研究のタイプ: 医学/生物学の研究 (experimental study)

[組織内マイクロ波ハイパサーミア後の正常な脳の反応] med./bio.

Normal brain response after interstitial microwave hyperthermia.

掲載誌: Int J Hyperthermia 1991; 7 (5): 795-808

この研究は、間隙ハイパサーミアの効果を、2450MHzマイクロ波の30分間処理した後の正常脳で評価した。単一のヘリカルコイルマイクロ波アンテナを前頭白質挿入し、アンテナに平行に5mm離して配置した測温プローブで測定される基準温度(40、41、42、43、44℃)を維持しつつ、30分間の照射を行った。維持した。高体温損傷の程度は、コンピュータ断層撮影法(CT)を用いて、6週間、毎週定量化された。超高速CTを用いて、局所脳血流(rCBF)および組織血管分布および平均通過時間の変化を測定した。定性的組織病理学的分析を、加熱後の様々な時点の組織に対して行った。結果として、CT画像における熱的損傷の特徴付け、組織壊死を生じさせる基準温度、治療終了後の回復、その他の知見を報告している。

The detailed summary of this article is not available in your language or incomplete. Would you like to see a complete translation of the summary? Then please contact us →

研究目的(著者による)

To assess the extent and time course of radiographic changes induced in dog brain after a single 30 min hyperthermia application (at temperatures of 40, 41, 42, 43 and 44°C). A helical coil microwave antenna was used to induce a small focal lesion in the frontal white matter, and the volumes of necrosis and contrast enhancement were measured weekly for 6 weeks using computed tomography.

影響評価項目

ばく露

ばく露 パラメータ
ばく露1: 2.45 GHz
Modulation type: CW
ばく露時間: 30 min
-

ばく露1

主たる特性
周波数 2.45 GHz
タイプ
  • electromagnetic field
波形
  • sinusoidal
ばく露時間 30 min
Modulation
Modulation type CW
ばく露装置
ばく露の発生源/構造
  • helical coil microwave antenna with 1cm long coil to antenna feed line at the tip
Distance between measurement device and exposure object 5 m
Distance between exposed object and exposure source 0.0135 m
ばく露装置の詳細 microwave antenna inserted inside the skull
Additional information CT scans for 0.1s at 130 kVp and exposures of 63mAs.
パラメータ

No parameters are specified for this exposure.

ばく露を受けた生物:

方法 影響評価項目/測定パラメータ/方法

研究対象とした生物試料:
研究対象とした臓器系:
調査の時期:
  • ばく露中
  • ばく露後

研究の主なアウトカム(著者による)

Heat lesions were characterized by rapid development and resolution and consisted of an area of focal low density surrounded by a ring of contrast enhancement. Histologically, the focus of low density corresponded to regions of tissue necrosis, whereas the ring enhancement showed local reactive changes (including endothelial cell proliferation and infiltration with macrophages).
Tissue necrosis was found at temperatures greater than 43.9 +/- 1.5°C, and volumes of necrosis and ring enhancement were at a maximum 1 week following application. Relative to the contralateral, unheated hemisphere, regional cerebral blood flow in the heated brain appeared to be reduced for the first 3 weeks after application but approached normal by week 4. The mean transit time of blood was increased for weeks 1-3 compared to the untreated hemisphere, and tissue vascularity reached a maximum, 3 weeks after application.
The rapid computed tomography changes together with ultrafast computed tomography and histopathological findings suggest that focal heat lesions in the brain stimulate a significant and rapid vascular response.

研究の種別:

研究助成