Park Hyunjin, Piert Morand R, Khan Asra, Shah Rajal, Hussain Hero, Siddiqui Javed, Chenevert Thomas L, Meyer Charles R
Department of Radiology, 109 Zina Pitcher Place, BSRB A520, University of Michigan, Ann Arbor, MI 48109, USA.
Acad Radiol. 2008 Aug;15(8):1027-39. doi: 10.1016/j.acra.2008.01.022.
Registration enables quantitative spatial correlation of features from different imaging modalities. Our objective is to register in vivo imaging with histologic sections of the human prostate so that histologic truth can be correlated with in vivo imaging features.
In vivo imaging of the prostate included T2-weighted anatomic and diffusion weighted 3-T magnetic resonance imaging (MRI) as well as 11C-choline positron emission tomography (PET). In addition, ex vivo 3-T MRI of the prostate specimen, histology, and associated block face photos of the prostate specimen were obtained. A standard registration method based on mutual information (MI) and thin-plate spline (TPS) was applied. Registration among in vivo imaging modalities is well established; however, accurate registration involving histology is difficult. Our approach breaks up the difficult direct registration of histology and in vivo imaging into achievable subregistration tasks involving intermediate ex vivo modalities like block face photography and specimen MRI. Results of subregistration tasks are combined to compute the intended, final registration between in vivo imaging and histology.
The methodology was applied to two patients and found to be clinically feasible. Overall registered anatomic MRI, diffusion MRI, and 11C-choline PET aligned well with histology qualitatively for both patients. There is no ground truth of registration accuracy as the scans are real patient scans. An indirect validation of the registration accuracy has been proposed comparing tumor boundary markings found in diffusion MRI and histologic sections. Registration errors for two patients between diffusion MRI and histology were 3.74 and 2.26 mm.
This proof of concept paper demonstrates a method based on intrinsic image information content for successfully registering in vivo imaging of the human prostate with its post-resection histology, which does not require the use of extrinsic fiducial markers. The methodology successfully mapped histology onto the in vivo imaging space, allowing the observation of how well different in vivo imaging features correspond to histologic truth. The methodology is therefore the basis for a systematic comparison of in vivo imaging for staging of human prostate cancer.
配准能够实现来自不同成像模态的特征的定量空间关联。我们的目标是将人体前列腺的活体成像与组织学切片进行配准，以便将组织学真相与活体成像特征相关联。
前列腺的活体成像包括T2加权解剖和扩散加权3-T磁共振成像（MRI）以及11C-胆碱正电子发射断层扫描（PET）。此外，还获得了前列腺标本的离体3-T MRI、组织学以及前列腺标本的相关块面照片。应用了基于互信息（MI）和薄板样条（TPS）的标准配准方法。活体成像模态之间的配准已经很成熟；然而，涉及组织学的精确配准却很困难。我们的方法将组织学与活体成像之间困难的直接配准分解为可实现的子配准任务，这些任务涉及诸如块面摄影和标本MRI等中间离体模态。子配准任务的结果被组合起来，以计算活体成像与组织学之间预期的最终配准。
该方法应用于两名患者，发现具有临床可行性。总体而言，对于两名患者，配准后的解剖MRI、扩散MRI和11C-胆碱PET在质量上与组织学良好对齐。由于扫描是真实患者的扫描，所以不存在配准准确性的金标准。已经提出了一种间接验证配准准确性的方法，即比较扩散MRI和组织学切片中发现的肿瘤边界标记。两名患者在扩散MRI和组织学之间的配准误差分别为3.74和2.26毫米。
这篇概念验证论文展示了一种基于固有图像信息内容的方法，用于成功地将人体前列腺的活体成像与其切除后的组织学进行配准，该方法不需要使用外部基准标记。该方法成功地将组织学映射到活体成像空间，从而能够观察不同的活体成像特征与组织学真相的对应程度。因此，该方法是系统比较人体前列腺癌分期的活体成像的基础。
