diagnostics, assessment, triage, and consult were redesigned. The Ottawa Hospital now provides a diagnosis to 80% of referrals within the provincial target of 28 days. The median patient journey from referral to initial treatment decreased by 48% from 92 to 47 days. Conclusions: The initiative optimized regional integration from referral to initial treatment. Use of a LHS lens enabled the creation of a system that is standardized to best practice and open to ongoing innovation. Continued transformation initiatives across the continuum of care are needed to incorporate best practice and optimize delivery systems for regional populations.

Rationale and Objectives The study aimed to identify a radiomic approach based on CT and or magnetic resonance (MR) features (shape and texture) that may help differentiate benign versus malignant pleural lesions, and to assess if the radiomic model may improve confidence and accuracy of radiologists with different subspecialty backgrounds. Materials and Methods Twenty-nine patients with pleural lesions studied on both contrast-enhanced CT and MR imaging were reviewed retrospectively. Three texture and three shape features were extracted. Combinations of features were used to generate logistic regression models using histopathology as outcome. Two thoracic and two abdominal radiologists evaluated their degree of confidence in malignancy. Diagnostic accuracy of radiologists was determined using contingency tables. Cohen's kappa coefficient was used to assess inter-reader agreement. Using optimal threshold criteria, sensitivity, specificity, and accuracy of each feature and combination of features were obtained and compared to the accuracy and confidence of radiologists. Results The CT model that best discriminated malignant from benign lesions revealed an AUC CT = 0.92 ± 0.05 ( P MR = 0.87 ± 0.09 ( P P P = 0.02). The most discriminative MR model was more accurate than one abdominal ( P = 0.04) and one thoracic radiologist ( P = 0.02). Conclusion Quantitative textural and shape analysis may help distinguish malignant from benign lesions. A radiomics-based approach may increase diagnostic confidence of abdominal radiologists on CT and MR and may potentially improve radiologists' accuracy in the assessment of pleural lesions characterized by MR.

Coronary artery anomalies constitute a diverse group of abnormalities, ranging from anatomic variants to those having hemodynamic consequences. This review focuses on major anomalies that have clinical implications requiring treatment, including anomalous origin of the coronary artery from the opposite sinus with interarterial course specifically with an intramural course, coronary artery origin from the pulmonary artery, and coronary artery fistula. Comprehensive imaging evaluation is necessary to precisely delineate the anatomy as well as pathophysiologic aspects of the anomaly before determining treatment options for a specific patient. Coronary computed tomographic angiography provides elegant depiction of coronary arterial anatomy and the relationship of the vessel to the adjacent structures, with the ability to perform three-dimensional reconstructions. Magnetic resonance (MR) imaging is emerging as an alternative noninvasive imaging strategy, particularly in young individuals, due to the lack of ionizing radiation and avoidance of iodinated contrast agents. This review describes the roles and recent technical advancements in computed tomography and MR imaging pertinent to coronary artery imaging. Additionally, this article will familiarize readers with the cross-sectional imaging appearance of clinically relevant coronary anomalies, hemodynamic considerations, and complex decision making. The different management strategies used for these anomalies, such as coronary unroofing, reimplantation, bypass grafting, Takeuchi repair, and surgical and interventional closure of fistulas, as well as specific posttreatment complications, are also discussed.

Background We aimed to determine the frequency and predictors of exercise limitation after pulmonary embolism (PE) and to assess its association with health-related quality of life (HRQoL) and dyspnea. Methods One hundred patients with acute PE were recruited at five Canadian hospitals from 2010 to 2013. Cardiopulmonary exercise testing (CPET) was performed at 1 and 12 months. Quality of life (QoL), dyspnea, 6-min walk distance (6MWD), residual clot burden (perfusion scan, CT pulmonary angiography), cardiac function (echocardiography), and pulmonary function tests (PFTs) were measured during follow-up. The prespecified primary outcome was percent predicted peak oxygen uptake (Vo2 peak) Results At 1 year, 40 of 86 patients (46.5%) had percent predicted Vo2 peak Conclusions Almost half of patients with PE have exercise limitation at 1 year that adversely influences HRQoL, dyspnea, and walking distance. CPET or 6MWD testing at 1 month may help to identify patients with a higher risk of exercise limitation at 1 year after PE. Based on our results, we believe that the deconditioning that occurs after acute PE could underlie this exercise limitation, but we cannot exclude the fact that this may have been present before PE. Trial Registry ClinicalTrials.gov; No.: NCT01174628; URL: www.clinicaltrials.gov.

Introduction Thoracic aortic aneurysm (TAA) is a clinically silent disease which can lead to significant morbidity when complicated by an acute aortic syndrome. Although TAA size is the only variable used in decision-making, it is an imperfect predictor of risk. Conversely, hemodynamic measures that reflect the aorta's function, such as aortic stiffness and pulsatile hemodynamics, may provide additional insights into risk of TAA expansion. Purpose We hypothesized that combining aortic size with measures of arterial function (stiffness and pulsatile hemodynamics) would improve prediction of TAA expansion, as compared to aortic size alone. Methods 105 unoperated participants with TAA were recruited between 2014 and 2017 and followed prospectively for ≥1 yr. TAA size was measured at enrolment and at the latest imaging study according to published consensus; TAA expansion was calculated as mm/year. Arterial function was non-invasively assessed at baseline with validated methods that integrate arterial tonometry with echocardiography. Multivariable linear regression assessed independent associations of baseline TAA size and each arterial function measure, initially separately and then in combination (by multiplying them when direction of association was the same, and dividing them when direction of association was opposite), with future TAA expansion. Standardized beta coefficients were calculated to allow direct comparisons. Models were adjusted for age, sex, body size, aneurysm location and etiology, type of imaging modality, follow-up time, mean arterial pressure, and history of hypertension, diabetes and smoking. Results Seventy-seven percent of participants were men, and the ratio of degenerative to heritable TAAs was 62/43. Mean ± SD age, baseline TAA size, and follow-up time were 62.8±11.3yrs, 46.3±3.9cm, and 2.2±0.7 years, respectively. Results of the multivariable linear regression models are summarized in the Table. While baseline TAA size and each arterial function measure were independently associated with TAA expansion, some of the arterial function measures were superior in predicting TAA growth (Table, left). In addition, combining aortic size and function further improved the prediction of TAA growth beyond each variable alone (Table, right). Conclusion(s) Combining aortic size with arterial function improved prediction of TAA expansion over any individual variable alone, independently of confounders. Assessing arterial function may confer a clinical advantage, when compared to current practice, in determining TAA disease activity and estimating one's TAA-related risk. Acknowledgement/Funding Canadian Institute of Health Research, Canadian Vascular Network, and Heart and Stroke Foundation of Canada

BACKGROUND: An important and common cause of pulmonary hypertension (PH) is chronic thromboembolic PH (CTEPH). Many care gaps exist in the evaluation of CTEPH including lack of awareness of the dia...

Objective Percutaneous biopsy of lung nodules is established as a safe procedure with high diagnostic yield and accuracy. Its role in the diagnosis of subcentimeter nodules is, however, less clear. The goal of this study was to evaluate diagnostic yield, accuracy, and safety of computed tomography (CT)-guided needle biopsy in the diagnosis of subcentimeter lung nodules. Material and methods A retrospective review of a prospectively maintained database over a 12-year period identified 133 eligible CT-guided needle biopsies of lesions ≤1 cm. Diagnostic yield and accuracy for the diagnosis of malignancy were calculated. Lesion features and procedure characteristics were assessed using univariate and multivariate logistic regression analysis to identify risk factors associated with biopsy failure and complications. Results Biopsy specimens were adequate for diagnosis in 116/133(87%) cases; the diagnostic yield for malignant and benign lesions was 93% and 65%, respectively. Final benign diagnosis was the strongest independent risk factor for biopsy failure. In multivariate logistic regression, fine-needle aspiration was an independent risk factor for diagnostic failure. Core needle biopsy was an independent risk factor for pneumothorax, and core needle biopsy, number of passes, and age were independent risk factors for pneumothorax requiring tube drainage. Conclusions CT-guided percutaneous needle biopsy had high diagnostic yield for the diagnosis of subcentimeter lung nodules with a similar complication rate to biopsy of larger lesions. Fine-needle aspiration may be an independent factor for diagnostic failure even for malignant lesions.

Background Bicuspid aortic valve ( BAV ) is the most common congenital cardiac abnormality. A thoracic aortic aneurysm ( TAA ) is present in ≈50% of BAV patients, who also have an 8‐fold higher risk of aortic dissection than the general population. Because the health of the aorta is directly reflected in its stiffness and pulsatile hemodynamics, we hypothesized that measures of aortic stiffness and arterial load would be associated with TAA growth in BAV . Methods and Results Twenty‐nine unoperated participants with TAA due to BAV who had serial imaging were recruited. Aortic stiffness and steady and pulsatile arterial load were evaluated with validated methods that integrate arterial tonometry with echocardiography. TAA growth was assessed retrospectively based on available imaging, blinded to hemodynamic status. Multivariable linear regression assessed associations of aortic stiffness and hemodynamic variables with TAA growth, adjusting for potential confounders. Overall, 66% of participants were men. Mean±SD for age, baseline aneurysm size, growth rate, and follow‐up time were 57.2±8.3 years, 46.9±3.6 mm, 0.75±0.81 mm/y, and 2.9±3.3 years, respectively. We found that greater aortic stiffness (β± SE for carotid‐femoral pulse wave velocity: 0.30±0.13. P =0.03) and aortic characteristic impedance (β± SE : 0.46±0.18, P =0.02), as well as lower total arterial and proximal aortic compliance (β± SE : −0.44±0.21, P =0.05, and −0.63±0.16, P =0.001, respectively) were independently associated with faster aneurysm growth. Conclusions In patients with TAA due to BAV , measures of greater aortic stiffness and pulsatile arterial load indicate an association with accelerated aneurysm expansion. Assessing arterial hemodynamics may be useful for risk stratification and disease monitoring in TAA patients with BAV .

Conventional chest radiography, computed tomography (CT), and with restrictions, magnetic resonance imaging (MRI) are the three most commonly used imaging modalities for evaluating patients with suspected pulmonary vascular disease. Very recently, the clinical usefulness of fluorodeoxyglucose positron emission tomography (FDG-PET) and FDG-PET/CT in the diagnosis of large-vessel vasculitis also has been recognized. However, in daily general clinical routine, most patients with suspected pulmonary vascular disease will be evaluated by CT. Moreover, the utility of CT has been improved by technical developments such as dual-source and dual-energy scanners, which simultaneously generate morphological and functional information from a sole dataset. In patients with pulmonary vascular diseases, this approach is of major interest for three main reasons: (1) Pulmonary vascular disorders require a thorough morphological evaluation, not only of the vascular tree per se, but also of the surrounding lung parenchyma; (2) given that we have reached an upper limit in terms of morphologic image resolution, but can simultaneously obtain functional information, CT ideally combines high-end morphologic imaging with perfusion and ventilation imaging; and (3) it is becoming increasingly important to determine the cardiac consequences or causes of pulmonary vascular diseases, which requires all of the advantages that CT can provide. For these reasons, and because of the general importance of CT, it is the focus of this chapter. Other imaging modalities are not ignored; rather, they are discussed in case-based presentations and in their distinct clinical contexts.

Women with thoracic aortic aneurysms (TAAs) have higher risk of acute aortic syndromes and death than men. We have shown that TAA growth is accelerated in women, helping explain the sex differences in TAA outcomes. Since aortic stiffness reflects the health of the aorta, we sought to determine the sex-specific role of aortic stiffness on TAA growth. One hundred thirty unoperated people with TAA were recruited. Maximal aneurysm size at the oldest and latest imaging studies was measured to calculate TAA growth rate. Aortic stiffness was assessed by carotid-femoral pulse wave velocity (cfPWV) using applanation tonometry. Multivariable linear regression adjusted for confounders assessed the association of cfPWV with TAA growth. Seventy-three percent of subjects were men. Mean±SD age, baseline aneurysm size, follow-up time, and cfPWV were 62.5±11.5 years, 45.3±4.0 mm, 3.3±3.0 years and 9.6±3.5 m/s, and not different based on sex. TAA growth rate was 0.96±1.00 mm/y in women and 0.45±0.58 mm/y in men ( P=0.006). In the whole group, cfPWV was independently associated with TAA growth (β±SE: 0.06±0.02, P=0.02). However, in sex-specific analyses cfPWV was independently associated with faster aneurysm growth in women (β±SE: 0.21±0.09, P=0.03), but not in men (β±SE: -0.002±0.02, P=0.94), with a significant sex×cfPWV interaction ( P0.0001). In patients with TAA, aneurysm growth is more than twice as fast in women than men, and aortic stiffness is associated with greater TAA growth in women, but not in men. Our findings highlight greater aortic stiffness as an important correlate of TAA expansion in women.