OPTIMIZING THE SPATIAL RESOLUTION OF MAMMOGRAPHY IMAGING QUALITY USING A CIRS-016A LINE PAIR GAUGE AND THE TAGUCHI METHODOLOGY.

This study optimized spatial resolution of mammography imaging quality using a CIRS-016A commercial line gauge and the Taguchi methodology. The line gauge with a precise line pair from 5 lp/mm to 20 lp/mm was placed on top of triangular PMMA plates to simulate the female breast undergoing mammography. Five factors: target/filter, kVp, mAs, PMMA plate thickness, and compression force, were organized into 18 groups according to the Taguchi L 1 8 orthogonal array. Tactically, the 18 various combinations of factors could provide similar confidence levels, as those following the full factorial combination in reality. Seven experienced radiology experts judged the 18 imaging qualities based on contrast, sharpness, and spatial resolution. Then the signal-to-noise ratio was calculated according to the "the larger, the better" ranking order. The optimal preset of mammography was verified from the unique fish bone plot and the follow-up analysis of variance (ANOVA) test. The optimal combination of factors was as follows: Rh/Ag as target/filter, 32 kVp, 36 mAs, a 45 mm thick PMMA plate, and a 13 daN compression force in routine diagnosis. The concurrent resolution of 6 lp/mm or about a 0.09 mm minimum detectable difference (MDD) was superior to 5 lp/mm of the conventional preset or combinations of factors of either highest Avg or lowest std. Compared to other studies with various facilities, this was the finest resolution among the routine X-ray, cardiac X-ray or computed tomography (CT), and computed tomography angiography (CTA). [ABSTRACT FROM AUTHOR]