ACR Appropriateness Criteria® Diffuse Lung Disease

Lung MRI: Indications, Capabilities, and Techniques-AJR Expert Panel Narrative Review

Lung MRI provides both structural and functional information across a spectrum of parenchymal and airway pathologies. MRI, using current widely available conventional sequences, provides high-quality diagnostic images that allow tissue characterization and delineation of lung lesions; dynamic evaluation of expiratory central airway collapse, diaphragmatic or chest wall motion, and the relations of lung masses to the chest wall; oncologic staging; surveillance of chronic lung pathologies; and differentiation of inflammation and fibrosis in interstitial lung disease. Ongoing technologic advances, including deep-learning acceleration methods, may enable future applications in longitudinal lung cancer screening without ionizing radiation exposure and in the regional quantification of ventilation and perfusion without hyperpolarized gas or IV contrast media. Although society statements highlight appropriate indications for lung MRI, and the modality has performed favorably relative to CT or FDG PET/CT in various indications, the examination's clinical utilization remains extremely low. Ongoing barriers to adoption include limited awareness by referring physicians, as well as insufficient proficiency and experience by radiologists and technologists. In this AJR Expert Panel Narrative Review, we review clinical indications for lung MRI, describe the examination's current capabilities, provide guidance on protocols comprised of widely available pulse sequences, introduce emerging techniques, and issue consensus recommendations.

Expert Panel on Thoracic Imaging, Christensen JD, Harowicz M, Walker CM, Little BP, Batra K, Brixey AG, Carroll MB, Chelala L, Cox CW, Drummond MB, Geissen NM, Halpern J, Madan R, Gopalakrishnan VP, Shroff GS, Thornton CS, Zreloff J, Chung JH. ACR Appropriateness Criteria® Chronic Dyspnea-Noncardiovascular Origin: 2024 Update

For patients with chronic dyspnea of noncardiovascular origin, chest radiography is usually appropriate as the first-line imaging modality. Chest CT without contrast is either usually appropriate or may be appropriate as a second-line option for conditions of unclear etiology or suspected chronic obstructive pulmonary disease, small airways disease, and post-COVID-19 complications. Chest CT with contrast may have a role in patients with pleura/chest wall disease or diaphragm dysfunction. Although MRI, fluoroscopy, and FDG-PET/CT have limited roles, special imaging techniques such as inspiratory/expiratory CT and hyperpolarized xenon gas MRI are noted for their specific uses. This document aims to help clinicians choose the most suitable imaging tests, enhancing diagnostic accuracy and patient care. 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.

Progressive Pulmonary Fibrosis and Interstitial Lung Abnormalities: AJR Expert Panel Narrative Review

Progressive pulmonary fibrosis (PPF) and interstitial lung abnormalities (ILA) are relatively new concepts in interstitial lung disease (ILD) imaging and clinical management. Recognition of signs of PPF and identification and classification of ILA are important tasks during chest high-resolution CT interpretation to optimize management of patients with ILD and those at risk of developing ILD. However, in professional society guidance, the role of imaging surveillance remains unclear for stable patients with ILD, asymptomatic patients with ILA who are at risk of progression, and asymptomatic patients at risk of developing ILD without imaging abnormalities. In this AJR Expert Panel Narrative Review, we summarize the current knowledge regarding PPF and ILA and describe the range of clinical practice with respect to imaging patients with ILD, those with ILA, and those at risk of developing ILD. In addition, we offer suggestions to help guide surveillance imaging in areas with an absence of published guidelines, where such decisions are currently driven primarily by local pulmonologists' preference.

Direct comparison of photon counting-CT and conventional CT in image quality of lung nodules: A systematic review and meta-analysis

PURPOSE

To evaluate and compare lung nodules' image quality and radiation dose exposure using photon-counting computed tomography (PC-CT) and conventional energy-integrating detector computed tomography (EID-CT).

METHODS

Protocol pre-registration was performed a priori at (https://osf.io/krj5y/). We searched PubMed, Web of Science, Embase, and Cochrane Library for studies until April 10, 2024. Risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) and QUADAS-C. The imaging modalities were compared with Likert scores of lung nodules and radiation dose exposure (measured in mGy and mS). Certainty of evidence was evaluated using Grading of Recommendations, Assessment, Development, and Evaluations (GRADE).

RESULTS

Thirteen studies were included with 718 patients and 362 lung nodules. PC-CT had a significantly higher image quality score of + 0.45 (CI = 0.12 to 0.79) than the EID-CT. Furthermore, 54.0 % (CI = 21.2 % to 86.8 %) of nodules were qualitatively identified as having better image quality in PC-CT than in EID-CT, while 1.9 % (CI = 0 % to 4.9 %) had lower image quality. In terms of radiation dose exposure, PC-CT showed a 30.4 % (CI = 19.1 % to 41.7 %) reduction in radiation dose exposure compared to EID-CT.

CONCLUSION

The as low as reasonably achievable (ALARA) principle emphasizes minimizing ionizing radiation exposure whenever possible. PC-CT has become an up-and-coming imaging method for chest, providing enhanced spatial resolution and less radiation exposure. Integrating PC-CT into daily medical practice and lung cancer screening may enhance the visibility of lung nodules and improve diagnostic accuracy.

Computed Tomography of Contemporary Occupational Lung Disease: A Pictorial Review

Occupational lung disease remains one of the most common work-related illnesses and accounts for most deaths from occupational illness. Occupational lung diseases often have delayed manifestation over decades and nonspecific clinical presentations, making it challenging for clinicians to promptly identify the disease and implement preventive measures. Radiologists play a crucial role in identifying and diagnosing occupational lung diseases, allowing for removal of the exposure and early medical intervention. In this review, we share our clinical and radiologic approach to diagnosing occupational lung disease and its subtypes. A collection of sample cases of occupational lung diseases commonly encountered in the modern era at a large Canadian university hospital is included to facilitate understanding. This review will provide radiologists with valuable insights into recognizing and diagnosing occupational lung diseases.

Canadian Association of Radiologists Thoracic Imaging Referral Guideline

The Canadian Association of Radiologists (CAR) Thoracic Expert Panel consists of radiologists, respirologists, emergency and family physicians, a patient advisor, and an epidemiologist/guideline methodologist. After developing a list of 24 clinical/diagnostic scenarios, a rapid scoping review was undertaken to identify systematically produced referral guidelines that provide recommendations for one or more of these clinical/diagnostic scenarios. Recommendations from 30 guidelines and contextualization criteria in the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) for guidelines framework were used to develop 48 recommendation statements across the 24 scenarios. This guideline presents the methods of development and the referral recommendations for screening/asymptomatic individuals, non-specific chest pain, hospital admission for non-thoracic conditions, long-term care admission, routine pre-operative imaging, post-interventional chest procedure, upper respiratory tract infection, acute exacerbation of asthma, acute exacerbation of chronic obstructive pulmonary disease, suspect pneumonia, pneumonia follow-up, immunosuppressed patient with respiratory symptoms/febrile neutropenia, chronic cough, suspected pneumothorax (non-traumatic), clinically suspected pleural effusion, hemoptysis, chronic dyspnea of non-cardiovascular origin, suspected interstitial lung disease, incidental lung nodule, suspected mediastinal lesion, suspected mediastinal lymphadenopathy, and elevated diaphragm on chest radiograph.

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.