Modeling radiologists' cognitive processes using a digital gaze twin to enhance radiology training

Predicting human gaze behavior is critical for advancing interactive systems and improving diagnostic accuracy in medical imaging. We present MedGaze, a novel system inspired by the "Digital Gaze Twin" concept, which models radiologists' cognitive processes and predicts scanpaths in chest X-ray (CXR) images. Using a two-stage training approach-Vision to Radiology Report Learning (VR2) and Vision-Language Cognition Learning (VLC)-MedGaze combines visual features with radiology reports, leveraging large datasets like MIMIC to replicate radiologists' visual search patterns. MedGaze outperformed state-of-the-art methods on the EGD-CXR and REFLACX datasets, achieving IoU scores of 0.41 [95% CI 0.40, 0.42] vs. 0.27 [95% CI 0.26, 0.28], Correlation Coefficient (CC) of 0.50 [95% CI 0.48, 0.51] vs. 0.37 [95% CI 0.36, 0.41], and Multimatch scores of 0.80 [95% CI 0.79, 0.81] vs. 0.71 [95% CI 0.70, 0.71], with similar improvements on REFLACX. It also demonstrated its ability to assess clinical workload through fixation duration, showing a significant Spearman rank correlation of 0.65 (p < 0.001) with true clinical workload ranks on EGD-CXR. The human evaluation revealed that 13 out of 20 predicted scanpaths closely resembled expert patterns, with 18 out of 20 covering 60-80% of key regions. MedGaze's ability to minimize redundancy and emulate expert gaze behavior enhances training and diagnostics, offering valuable insights into radiologist decision-making and improving clinical outcomes.