Using Multiple Images and Contours for Deformable 3D-2D Registration of a Preoperative CT in Laparoscopic Liver Surgery

Deformable registration is required to achieve laparoscopic augmented reality but still is an open problem. Some of the existing methods reconstruct a preoperative model and register it using anatomical landmarks from a single image. This is not accurate due to depth ambiguities. Other methods require of non-standard devices unadapted to the clinical practice. A reasonable way to improve accuracy is to combine multiple images from a monocular laparoscope. We propose three novel registration methods exploiting information from multiple images. The first two are based on rigidly-related images (MV-B and MV-C) and the third one on non-rigidly-related images (MV-D). We evaluated registration accuracy quantitatively on synthetic and phantom data, and qualitatively on patient data, comparing our results with state of the art methods. Our methods outperforms, reducing the partial visibility and depth ambiguity issues of single-view approaches. We characterise the improvement margin, which may be slight or significant, depending on the scenario.