3D visualization of a medical object is an important and actual task in medical engineering. At the same time, the input data for this task often is described in 2D layer form (for example, medical images acquired with Magnetic Resonance Imaging, Computer Tomography, etc). In this case, the most important part of the complex visualization task is the 3D modelling of a medical object. One approach, based on Bezier surfaces is described in [1]. This approach uses local surface interpolation and produces a mathematical model based on the set of Bezier surfaces as a result. In this work, the approach of using only one B-spline surface for 3D modelling is described. This approach is based on the global surface interpolation method.