A computer system that provides a simulated 2D fluoroscopy image is described. During operation, the computer system may generate the simulated 2D fluoroscopy image based on data in a predetermined 3D image associated with an individual's body. For example, generating the simulated 2D fluoroscopy image may involve a forward projection. Moreover, the forward projection may involve calculating accumulated absorption corresponding to density along X-ray lines through pixels in the predetermined 3D image. Then, the computer system may provide the simulated 2D fluoroscopy image with a 3D context associated with a predefined cut plane in the individual's body. Note that the providing may involve displaying, on a display, the simulated 2D fluoroscopy image with the 3D context.