Japanese
Title半導体スキャンの基礎的実験
Subtitle原著
Authors東与光*, 閑野政則*, 栗原英明**, 石塚安廣***
Authors(kana)
Organization*神奈川歯科大学 放射線学教室, **立教大学 原子力研究所, ***横浜国立大学教育学部 物理学科
Journal核医学
Volume9
Number3
Page265-271
Year/Month1972/6
Article原著
Publisher日本核医学会
Abstract「I. はじめに」現在のシンチスキャンナーや, シンチカメラの検出器には, もっぱら, NaI(Tl)検出器が使用されている. 近年, 新らしい核種の開発や, コリメータの改良により, 像の分解能はある程度, 向上したとはいえ, 臨床的にまだ満足すべきものでない. 最近, 従来のNaI(Tl)検出器に比らべてγ線に対する感度はやや劣るが, 分解能がはるかに優れている半導体検出器のGe(Li)検出器の医学的利用が注目されつつある. Hoffer, Mc Cready, Patton, らは, Ge(Li)検出器をスキャンナーや, カメラに利用して非常に興味ある結果を報告している. 私たちも, 1968年よりカテーテル型の半導休検出器の医学的利用をこころみ, 32Pを用いて悪性腫瘍の診断に利用してきた. 今回は, 半導体検出器のスキャンナーへの利用の基礎的実験の結果を報告する.
Practice臨床医学：一般
Keywords
English
TitleEvaluation of semiconductor detectors for scanning
Subtitle
AuthorsTomomitu HIGASI*, Masanori KANNO*, Hideaki KURIHARA**, Yasuhiro ISHIZUKA***
Authors(kana)
Organization*Kanagawa Dental College, Department of Radiology, **Institute for Atomic Energy, Rikkyo University, ***Yokohama National University, Department of Physics.
JournalThe Japanese Journal of nuclear medicine
Volume9
Number3
Page265-271
Year/Month1972/6
ArticleOriginal article
PublisherTHE JAPANESE SOCIETY OF NUCLEAR MEDICINE
Abstract[Summary] Recent developments in semiconductor detector technology have caused much interest. However, the medical use of semiconducter detectors is, at the present time, restricted to certain research institutes. The authors have developed a catheter type p-i-n semiconductor detector in 1968, as shown in figure 1, and have used it to examine cases of cancer of the oesophagus, uterus and rectum 24 hours after the administration of 32p. Presently we are investigating the 32p image of malignant tumors with the catheter type semiconductor detector. The semiconductor detector was attoched to the detector portion of a conventional scintiscanner as shown in figure 2. Studies were made in a phantom with various concentrations of 32p to determine the ability of imaging with 32p as shown in figure 3. However, in clinical cases the 32p image in metastatic lesions was poorly differentiated from background activity as shown in figure 4. Therefore we concluded that 32p scanning with semiconductor detectors was little clinical value. Furthermore, we attempted to obtain gamma-ray imaging with a germanium detector. The germanium detector used in this study has a capacity of 10cc with a full width half maximum of 4.5 KeV for the 60Co gamma-ray (1.33 KeV). This semicon-ductor detector has a high-resolution for gamma-rays as compared with a conventional NaI (Tl) detector as shown in figure 5. The use of these high-resolution detectors should make it possible to map radioactive emission distributions from patients with minimum loss of detail due to scattered radiation. The fundamental experiments were done as shown in figure 7. The line spread functions of 265-hole collimator using a 57Co source in water shows a good resolution compared with a NaI (Tl) detector as shown in ufigre 8. Studies were made using a thyroid phantom with 67Ga to determine the relative imaging ability of the NaI (Tl) detector and the Ge (Li) detector. When the scans were made with equal scan times, the NaI image was better than germanium image as shown in figure 8 (A). Scanning time was adjusted so that epual connts were obtained with germanium detector and the NaI detector using the 37-hole collimator. In this case, the cold spots in the germanium image showed slightly better resolution due to the increase in sharpness at the edges. From these studies, we have concluded that the imaging ability of the semiconductor detector is superior to that of the NaI (Tl) detector when equal counts are obtained. We feel that the use of germanium detectors for emission scanning in diagnostic Nuclear Medicine will be limited until such time as their sensitivity can be increased to the point where they can compete with NaI (Tl) detectors.
PracticeClinical medicine
Keywords

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