Canadian Association of Radiologists Journal-Journal De L Association Canadienne Des Radiologistes最新文献

Immunotherapy with checkpoint inhibitors (ICI) has revolutionized oncology by stimulating the immune system to target cancer cells. While effective in treating various malignancies, ICI presents unique challenges in radiological response assessment. Traditional criteria, such as RECIST 1.1, were designed for cytotoxic chemotherapy and fail to account for pseudo-progression-an immune-related phenomenon where tumour size transiently increases due to immune cell infiltration before eventual shrinkage. This occurs in a minority of patients and can lead to misclassification of treatment response. To address this, new assessment criteria have been developed. The immune-related response criteria (irRC) introduced a delayed assessment of new lesions, followed by immune-related RECIST (irRECIST), which sought to align with RECIST 1.1. However, inconsistencies in its application led to the development of iRECIST in 2016, a standardized framework integrating RECIST 1.1 with immunotherapy-specific modifications. Despite its potential to become the gold standard, iRECIST is complex and challenging to implement consistently. This review outlines key differences between RECIST 1.1 and iRECIST, explains their necessity, and provides comprehensive flowcharts and graphical representations to aid interpretation. By addressing common clinical scenarios and frequently asked questions, this article aims to enhance understanding and application of iRECIST in clinical practice.

Radiology research at Canadian institutions is advancing patient care through multidisciplinary collaboration, technological innovation, and quality improvement initiatives. Investigators at Dalhousie University, the University of British Columbia (UBC), the University of Ottawa, and Université de Montréal are leading efforts in diverse areas of imaging research, including lung cancer detection, sports medicine imaging, mammography and supplemental screening, and advanced imaging modalities. Dalhousie researchers have developed initiatives for incidental lung nodule management and imaging protocol optimization to ensure efficient and high-quality care. At UBC, investigations into imaging appropriateness and sports medicine imaging at elite athletic competitions are shaping global practice standards. The University of Ottawa has played a key role in refining mammography guidelines, improving early breast cancer detection and influencing national screening practices. The Université de Montréal is advancing innovations in cardiovascular and neurovascular imaging, contributing to improved diagnostic accuracy and therapeutic planning. Collectively, these contributions highlight Canada's pivotal role in the global radiology community and its ongoing commitment to improving patient outcomes through research and innovation. This article reviews major research initiatives from several leading Canadian institutions and highlights the ongoing need for collaboration and innovation to further elevate the quality and effectiveness of radiology practices worldwide.

Radiomics is a mathematical approach to medical images to extract quantitative features generating a "radiomics signature." The radiomics workflow involves image acquisition and pre-processing, region of interest segmentation, feature extraction, and then model training and validation. It has generated promising results, however, clinical implementation for early detection remains a challenge. Pancreatic ductal adenocarcinoma (PDAC), the most common pancreatic cancer, has a highly aggressive nature with an aggregated 5-year survival rate of only 13%. Early detection of PDAC provides timely surgical intervention, hoping for improved survival rates. Radiomics has been applied to the detection of PDAC; however, its sensitivity to variations in image acquisition parameters has posed significant challenges, limiting the development of robust and generalizable models. This review explores the current landscape of radiomics for the early detection of PDAC, highlighting key challenges within the radiomics workflow and barriers to its progression from a proof-of-concept into clinical practice.

The Canadian Association of Radiologists (CAR) metabolic dysfunction-associated steatotic liver disease (MASLD) Working Group (WG) is a multidisciplinary working group composed of radiologists, hepatologists, and family physicians. In this 3-part series, we provide Delphi consensus-based guidance on clinical and imaging findings for patients with known or suspected MASLD (formerly termed nonalcoholic fatty liver disease or NAFLD). Part 1 focuses on the detection and grading of hepatic steatosis on imaging; Part 2 on risk stratification of patients with MASLD, including a patient pathway that applies blood-based and imaging-based investigations; and Part 3 on the implementation of practice recommendations for quality assurance using shear wave elastography (SWE) and magnetic resonance elastography (MRE) for disease staging. In the third part of these guidelines, the WG provides 18 recommendations for standardized implementation, remuneration, and quality assurance for SWE and MRE programs. Structured reporting templates for standardized SWE and MRE are provided. Introductory training presentations for technologists and radiologists are also provided. The goal of these guidelines is to enable standardized image-based screening and risk stratification of patients with MASLD across Canada.

Introduction: Computed tomography angiography (CTA) plays an important role in assessing patients with suspected lower extremity traumatic vascular injury. However, CTA overutilization has been reported in some centres, and improper use has been linked to increased healthcare costs and prolonged Emergency Department wait times. This study evaluated CTA utilization in a Canadian Level I trauma centre, determined the rate of positive CTA studies requiring intervention, and identified factors that may reduce unnecessary examinations. Methods and Materials: This retrospective study included trauma patients who underwent lower extremity CTA between January 2020 and September 2024. Data regarding patient demographics, mechanism of injury, physical exam and computed tomography findings, ankle-brachial index value, and interventions were collected and evaluated. Statistical analysis included descriptive statistics and chi-square or Fisher's exact tests for categorical associations. Results: Six hundred twelve patients (82% male, median age 32 years) were included. Forty-six percent had a normal physical exam, and CTA was positive in 27% of cases. Eight percent of patients required an intervention, all of whom had at least one hard sign of vascular injury. A statistically significant association was identified between hard signs of a vascular injury and positive CTA findings (P < .001) and major vascular injuries (P < .01). No patients with a normal physical exam and a positive CTA required intervention. Conclusion: Nearly half of the CTA studies were performed on patients with a normal physical exam, none requiring intervention. Our findings suggest that implementing institution-specific appropriate criteria may reduce unnecessary CTA studies.

Objective: Radiology residents must demonstrate competence in breast imaging prior to entering practice. Breast imaging fellowship training programs have attracted fewer trainees, contributing to the ongoing shortage in the field. This survey aimed to evaluate the structure, supports, and barriers to breast imaging training in Canadian residency programs to help guide future curriculum development. Methods: Following ethical approval, a 45-question cross-sectional survey was distributed to all 16 diagnostic radiology program directors of Canadian residency programs via email using the online platform SurveyMonkey between March and May 2024. The questions covered program demographics, breast imaging and procedural experience, integration into multidisciplinary care, the impact of other learners, scheduling, and departmental leadership. Results/Discussion: Twelve (75%) program directors across 7 provinces responded. Responses revealed variability in program structures and resources. All programs provided the suggested 4 months of breast imaging training. Exposure to interpreting screening mammography was offered by 75% (9/12) of programs, however, 75% (9/12) of programs did not involve residents in multidisciplinary rounds, limiting collaborative care training. Simulation sessions for breast imaging procedures were offered in 33% (4/12) of programs. Assessment methods across programs lacked uniformity, with only 17% (2/12) of programs using post-rotation tests, and all relying on subjective evaluations. Conclusion: This study highlights the need to address disparities and enhance standardization to improve residents' breast imaging education. Establishing clear guidelines for integration of multimodality breast imaging exposure, increasing procedural training, and providing opportunities to participate in multidisciplinary care conferences are essential for developing a more uniform and comprehensive breast imaging curriculum nationally.

Dual-energy computed tomography has become a pivotal tool in abdominal imaging, particularly for pancreatic pathologies such as pancreatic ductal adenocarcinoma, trauma assessment, and acute pancreatitis. Its ability to provide enhanced contrast resolution, reduce artifacts, and optimize radiation dose makes it invaluable in both acute and non-acute clinical settings. This narrative review summarizes the technological advancements and clinical applications of dual-energy computed tomography in pancreatic imaging. A comprehensive review of 21 peer-reviewed studies published between 2013 and 2024 was conducted to evaluate the role of dual-energy computed tomography in all pancreatic imaging indications, including tumor detection, pancreatitis assessment, trauma evaluation, and radiation dose optimization. The analysis included retrospective and prospective studies retrieved from multiple databases, including PubMed, Scopus, and Google Scholar. The findings highlight the technology's capacity to improve diagnostic accuracy, reduce image artifacts, and lower radiation exposure through techniques such as virtual monoenergetic imaging and iodine quantification. Comparisons with conventional computed tomography focused on diagnostic performance metrics such as contrast-to-noise ratio, and signal-to-noise ratio. Additionally, this narrative review underscores the clinical relevance of dual-energy computed tomography in evaluating non-traumatic acute abdominal conditions, especially among elderly patients.