Vertebral Deformity Measurements at MRI, CT, and Radiography Using Deep Learning

Purpose: To construct and evaluate the efficacy of a deep learning system to rapidly and automatically locate six vertebral landmarks, which are used to measure vertebral body heights, and to output spine angle measurements (lumbar lordosis angles [LLAs]) across multiple modalities. Materials and Methods: In this retrospective study, MR (n = 1123), CT (n = 137), and radiographic (n = 484) images were used from a wide variety of patient populations, ages, disease stages, bone densities, and interventions (n = 1744 total patients, 64 years +/- 8, 76.8% women; images acquired 2005-2020). Trained annotators assessed images and generated data necessary for deformity analysis and for model development. A neural network model was then trained to output vertebral body landmarks for vertebral height measurement. The network was trained and validated on 898 MR, 110 CT, and 387 radiographic images and was then evaluated or tested on the remaining images for measuring deformities and LLAs. The Pearson correlation coefficient was used in reporting LLA measurements. Results: On the holdout testing dataset (225 MR, 27 CT, and 97 radiographic images), the network was able to measure vertebral heights (mean height percentage of error +/- 1 standard deviation: MR images, 1.5% +/- 0.3; CT scans, 1.9% +/- 0.2; radiographs, 1.7% 6 0.4) and produce other measures such as the LLA (mean absolute error: MR images, 2.90 degrees; CT scans, 2.26 degrees; radiographs, 3.60 degrees) in less than 1.7 seconds across MR, CT, and radiographic imaging studies. Conclusion: The developed network was able to rapidly measure morphometric quantities in vertebral bodies and output LLAs across multiple modalities. (C) RSNA, 2021