Abstract: Certain embodiments provide a system for calibrating an X-ray image. The system may receive an X-ray image of an anatomical part of a patient. The system may further receive a 3-D surface scan of a surface of the patient where the anatomical part is located. The system may derive a measurement correction to apply to measurements of the X-ray image based on the 3-D surface scan. The measurement correction may account for: an orientation of the patient with respect to the X-ray detector plate, a first distance between the patient and the detector plate, or a second distance between the patient and an X-ray source used to generate the X-ray image. The system may further determine a corrected measurement of the anatomical part based on the measurement correction and a measurement taken from the X-ray image.