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3.0‐T MR‐guided focused ultrasound for preoperative localization of nonpalpable breast lesions: An initial experimental ex vivo study
Author(s) -
Schmitz Annemarie C.,
van den Bosch Maurice A.A.J.,
Rieke Viola,
Dirbas Frederick M.,
Butts Pauly Kim,
Mali Willem P.Th.M.,
Daniel Bruce L.
Publication year - 2009
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.21896
Subject(s) - ex vivo , medicine , ultrasound , radiology , in vivo , magnetic resonance imaging , nuclear medicine , microbiology and biotechnology , biology
Purpose To compare the accuracy of magnetic resonance‐guided focused ultrasound (MRgFUS) with MR‐guided needle‐wire placement (MRgNW) for the preoperative localization of nonpalpable breast lesions. Materials and Methods In this experimental ex vivo study, 15 turkey breasts were used. In each breast phantom an artificial nonpalpable “tumor” was created by injecting an aqueous gel containing gadolinium. MRgFUS ( n = 7) was performed with the ExAblate 2000 system (InSightec). With MRgFUS the ablated tissue changes in color and increases in stiffness. A rim of palpable and visible ablations was created around the tumor to localize the tumor and facilitate excision. MRgNW ( n = 8) was performed by MR‐guided placement of an MR‐compatible needle‐wire centrally in the tumor. After surgical excision of the tumor, MR images were used to evaluate tumor‐free margins (negative/positive), minimum tumor‐free margin (mm), and excised tissue volume (cm 3 ). Results With MRgFUS localization no positive margins were found after excision (0%). With MRgNW two excision specimens (25%) had positive margins ( P = 0.48). Mean minimum tumor‐free margin (±SD) with MRgFUS was significantly larger (5.5 ± 2.4 mm) than with MRgNW (0.9 ± 1.4 mm) ( P < 0.001). Mean volume ± SD of excised tissue did not differ between MRgFUS and MRgNW localization, ie, 44.0 ± 9.4 cm 3 and 39.5 ± 10.7 cm 3 ( P = 0.3). Conclusion The results of this experimental ex vivo study indicate that MRgFUS can potentially be used to localize nonpalpable breast lesions in vivo. J. Magn. Reson. Imaging 2009;30:884–889. © 2009 Wiley‐Liss, Inc.