As an extension to this - its possible to create 3D models direct from CT Scan DICOM data. I've made a few for various surgeries.
Some people look to immortalize those they love - I've done several that came from CT Scans of patients just before they passed away and made the models. Its remarkable how lifelike the end results are, and its an incredibly emotional experience for the customer. Theres nothing quite like having a fully grown man start to break down in the middle of your engineering firm when he sees the model of his grandfather realized. Powerful stuff.