Burnout among radiologists is increasingly prevalent, with potential for substantial negative impact on physician well-being, care delivery, and health outcomes. To evaluate this phenomenon using reliable and accurate means, validated quantitative instruments are essential. Variation in measurement can contribute to wide-ranging findings. This article evaluates radiologist burnout rates globally and dimensions of burnout as reported using different validated instruments and provide guidance on best practices to characterize burnout. Fifty-seven studies between 1990 and 2023 were included in a systematic review, and 43 studies were included in a meta-analysis of burnout prevalence using random effects models. Reported burnout ranged from 5% to 85%. With the Maslach Burnout Inventory (MBI), burnout prevalence varied significantly depending on instrument version. Among MBI subcategories, the prevalence of emotional exhaustion was 54% (95% CI, 45-63%), depersonalization was 52% (95% CI, 41-63%), and low personal accomplishment was 36% (95% CI, 27-47%). Other validated burnout instruments showed less heterogeneous results; studies using the Stanford Professional Fulfillment Index yielded burnout prevalence of 39% (95% CI, 34-45%), whereas the Validated Single-Item instrument yielded 34% (95% CI, 29-39%). Standardized instruments for prevalence alongside multidimensional profiles capturing experiences may better characterize radiologist burnout, including change over time.