Mousavi Seyed Reza, Wang Haisu, Hesabgar Seyyed Mohammad, Scholl Timothy J, Samani Abbas
Department of Electrical and Computer Engineering, Western University, London, Ontario N6A 5C1, Canada.
Department of Medical Biophysics, Western University, London, Ontario N6A 5C1, Canada.
Med Phys. 2015 Sep;42(9):5110-9. doi: 10.1118/1.4927572.
Association between tissue stiffness alteration and pathology is well known. This has formed the basis for prostate elastography imaging techniques where images of prostate tissue mechanical properties are reconstructed. In this paper, the authors present a novel prostate elastography technique which, unlike other techniques, relies on magnitude image data only.
This proposed technique works in conjunction with ultrasound or magnetic resonance imaging (MRI) imaging modalities and it requires the prostate's pre- and postdeformation images as input. It uses a constrained reconstruction method where the elastic moduli of the prostate's normal and pathological tissues are determined based on an essential subset of the tissue deformation provided by the images data. The elasticity reconstruction technique uses optimization where similarity between calculated and observed shape features of the postcompression prostate image is maximized. The method was validated with an in silico phantom study followed by studies using ultrasound and MR with tissue-mimicking phantoms.
Using the proposed methods, it was observed that the maximum uncertainties of the reconstructed Young's modulus ratios of tumor to normal tissue were 15.6% and 9.7%, which were obtained from the transrectal ultrasound (TRUS) and MR tissue-mimicking phantom studies, respectively.
This novel prostate elastography technique relies on prostate TRUS or MRI images that can be routinely acquired without additional imaging hardware. The phantom studies provided evidence that the proposed technique has a good potential to reconstruct prostate stiffness maps noninvasively particularly when applied in conjunction with MRI. Further studies are necessary to evaluate the technique's merits for clinical use.
组织硬度改变与病理学之间的关联已广为人知。这构成了前列腺弹性成像技术的基础，在该技术中可重建前列腺组织力学特性的图像。在本文中，作者提出了一种新颖的前列腺弹性成像技术，与其他技术不同，它仅依赖于幅度图像数据。
该提议的技术与超声或磁共振成像（MRI）模态协同工作，并且需要前列腺的变形前和变形后图像作为输入。它使用一种约束重建方法，其中根据图像数据提供的组织变形的一个基本子集来确定前列腺正常组织和病理组织的弹性模量。弹性重建技术使用优化方法，以使压缩后前列腺图像的计算形状特征与观察到的形状特征之间的相似度最大化。该方法先通过计算机模拟体模研究进行验证，随后使用超声和带有组织模拟体模的磁共振进行研究。
使用所提出的方法，观察到肿瘤与正常组织重建杨氏模量比的最大不确定性分别为15.6%和9.7%，这分别是通过经直肠超声（TRUS）和磁共振组织模拟体模研究获得的。
这种新颖的前列腺弹性成像技术依赖于可常规获取的前列腺TRUS或MRI图像，无需额外的成像硬件。体模研究提供了证据，表明所提议的技术具有无创重建前列腺硬度图的良好潜力，特别是与MRI结合应用时。有必要进行进一步研究以评估该技术在临床应用中的优点。
