乳房攝影檢查的乳腺吸收劑量一直以來都備受關注，(International Commission on Radiological Protection, ICRP)第103 號報告更是將乳腺的組織加權因素(WT)從0.05 增加至0.12，而我國目前則以(Mammography Quality Standards Act, MQSA)為依據管控乳房攝影的影像品質(AGD<3mGy)，因此(American College of Radiology, ACR) 品質保證假體(RMI-156)則是一項很重要的驗證工具。本研究採ACR 認證假體做模擬攝影，以(As Low As Reasonably Achievable, ALARA)原則尋求最佳化參數組合，並從中探討一重要之議題，乳房攝影檢察壓迫力之必 要性。依臨床經驗找出重要因子並以±15%原則調整控制因子水準，依L18(21×33)直交表的實驗組合對ACR 假體 進行曝露，由3 位放射師以信號雜訊比的望大(Larger the better, LTB) 模式第I-I 型對影像評分，將結果進行因子 效應及交互作用分析，以ANOVA(F-test)檢定，尋求品質最佳化。由望大I-I 型因子反應表可知，改變kVp 會影 響品質特性使影像產生變異，屬最具影響力之因子，其ȳ、(signal noise ratio, S/N )、Sd 分別為5.4、5.2、0.06， 信心水準門檻為99%，因不飽和直交表實驗無充分利用所有自由度，SSc 的值最大(311.044)， F 值也會隨之變大 (5118.90)， kVp 的貢獻度也高達86.60%，信賴水準大於99%，所以此實驗的參數最佳化結果為A1(Mo/Mo)，B3(80 mAs)，C2(30 kVp)，D2(8 dekanewton, daN)，kVp 和壓迫力有很強的交互作用，但實驗中發現只有壓迫力8daN 時會隨著kVp 的增加S/N 穩定的呈線性成長，不過在高kVp 時皆會出現S/N 飽和的狀態，所以臨床上平壓厚度 約4 cm 乳房時，只需8daN 的壓迫力和適切的kVp 即可達到佳的影像品質。

Average glandular dose (AGD) in digital mammography is very important. ICRP released Publication 103 in 2007 with recommended values for the tissue weighting factors. Major changes from the prior weighting factors published in ICRP Publication 60 include an increase in breast tissue weighting factor from 0.05 to 0.12. The mammographic phantom image quality was trying to follow the MQSA suggestion, and minimize the dose below 3 mGy. So the ACR phantom is an important tool. The Taguchi methodology as applied herein was compiled for optimizing the mammographic setting or measuring compression force. The critical parameters that determined the quality of a mammographic image were identified as the target/filter, mAs, kVp, daN of the X-ray. The optimized result were indicated as A1(Mo/Mo), B3(80 mAs), C2(30 kVp), D2(8 daN). kVp and compression force has a strong interaction. But the experiment found, as the kVp will increase S/N stable linear growth when the pressing force 8 daN. But it at high kVp will appear saturated state B/N ratio. So the clinically useful platen thickness of about 4 cm breast, Just pressing force 8 daN and right kVp to achieve excellent image quality.