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Pulmonary nodules are managed on the basis of their size and morphologic characteristics. Radiologists are familiar with assessing nodule size by measuring diameter using manually deployed electronic calipers. Size may also be assessed with 3D volumetric measurements (referred to as volumetry) obtained with software. Nodule size and growth are more accurately assessed with volumetry than on the basis of diameter, and the evidence supporting clinical use of volumetry has expanded, driven by its use in lung cancer screening nodule management algorithms in Europe. The application of volumetry has the potential to reduce recommendations for imaging follow-up of indeterminate solid nodules without impacting cancer detection. Although changes in scanning conditions and volumetry software packages can lead to variation in volumetry results, ongoing technical advances have improved the reliability of calculated volumes. Volumetry is now the primary method for determining size of solid nodules in the European lung cancer screening position statement and British Thoracic Society recommendations. The purposes of this article are to review technical aspects, advantages, and limitations of volumetry and, by considering specific scenarios, to contextualize the use of volumetry with respect to its importance in morphologic evaluation, its role in predicting malignancy in risk models, and its practical impact on nodule management. Implementation challenges and areas requiring further evidence are also highlighted.

Although recommended lung cancer screening with low-dose computed tomography scanning (LDCT) reduces mortality among high-risk adults, annual screening rates remain low. This study complements a previous nationwide assessment of access to lung cancer screening within 40 miles by evaluating differences in accessibility across rural and urban settings for the population aged 50 to 80 years and a subset eligible population based on the 2021 US Preventive Services Task Force LDCT lung screening recommendations.Distances from population centers to screening facilities (American College of Radiology Lung Cancer Screening Registry) were calculated, and the number of individuals who had access within graduating distances, including 10, 20, 40, 50, and 100 miles, were estimated. Census tract results were aggregated to counties, and both geographies were classified with rural-urban schemas.Approximately 5% of the eligible population did not have access to lung cancer screening facilities within 40 miles; however, different patterns of accessibility were observed at different distances, between regions, and across rural-urban environments. Across all distances and geographies, there was a larger percentage of the population in rural geographies with no access. Although the rural population represented approximately 8% of the eligible population, the larger percentage of the rural population with no access was noteworthy and translated into a larger number of individuals with no access at longer distance thresholds (≥40 miles).Disparities in access should be examined as both percentages of the population and numbers of individuals with no access in order to tailor interventions to communities and increase access. Geospatial analysis at the census tract level is recommended to help to identify optimal focus areas and reach the most people.As annual lung cancer screening rates remain low, this study examines access to lung cancer screening nationwide and across rural and urban settings. A geographic information system network analysis of census tract-level populations is used to estimate access at different distances, including 10, 20, 40, 50, and 100 miles, and the results are aggregated to counties. Approximately 5% of the eligible population does not have access to screening facilities within 40 miles; however, different patterns of accessibility are observed at different distances, between regions, and across rural-urban environments. Across all distances and geographies, there is a larger percentage of the population in rural geographies with no access.

Pulmonary nodules are managed based on their size and morphologic characteristics. Radiologists are familiar with assessing nodule size by diameter measured using manually deployed electronic calipers. Size may also be assessed by 3D volumetric measurements (referred to as volumetry) using software. Nodule size and growth are more accurately assessed by volumetry than by diameter, and the evidence supporting clinical use of volumetry has expanded, driven by its use in lung cancer screening (LCS) nodule management algorithms in Europe. The application of volumetry has the potential to reduce recommendations for imaging follow-up of indeterminate solid nodules without impacting cancer detection. Although changes in scanning conditions or volumetry software package may lead to variation in volumetry results, ongoing technical advances have improved the reliability of calculated volumes. Volumetry is now the primary method for determining size of solid nodules in the European LCS position statement and British Thoracic Society recommendations. In this article, we review technical aspects, advantages, and limitations of volumetry, and contextualize its use with respect to its importance relative to morphologic evaluation, role for predicting malignancy in risk models, and practical impact on nodule management, by considering specific scenarios. Implementation challenges and areas requiring further evidence are also highlighted.

In 2014, the American College of Radiology (ACR) created Lung-RADS 1.0. The system was updated to Lung-RADS 1.1 in 2019, and further updates are anticipated as additional data become available. Lung-RADS provides a common lexicon and standardized nodule follow-up management paradigm for use when reporting lung cancer screening (LCS) low-dose CT (LDCT) chest examinations and serves as a quality assurance and outcome monitoring tool. The use of Lung-RADS is intended to improve LCS performance and lead to better patient outcomes. To date, the ACR's Lung Cancer Screening Registry is the only LCS registry approved by the Centers for Medicare & Medicaid Services and requires the use of Lung-RADS categories for reimbursement. Numerous challenges have emerged regarding the use of Lung-RADS in clinical practice, including the timing of return to LCS after planned follow-up diagnostic evaluation; potential substitution of interval diagnostic CT for future LDCT; role of volumetric analysis in assessing nodule size; assessment of nodule growth; assessment of cavitary, subpleural, and category 4X nodules; and variability in reporting of the S modifier. This article highlights the major updates between versions 1.0 and 1.1 of Lung-RADS, describes the system's ongoing challenges, and summarizes current evidence and recommendations.

The US Preventive Services Task Force has recommended lung cancer screening (LCS) with low-dose CT (LDCT) in high-risk individuals since 2013. Because LDCT encompasses the lower neck, chest, and upper abdomen, many incidental findings (IFs) are detected. The authors created a quick reference guide to describe common IFs in LCS to assist LCS program navigators and ordering providers in managing the care continuum in LCS.The ACR IF white papers were reviewed for findings on LDCT that were age appropriate for LCS. A draft guide was created on the basis of recommendations in the IF white papers, the medical literature, and input from subspecialty content experts. The draft was piloted with LCS program navigators recruited through contacts by the ACR LCS Steering Committee. The navigators completed a survey on overall usefulness, clarity, adequacy of content, and user experience with the guide.Seven anatomic regions including 15 discrete organs with 45 management recommendations were identified as relevant to the age of individuals eligible for LCS. The draft was piloted by 49 LCS program navigators from 32 facilities. The guide was rated as useful and clear by 95% of users. No unexpected or adverse experiences were reported in using the guide. On the basis of feedback, relevant sections were reviewed and edited.The ACR Lung Cancer Screening CT Incidental Findings Quick Reference Guide outlines the common IFs in LCS and can serve as an easy-to-use resource for ordering providers and LCS program navigators to help guide management.

Given that an incidental pulmonary nodule (IPN) on chest computed tomography (CT) may represent nascent lung cancer, timely follow-up imaging is critical to assess nodule growth and the need for tissue sampling. We previously reported our institution's systematic process to identify and track patients with an IPN associated with improved CT on follow-up. We hypothesized that this improvement may have led to a higher frequency of early-stage lung cancer. To evaluate this, we performed a study to determine whether cases of early-stage lung cancer were more likely to have had our tracking system applied to suspicious findings.An observational study was performed by identifying cases of lung cancer that were detected as IPNs on chest CT scans performed at our institution, from 2006 to 2016. A total of 314 cases were dichotomized into early-stage (stage 1) or late-stage (stages II to IV) disease. A multivariant regression analysis with modeling was used to determine factors associated with a diagnosis of early-stage disease. Factors included the use of the tracking system and nodule registry.The following factors were independently associated with early-stage lung cancer: index nodule diameter, (OR = 0.971, confidence interval [CI]: 0.948-0.995],The application of a patient tracking system and computerized lung nodule registry lead to an increased frequency in the diagnosis of stage 1 NSCLC from IPNs. This is a meaningful outcome for patients and should be adapted for IPN management.

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...

Small pulmonary nodules are most often managed by surveillance imaging with computed tomography (CT) of the chest, but the optimal frequency and duration of surveillance are unknown. The Watch the Spot Trial is a multicenter, pragmatic, comparative-effectiveness trial with cluster randomization by hospital or health system that compares more- versus less-intensive strategies for active surveillance of small pulmonary nodules. The study plans to enroll approximately 35,200 patients with a small pulmonary nodule that is newly detected on chest CT imaging, either incidentally or by screening. Study protocols for more- and less-intensive surveillance were adapted from published guidelines. The primary outcome is the percentage of cancerous nodules that progress beyond American Joint Committee on Cancer seventh edition stage T1a. Secondary outcomes include patient-reported anxiety and emotional distress, nodule-related health care use, radiation exposure, and adherence with the assigned surveillance protocol. Distinctive aspects of the trial include: 1) the pragmatic integration of study procedures into existing clinical workflow; 2) the use of cluster randomization by hospital or health system; 3) the implementation and evaluation of a system-level intervention for protocol-based care; 4) the use of highly efficient, technology-enabled methods to identify and (passively) enroll participants; 5) reliance on data collected as part of routine clinical care, including data from electronic health records and state cancer registries; 6) linkage with state cancer registries for complete ascertainment of the primary study outcome; and 7) intensive engagement with a diverse group of patient and nonpatient stakeholders in the design and execution of the study.

Author(s): Regan, Elizabeth A; Lowe, Katherine E; Make, Barry J; Lynch, David A; Kinney, Gregory L; Budoff, Matthew J; Mao, Song Shou; Dyer, Debra; Curtis, Jeffrey L; Bowler, Russell P; Han, MeiLan K; Beaty, Terri H; Hokanson, John E; Kern, Elizabeth; Humphries, Stephen; Curran-Everett, Douglas; van Beek, Edwin JR; Silverman, Edwin K; Crapo, James D; Finigan, James H; COPDGene® Investigators | Abstract: BackgroundLung cancer screening (LCS) via chest computed tomography (CT) scans can save lives by identifying early-stage tumors. However, most smokers die of comorbid smoking-related diseases. LCS scans contain information about smoking-related conditions that is not currently systematically assessed. Identifying these common comorbid diseases on CT could increase the value of screening with minimal impact on LCS programs. We determined the prevalence of 3 comorbid diseases from LCS eligible scans and quantified related adverse outcomes.MethodsWe studied COPD Genetic Epidemiology study (COPDGene®) participants (n=4078) who met criteria for LCS screening at enrollment (age g 55 years, and l 80 years, g 30 pack years smoking, current smoker or former smoker within 15 years of smoking cessation). CT scans were assessed for coronary artery calcification (CAC), emphysema, and vertebral bone density. We tracked the following clinically significant events: myocardial infarctions (MIs), strokes, pneumonia, respiratory exacerbations, and hip and vertebral fractures.ResultsOverall, 77% of eligible CT scans had one or more of these diagnoses identified. CAC (g 100 mg) was identified in 51% of scans, emphysema in 44%, and osteoporosis in 54%. Adverse events related to the underlying smoking-related diseases were common, with 50% of participants reporting at least one. New diagnoses of cardiovascular disease, emphysema and osteoporosis were made in 25%, 7% and 46%, of participants respectively. New diagnosis of disease was associated with significantly more adverse events than in participants who did not have CT diagnoses for both osteoporosis and cardiovascular risk.ConclusionsExpanded analysis of LCS CT scans identified individuals with evidence of previously undiagnosed cardiovascular disease, emphysema or osteoporosis that corresponded with adverse events. LCS CT scans can potentially facilitate diagnoses of these smoking-related diseases and provide an opportunity for treatment or prevention.

The ACR Incidental Findings Committee presents recommendations for managing incidentally detected lung findings on thoracic CT. The Chest Subcommittee is composed of thoracic radiologists who endorsed and developed the provided guidance. These recommendations represent a combination of current published evidence and expert opinion and were finalized by informal iterative consensus. The recommendations address commonly encountered incidental findings in the lungs and are not intended to be a comprehensive review of all pulmonary incidental findings. The goal is to improve the quality of care by providing guidance on management of incidentally detected thoracic findings.

Purpose Despite established guidelines, radiologists’ recommendations and timely follow-up of incidental lung nodules remain variable. To improve follow-up of nodules, a system using standardized language (tracker phrases) recommending time-based follow-up in chest CT reports, coupled with a computerized registry, was created. Materials and Methods Data were obtained from the electronic health record and a facility-built electronic lung nodule registry. We evaluated two randomly selected patient cohorts with incidental nodules on chest CT reports: before intervention September 2008 to March 2011 and after intervention August 2011 to December 2016. Multivariable logistic regression was used to compare the cohorts for the main outcome of timely follow-up, defined as a subsequent report within 13 months of the initial report. Results In all, 410 patients were included in the pretracker cohort versus 626 in the tracker cohort. Before system inception, 30% of CT reports lacked an explicit time-based recommendation for nodule follow-up. The proportion of patients with timely follow-up increased from 46% to 55%, and the proportion of those with no documented follow-up or follow-up beyond 24 months decreased from 48% to 31%. The likelihood of timely follow-up increased 41%, adjusted for high risk for lung cancer and age 65 years or older. After system inception, reports missing a tracker phrase for nodule recommendation averaged 6%, without significant interyear variation. Conclusions Standardized language added to CT reports combined with a computerized registry designed to identify and track patients with incidental lung nodules was associated with improved likelihood of follow-up imaging.

Purpose The aim of this study was to examine radiologists’ beliefs about existing guidelines for pulmonary nodule evaluation. Methods A self-administered survey was developed to ascertain awareness of, agreement with, and adherence to published guidelines, including those from the Fleischner Society and the Lung CT Screening Reporting and Data System (Lung-RADS™). Surveys were distributed to 514 radiologists at 13 health care systems that are participating in a large, pragmatic trial of pulmonary nodule evaluation. Prespecified comparisons were made among groups defined by type of health system, years of experience, reader volume, and study arm. Results The response rate was 26.3%. Respondents were most familiar with guidelines from Fleischner (94%) and Lung-RADS (71%). For both incidental and screening-detected nodules, self-reported adherence to preferred guidelines was very high (97% and 94%, respectively), and most respondents believed that the benefits of adherence outweigh the harms (81% and 74%, respectively). Underlying evidence was thought to be high in quality by 68% of respondents for screening-detected nodules and 41% for incidental nodules. Approximately 70% of respondents believed that the frequency of recommended follow-up was “just right” for both guidelines. Radiologists who practice in nonintegrated health care systems were more likely to believe that the evidence was high in quality (79.5% versus 57.1%) and that the benefits of adherence outweigh the harms (85.1% versus 67.5%). Low-volume readers had lower awareness and self-reported adherence than higher volume readers. Conclusions Radiologists reported high levels of familiarity and agreement with and adherence to guidelines for pulmonary nodule evaluation, but many overestimated the quality of evidence in support of the recommendations.

Background Screening current and former heavy smokers 55 to 80 years of age for lung cancer (LC) with low-dose chest CT scanning has been recommended by the United States Preventive Services Task Force since 2013. Although the number of screening facilities in the United States has increased, screening uptake has been slow. Research Question To what extent is geographic access to screening facilities a barrier for screening uptake nationally? Study Design and Methods Screening facilities were defined as American College of Radiology (ACR) Lung Cancer Screening Registry (LCSR) facilities. Analysis was performed at different geographic levels using a road network to calculate travel distances for the recommended age groups. Full access to screening was defined as the entire 55- to 79-year-old population being within 40 miles of an ACR LCSR facility. No access was defined as lack of access by the entire target population. Partial access was expressed in intervening quartiles. A geospatial approach then was used to integrate accessibility with smoking prevalence and LC mortality rates to identify potential focus areas visually. Results Screening facilities addresses were geocoded to identify 3,592 unique locations. Analysis of census tracts and aggregation to counties revealed that among 3,142 counties, adults 55 to 79 years of age have full access to an LC screening registry facility in 1,988 (63%) counties, partial access in 587 (19%) counties, and no access in 567 (18%) counties. Overall, less than 6% of those 55 to 79 years of age do not have access to registry screening facilities. Variation in screening facility access was noted across the United States, between states, and within some states. Interpretation It is recommended to calculate accessibility using subcounty geographies and to examine variation regionally and within states. A foundation geographic accessibility layer can be integrated with other variables to identify geographic disparities in access to screening and to focus on areas for interventions. Identifying areas of greatest need can inform state and local officials and healthcare organizations when planning and implementing LC screening programs.

The immunocompromised patient with an acute respiratory illness (ARI) may present with fever, chills, weight loss, cough, shortness of breath, or chest pain. The number of immunocompromised patients continues to rise with medical advances including solid organ and stem cell transplantation, chemotherapy, and immunomodulatory therapy, along with the continued presence of human immunodeficiency virus and acquired immunodeficiency syndrome. Given the myriad of pathogens that can infect immunocompromised individuals, identifying the specific organism or organisms causing the lung disease can be elusive. Moreover, immunocompromised patients often receive prophylactic or empiric antimicrobial therapy, further complicating diagnostic evaluation. Noninfectious causes for ARI should also be considered, including pulmonary edema, drug-induced lung disease, atelectasis, malignancy, radiation-induced lung disease, pulmonary hemorrhage, diffuse alveolar damage, organizing pneumonia, lung transplant rejection, and pulmonary thromboembolic disease. As many immunocompromised patients with ARI progress along a rapid and potentially fatal course, timely selection of appropriate imaging is of great importance in this setting. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking, or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Asthma is one of the most common diseases of the lung. Asthma manifests with common, although often subjective and nonspecific, imaging features at radiography and high-resolution computed tomography. The primary role of imaging is not to make a diagnosis of asthma but to identify complications, such as allergic bronchopulmonary aspergillosis, or mimics of asthma, such as hypersensitivity pneumonitis. This article reviews the imaging features of asthma as well as common complications and mimics.

Disparities in outcomes exist for breast, colon, and lung cancer among diverse populations, particularly racial and ethnic underrepresented minorities (URMs) and individuals from lower socioeconomic status. For example, blacks experience mortality rates up to about 42% higher than whites for these cancers. Furthermore, although overall death rates have been declining, the differential access to screening and care has aggravated disparities. Our purpose is to assess how the coverage policies of CMS and the United States Preventive Services Task Force (USPSTF) influence these disparities. Additionally, barriers are often encountered in accessing screening tests and receiving prompt treatment. To narrow, and potentially eliminate, outcomes disparities, CMS and USPSTF could consider revising their decision-making processes regarding coverage. Some options include (1) extending their evidence base to include observational studies that involve groups at higher risk; (2) lowering the threshold ages for screening to encompass differences in incidence; (3) CMS approving screening CT colonography coverage, which can even increase compliance with other screening tests; (4) clarifying and streamlining guidelines; (5) supporting research on improving access to screening; and (6) encouraging the development of more navigation services for URMs.

RationaleThe demographic, physiological, and computed tomography (CT) features associated with pneumothorax in smokers with and without chronic obstructive pulmonary disease (COPD) are not clearly defined.ObjectivesWe evaluated the hypothesis that pneumothorax in smokers is associated with male sex, tall and thin stature, airflow obstruction, and increased total and subpleural emphysema.MethodsThe study included smokers with and without COPD from the COPDGene Study, with quantitative chest CT analysis. Pleural-based emphysema was assessed on the basis of local histogram measures of emphysema. Pneumothorax history was defined by subject self-report.Measurements and main resultsPneumothorax was reported in 286 (3.2%) of 9,062 participants. In all participants, risk of prior pneumothorax was significantly higher in men (odds ratio [OR], 1.55; 95% confidence interval [CI], 1.08-2.22) and non-Hispanic white subjects (OR, 1.90; 95% CI, 1.34-2.69). Risk of prior pneumothorax was associated with increased percent CT emphysema in all participants and participants with COPD (OR, 1.04 for each 1% increase in emphysema; 95% CI, 1.03-1.06). Increased pleural-based emphysema was independently associated with risk of past pneumothorax in all participants (OR, 1.05 for each 1% increase; 95% CI, 1.01-1.10). In smokers with normal spirometry, risk of past pneumothorax was associated with non-Hispanic white race and lifetime smoking intensity (OR, 1.20 for every 10 pack-years; 95% CI, 1.09-1.33).ConclusionsAmong smokers, pneumothorax is associated with male sex, non-Hispanic white race, and increased percentage of total and subpleural CT emphysema. Pneumothorax was not independently associated with height or lung function, even in participants with COPD. Clinical trial registered with www.clinicaltrials.gov (NCT00608764).

Imaging is paramount in the setting of blunt trauma and is now the standard of care at any trauma center. Although anteroposterior radiography has inherent limitations, the ability to acquire a radiograph in the trauma bay with little interruption in clinical survey, monitoring, and treatment, as well as radiography's accepted role in screening for traumatic aortic injury, supports the routine use of chest radiography. Chest CT or CT angiography is the gold-standard routine imaging modality for detecting thoracic injuries caused by blunt trauma. There is disagreement on whether routine chest CT is necessary in all patients with histories of blunt trauma. Ultimately, the frequency and timing of CT chest imaging should be site specific and should depend on the local resources of the trauma center as well as patient status. Ultrasound may be beneficial in the detection of pneumothorax, hemothorax, and pericardial hemorrhage; transesophageal echocardiography is a first-line imaging tool in the setting of suspected cardiac injury. In the blunt trauma setting, MRI and nuclear medicine likely play no role in the acute setting, although these modalities may be helpful as problem-solving tools after initial assessment. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Daily routine chest radiographs in the intensive care unit (ICU) have been a tradition for many years. Anecdotal reports of misplacement of life support items, acute lung processes, and extra pulmonary air collections in a small number of patients served as a justification for routine chest radiographs in the ICU. Having analyzed this practice, the ACR Appropriateness Criteria Expert Panel on Thoracic Imaging has made the following recommendations: • When monitoring a stable patient or a patient on mechanical ventilation in the ICU, a portable chest radiograph is appropriate for clinical indications only. • It is appropriate to obtain a chest radiograph after placement of an endotracheal tube, central venous line, Swan-Ganz catheter, nasogastric tube, feeding tube, or chest tube. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. The strongest data contributing to these recommendations were derived from a meta-analysis of 8 trials comprising 7,078 ICU patients by Oba and Zaza [1].

Objective The literature supports a negative D-dimer (−DD) excluding venous thromboembolic disease (VTE) in low-risk patients. We determined the radiologic diagnoses in patients where imaging was ordered despite a −DD. Methods This is a retrospective chart review of patients with a −DD (Tinaquant; Roche Diagnostics, Mannheim, Germany) and a radiologic study within 48 hours, sought to determine radiologic diagnosis (primary outcome), treatment of VTE, and consensus diagnosis of acute VTE. Results Among 3462 DD tests, 1678 met the inclusion criteria. Of 1362 patients with DD values of 350 ng/mL or less, 166 (12.2%) had radiologic studies: 93.4% of the final radiologic diagnoses were negative for VTE, 3.6% were indeterminate, and 3.0% (1.0%-6.9%) were positive; 1.8% ultimately had a consensus diagnosis of acute VTE. In 316 patients with DD values between 351 and 500 ng/mL, 88 (27.8%) had radiologic studies: 95.5% were negative, 1.1% were indeterminate, and 3.4% (0.7%-9.6%) were positive. Conclusions Of patients who receive radiologic studies despite −DD tests, 3.0% have positive radiologic diagnoses for acute VTE; only 1.8% had acute VTE after the review of their hospital course.

Acute respiratory illness is defined as one or more of the following: cough, sputum production, chest pain, or dyspnea (with or without fever). The workup of these patients depends on many factors, including clinical presentation and the suspected etiology. This study reviews the literature on the indications and usefulness of radiologic studies for the evaluation of acute respiratory illness in the immunocompetent patient. The following recommendations are the result of evidence-based consensus by the American College of Radiology Appropriateness Criteria Expert Panel on Thoracic Radiology. Chest radiographs are usually appropriate in (1) patients with positive physical examination or risk factors for pneumonia, (2) for the assessment of complicated pneumonia, or (3) in cases of emerging infections and biological warfare agents such as severe acute respiratory syndrome, H1N1, and anthrax. Computed tomography, although having a more limited role, is usually appropriate (1) in the assessment of complicated pneumonia and (2) in patients with suspected severe acute respiratory syndrome, H1N1, or anthrax and a normal radiograph.

The American College of Radiology, with more than 30,000 members, is the principal organization of radiologists, radiation oncologists,and clinical medical physicists in the United States. The College is a nonprofit professional society whose primary purposes are to advance thescience of radiology, improve radiologic services to the patient, study the socioeconomic aspects of the practice of radiology, and encouragecontinuing education for radiologists, radiation oncologists, medical physicists, and persons practicing in allied professional fields.The American College of Radiology will periodically define new practice parameters and technical standards for radiologic practice to helpadvance the science of radiology and to improve the quality of service to patients throughout the United States. Existing practice parameters andtechnical standards will be reviewed for revision or renewal, as appropriate, on their fifth anniversary or sooner, if indicated.Each practice parameter and technical standard, representing a policy statement by the College, has undergone a thorough consensusprocess in which it has been subjected to extensive review and approval. The practice parameters and technical standards recognize that the safeand effective use of diagnostic and therapeutic radiology requires specific training, skills, and techniques, as described in each document.Reproduction or modification of the published practice parameter and technical standard by those entities not providing these services is notauthorized.?

To determine whether chest computed tomography (CT) can be used to exclude aortic injury.Patients in whom there was very high suspicion of traumatic aortic injury were examined with aortography only. Other patients were examined with contrast material-enhanced CT. Follow-up aortography was performed in all patients with moderate to high suspicion of traumatic aortic injury and in all patients with CT scans that were positive for traumatic aortic injury. CT scans were regarded as positive when they showed mediastinal hematoma or direct findings of aortic injury. During a 4 1/2-year period, 1,009 patients (263 female, 746 male; age range, 3-90 years) were evaluated for possible traumatic aortic injury.Of the 207 patients who underwent aortography directly without CT, 10 had traumatic aortic injury. Of the 802 patients who were examined with CT, 382 underwent follow-up aortography. In this group, there were 10 true-positive and no false-negative CT scans. CT had 100% sensitivity and a 100% negative predictive value for the detection of traumatic aortic injury.

Pulmonary hypertension (PH) may be idiopathic or related to a variety of diseases. The diagnosis, accurate assessment of etiology and severity, prognosis, treatment response, and follow-up of PH can be achieved using a diverse set of diagnostic examinations. In this review, the role of imaging in the evaluation of PH as suggested by the American College of Radiology Appropriateness Criteria® Expert Panel on Thoracic Imaging has been discussed. The American College of Radiology Appropriateness Criteria® are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The development and review of the guidelines include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

The solitary pulmonary nodule (SPN) is a common medical problem for which management can be quite complex. Imaging remains at the center of management of SPNs, and computed tomography is the primary modality by which SPNs are characterized and followed up for stability. This manuscript summarizes the American College of Radiology Appropriateness Criteria for radiographically detected solitary pulmonary nodules and briefly reviews the various imaging techniques available. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

The respiratory system is often affected by complications of immunodeficiency, typically manifesting clinically as acute respiratory illness. Ongoing literature reviews regarding the appropriateness of imaging in these patients are critical, as advanced medical therapies such as stem cell transplantation, chemotherapy, and immunosuppressive therapies for autoimmune disease continue to keep high the population of immunosuppressed patients in our health care system today. This ACR Appropriateness Criteria(®) topic describes clinical scenarios of acute respiratory illness in immunocompromised patients with cough, dyspnea, chest pain, and fever; in those with negative, equivocal, or nonspecific findings on chest radiography; in those with diffuse or confluent opacities on chest radiography; and in those in whom noninfectious disease is suspected. The use of chest radiography, chest CT, transthoracic needle biopsy, and nuclear medicine imaging are all discussed in the contexts of these clinical scenarios. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Screening for pulmonary metastatic disease is an important step for staging a patient with a known or recently discovered malignancy. Here we present our recommendations for screening for metastatic disease based on recommendations from the literature and experiences of pulmonary radiologists. In short, chest computed tomographic (CT) screening is the most appropriate tool for evaluation of pulmonary metastasis in the majority of cases. Chest computed tomographic screening is also recommended for follow-up and to determine response to therapy. Other modalities such as chest radiography, magnetic resonance imaging, and scintigraphy will also be discussed. Please note that this study is a summary of the complete version of this topic, which is available on the ACR website at www.acr.org. Practitioners are encouraged to refer to the complete version.

Background: Thoracic aortic injury (TAI) is a devastating condition in which prompt recognition can obviate morbidity and mortality. It is a long-held belief that TAI is more likely when there is a major mechanism of injury. The purposes of this prospective study were to determine mechanism characteristics that are predictive of TAI and to evaluate chest computed tomography (CT) as a screening tool for TAI. Methods: Over a 5 1/2year period, blunt chest trauma patients at two Level I trauma centers were evaluated for potential TAI. Patients were assigned mechanism and radiograph scores from 1 (low suspicion for TAI) to 5 (very high suspicion for TAI). Immediate aortography was obtained when suspicion for TAI was very high. The remaining patients were evaluated with contrast-enhanced chest CT. Confirmatory aortography was obtained on all positive chest CT scans and on all patients with mechanism scores of 4 or 5 even if the CT was negative. Mechanism and radiographic data were correlated with the results of aortic imaging. Results: Of the 1,561 patients evaluated for TAI, 30 aortic injuries were found. The assessment of mechanism was imperfect with a reliance on often incomplete and subjective data. The subjective mechanism score proved to be the most useful predictor of TAI. Radiographic scores were useful but insensitive for intimal injuries. Computed tomography was found to have 100% and 100% NPV for TAI. Conclusion: Considering the inherent difficulties in identifying patients at risk for TAI and the effectiveness of chest CT as a screening tool for aortic injury, we recommend liberal use of chest CT in blunt chest trauma. Guidelines for determining the need for aortic imaging are outlined.