| Japanese |
|---|
| Title | シンチレーションカメラの感度不均一性に関する研究 - 第1報 不均一性の表示法 - |
|---|
| Subtitle | 原著 |
|---|
| Authors | 松本徹* |
|---|
| Authors(kana) | |
|---|
| Organization | *放射線医学総合研究所臨床研究部 |
|---|
| Journal | 核医学 |
|---|
| Volume | 14 |
|---|
| Number | 6 |
|---|
| Page | 849-855 |
|---|
| Year/Month | 1977/12 |
|---|
| Article | 原著 |
|---|
| Publisher | 日本核医学会 |
|---|
| Abstract | 「I. 緒言」アンガー型シンチレーションカメラには視野内で感度の不均一性が内在し, RIイメージの読影の妨げになることがある. そのため不均一性を補IEしようとする試みがなされている. その方法には多くの種類があるが, もっとも厳密な方法はデジタル電子計算機を利用するものである. この場合, 補正の手順は大きく分けて, 次の3段階となる. (a) 感度不均一性の測定, (b) 不均一性の定量的評価, (c) 補正用マトリックスの作成および補正の実行. しかし, 実際に不均一性補正を行なう時, 上述の各段階において, 具体的に手順をどのようにしたらよいかを, 系統的に論じた報告はない. そこで著者はデジタル電子計算機によるシンチレーションカメラの感度不均一性補正の方法を確立するため, まず (1) 不均一性の尺度をあらわす指標, および不均一性補正用の, smoothing処理法について検討した. 次に, (2) 不均一性をあらわす後述のflood像を多くの因子の関数として測定し, 各種因子による不均一性の変化を定量的に評価した. |
|---|
| Practice | 臨床医学：一般 |
|---|
| Keywords | |
|---|
| English |
|---|
| Title | Non - Uniform Sensitivity of Delay - Line Scintillation Camera (No.1) ; Methods for Expressing the Non - Uniformity |
|---|
| Subtitle | Original articles |
|---|
| Authors | Toru MATSUMOTO |
|---|
| Authors(kana) | |
|---|
| Organization | Clinical Division, National Institute of Radiological Sciences |
|---|
| Journal | The Japanese Journal of nuclear medicine |
|---|
| Volume | 14 |
|---|
| Number | 6 |
|---|
| Page | 849-855 |
|---|
| Year/Month | 1977/12 |
|---|
| Article | Original article |
|---|
| Publisher | THE JAPANESE SOCIETY OF NUCLEAR MEDICINE |
|---|
| Abstract | [Summary] : Methods for expressing non-uniformity of the camera are presented in this report. (1) The parameter expressing the extent of non-uniformity is defined as, √σt2-c/c×100 (%) , whereσt is the standard deviation of counts per pixel and c is the average counts per pixel in a region of interest. It is confirmed by the experiment that even if number of collected data for the flood image varies from 10 to 5×10 4 counts per pixel, this parameter has a constant value as compared with those of others in which the non-uniformity varies inversely with the increase of average counts per pixel in a region of interest. (2) The parameter expressing the differences in the pattern of non-uniformity between the two flood images is defined as the correlation coefficients (r) between those images. Calculating this parameter, it is necessary that the statistical fluctuation in flood images must be kept less than 1% of the average counts per pixel c. (3) Because of the elmination of statistical fluctuation and the reduction of time required for non-uniformity measurements, it is effective to apply the smoothing procedures by the Gaussian filter to the flood image. Experimentally and theoretically, it is proved that the statistical fluctuation in a flood image can be reduced by the optimal smoothing procedures without changing the pattern of non-uniformity. |
|---|
| Practice | Clinical medicine |
|---|
| Keywords | |
|---|