1. A method for identifying a target in a three-dimensional CT image, the method comprising: displaying a three-dimensional CT image generated by a CT apparatus on a physical display apparatus; receiving a selection, via one or more physical input devices of a computer system connected to the physical display apparatus, by a user of at least one area of the three-dimensional CT image at a first viewing direction to generate a first three-dimensional description; receiving a selection, via the one or more physical input devices of the computer system, by the user of at least one area of the three-dimensional CT image at a second viewing direction to generate a second three-dimensional description, wherein an angle between the first viewing direction and the second viewing direction is in a predetermined range and the first three-dimensional description and the second three-dimensional description are related to at least one of dimensions, positions, or physical attributes of the target at a corresponding viewing direction; and identifying the target in the three-dimensional CT image based on the first three-dimensional description and the second three-dimensional description, wherein the first three-dimensional description is a first bounding box/data subset and the second three-dimensional description is a second bounding box/data subset.