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

Diffuse liver diseases, including steatosis, cirrhosis, and fibrosis, significantly alter hepatic architecture, and can obscure, mimic, or alter the imaging features of focal liver lesions and reduce the diagnostic accuracy of specific imaging modalities. This review outlines the key imaging pitfalls created by diffuse liver disease and offers practical, evidence-based strategies to overcome them. We describe several key imaging pitfalls in interpreting liver lesions in diffuse liver disease, including the atypical appearance of focal lesions on ultrasound and CT due to altered background parenchyma; the phenomenon of "vanishing washout" of hepatocellular carcinoma on CT in steatotic livers; and the significant risk of underestimating metastatic disease burden or missing occult lesions. For each pitfall, we discuss the strengths and weaknesses of various imaging modalities and suggest problem-solving strategies, such as guidance on selecting the most appropriate next-line imaging modality for lesion characterization. We highlight the roles of contrast-enhanced ultrasound and MRI in resolving diagnostic uncertainty when initial ultrasound or CT imaging is atypical or equivocal. A comprehensive understanding of how diffuse liver disease affects the imaging of both benign and malignant lesions is important for accurate diagnosis. Recognizing these pitfalls allows a tailored, multimodality imaging approach that optimizes the detection and characterization of focal liver lesions, ultimately guiding clinical management and improving patient care.

Purpose: Evaluate global interest in middle meningeal artery (MMA) embolization, for subdural hematoma, by analyzing search behavior and academic output using Google Trends and PubMed data.

Materials and methods: Retrospective analysis conducted using Google Trends data from January 2004 to March 2025 and PubMed publication records from 1965 to 2025. The Google dataset included normalized monthly search volume indices (SVI: 0-100), geographic distribution, and related queries. Academic interest was assessed by annual publication counts. Statistical methods included Mann-Kendall trend tests, Augmented Dickey-Fuller (ADF) unit root tests, Portmanteau white noise tests, and Spearman correlations to evaluate significance and associations. Forecasts were generated using polynomial regression models.

Results: Search interest remained negligible from 2004 to 2011, increasing modestly through 2019 before accelerating significantly. PubMed publications followed a similar pattern, with sharp growth beginning in 2015. Both datasets exhibited significant upward trends (Mann-Kendall: Tau = 0.80 for PubMed; 0.75 for Google, P < .000001). Trends were confirmed as deterministic (ADF P < .001) and non-random (Portmanteau P < .001). A strong correlation was observed between academic and public interest (Spearman r = .86, R² = .74, P < .001). Polynomial forecasting (R² = .93) projects continued publication growth, estimating 267 ± 24 publications by 2027. Search interest is expected to stabilize at high levels (SVI 70-90).

Conclusion: Interest in MMA embolization is rapidly accelerating across both public and academic domains. These trends suggest a paradigm shift that may soon influence treatment guidelines, care delivery models, and the global adoption of this technique.

Introduction: This study aimed to determine the positive predictive value (PPV) of magnetic resonance imaging-transrectal ultrasound (MRI-TRUS) machine fusion prostate biopsies, and to identify factors associated with a positive biopsy.

Methods: With ethics approval, we retrospectively evaluated all MRI-TRUS machine fusion prostate biopsies at our institution from September 2022 to April 2025. True positive clinically significant prostate cancers (csPCa) were defined as Gleason ≥7. PPVs were calculated overall and for PI-RADS 3, 4 and 5 categories. A generalized linear mixed model (GLMM) was created evaluating the following factors as fixed effects: PI-RADS category; prostate-specific antigen (PSA) density (<0.10, 0.10-0.15, ≥0.15 ng/mL²); lesion size (<7, 7-15, ≥15 mm); lesion location (peripheral vs transition zone); ultrasound correlate (present/absent); prostate size (<60 vs ≥60 mL); interval from MRI to biopsy (<6 months or not); and biopsy operator (2 radiologists). Referring urologist (n = 19) and reporting radiologist (n = 8) were included as random effects.

Results: 372 patients (mean age, 67 ± 7 years) with 529 lesions underwent biopsy. The overall PPV was 314/529 (59.4%). For PI-RADS 3 to 5, PPVs were 32/72 (44.4%), 123/243 (50.6%), and 159/214 (74.3%), respectively. In GLMM analysis, PI-RADS 5 versus 3 (OR 3.6, 95% CI, 1.7-7.4), PSA density ≥0.15 ng/mL² (OR 2.2, 95% CI, 1.2-3.8), and presence of an ultrasound correlate (OR 2.7, 95% CI, 1.7-4.2) were associated with true positive biopsies. Small lesion size <7 mm was associated with a false positive biopsy (OR 0.4, 95% CI, 0.2-0.8).

Conclusion: The yield of fusion prostate biopsies at our institution is high. PI-RADS 5, PSA density ≥0.15 ng/mL², and an ultrasound correlate at biopsy were associated with csPCa, whereas sub-7 mm lesions were negatively associated with csPCa.

Objectives: Domain shift has been shown to have a major detrimental effect on AI model performance however prior studies on domain shift for MRI prostate cancer segmentation have been limited to small, or heterogenous cohorts. Our objective was to assess whether prostate cancer segmentation models trained on local MRI data continue to outperform those trained on external data with cohorts exceeding 1000.

Methods: We simulated a multi-institutional consortium using the public PICAI dataset (PICAI-TRAIN: 1241 exams, PICAI-TEST: 259) and a local dataset (LOCAL-TRAIN: 1400 exams, LOCAL-TEST: 308). IRB approval was obtained and consent waived. We compared nnUNet-v2 models trained on the combined data (CENTRAL-TRAIN) and separately on PICAI-TRAIN and LOCAL-TRAIN. Accuracy was evaluated using the open source PICAI Score on LOCAL-TEST. Significance was tested using bootstrapping.

Results: Just 22% (309/1400) of LOCAL-TRAIN exams would be sufficient to match the performance of a model trained on PICAI-TRAIN. The CENTRAL-TRAIN performance was similar to LOCAL-TRAIN performance, with PICAI Scores [95% CI] of 65 [58-71] and 66 [60-72], respectively. Both of these models exceeded the model trained on PICAI-TRAIN alone which had a score of 58 [51-64] (P < .002). Reducing training set size did not alter these relative trends.

Conclusion: Domain shift limits MRI prostate cancer segmentation performance even when training with over 1000 exams from 3 external institutions. Use of local data is paramount at these scales.

Purpose: This study aimed to assess the experiences and challenges faced by Canadian radiologists participating in Multidisciplinary Team rounds (MDT), with a focus on demographics, meeting characteristics, preparation processes, and perceptions of workload and compensation.

Methods: The Canadian Association of Radiologists constituted a working group which developed a 35-question survey that was distributed to 1958 radiologists and radiology trainees across Canada. The survey garnered 129 complete responses, for a response rate of 6.6%.

Results: Respondents predominantly practiced in academic settings (65.9%) and had subspecialty training (96.1%). The majority reported that MDT rounds lasted 30 to 60 minutes and discussed 6 to 10 cases. Most radiologists (62.8%) were the sole presenters of imaging. Preparation time was often limited, with only 6.2% having dedicated time for preparation. 59.8% of respondents reported receiving additions to caseloads within the 24-hour period prior to the meetings. While 93.8% valued the opportunity for interaction with colleagues, 93.8% felt inadequately compensated for their efforts by their practices, while 92.3% felt inadequately compensated by their province.

Conclusions: While most radiologists indicated adequate time for discussion and meaningful clinical engagement during rounds, many highlighted repeated challenges such as last-minute case additions, lack of protected preparation time, and technological barriers. Systemic barriers also play a role and include lack of provincial remuneration and workforce issues which in turn impact individual workload pressures.