Multi-view AI output variability as a teaching resource in a micro-course for thyroid TI-RADS interpretation among ultrasound residents: a randomized controlled trial.

Introduction: Thyroid TI-RADS interpretation requires integration of sonographic features across image planes, yet routine teaching often emphasizes the final category more than the cross-plane reasoning process. We evaluated whether a structured micro-course using multi-view AI output variability as a teaching resource could improve TI-RADS interpretation among ultrasound residents. Methods: In this single-center randomized controlled trial, 52 ultrasound residents were randomized 1:1 to either a structured micro-course using multi-view AI output variability as a teaching resource or time-matched conventional TI-RADS teaching. The primary outcome was participant-level TI-RADS interpretation accuracy at baseline (T0), immediately after teaching (T1), and 4 weeks later (T2). Secondary outcomes were inter-learner consistency, representative plane hit score, and self-efficacy. Justification quality in discordant cases was analyzed exploratorily. Results: Baseline characteristics were comparable between groups. Accuracy showed a significant group-by-time interaction [ Conclusions: A structured micro-course using multi-view AI output variability as a teaching resource improved immediate TI-RADS interpretation accuracy, but the between-group advantage was not sustained at 4 weeks, despite persistently higher inter-learner consistency. These findings support the short-term educational value of the structured micro-course rather than an independent effect of AI output variability and warrant evaluation of repeated or booster instruction.