Abstract and Introduction
Abstract
Objective: The purposes of this study were to assess the sensitivity and specificity of 3-T MRI compared with those of mammography and sonography in the evaluation of breast cancer and to evaluate the results in light of previously published data obtained with 1-T and 1.5-T systems.
Materials and Methods: A retrospective review was conducted with data on 434 women (mean age, 53 years) who underwent MRI evaluation of the breasts (n = 868). Results obtained from 3-T MRI, mammographic, and sonographic examinations of all patients were compared. Sensitivity, specificity, and predictive values were calculated, and statistics were analyzed with the chi-square test.
Results: The sensitivities of MRI, mammography, and sonography in the detection of malignancy were 100%, 81.8%, and 86.4%, and the specificities were 93.9%, 99%, and 98.1%. The specificity of MRI increased from 92.8% to 94.5% over the course of the study (2006-2007). Compared with mammography (p < 0.001) and sonography (p = 0.001), MRI depicted a significantly higher number of malignant tumors of the breast. There was no significant difference between mammography and sonography (p = 0.095). Results were compared with those in earlier reports in the literature.
Conclusion: MRI at 3 T is more sensitive than mammography and sonography in the detection of breast cancer and the characterization of small lesions (reaching 4 mm) but has lower specificity. Compared with the results of 1-T and 1.5-T MRI in the literature, 3-T MRI has higher sensitivity in the detection of breast cancer with no significant difference in specificity.
Introduction
Contrast-enhanced MRI of the breast was first performed in the late 1980s on women with biopsy-proven breast cancer.[1] Since then, advances in this field have included the introduction of contrast agents, developments in surface coil technology, and innovation in imaging protocols. These advances have made contrast-enhanced MRI a promising technique for the detection, diagnosis, and staging of breast cancer.[1,2,3,4]
Because of its high sensitivity, MRI is more useful than mammography in the early detection of breast cancer in patients at high risk, especially those with dense breast tissue. MRI can depict occult breast tumors not detected clinically or with mammography, resulting in changes in patient care.[1,2,3,4] Moreover, MRI findings can be used to improve estimation of residual cancer after neoadjuvant chemotherapy.[5,6,7] The major limitation of MRI, however, is the low-to-moderate specificity, which in combination with high sensitivity can lead to unnecessary biopsy, patient anxiety, and expense.[2,3,8]
High-field-strength (3 T) MRI systems are becoming increasingly available in the clinical setting. With the inherently high signal-to-noise ratio of these systems, appropriate acquisitions can be used to achieve high spatial and temporal resolution that ensures accurate detection of a lesion and its pattern of enhancement.[2,9,10,11] These advantages of 3-T MRI have raised expectations about overcoming previous limitations in evaluating breast cancer. The aim of this study was to analyze the sensitivity and specificity of 3-T MRI compared with mammography and sonography in the evaluation of breast cancer and to assess the results in light of previously published data obtained with lower-strength (1 and 1.5 T) systems.
Am J Roentgenol. 2009;192(4):1142-1148. © 2009 American Roentgen Ray Society
Cite this: Increasing Accuracy of Detection of Breast Cancer with 3-T MRI - Medscape - Apr 01, 2009.
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