可壓迫乳房假體實驗設計－應用於評估乳房攝影中平均乳腺劑量

Application of Compressible Breast Phantoms for Estimating the Average Glandular Dose in Mammography

林芮祁(Ruei-Chi Lin) ； 洪思穎(Szu-Ying Hung) ； 董尚倫(Shang-Lung Dong) ； 黃正達(Cheng-Ta Huang) ； 錢信德(Hsin-Te Chian)

《北市醫放雜誌》 10卷1期 (2020/12) Pp. 31-36

https://doi.org/10.6663/TPART.202012_10(1).0005

摘要

本研究旨在開發一適用於厚度測量裝置（thickness measurement device，以期能在不同的壓迫條件下有效地評估平均乳腺劑量（Average Glandular Dose），並取得厚度校正（Thickness correction）模型。實驗設計中使用配有軟式壓迫板及硬式壓迫板的數位乳房系統（Mammomat Novation DR, Siemens）、使用壓克力板和壓克力棒製作厚度測量裝置（34×20×27cm3），在不同臨床攝影條件下評估乳房假體的平均乳腺劑量，藉此能模擬受壓迫後的乳房厚度，並且得到近似於實際檢查中的乳腺劑量。為測量假體厚度，採用了硬式及軟式壓迫板對於4公分厚的軟性假體施加不同的壓迫力。另為評估平均乳腺劑量，採用可壓迫乳房假體（SNB, MODEL: 013，CIRS），分別使用軟式及硬式壓迫板，接受80-200牛頓力（N）壓迫後成像。使用厚度校正模型評估壓迫厚度，並以厚度測量裝置評估不同壓迫情形下乳房平均乳腺劑量的變化，依據研究結果顯示，在硬式或是軟式壓迫板下，乳腺劑量會隨著壓迫力的增加而增加。分析相關研究結果顯示，使用SID計算平均乳腺劑量會被高估，而本研究設計結合厚度測量裝置及軟式假體所提出的厚度校正模型可以快速且準確的評估壓迫後的假體厚度。因此應用厚度測量裝置及厚度校正模型，搭配膠體填充物假體所計算出來的平均乳腺劑量為具有高度準確且可運用於後續的劑量評估。

關鍵字

平均乳腺劑量 ； 厚度測量裝置 ； 厚度校正模型

並列摘要

In this study, a thickness measurement device was developed to effectively evaluate the average glandular dose under different compression conditions. The thickness correction model was developed to evaluate the dose of the breast prosthesis under different clinical mammography conditions, thereby simulating the breast thickness after compression, and obtaining the glandular dose similar to the examination. A digital mammography equipped with a soft and hard compression paddle was used, and an acrylic phantom and acrylic rod were used to make a thickness measuring device (34×20×27cm^3). To measure the thickness of the prosthesis, compression paddle are used to apply different compression forces to the 4cm bolus phantom, the breast phantom (SNB, MODEL: 013, CIRS) were used, soft and hard compression paddle were used respectively, and images were taken after 80-200 (N) compression. It'll increase with the increase of the compression force under the compression paddle. The results show that using SID to calculate the dose will be overestimated, and the thickness correction model proposed by the design of this study combined with the thickness measurement device and the soft bolus phantom can quickly and accurately the thickness after compression. Therefore, the breast dose calculated by using the thickness measuring device and the thickness correction model with the bolus phantom is highly accurate.

並列關鍵字

average glandular dose ； thickness measurement device ； thickness correction model