Utility of Real-time Virtual Sonography (RVS), anew breast imaging method for coordinating sonography with an MRIusing an image fusion technique

我们开发了实时虚拟超声检查（RVS），一种使用图像融合技术协调超声检查与MRI系统的方法。自2005年以来，我们已将此方法应用于MRI检测到的乳腺病变的超声评价。我们之前报道，在2009年，使用RVS识别了98%的MRI增强指示质量和83%的MRI检测到的病变（中野等人，Jpn J Clinic Oncol 2009）。本研究的目的是（1）评价RVS在超声识别乳腺MRI检测到的增强病变中的靶向准确性，（2）验证使用RVS进行二次超声检查的实用性。(1)我们分析了定位误差，从实际超声位置到预期MRI位置的三维距离。横向和矢状面以及距皮肤深度的平均定位误差分别为7.7、6.9和2.8 mm。总体平均三维定位误差为12.0 mm（中野等人，超声医学生物学，2012）。(2)我们分析了使用传统B型或RVS的二次超声检查的病变检出率之间的相关性。在67个病变（24个恶性病变和43个良性病变）中，常规B模式的检出率为27%（18/67）; RVS显著提高了这些检出率，达到90%（60/67）（p <0.001）（中野等人，乳腺癌研究治疗2012）。我们的研究结果表明，RVS在超声图像与MRI结果的直接比较中具有良好的靶向准确性，并且在二次超声检查中额外使用RVS显著增加了MRI检测到的病变的超声检出率，而无需依赖于操作者。我们相信RVS是一种很有前途的乳腺成像新方法。

We have developed real-time virtual sonography (RVS), a method for coordinating sonography with an MRI system using an image fusion technique. Since 2005, we have applied this method to sonographic evaluation of MRI-detected lesions of the breast. We reported previously that in 2009, 98% of MRI enhanced index mass and 83% of MRI-detected lesions were identified using RVS (Nakano, et al. Jpn J Clinic Oncol 2009). The aims of this study were (1) to evaluate the targeting accuracy of RVS in sonographic identification of enhancing lesions detected by breast MRI, and (2) to verify the utility of second-look sonography using RVS. (1) We analyzed the positioning error, i.e., the distance from the actual sonographic position to the expected MRI position, in three dimensions. The meanpositioning errors for the transverse and sagittal planes and the depth from the skin were 7.7, 6.9, and 2.8 mm, respectively. The overall mean three-dimensional positioning error was 12.0 mm (Nakano, et al. Ultrasound Med Biol 2012). (2) We analyzed the correlations between lesion detection rates on second-look sonography using conventional B-mode or RVS. Among 67 lesions (24 malignant and 43 benign), the detection rate of conventional B-mode was 27% (18/67); RVS increased these rates signi〓cantly, to 90 % (60/67) (p <0.001) (Nakano, et al. Breast Cancer Res Treat 2012). Our results suggest that RVS has good targeting accuracy in a direct comparison of a sonographic image with MRI results, and the additional use of RVS on second-look sonography signi〓cantly increases the sonographic detection rate of MRI-detected lesions without operator dependence. Webelieve that RVS represents a promising new modality for breast imaging.