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
Department of Radiology, Stanford University Medical Center, Stanford, California, USA.
J Magn Reson Imaging. 2009 Oct;30(4):884-9. doi: 10.1002/jmri.21896.
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.
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)).
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).
The results of this experimental ex vivo study indicate that MRgFUS can potentially be used to localize nonpalpable breast lesions in vivo.
比较磁共振引导聚焦超声（MRgFUS）与磁共振引导针丝定位（MRgNW）在不可触及乳腺病变术前定位中的准确性。
在这项实验性离体研究中，使用了15个火鸡乳房。在每个乳房模型中，通过注射含钆的水性凝胶创建一个人工不可触及的“肿瘤”。使用ExAblate 2000系统（InSightec）进行MRgFUS（n = 7）。通过MRgFUS，消融组织颜色发生变化且硬度增加。在肿瘤周围创建一圈可触及且可见的消融区以定位肿瘤并便于切除。通过磁共振引导将与磁共振兼容的针丝置于肿瘤中心进行MRgNW（n = 8）。肿瘤手术切除后，使用磁共振图像评估切缘有无肿瘤残留（阴性/阳性）、最小无瘤切缘（mm）以及切除组织体积（cm³）。
MRgFUS定位切除后未发现阳性切缘（0%）。MRgNW有两个切除标本（25%）切缘阳性（P = 0.48）。MRgFUS的平均最小无瘤切缘（±标准差）显著大于MRgNW，分别为5.5 ± 2.4 mm和0.9 ± 1.4 mm（P < 0.001）。MRgFUS和MRgNW定位切除组织的平均体积±标准差无差异，分别为44.0 ± 9.4 cm³和39.5 ± 10.7 cm³（P = 0.3）。
这项实验性离体研究结果表明，MRgFUS可能可用于体内不可触及乳腺病变的定位。
