Ultrasound (US) simulation systems and methods are provided, which utilize computer tomography (CT) data to generate US simulation images, offline or online. Systems and methods repeatedly derive and display consecutive US simulation images that correspond to consecutively-derived corresponding US slices (according to the changing locations and orientations of a dummy US transducer mimicking the US transducer with respect to a physical patient model)—that define geometrically US simulation regions. The US simulation images are at least partly derived from CT data using a CT to US conversion model. Acoustic parameters (e.g., tissue density, acoustic attenuation and impedance) are calculated and integrated per pixel, along beams in the US slice, to form the US image. Additional modelling may be used to calculate reflection and scattering and their effects on the image pixels, and enhancements such as animation and flow data may be added.