Diagnostic performance of detecting breast cancer on computed radiographic (CR) mammograms: comparison of hard copy film, 3-megapixel liquid-crystal-display (LCD) monitor and 5-megapixel LCD monitor

Abstract

The purpose was to compare observer performance in the detection of breast cancer using hard-copy film, and 3-megapixel (3-MP) and 5-megapixel (5-MP) liquid crystal display (LCD) monitors in a simulated screening setting. We amassed 100 sample sets, including 32 patients with surgically proven breast cancer (masses present, N = 12; microcalcifications, N = 10; other types, N = 10) and 68 normal controls. All the mammograms were obtained using computed radiography (CR; sampling pitch of 50 mum). Twelve mammographers independently assessed CR mammograms presented in random order for hard-copy and soft-copy reading at minimal 4-week intervals. Observers rated the images on seven-point (1 to 7) and continuous (0 to 100) malignancy scales. Receiver-operating-characteristics analysis was performed, and the average area under the curve (AUC) was calculated for each modality. The jackknife method with the Bonferroni correction was applied to multireader/multicase analysis. The average AUC values for the 3-MP LCD, 5-MP LCD, and hard-copy film were 0.954, 0.947, and 0.956 on the seven-point scale and 0.943, 0.923, and 0.944 on the continuous scale, respectively. There were no significant differences among the three modalities on either scale. Soft-copy reading using 3-MP and 5-MP LCDs is comparable to hard-copy reading for detecting breast cancer.

Current status and issues of screening digital mammography in Japan

“…However, soft-copy reading has the advantage of optimizing the display for each mammogram. A recent study by receiver operating characteristics (ROC) analysis demonstrated there were no significant differences between hard-copy and soft-copy reading [14][15][16]. The soft-copy reading in these studies was performed by using monochrome crystal ray tube (CRT) or liquid-crystal display (LCD) monitors with old specifications, for example 8-bit gray scale.…”

“…Then even a 5-MP monitor has a critical shortage of pixels and requires 2-fold magnification of the images with sampling pitch at 50 lm to display the images at the same number of pixels (Tables 3, 5). The past report demonstrated that diagnostic performance of digital mammograms with 3-MP LCD monitors and 5-MP LCD or CRT monitors was equivalent to each other [15,18]. This is probably because both of them allowed magnified observation.…”

Diagnostic digital mammography in Japan: issues to consider

“…Recently, Yamada et al also reported that soft-copy reading using 3 and 5 MP displays is comparable to hard-copy reading for detecting breast cancer using a sampling pitch with a 50-lm imaging plate [7].…”

Initial clinical evaluation of observer performance using a tablet computer with a 4K high-resolution display for detection of breast cancer by digital mammography

“…High-grade (so-called medical purpose) LCDs, such as the 5-megapixel (MP) LCD, are recommended for soft-copy reading in digital mammography [10][11][12].…”