在乳房攝影中許多國家採用CDMAM 假體加上4 公分厚的PMMA 來模擬中等大小乳房以評估影像品質，此一CDMAM 組成約等效於5 公分厚之PMMA。由我們先前的研究顯示，台灣女性乳房的平均厚度比西方女性薄，因此，本研究的目的為比較CDMAM 假體加上4 公分PMMA 與加上台灣女性乳房平均等效厚度的PMMA 之影像品質差異。本研究共收集3910 頭腳方向（CC views）乳房影像之攝影參數，同時對每個乳房評估PMMA 的等效厚度，並評估三種乳房攝影系統攝影－底片式（SF）、電腦放射影像式（CR）與數位全景式（FFD）系統。本研究的結果顯示，台灣女性乳房平均等效厚度為4 公分PMMA，相當於CDMAM假體加上3 公分厚PMMA，本實驗中含4 公分PMMA 的CDMAM 假體之影像品質係數（IQFinv）為66 到83 (μm × mm)-1，含3 公分PMMA 的CDMAM 假體之影像品質係數（IQFinv）為80 到102 (μm × mm)-1。就結論而言，以CDMAM 假體加上3 公分PMMA 所測量之每一

The contrast-detail mammography phantom (CDMAM) with 4-cm PMMA slabs
is frequently used for estimation of the image quality of a medium-sized breast in many countries. This CDMAM configuration is equivalent to 5-cm PMMA slabs. In our previous studies, the average equivalent thickness of PMMA to breasts of Taiwanese women is thinner than that of western female. The purpose of this study is to compare the differences of image quality acquired between the CDMAM phantom with 4-cm PMMA slabs and the average equivalent thickness of PMMA to breasts of Taiwanese women. The imaging parameters from 3910 craniocaudal screen/film mammograms are collected and the equivalent thickness of PMMA is determined for each breast image. Three types of mammography imaging systems – screen/film (SF), computed radiography (CR) and full-field digital (FFD), were evaluated. Results from this study show that the average thickness of PMMA to the studied breasts is 4 cm which equivalent to the CDMAM phantom with 3-cm PMMA slabs. The inverse image quality factors (IQFinv) are ranged from 66 to 83 (μm × mm)-1 for the CDMAM phantom with 4-cm PMMA slabs and ranged from 80 to 102 (μm × mm)-1 for the CDMAM phantom with 3-cm PMMA slabs respectively. In conclusion, the threshold thickness of each detail diameter measured from the CDMAM phantom with 3-cm PMMA slabs is thinner than that of acquired from the CDMAM phantom with 4-cm PMMA slabs, which makes better image quality in mammography.