Extended Reality (XR) technologies have opened new possibilities for image visualization in healthcare, but eliciting user requirements for XR development is challenging. Human-computer interaction can help obtain User Mental Models, mostly unexplored in XR for health. An ongoing project aims to address this gap by studying the skills and backgrounds of radiologists and surgeons using the same XR tool in Preoperative Surgical Planning for Complex Malformations through elucidating mental model, performing technical review and proposing Potential Interaction Models or Interaction Concepts. The work aims to contribute insights for designing more intuitive, immersive medical visualization tools.