探討CT-SD16固態偵檢器應用於電腦斷層掃描X射束劑量品質的可行性

Feasibility of Using a Novel CT-SD16 Solid-state Detector to Perform Multi-slice CT Quality Assurance

賴南谷(Nan-Ku Lai) ； 田雨生(Yu-Sheng Tyan) ； 廖英蘭(Ying-Lan Liao) ； 鄭凱元(Kai-Yuan Cheng) ； 蔡惠予(Hui-Yu Tsai)

《中華放射線技術學雜誌》 33卷2期 (2009/12) Pp. 85-92

https://doi.org/10.30045/CJRT.200912.0003

摘要

本研究目的是探討CT-SD16固態偵檢器用於多切片電腦斷層X射束劑量的品質保證之可行性。傳統上是以底片與長棒狀游離腔分別來量測電腦斷層的射束寬度與劑量指標。本研究分別以底片、DCT10游離腔及CT-SD16固態偵檢器，進行射束寬度與多切片電腦斷層劑量指標兩項品質保證量測作業。結果顯示對射束寬度的評估，CT-SD16固態偵檢器的結果會略低於底片1.2~4.5%，而CT-SD16固態偵檢器放在空氣與假體中的量測結果差異小於1%。評估有效電腦斷層劑量指標時，CT-SD16固態偵檢器的量測值會大於DCT10游離腔的量測值，差異在10%以內，此乃因螺旋式掃描與軸狀掃描方式所造成。由於CT-SD16固態偵檢器可在一次螺旋掃描下，立即量測到射束寬度與有效電腦斷層劑量指標，因此新型CT-SD16固態偵檢器用於多切片電腦斷層在劑量方面的品質保證，既快速又方便，且其在螺旋式下掃描是更接近臨床的使用狀況。

關鍵字

多切片電腦斷層 ； 品質保證 ； 射束寬度 ； 電腦斷層劑量指標 ； 固態偵檢器

並列摘要

The purpose of this study is using a new CT-SD16 solid-state detector to progress multi-slice computed tomography (MSCT) quality assurance, such as radiation beam width and CT dose index (CTDI). The CT-SD16 solid-state detector was used to measure beam widths and CTDI values for two multi-slice CT scanners, and the results were compared with those from the film and the ionization chamber. The beam widths estimated by the CT-SD16 solid-state detector were lower about 1.2~4.5% than those from film. The CT-SD16 solid-state detector could estimate the amount of the scatter, so the beam widths estimated in air or in phantom were similar; their differences were within 1%. The CTDIs measured by the CT-SD16 solid-state detector were slightly higher than those by the ionization chamber. The difference was within 10% due to different scanning modes. This new solid-state CT-SD16 solid-state detector can be used to measure radiation dose distribution, beam width and CTDI simultaneously within one helical scanning series. It is suitable for MSCT quality assurance because it can provide a fast and convenient measurement.

並列關鍵字

MSCT ； QA ； Beam width ； CTDI ； Solid-state detector