Methods and apparatus are disclosed to label radiology images are disclosed. An example apparatus, includes: means for obtaining user input identifying a vertebra on a spinal image; means for generating first annotations on the spinal image based on: 1) the user input; 2) connected regions on the spinal image; and 3) a number of viewable vertebrae on the spinal image; means for generating second annotations on the spinal image based on: 1) the error; 2) second connected regions on the spinal image; and 3) the number of viewable vertebrae on the spinal image, the second connected regions on the spinal image being determined based on second contextual-information features that account for the error; means for displaying the spinal image including the second annotations; means for validating the second annotations in association with the spinal image; and means for storing the second annotations in association with the spinal image.