Automatic passive tracking of an endorectal prostate biopsy device using phase-only cross-correlation
Automatic passive tracking of an endorectal prostate biopsy device using phase-only cross-correlation
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DOI：
10.1002/mrm.21430
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发表时间：
2008-05-01
影响因子：
3.3
通讯作者：
Bock, Michael
中科院分区：
文献类型：
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作者：
de Oliveira, Andre;Rauschenberg, Jaane;Bock, Michael
MR引导经直肠前列腺活检目前是一个耗时的过程，因为在病变靶向期间成像切片通常与活检针手动重新对准。在这项工作中，脉冲序列，自动遵循被动标记附在一个专用的MR活检设备保持器，从而提供了一种替代现有的主动跟踪方法。在标记的两个正交跟踪FLASH图像中，使用仅相位互相关（POCC）算法自动识别针轴的位置。然后，位置信息用于在真实的时间中重新对准真实的FISP成像切片。在体模实验中，评价了该技术对标记物初始未对准和信噪比的灵敏度。在几次穿刺实验中，分析了针放置的精度。POCC算法允许精确识别图像中的标记，即使在高达45度的严重初始失准下。在帧速率1图像/s下，可以实现1.5 +/- 1.1 mm的针放置精度。
MR-guided transrectal prostate biopsy is currently a time-consuming procedure because the imaging slice is often manually realigned with the biopsy needle during lesion targeting. In this work a pulse sequence is presented that automatically follows a passive marker attached to a dedicated MR biopsy device holder, thus providing an alternative to existing active tracking methods. In two orthogonal tracking FLASH images of the marker the position of the needle axis is automatically identified using a phase-only cross-correlation (POCC) algorithm. The position information is then used to realign a trueFISP imaging slice in real time. In phantom experiments the sensitivity of this technique to initial misalignments of the marker and to the signal-to-noise ratio was evaluated. In several puncture experiments the precision of the needle placement was analyzed. The POCC algorithm allowed for a precise identification of the marker in the images even under severe initial misalignments of up to 45 degrees. At a frame rate 1 image/s a precision of the needle placement of 1.5 +/- 1.1 mm could be achieved.