MR Imaging of the breast. Localization of focal breast lesions with the magnetom open at 0.2 T

Summary Purpose: To answer the following questions: whether reliable detection of lesions is possible in low-field-MRI-system (Magnetom Open 0.2 T) equipped with currently available hard- and software components in comparison to high field system (Magnetom Impact 1.0 T). Furthermore, whether localization of lesions suspect in MR-mammography can be realized in MR system of low field (Magnetom Open 0.2 T). Patients and Methods: In 11 patients, suspect lesions were diagnosed in diagnostic MR-mammography acquired with high field system (Magnetom Impact 1.0 T) and were compared to low field MR-mammographies of 0.2 T (Magnetom Open 0.2 T). In six of the 11 patients a suspect lesion was localized using wire marking. Results: All lesions considered suspect in diagnostic MR-mammography (Magnetom Impact 1.0 T) were also clearly identified in the 0.2 T system (Magnetom Open). In six cases wire marking was performed without any complications and with an accuracy of K 0.5 cm distance to the lesion. Conclusion: Although studies in the 0.2 T system clearly showed inferior SNR (34.6 vs. 83.1) and CNR (14.6 vs. 43.5) compared to studies with the high field system, all lesions considered suspect in diagnostic MR-mammography were reliably identified also in 0.2 T studies. Due to its open construction permitting permanent access to the breast and due to sufficient image quality, the Magnetom Open is suitable for interventions on the breast.