Comparison of slot scanning digital mammography system with full-field digital mammography system.
The purpose of this study was to evaluate and compare microcalcification detectability of two commercial full-field digital mammography (DM) systems. The first unit was a flat panel based DM system (FFDM) which employed an anti-scatter grid method to reject scatter, and the second unit was a charge-coupled device-based DM system (SSDM) which used scanning slot imaging geometry to reduce scatter radiation. Both systems have comparable scatter-to-primary ratios. In this study, 125-160 and 200-250 microm calcium carbonate grains were used to simulate microcalcifications and imaged by both DM systems. The calcium carbonate grains were overlapped with a 5-cm-thick 50% adipose/50% glandular simulated breast tissue slab and an anthropomorphic breast phantom (RMI 165, Gammex) for imaging at two different mean glandular dose levels: 0.87 and 1.74 mGy. A reading study was conducted with seven board certified mammographers with images displayed on review workstations. A five-point confidence level rating was used to score each detection task. Receiver operating characteristic (ROC) analysis was performed and the area under the ROC curve (A(z)) was used to quantify and compare the performances of these two systems. The results showed that with the simulated breast tissue slab (uniform background), the SSDM system resulted in higher A(z)'s than the FFDM system at both MGD levels with the difference statistically significant at 0.87 mGy only. With the anthropomorphic breast phantom (tissue structure background), the SSDM system performed better than the FFDM system at 0.87 mGy but worse at 1.74 mGy. However, the differences were not found to be statistically significant.
Lai
Chao-Jen
CJ
Department of Imaging Physics, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030-4009, USA. chaolai@di.mdacc.tmc.edu
Shaw
Chris C
CC
Geiser
William
W
Chen
Lingyun
L
Arribas
Elsa
E
Stephens
Tanya
T
Davis
Paul L
PL
Ayyar
Geetha P
GP
Dogan
Basak E
BE
Nguyen
Victoria A
VA
Whitman
Gary J
GJ
Yang
Wei T
WT
D002113:Calcification, Physiologic; D006801:Humans; D042361:Mammary Glands, Human / Q000502:physiology; D008327:Mammography / Q000379:methods*; D008954:Models, Biological; D019047:Phantoms, Imaging; D012372:ROC Curve; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity