Augmented reality (AR) can be used to visualize virtual 3D models of medical imaging in actual 3D physical space. Accurate registration of these models onto patients will be essential for AR-assisted image-guided interventions. In this study, registration methods were developed, and registration times for aligning a virtual 3D anatomic model of patient imaging onto a CT grid commonly used in CT-guided interventions were compared. The described methodology enabled automated and accurate registration within seconds using computer vision detection of the CT grid as compared to minutes using user-interactive registration methods. Simple, accurate, and near instantaneous registration of virtual 3D models onto CT grids will facilitate the use of AR for real-time procedural guidance and combined virtual/actual 3D navigation during image-guided interventions.