Evaluation of the effect of zoom function on lesion detection by soft-copy reading of screening mammograms.

INTRODUCTION: This study aims to evaluate the effectiveness of zooming in improving screen-reader performance in reporting digital mammograms. METHOD: Two experiments were conducted. In the first experiment, 5 readers were asked to report 59 two-view bilateral mammograms retrospectively with zooming function turned off. The second session was similar to the first one except that zooming was enabled. The task of readers was to assess if the mammograms were normal or abnormal and rate the confidence levels for each of the lesion they detected. The reader performances were evaluated via case sensitivity, lesion sensitivity, specificity, receiver operating characteristics (ROC) area under the curve (AUC) and jackknife free-response receiver operating characteristics (JAFROC) figure of merit (FOM). RESULTS: There was no significant improvement in overall reader performance in detecting abnormalities in zooming condition compared with no zooming in terms of case sensitivity (96% and 87%, P = 0.285) or lesion sensitivity (88% and 81%, P = 0.224). However, differences in ROC AUC and JAFROC FOM (P ≤ 0.05) were found in two readers when they performed the test set with zooming function. CONCLUSION: The results suggested that the use of the zooming function did improve the performance of some readers in detecting abnormal cases.

Preoperative breast MRI for early-stage breast cancer: effect on surgical and long-term outcomes.

OBJECTIVE: The purpose of this study was to evaluate the effect of the use of preoperative breast MRI on surgical and long-term outcomes among women with early-stage breast cancer undergoing breast conservation therapy. MATERIALS AND METHODS: A retrospective review yielded the cases of 174 women with stage 0, I, or II breast cancer who underwent preoperative MRI between 2000 and 2004. A control group of 174 patients who did not undergo preoperative MRI before breast conservation therapy was matched by age, histopathologic finding, stage, and surgeon. Features compared included breast density, presence of mammographically occult disease, margin status, lymph node involvement, lymphovascular invasion, extensive intraductal component, hormone receptor status, and use of adjuvant therapy. Outcomes, including rates of reexcision, ipsilateral recurrence, and disease-free survival, were compared by Kaplan-Meier methods and the log-rank test. RESULTS: Patients referred for preoperative breast MRI were more likely to have extremely dense breasts (28% vs 6%, p < 0.0001) and mammographically occult cancer (24% vs 9%, p = 0.0003). The two groups had identical rates of final negative margins, lymph node involvement, lymphovascular invasion, extensive intraductal component status, positive hormone receptor results, and systemic adjuvant therapy. Fewer patients in the preoperative MRI group needed reexcision (29% vs 45%, p = 0.02). The median follow-up period after treatment was 8 years. There was no significant difference in locoregional recurrence (p = 0.33) or disease-free survival (p = 0.73) rates between the two groups. CONCLUSION: Reexcision rates among patients with early breast cancer undergoing conservation therapy were lower among women who underwent preoperative breast MRI. There was no statistically significant effect of the use of preoperative MRI on rates of locoregional recurrence or disease-free survival.