Canadian Radiology Update

Early Detection of Lung Cancer

Lung cancer screening will reduce lung cancer mortality globally. Recognizing that benefits are maximized when screening is implemented safely, Dalhousie radiologists have been instrumental in the Canadian Society of Thoracic Radiology/Canadian Association of Radiologists practice guideline for lung cancer screening, which provides guidance specific to Canada’s publicly funded health care system. ² However, even where screening is well established, the most common path to early lung cancer detection and curative-intent treatment will continue to be through the detection of lung nodules found on imaging obtained for another reason. Dalhousie’s thoracic imaging section has pioneered 2 initiatives to help ensure quality care for patients with incidental nodules: obtaining quick point-of-care lung-cancer risk assessments for every patient presenting for thoracic CT; and embedding surveillance imaging appointments in CT reports for patients with actionable incidental nodules. ³ Dalhousie also leads a national multidisciplinary working group providing concrete incidental nodule recommendations to ensure the opportunity to identify early treatable lung cancer is not lost, that patients receive accurate information delivered sensitively, and that resources are used appropriately and safely. ⁴

Advancing Imaging Protocols

As the home of the Biomedical Translational Imaging Centre (BIOTIC), Dalhousie brings together radiologists, physicists, and other scientists to push the boundaries of imaging excellence, including perfecting imaging protocols, advancing complex imaging of the brain, and exploring the frontiers of artificial intelligence. The collaborative nature of the centre allows radiologists and scientists (and often health care industry partners) to produce work with deep scientific roots grounded in clinical practicality. Recently, the team developed 0.5 T MRI protocols that lower capital and operational costs to the healthcare system without sacrificing diagnostic ability. ⁵ BIOTIC’s quality metrics research has had lasting impact on how the radiology community assesses MR imaging quality. ⁶ Other imaging innovation research at Dalhousie has led to improvements in image quality, patient safety and resource use, including for pediatric neuroblastoma, ⁷ urothelial carcinomas, ⁸ and chronic liver disease. ⁹

Quality Audits as a Driver of Health Care Excellence

Although innovation impacts the care of tomorrow, often the best way to improve health outcomes today is to ensure patients receive guideline-concordant care. Unless radiology departments regularly assess standards, we may be unaware of lapses. Quality audits identify opportunities to improve disease detection, resource use, and patient safety. Dalhousie’s commitment to quality has resulted in discovery that results in immediate clinical impact. For example, a study monitoring CT radiation found that many protocols, including those labelled “low dose” were unknowingly exposing patients to higher than recommended levels of radiation. ¹⁰ A study assessing abdominal aortic aneurysm screening found that many patients received imaging inappropriately, including because a recent CT rendered sonographic screening unnecessary. ¹¹ Dalhousie’s imaging department has also shown that quality audits allow those in early career to learn essential investigator skills and to become more comfortable with clinical research. ¹²

Sports Medicine

The Olympic and Paralympic games provide a unique opportunity to conduct sports medicine research on a truly global cohort of elite athletes. Researchers at UBC were part of a team that investigated the relationship between symptoms, imaging findings of bone stress injuries, and competition withdrawal rate at the Olympics. They found that 75% of the athletes with bone stress injuries had symptoms prior to competing, and over 20% did not finish their competitions. This work has implications for injury prevention strategies, optimizing return-to-play protocols, and may suggest a role for early MR imaging of symptomatic athletes at the Olympics. ¹³

UBC researchers have also explored the correlation between image-detected muscle injuries sustained by Paralympic athletes in competition and subsequent performance. Interestingly, they observed that many athletes with muscle injuries completed their competition and concluded that MRI alone is insufficient for making decisions about return-to-play. This study is among the first to examine this relationship, providing insight into athlete resilience and injury management, thus helping to inform future decisions regarding competition readiness. ¹⁴

Additionally, UBC has contributed to the development of the British Journal of Sports Medicine (BJSM) educational series “Images in Sports Medicine.” The series aims to illustrate findings of challenging clinical cases encountered by practicing clinicians, emphasizing advances in imaging techniques and their impact on injury management of athletes at all levels. ¹⁵

Imaging Appropriateness

Imaging appropriateness remains an under-researched area with broad implications for patient care, healthcare resource utilization, and carbon footprint reduction. One way to mitigate inappropriate imaging investigations is through integrated decision support systems. UBC researchers have examined the role of such a system in curtailing inappropriate imaging requests to assess back pain in the Emergency Department. Findings demonstrated that such systems can be deployed successfully and reduce unnecessary exams without jeopardizing patient safety. ¹⁶

UBC has also evaluated approaches for optimizing imaging pathways. One study demonstrated that the strategic use of plain radiographs before choosing more advanced modalities led to a reduction in MRI and CT arthrogram utilization for evaluating osteoarthritis-related joint pain. ¹⁷

Additionally, early work on the impact of radiology departments on greenhouse gas emissions has shown the benefits of powering down CT units when not in use. ¹⁸

Medical Education

UBC groups have investigated possible adaptations to undergraduate medical education. Research has explored the incorporation of novel teaching methodologies, such as virtual dissection, to create a more adaptable and effective learning experience, particularly in situations where traditional teaching methods may be disrupted, as seen during the COVID-19 pandemic.^19,20

Lastly, UBC has researched the integration of AI into medical education. A review of existing literature identified current evidence-based recommendations for the inclusion of AI-related topics in the medical undergraduate curriculum, while another study established an expert-informed AI curriculum for Canadian medical students.^21,22 Additionally, UBC researchers have emphasized the importance of incorporating the patient perspective in AI-driven radiology, offering literature-based recommendations to ensure its consideration in system design and deployment. ²³ Given AI’s potential to be one of the most disruptive technological advancements in modern medicine, defining an effective educational framework for medical trainees and establishing guidelines for its implementation into practice are both crucial for preparing future clinicians to navigate AI-driven clinical environments.

Mammography Screening

There has been considerable work devoted to screening guidelines and supplemental screening in Canada. A study by Dr Seely et al highlighted the flaws of the Canadian Breast Cancer Screening Studies performed in the 1980s, ²⁴ reducing their validity in assessing the impact of screening mammography for early detection of breast cancer. A national study of 50 921 women aged 40 to 59 years diagnosed with breast cancer from 2002 to 2007 found a significant increase in 10-year net survival among women living in jurisdictions that included ages 40 to 49 in screening programs. ²⁵ Another large study showed that race/ethnicity played a critical role in the age and stage at diagnosis of breast cancer in Canada, where the peak age of diagnosis for White women was 63 years compared to age 52 to 60 for all others, with significantly higher proportions of advanced stage breast cancer and 40% higher age-specific mortality ratios in 40 to 49 year-old Black women. ²⁶ Canadian women under age 55 diagnosed with breast cancer from 1984 to 2019 had significant increases in age-specific incidence of breast cancer that was most marked for those younger than 40. ²⁷ The escalating costs of treating breast cancer with stage IV breast cancer were published, 35 times higher than stage 0, averaging 360 000 CDN$ per woman diagnosed. ²⁸ Screening women aged 40 to 74 annually with mammography was shown to be highly cost-effective, saving an average of 439 million CDN$ per year. ²⁹ These studies led to major changes in screening policies, and at the time of writing, 7/12 screening jurisdictions in Canada now permit self-referral for women 40 to 49 in their programs, 2 more start at age 45, and 2 more will gradually lower the starting age to 40.

Supplemental Screening

While mammography is established for screening for breast cancer, women with dense breast tissue benefit less from screening mammography than those with non dense breasts; they have higher interval cancers, cancers that are diagnosed after a normal screening mammogram. Seely et al found that women screened biennially with dense breasts had 63% higher interval cancer rates than those screened annually in a study of 145 000 individuals. ³⁰ Other strategies for dense breasts include adding other screening modalities to overcome the masking effect of breast tissue density. Hussein et al published a systematic review showing that the best supplemental screening strategy is breast MRI, ³¹ although it is less available. The most widely available modality is breast ultrasound. Gordon et al found that in a single centre, screening breast ultrasound had a high incremental cancer detection rate of 6/1000 in 5257 women screened biennially with normal 2D digital mammograms. ³² A review summarized the best screening strategies for women at higher-than-average risk. ³³ In addition to screening, MRI is essential in surgical planning in the systematic review published by Eisen et al. ³⁴ Hamel and other experts developed the 2024 Canadian Association of Radiologists Breast Disease Imaging Referral Guideline, providing the evidence-based recommendations for screening beginning at age 40, the best supplemental screening approaches, and referring patients for diagnostic breast imaging. ³⁵

Significant advances have been made in breast cancer screening practice and technology; the evidence shows that early detection of breast cancer saves lives from breast cancer and improves clinical outcomes.

Cardiovascular Imaging

Significant research efforts are underway at CHUM, CHUSJ, and MHI to develop new biomarkers to predict vascular vulnerability, mainly for atherosclerotic disease (carotid, cardiac, aortic disease). The technologies used include ultrasound strain and shear wave elastography, quantitative ultrasound, photoacoustic imaging, plaque imaging by computed tomography, magnetic resonance imaging, and nuclear medicine modalities. Fundamental studies in radiochemistry and radio-pharmacy are also conducted. Cardiac ultrasound elastography is also being studied. PET-CT myocardial perfusion studies and perfusion quantification are conducted in the context of atherosclerotic coronary diseases and microvascular circulation impairment. Studies encompass cohort studies, which may be followed by clinical trials aimed at validating proposed approaches. Hybrid PET-CT imaging is being investigated in evaluating infiltrative cardiovascular diseases such as cardiac sarcoidosis and amyloidosis. The populations studied include the general population as well as specific populations such as pediatric patients or individuals living with HIV.^36,37

Neurovascular Imaging and Intervention

Diagnostic neuroradiologists and neuro-interventional radiologists are collaborating at CHUM to improve stroke management comparing neuro-interventional approaches through pragmatic randomized trials. ³⁸ They also develop and validate imaging biomarkers using AI methods to improve their reproducibility and prognosis value. ³⁹ At CHUSJ, the Imagine research group is working on MRI techniques in utero and in premature populations to predict neurologic outcomes in these populations. ⁴⁰ At CRIUGM, research activities involve neuroimaging and neuroplasticity, open science, and digital health, in the field of age-related brain diseases. ⁴¹

MSK Imaging

Low-dose volumetric X-ray reconstruction technologies using the EOS technology are being developed for the diagnosis of bone and spine diseases. ⁴² Optical methods are used to study movement kinetics, while developments in quantitative ultrasound and MRI focus on muscles, tendons, and spinal pathologies. ⁴³ Randomized prospective studies aim to evaluate new ultrasound-guided therapeutic approaches. ⁴⁴

Abdominal Imaging

Multi-parametric MRI and quantitative ultrasound are investigated for tissue characterization. In particular, intrinsic magnetic resonance elastography and ultrasound shear wave viscoelastography are developed to grade steatosis, inflammation, and hepatic fibrosis non-invasively. Similar techniques are also under evaluation to improve liver tumour characterization, classification, and prognosis following interventional procedures.^45,46

Interventional Radiology

New guidance approaches using image fusion and finite element analysis techniques have been developed to improve guidance of endovascular aortic repair. ⁴⁷ Theranostic approaches using ultrasound contrast microbubbles are proposed to improve tumour response after radiotherapy or immunotherapy. ⁴⁸ Microrobots made of magnetic drug eluting beads are also developed to treat liver tumours by chemoembolization using the MR navigation technique instead of selective catheterization under fluoroscopy. ⁴⁹ New biomaterials dedicated to interventional radiology and endovascular surgery are also being developed within the department. Bioactive stent-grafts to improve healing after endovascular repair of aortic aneurysms are currently in preclinical testing. This same group also works on Chitosan-based embolic gels. ⁵⁰