筆者らは,動画撮影の可能なX線フラットパネルディテクタを用いて,様々な生理的情報や機能的情報を取得できるスクリーニング動画像検査法を開発してきた.たとえば短時間時系列の呼吸過程を撮像して,横隔膜の動態解析を行った.また,肺野局所の画素値の変化を解析して,肺換気と胸部循環の概略を評価した.手関節,肩関節,膝関節など四肢関節系については,屈曲と伸展運動中の関節要素の動態変化を定量的に解析して,それらの運動機能を評価した.これらの動画像検査法は,“ コンピュータ解析によって解剖・生理的,機能的情報を付加した一般初期検査としてのX線動態機能画像法(physiologic-functional radiography:pfRAD)” という位置づけである.患者被曝線量について,皮膚表面線量は,胸部では 1.9 mGy,股関節では 5.11 mGy と,いずれも国際原子力機関(IAEA)の推奨する線量限度を超えない.本稿では関連する他の研究報告も併せて概説する.We have developed a functional digital radiography system that allows assessment of physiological and functional information of the chest and/or joints using an X-ray flat-panel detector. Sequential chest radiographs are obtained throughout the inspiration and expiration cycle to analyze diaphragmatic movements during chest examination. Ventilation and circulation are analyzed by assessing changes in pixel values in localized areas of the lung. For limb joints, such as the wrist, shoulder, and knee, flexion and extension or rotational movement is assessed using sequential radiographs to analyze movement angles. These imaging techniques and quantitative analyses, referred to as physiologic-functional radiography (pfRAD), provide physiological and functional information. The pfRAD method is promising for screening examinations because of its simplicity and precision. The entrance surface dose for the detector is within the limits recommended by the International Atomic Energy Agency (approximately 1.9 and 5.11 mGy for chest and hip examinations, respectively). Recent relevant studies are reviewed