Radiographic Imaging of Community-Acquired Pneumonia: A Case-Based Review.

The chest radiograph is the most common imaging examination performed in most radiology departments, and one of the more common indications for these studies is suspected infection. Radiologists must therefore be aware of less common radiographic patterns of pulmonary infection if they are to add value in the interpretation of chest radiographs for this indication. This review uses a case-based format to illustrate a range of imaging findings that can be associated with acute pulmonary infection and highlight findings that should prompt investigation for diseases other than community-acquired pneumonia to prevent misdiagnosis and delays in appropriate management.

Characterizing Lung-RADS category 4 lesions in a university lung cancer screening program.

OBJECTIVES: To assess the prevalence of lung cancer in Lung-RADS category 4 patients, and to elucidate if clinical or imaging features help differentiate benign lesions from lung cancer. MATERIALS/METHODS: A retrospective review of lung cancer screening (LCS) studies at a single university screening program between January 2018 and December 2021 identified all patients with Lung-RADS category 4 lesions. Patient demographics, symptoms within the prior 6 months, and imaging features were recorded. RESULTS: During the defined period, 4819 baseline and annual LCS exams were performed; 7.6 % (n = 368) of exams had category 4 nodules and 59 (1.2 %) patients had biopsy-proven lung cancer. Distribution of Lung-RADS category 4 lesions and lung cancer diagnosis were as follows: 4A - 223 nodules, 6.3 % malignant; 4B - 114 nodules, 20.2 % malignant; and 4X - 31 nodules, 71.0 % malignant. Symptoms were reported in 9.0 % (n = 20) of category 4A (2 were malignant), 15.8 % (n = 18) category 4B (1 was malignant) and 22.6 % (n = 7) category 4X (5 were malignant). Imaging features associated with malignancy included endobronchial obstruction with distal atelectasis, pleural tethering, irregular shape, cavitation, and heterogeneous cystic appearance. Twenty-four nodules increased in size, however, only 7 were biopsy proven. Relative to the risk seen with 4A disease, multivariable logistic analyses showed that the odds of a malignancy increased significantly by 3.8 fold (95 % CI: 1.9, 7.9) and 39.2 fold (95 % CI: 14.9, 103.0) with 4B and 4X disease, respectively (p < 0.0001). A separate analysis involving only category 4A and 4B patients jointly showed that disease category (OR = 3.0; 95 % CI: 1.5, 6.4) and additional imaging features (OR = 3.2; 95 % CI: 1.4, 7.0) were significant predictors of malignancy. The presence of clinical symptoms was not statistically associated with lung cancer. CONCLUSIONS: Lung-RADS 4 nodules were found in 7.6% of LCS examinations and 16% of these nodules were lung cancer. The probability of lung cancer increases from category 4A to 4X, and imaging features may help differentiate benign from malignant nodules in this LCS category.

ACR Appropriateness Criteria® Routine Chest Imaging.

Routine chest imaging has been used to identify unknown or subclinical cardiothoracic abnormalities in the absence of symptoms. Various imaging modalities have been suggested for routine chest imaging. We review the evidence for or against the use of routine chest imaging in different clinical scenarios. This document aims to determine guidelines for the use of routine chest imaging as initial imaging for hospital admission, initial imaging prior to noncardiothoracic surgery, and surveillance imaging for chronic cardiopulmonary disease. 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 process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Radiographic Imaging of Community-Acquired Pneumonia: A Case-Based Review.

The chest radiograph is the most common imaging examination performed in most radiology departments, and one of the more common indications for these studies is suspected infection. Radiologists must therefore be aware of less common radiographic patterns of pulmonary infection if they are to add value in the interpretation of chest radiographs for this indication. This review uses a case-based format to illustrate a range of imaging findings that can be associated with acute pulmonary infection and highlight findings that should prompt investigation for diseases other than community-acquired pneumonia to prevent misdiagnosis and delays in appropriate management.

ACR Appropriateness Criteria® Diffuse Lung Disease.

Diffuse lung disease, frequently referred to as interstitial lung disease, encompasses numerous disorders affecting the lung parenchyma. The potential etiologies of diffuse lung disease are broad with several hundred established clinical syndromes and pathologies currently identified. Imaging plays a critical role in diagnosis and follow-up of many of these diseases, although multidisciplinary discussion is the current standard for diagnosis of several DLDs. This document aims to establish guidelines for evaluation of diffuse lung diseases for 1) initial imaging of suspected diffuse lung disease, 2) initial imaging of suspected acute exacerbation or acute deterioration in cases of confirmed diffuse lung disease, and 3) clinically indicated routine follow-up of confirmed diffuse lung disease without acute deterioration. 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.

ACR Appropriateness Criteria® Nontraumatic Chest Wall Pain.

Chest pain is a common reason that patients may present for evaluation in both ambulatory and emergency department settings, and is often of musculoskeletal origin in the former. Chest wall syndrome collectively describes the various entities that can contribute to chest wall pain of musculoskeletal origin and may affect any chest wall structure. Various imaging modalities may be employed for the diagnosis of nontraumatic chest wall conditions, each with variable utility depending on the clinical scenario. We review the evidence for or against use of various imaging modalities for the diagnosis of nontraumatic chest wall pain. 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.

Lung-RADS Version 1.1: Challenges and a Look Ahead, From the AJR Special Series on Radiology Reporting and Data Systems.

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.

Geographic Access to CT for Lung Cancer Screening: A Census Tract-Level Analysis of Cigarette Smoking in the United States and Driving Distance to a CT Facility.

PURPOSE: Spatial access to health care resources is a requisite for utilization. Our purpose was to determine, at a census tract level, the geographic distribution of US smokers and their driving distance to an ACR-accredited CT facility. METHODS: The number of smokers per US census tract was determined from US Census Bureau data (American Community Survey, 2011-2015) and census tract smoking prevalence estimates. Driving distance, from the centroid of each census tract to the nearest CT facility, was determined using a geographic information system. Distance variations were assessed, and relationships with tract population density were examined with regression models. RESULTS: Most US smokers (81.8%) were within 15 miles of a CT facility; however, there was considerable inter- and intrastate variability. For census tracts containing ≥500 smokers, median distance to a CT was 4.3 miles. At the state level, median distance ranged from 1.4 (Washington DC) to 29.1 miles (Wyoming). Within each state, this variation was higher, with Washington, DC, exhibiting the lowest range (range, 4.3; 0.2-4.5 miles) and Maine exhibiting the highest range (range, 244.8; 0.2-245.0 miles). Distance to a CT facility was inversely associated with census tract population density. CONCLUSIONS: Geographic variability in CT facility access has implications for lung cancer screening (LCS) implementation. Individuals in densely populated areas have relatively greater spatial access to CT facilities than those in sparsely populated tracts. Further work is needed to identify access disparities to LCS to optimize LCS for all eligible populations.

Multidisciplinary Management of Oligometastatic Soft Tissue Sarcoma.

Soft tissue sarcomas (STS) encompass a group of rare but heterogeneous diseases. Nevertheless, many patients, particularly those with oligometastatic disease can benefit from thoughtful multimodality evaluation and treatment regardless of the STS subtype. Here, we review surgical, interventional radiology, radiation, and chemotherapy approaches to maximize disease palliation and improve survival, including occasionally long-term disease-free survival. Surgical resection can include lung or other visceral, soft tissue and bone metastases with a goal of rendering the patient disease free. Staged resections can be appropriate, and serial resection of oligometastatic recurrent disease can be appropriate. Retrospective series suggest survival benefit from this approach, although selection bias may contribute. Interventional radiology techniques such as percutaneous thermal ablation (PTA) and arterial embolization can present nonoperative local approaches in patients who are not medically fit for surgery, surgery is too morbid, or patients who decline surgery. Similarly, radiation therapy can be delivered safely to areas that are inaccessible surgically or would result in excessive morbidity. Currently no randomized trials exist comparing interventional radiologic approaches or radiation therapy to surgery but retrospective reviews show relatively similar magnitude of benefit in terms of disease palliation and survival, although it is felt unlikely that these procedures will render a patient to long-term disease-free status. Chemotherapy has evolved recently with the addition of several new treatment options, briefly reviewed here. Importantly, if a patient sustains a good response to chemotherapy resulting in true oligometastatic disease, consideration of multimodality local therapy approaches can be considered in the appropriate patient.

Surgical Outcomes After Neoadjuvant Chemotherapy and Ipilimumab for Non-Small Cell Lung Cancer.

BACKGROUND: The objective of this study was to evaluate the safety and feasibility of using neoadjuvant chemotherapy plus ipilimumab followed by surgery as a treatment strategy for stage II-IIIA non-small cell lung cancer. METHODS: From 2013 to 2017, postoperative data from patients who underwent surgery after neoadjuvant chemotherapy plus ipilimumab in the TOP1201 trial, an open label phase II trial (NCT01820754), were prospectively collected. The surgical outcomes from TOP1201 were compared with outcomes in a historical cohort of patients receiving standard preoperative chemotherapy followed by surgery identified from our institution's prospectively collected thoracic surgery database. RESULTS: In the TOP1201 trial, 13 patients were treated with preoperative chemotherapy and ipilimumab followed by surgery. In the historical cohort, 42 patients received preoperative chemotherapy by a platinum doublet regimen preoperative chemotherapy by a platinum doublet regimen without ipilimumab followed by lobectomy or pneumonectomy. The 30-day mortality in both groups was 0%. The most frequently occurring perioperative complications in the TOP1201 group were prolonged air leak (n = 2, 15%) and urinary tract infection (n = 2, 15%). The most common perioperative complication in the preoperative chemotherapy alone group was atrial fibrillation (n = 6, 14%). One patient (8%) had atrial fibrillation in the TOP1201 group. There was no apparent increased occurrence of adverse surgical outcomes for patients in the TOP1201 group compared with patients receiving standard of care neoadjuvant chemotherapy alone before surgery for stage II-IIIA non-small cell lung cancer. CONCLUSIONS: This report is the first to demonstrate the safety and feasibility of surgical resection after treatment with ipilimumab and chemotherapy in stage II-IIIA non-small-cell lung cancer.

Immune Activation in Early-Stage Non-Small Cell Lung Cancer Patients Receiving Neoadjuvant Chemotherapy Plus Ipilimumab.

Purpose: To determine the immunologic effects of neoadjuvant chemotherapy plus ipilimumab in early-stage non-small cell lung cancer (NSCLC) patients.Experimental Design: This is a single-arm chemotherapy plus phased ipilimumab phase II study of 24 treatment-naïve patients with stage IB-IIIA NSCLC. Patients received neoadjuvant therapy consisting of 3 cycles of paclitaxel with either cisplatin or carboplatin and ipilimumab included in the last 2 cycles.Results: Chemotherapy alone had little effect on immune parameters in PBMCs. Profound CD28-dependent activation of both CD4 and CD8 cells was observed following ipilimumab. Significant increases in the frequencies of CD4+ cells expressing activation markers ICOS, HLA-DR, CTLA-4, and PD-1 were apparent. Likewise, increased frequencies of CD8+ cells expressing the same activation markers, with the exception of PD-1, were observed. We also examined 7 resected tumors and found higher frequencies of activated tumor-infiltrating lymphocytes than those observed in PBMCs. Surprisingly, we found 4 cases of preexisting tumor-associated antigens (TAA) responses against survivin, PRAME, or MAGE-A3 present in PBMC at baseline, but neither increased frequencies nor the appearance of newly detectable responses following ipilimumab therapy. Ipilimumab had little effect on the frequencies of circulating regulatory T cells and MDSCs.Conclusions: This study did not meet the primary endpoint of detecting an increase in blood-based TAA T-cell responses after ipilimumab. Collectively, these results highlight the immune activating properties of ipilimumab in early-stage NSCLC. The immune profiling data for ipilimumab alone can contribute to the interpretation of immunologic data from combined immune checkpoint blockade immunotherapies. Clin Cancer Res; 23(24); 7474-82. ©2017 AACR.

Maximum-Intensity-Projection and Computer-Aided-Detection Algorithms as Stand-Alone Reader Devices in Lung Cancer Screening Using Different Dose Levels and Reconstruction Kernels.

OBJECTIVE: The objective of our study was to evaluate lung nodule detection rates on standard and microdose chest CT with two different computer-aided detection systems (SyngoCT-CAD, VA 20, Siemens Healthcare [CAD1]; Lung CAD, IntelliSpace Portal DX Server, Philips Healthcare [CAD2]) as well as maximum-intensity-projection (MIP) images. We also assessed the impact of different reconstruction kernels. MATERIALS AND METHODS: Standard and microdose CT using three reconstruction kernels (i30, i50, i70) was performed with an anthropomorphic chest phantom. We placed 133 ground-glass and 133 solid nodules (diameters of 5 mm, 8 mm, 10 mm, and 12 mm) in 55 phantoms. Four blinded readers evaluated the MIP images; one recorded the results of CAD1 and CAD2. Sensitivities for CAD and MIP nodule detection on standard dose and microdose CT were calculated for each reconstruction kernel. RESULTS: Dose for microdose CT was significantly less than that for standard-dose CT (0.1323 mSv vs 1.65 mSv; p < 0.0001). CAD1 delivered superior results compared with CAD2 for standard-dose and microdose CT (p < 0.0001). At microdose level, the best stand-alone sensitivity (97.6%) was comparable with CAD1 sensitivity (96.0%; p = 0.36; both with i30 reconstruction kernel). Pooled sensitivities for all nodules, doses, and reconstruction kernels on CAD1 ranged from 88.9% to 97.3% versus 49.6% to 73.9% for CAD2. The best sensitivity was achieved with standard-dose CT, i50 kernel, and CAD1 (97.3%) versus 96% with microdose CT, i30 or i50 kernel, and CAD1. MIP images and CAD1 had similar performance at both dose levels (p = 0.1313 and p = 0.48). CONCLUSION: Submillisievert CT is feasible for detecting solid and ground-glass nodules that require soft-tissue kernels for MIP and CAD systems to achieve acceptable sensitivities. MIP reconstructions remain a valuable adjunct to the interpretation of chest CT for increasing sensitivity and have the advantage of significantly lower false-positive rates.

What's New in 10 Years? A Revised Cardiothoracic Curriculum for Diagnostic Radiology Residency with Goals and Objectives Related to General Competencies.

This is a cardiothoracic curriculum document for radiology residents meant to serve not only as a study guide for radiology residents but also as a teaching and curriculum reference for radiology educators and radiology residency program directors. This document represents a revision of a cardiothoracic radiology resident curriculum that was published 10 years ago in Academic Radiology. The sections that have been significantly revised, expanded, or added are (1) lung cancer screening, (2) lung cancer genomic profiling, (3) lung adenocarcinoma revised nomenclature, (4) lung biopsy technique, (5) nonvascular thoracic magnetic resonance, (6) updates to the idiopathic interstitial pneumonias, (7) cardiac computed tomography updates, (8) cardiac magnetic resonance updates, and (9) new and emerging techniques in cardiothoracic imaging. This curriculum was written and endorsed by the Education Committee of the Society of Thoracic Radiology. This curriculum operates in conjunction with the Accreditation Council for Graduate Medical Education (ACGME) milestones project that serves as a framework for semiannual evaluation of resident physicians as they progress through their training in an ACGME-accredited residency or fellowship programs. This cardiothoracic curriculum document is meant to serve not only as a more detailed guide for radiology trainees, educators, and program directors but also complementary to and guided by the ACGME milestones.

Adaptive planning using positron emission tomography for locally advanced lung cancer: A feasibility study.

PURPOSE: To evaluate the feasibility of adaptive planning using positron emission tomography-computed tomography (PET-CT) in locally advanced non-small cell lung cancer. METHODS AND MATERIALS: Patients with locally advanced non-small cell lung cancer receiving definitive radiation therapy (RT) were eligible. Initial planning PET-CT was performed and a conventional RT plan (2 Gy/fraction to 60 Gy) was designed. A second planning PET-CT was obtained at ~50 Gy. Dose escalation to ~70 Gy for residual fludeoxyglucose-avid disease was pursued at the discretion of the treating oncologists. The primary endpoint was feasibility of adaptive planning using interim PET-CT. Normal tissue dose-volume parameters were calculated for both adaptive and simulated nonadaptive plans. RESULTS: From 2012 to 2014, 33 eligible patients were enrolled and underwent planning PET-CT, 3 of which were found to have new distant metastases. Of 30 patients who initiated RT, interim PET-CT was obtained in 29. This showed complete response in 2 patients, partial response/stable disease in 24, and new distant metastases in 3. Selective dose escalation was performed in 17 patients. For those receiving a boost, the median gross tumor volumes pre-RT and at ~50 Gy were 78 mL and 29 mL, respectively (P = .01). Reasons for no dose escalation were normal tissue constraints (n = 3), poorly defined residual disease (n = 2), acute toxicity (n = 1), and refusal of further therapy (n = 1). Adaptive planning compared with a simulated nonadaptive approach allowed for significant dose reductions to the lungs, heart, and esophagus (all P < .01). CONCLUSIONS: Adaptive planning using PET-CT was feasible and allows for significant dose reductions to normal tissues compared with traditional planning techniques.

Low-dose computed tomographic screening for lung cancer.

Low-dose computed tomographic (LDCT) screening is now moving from clinical trials to clinical practice, following the report from the National Lung Screening Trial that LDCT screening for lung cancer can reduce the number of deaths from lung cancer by 20% in current and former smokers, ages 55 to 74 years, with a 30 pack-year smoking history. This article reviews the current evidence for screening, key elements of a successful lung cancer screening clinic, and reporting and management guidelines for LDCT screening findings.

Imaging of complications of thoracic and cardiovascular surgery.

Iatrogenic complications of thoracic and cardiovascular surgery are relatively uncommon, but contribute to potentially significant patient morbidity and mortality. The incidence of iatrogenic disease reflects the complexity of surgical procedures, including lung resection, esophagectomy, coronary artery bypass grafting, thoracic aorta repair, and cardiac valve replacement. Some iatrogenic complications are minor and common to all procedures, whereas others can be potentially devastating and are associated with precise technical components of specific surgeries. Multimodality imaging plays an important role in the diagnosis and management of operative thoracic and cardiovascular iatrogenic disease.

Assessment of vascular contrast and wall motion of the aortic root and ascending aorta on MDCT angiography: dual-source high-pitch vs non-gated single-source acquisition schemes.

OBJECTIVES: This retrospective study assessed whether dual-source high-pitch computed tomographic angiography (CTA) offered advantages over single-source standard-pitch techniques in the evaluation of the ascending aorta. METHODS: Twenty patients who received both thoracic dual-source high-pitch and single-source standard-pitch CTAs within 1 year were assessed. Dual-source CTAs were performed; standard-pitch imaging used dose-modulated 120 kVp/150 mAs and 0.8 pitch compared with high-pitch protocols employing dose-modulated 120 kVp/250 mAs and 2.4 target pitch. Radiation dose was documented. Contrast-to-noise ratios (CNRs) at sinuses of the Valsalva (CNRValsalva) and ascending aorta (CNRAorta) were calculated. Dose/CNR for each technique was compared with paired t-tests. Motion at aortic valve, aortic root and ascending aorta were assessed with four-point scales and Mann-Whitney U tests; longitudinal extension of motion was compared with paired t-tests. RESULTS: Significantly lower motion scores for high-pitch, compared with standard-pitch acquisitions for aortic annulus, 0 vs. 2, aortic root, 0 vs. 3, and ascending aorta, 0 vs. 2, were achieved. Significantly reduced longitudinal extension of motion at aortic root, 4.9 mm vs 15.7 mm, and ascending aorta, 4.9 mm vs 21.6 mm, was observed. Contrast was not impacted: CNRValsalva, 45.6 vs 46.3, and CNRAorta, 45.3 vs 47.1. CTDIvol was significantly decreased for high-pitch acquisitions, 13.9 mGy vs 15.8 mGy. CONCLUSIONS: Dual-source high-pitch CTAs significantly decreased motion artefact without negatively impacting vascular contrast and radiation dose. KEY POINTS: • Dual-source high-pitch CTA significantly decreased motion artefact of the ascending aorta. • Dual-source high-pitch CTA did not negatively impact on vascular contrast. • Dual-source high-pitch CTA significantly decreased radiation dose compared with single-source standard-pitch acquisitions.