Functional dynamic radiography with computer analysis-for physiological chest imaging and kinematic joint imaging.

We developed a functional digital radiography system that provides physiological and functional information of the chest and/or joints using an X-ray flat-panel detector (FPD) system. During chest examination, sequential chest radiographs are taken from inspiration to expiration in order to analyze diaphragmatic movements. Pixel value changes in localized areas of the lung are then assessed to analyze ventilation and circulation. For limb joints, such as the wrist, shoulder, and knee, sequential radiographs during flexion and extension or rotational movement are considered, and movement angles are analyzed. These imaging techniques and quantitative analyses are promising in screening examinations because they provide physiological and functional information. The entrance surface dose for the detector is approximately 1.9 mGy for chest examination, which is comparable to the dose limit recommended by the International Atomic Energy Agency. Recent related studies are reviewed in this paper.