スリット撮影を用いた長尺撮影装置における全脊椎撮影の最適化

摘要

全脊椎撮影は主に側攣症患者を対象として施行され，経過観察のため長期間にわたり撮影が行われる．従来全脊椎撮影は長尺フイルムが用いられてきたが，近年のⅩ線装置のディジタル化，フイルムレス化に伴いcomputed radiography（CR）やflat panel detector（FPD）などのディジタル装置での撮影が主流となってきた．%The purpose of this study was to optimize X-ray conditions for full spine X-ray examinations in slot-scan digital radiography (SSDR). Follow-up of spinal deformities, such as scoliosis, typically involves many radiographs of the patient throughout childhood and adolescence. The Radiation doses for the full spine X-ray examination should be minimized. Recently, SSDR has been introduced for full spine as well as lower extremity examinations. This system utilizes slot scanning geometry to acquire the radiographic images. X-ray energy characteristics of direct amorphous Selenium (a-Se) digital fluoroscopy and short time X-ray tube loads of this system were investigated. Orthopedists evaluated the irradiation time for full spine radio­graphs in various conditions using an observer study. Patient doses were measured with radiophotolumines-cence glass dosimeters, which were implanted in various tissue and organ positions within an anthropomor­phic phantom. In the optimization of conditions for SSDR, patient doses are reduced by approximately 60% compared to default setting.