The clinical utility of a one-shot energy subtraction method for thoracic spine radiography.

BACKGROUND The interpretation of thoracic spine X-rays is difficult because these images cannot clearly visualize the thoracic spine because of the overlap with soft tissues, such as the heart and pulmonary blood vessels. Thus, to improve the clarity of thoracic spine radiographs using existing radiograph equipment, we have investigated a one-shot energy subtraction method to visualize thoracic spine radiographs. Our objective was to evaluate whether the thoracic spine radiographs generated using this method could visualize the spine more clearly than the corresponding original thoracic spine radiographs. METHODS This study included 29 patients who underwent thoracic spine radiographs. We used a one-shot energy subtraction method to improve the clarity of thoracic spine radiographs. Image definition was evaluated using vertebrae sampled from each region of the thoracic spine. Specifically, these were: Th1, Th5, Th9, and Th12. Image definition was assessed using a three-point grading system. The conventional and processed computed radiographs (both frontal and lateral views) of all 29 study patients were evaluated by 5 spine surgeons. RESULTS In all thoracic regions on both frontal and lateral views, the processed images showed statistically significantly better clarity than the corresponding conventional images, especially at all sampling sites on the frontal view and T5 and 9 on the lateral view. CONCLUSIONS Thoracic spine radiographs generated using this method visualized the spine more clearly than the corresponding original thoracic spine radiographs. The greatest advantages of this image processing technique were its ability to clearly depict the whole thoracic spine on frontal views and the middle thoracic spine on lateral views.