@article{oai:niigata-u.repo.nii.ac.jp:00025656,
 author = {長濱, 航永 and 豊里, 晃 and 竹内, 由一 and 植田, 耕一郎 and 林, 孝文 and 野村, 修一},
 issue = {2},
 journal = {新潟歯学会雑誌, 新潟歯学会雑誌},
 month = {Dec},
 note = {Since videofluorography (VF) simultaneously evaluates structure and function of the organs altered by dysphagia, it became the gold standard for the diagnosis of dysphagia. However, the exposure dose will increase by long-time and frequent examination. Thus, this study investigated the appropriate examination time and method of protection, after measuring the skin absorbed dose in VF. For the measurement of the skin absorbed dose, the TLD element (MSO-S) was used. The TLD element (consisting of 3 pieces) was bonded on angulus oculi lateralis, temporal and thyroid gland regions of the head phantom, and the skin absorbed dose was measured. In addition, similar measurements were carried out in dysphagia patients after getting agreement for VF. The setting conditions of the fluoroscopic apparatus were, as follows : FSD : 60cm, tube voltages : 55kV, tube current automatic control, frame rate : 12.5F/s and maximum value of pulse duration : 8ms. In the phantom, skin absorbed dose rate was 4.3 mGy/s in the angulus oculi lateralis region and 3.6mGy/s in the temporal and thyroid gland regions. At this dose, the time until the threshold dose in which the lens nebula occurs (1Gy) is exceeded is 4'30 seconds and the time until the threshold dose in which early skin erythema occurs (2Gy) is exceeded is 7'30 seconds. It is considered that, since in the Niigata University Dental Hospital, the examination time of VF is 2'30 seconds, the occurance probability of these side effects is low. Moreover, it is effective to reduce the exposure dose in VF by shortening the examination time, by increasing the distance from the bulb, and by reducing the ecposure dose of the equipment within the limits of image interpretability. Furthermore, it is also effective to keep away the eyes from the radiation field, in order to reduce the dose directed to the eye lenses, which are most sensitive to radiation., Ⅹ線嚥下造影検査は障害された器官の構造と機能を同時に評価することができるため、摂食･嚥下障害の診断には、ゴールドスタンダードとなっている｡しかし、長時間の検査や回数が多くなると、この検査による被曝線量も大きくなる｡そこで今回、われわれは嚥下造影検査時の皮膚吸収線量を測定し、適切な検査時間、防護方法を検討したので報告する｡皮膚吸収線量の測定には、TLD素子(MSO-S)を使用した｡頭部ファントムに、TLD素子を3本1組で外眼角部、側頭部、甲状腺部に貼り付け、各部位における皮膚吸収線量を測定した｡さらに、摂食･嚥下障害者の嚥下造影検査時に本人の同意を得て同様の測定を行った｡Ⅹ線透視装置の設定条件は、FSD:60cm、管電圧55kV、管電流自動制御、フレームレートは12.5F/S、パルス幅の最大値を8msに設定した｡皮膚吸収線量率は、ファントムでは外眼角部で3.6mGy/S、側頭部、甲状腺部で4.3mGy/Sであった｡この線量で、水晶体白濁が起こるしきい線量(1Gy)を超えるまでの時間は4分30秒、初期皮膚紅斑が起こるしきい線量(2Gy）を超えるまでの時間は7分30秒である｡新潟大学歯学部附属病院における1回の検査時間はおよそ2分30秒であるため、これらの確定的影響がでる恐れは少ないと考えられる｡嚥下造影検査時の被曝線量を低減するためには、検査時間の短縮のほか、読影可能な範囲で装置の線量を減らす、Ⅹ線管装置から被写体までの距離を離すことが有効であった｡また、放射線の感受性の高い水晶体の被曝を低減するため、眼を照射野から外すことも有効である｡},
 pages = {31--35},
 title = {嚥下造影検査における皮膚吸収線量の測定},
 volume = {33},
 year = {2003}
}