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.


Introduction
Beginning in November 2022, an Expert Panel (EP) comprised of radiologists, respirologists, emergency and family physicians, a patient advisor, and an epidemiologist/guideline methodologist met to develop a new set of recommendations specific to referral pathways for conditions related to the thorax, including asymptomatic individuals, symptomatic patients, and other scenarios requiring imaging of the thorax.Through discussion (via a virtual meeting) followed by offline communication, the EP developed a list of 24 clinical/diagnostic scenarios to be covered by this guideline.These recommendations are intended primarily for referring clinicians (eg, family physicians, specialty physicians, nurse practitioners); however, they may also be used by radiologists, individuals/ patients, and patient representatives.
Our methods describing the guideline development process, including the rapid scoping review to identify the evidence base, has been published in CMAJ Open 1 and an editorial to this series of guideline publications is available in CARJ. 2 The application of well-established scoping review and rapid review guidance (JBI, 3 Cochrane Handbook, 4 Cochrane Rapid Review Methods Group 5 ) and guideline methodology (ie, Grading of Recommendations Assessment, Development, and Evaluation or GRADE 6,7 ) were used to identify the evidencebase and to guide the Expert Panel in determining the strength and direction of the recommendations for each clinical scenario (Table 1).The quality of conduct and reporting of the included guidelines identified in the scoping review were evaluated with the AGREE-II checklist, 8 using a modified scoring system.In instances where guidelines were lacking, expert consensus was used to develop the recommendation.Contextualization to the Canadian health care system was considered for each recommendation, with discussion around the factors found in the Evidence to Decision framework in GRADE for guidelines (eg, balance of desirable and undesirable outcomes, values and preferences, resources implications). 7 systematic search for guidelines (with an a priori defined inclusion criteria) was run in Medline and Embase on January 5, 2023.The search was limited to publications from 2017 onward (Supplemental Appendix 1).Supplemental searching included the following national radiology and/or guideline groups: the American College of Radiology, the National Institute for Health and Care Excellence, and the Royal " we recommend" ( ) ( ) ■ All or almost all informed people would not recommend/ choose the course of action and only a small proportion would.
■ All or almost all informed people would recommend/ choose the course of action and only a small proportion would not.■ Request discussion if the intervention is not offered.CONDITIONAL Conditional, against Conditional, for "we suggest against" " we suggest" ( ) ( ) ■ Most informed people would not recommend/choose the course of action, but a substantial number would.
■ Most informed people would recommend/choose the course of action, but a substantial number would not.■ This may be conditional upon patient values and preferences, the resources available or the setting in which the intervention will be implemented.
■ This may be conditional upon patient values and preferences, the resources available or the setting in which the intervention will be implemented.
Note: Down arrows are red and Up arrows are green when available in colour.Created using the guidance provided in Andrews and colleagues. 6ollege of Radiologists 8th Edition (2017).Recommendations for each clinical scenario were formulated over 2 virtual meetings in April 2023.External review and feedback were obtained from radiologists, emergency and family physicians, and a nurse practitioner.The full guideline can be found on the CAR website (www.car.ca).

Systematic Scoping Review
A total of 8479 records were identified through the electronic database and 7 additional records were added from the supplemental search.Thirty guidelines, plus 2 companion papers, were included (Figure 1).Potentially relevant guidelines published in languages other than English can be found in Supplemental Appendix 2. A list of excluded records with justifications for exclusion is available upon request.Most guidelines were rated as moderate or high quality, using the modified AGREE-II checklist 8 (Supplemental Appendix 3).
The number of guidelines included per clinical/diagnostic scenario ranged from 0 to 10, with a median of 3 guidelines per clinical scenario.

Recommendations Additional details of the included guidelines, including which imaging modalities (eg, computed tomography [CT], magnetic resonance imaging [MRI], radiograph [XR], ultrasound [US]
) that were discussed can be found in Supplemental Appendix 4.
A guideline is intended to guide and not be an absolute rule.Medical care is complex and should be based on evidence, a clinician's expert judgment, the patient's circumstances, values, preferences, and resource availability.Not all imaging modalities are available in all clinical environments, particularly in rural or remote areas of Canada.Decisions about patient transfer, use of alternative imaging or serial clinical examination and observation can be complex and difficult.Therefore, the expected benefits of recommended imaging, risks of travel, patient preference, and other factors must be considered.The guideline recommendations are  designed to assist the choice of imaging modality in situations where it is deemed clinically necessary to obtain imaging.
Recommendations do not specify when contrast should or should not be used, as this may vary based on clinical presentation, regional practice preferences, preference of the referring clinician, radiologist and/or the patient, and resource availability.
We reviewed relevant recommendations related to the 24 clinical/diagnostic scenarios previously published by radiology and specialty societies, including: the Canadian Association of Radiologists, 9 the American College of Radiology, [10][11][12][13][14][15][16][17][18][19] the American Thoracic Society and Infectious Diseases Society of America, 20 the CHEST Expert Panel, [21][22][23] the Emergency Medicine Association of Turkey/Turkish Thoracic Society, 24 the European Respiratory Society, 25 the Fleischner Society, 26,27 the French Language Pulmonology Society, 28 the German S3 guideline, 29 the Indian Chest Society National College of Chest Physicians, 30 the Indian Society of Anesthaesiologists, 31 the Italian intersociety consensus, 32,33 the Korean guideline, 34 the National Institute for Health and Clinical Excellence, 35 the Polish recommendations for lung ultrasound in internal medicine, 36 the S2K guideline, 37 the combined guideline by the Société Française de Médecine d'Urgence, the Société de Réanimation de Langue Française and the French Group for Pediatric Intensive Care and Emergencies, 38 the Spanish Society of Medical Oncology, 39 and the Royal College of Radiologists. 40ecommendations are presented in 3 tables: Non-specific chest pain, long-term care, and hospital-based scenarios (Table 2), Upper respiratory tract infections, asthma, chronic obstructive pulmonary disease (COPD), pneumonia, and chronic cough scenarios (Table 3), Pneumothorax, pleural effusion, hemoptysis, chronic dyspnea, interstitial lung disease, lung nodule, mediastinal lesion, mediastinal lymphadenopathy, and elevated diaphragm scenarios (Table 4).