Detection of breast cancer by soft-copy reading of digital mammograms: comparison between a routine image-processing parameter and high-contrast parameters.
BACKGROUND
Recent studies have reported the clinical usefulness of the soft-copy reading of mammograms. However, image-processing parameters for soft-copy reading of digital mammograms have not been established.


OBJECTIVE
To compare observer performance in detecting breast cancer by soft-copy reading of digital mammograms using a routine image-processing parameter versus each of several high-contrast parameters.


METHODS
The mammograms of 154 breasts, including 48 abnormal breasts with breast cancer and 106 normal breasts, were examined. Cancers were classified into 34 mass-dominant cancers, 11 microcalcification-dominant cancers, two cancers showing only architectural distortion, and one cancer without abnormal findings. All mammograms were performed using a computed radiography (CR) system. Each image was processed using GA (1.2), which was the contrast parameter recommended by the manufacturer for hard-copy film, GA (1.4), GA (1.6), and GA (1.8). These images were displayed on 5-megapixel (M) liquid-crystal display monitors. Five experienced radiologists classified them into BI-RADS category 1-2 or 3-5, and were also asked to rate the images on a scale of 0 to 100 for the likelihood of the presence of masses and microcalcifications in each breast.


RESULTS
In mass-dominant cancers of dense breast tissue, the mean sensitivities of GA (1.2), GA (1.4), GA (1.6), and GA (1.8) were 32.7, 38.2, 36.4, and 40.0, and the A(Z) values were 0.67, 0.73, 0.71, and 0.73, respectively; in microcalcification-dominant cancers, the mean sensitivities were 80.0, 74.5, 80.0, and 78.2, respectively; however, there were no significant differences among them.


CONCLUSIONS
High-contrast parameters tended to show relatively high sensitivity and A(Z) values in the detection of masses in dense breast tissue, but relatively low sensitivity for microcalcifications.
Kamitani
Takeshi
T
Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. kamitani@radiol.med.kyushu-u.ac.jp
Yabuuchi
Hidetake
H
Soeda
Hiroyasu
H
Matsuo
Yoshio
Y
Okafuji
Takashi
T
Sakai
Shuji
S
Setoguchi
Taro
T
Hatakenaka
Masamitsu
M
Ishii
Nobuhide
N
Honda
Hiroshi
H
D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008327:Mammography / Q000379:methods*; D012372:ROC Curve; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D012680:Sensitivity and Specificity; D014584:User-Computer Interface