Computer Assisted Clinical Medicine, Mannheim Institute for Intelligent Systems in Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
Fraunhofer Institute for Manufacturing Engineering and Automation, Department of Clinical Health Technologies, Mannheim, Germany.
Med Phys. 2022 Jul;49(7):4445-4454. doi: 10.1002/mp.15701. Epub 2022 May 11.
The liver is a common site for metastatic disease, which is a challenging and life-threatening condition with a grim prognosis and outcome. We propose a standardized workflow for the diagnosis of oligometastatic disease (OMD), as a gold standard workflow has not been established yet. The envisioned workflow comprises the acquisition of a multimodal image data set, novel image processing techniques, and cone beam computed tomography (CBCT)-guided biopsy for subsequent molecular subtyping. By combining morphological, molecular, and functional information about the tumor, a patient-specific treatment planning is possible. We designed and manufactured an abdominal liver phantom that we used to demonstrate multimodal image acquisition, image processing, and biopsy of the OMD diagnosis workflow.
The anthropomorphic abdominal phantom contains a rib cage, a portal vein, lungs, a liver with six lesions, and a hepatic vessel tree. This phantom incorporates three different lesion types with varying visibility under computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography CT (PET-CT), which reflects clinical reality. The phantom is puncturable and the size of the corpus and the organs is comparable to those of a real human abdomen. By using several modern additive manufacturing techniques, the manufacturing process is reproducible and allows to incorporate patient-specific anatomies. As a first step of the OMD diagnosis workflow, a preinterventional CT, MRI, and PET-CT data set of the phantom was acquired. The image information was fused using image registration and organ information was extracted via image segmentation. A CBCT-guided needle puncture experiment was performed, where all six liver lesions were punctured with coaxial biopsy needles.
Qualitative observation of the image data and quantitative evaluation using contrast-to-noise ratio (CNR) confirms that one lesion type is visible only in MRI and not CT. The other two lesion types are visible in CT and MRI. The CBCT-guided needle placement was performed for all six lesions, including those visible only in MRI and not CBCT. This was possible by successfully merging multimodal preinterventional image data. Lungs, bones, and liver vessels serve as realistic inhibitions during needle path planning.
We have developed a reusable abdominal phantom that has been used to validate a standardized OMD diagnosis workflow. Utilizing the phantom, we have been able to show that a multimodal imaging pipeline is advantageous for a comprehensive detection of liver lesions. In a CBCT-guided needle placement experiment we have punctured lesions that are invisible in CBCT using registered preinterventional MRI scans for needle path planning.
肝脏是转移瘤的常见部位，这是一种具有挑战性和危及生命的疾病，预后和结果都很严峻。我们提出了一种用于诊断寡转移瘤（OMD）的标准化工作流程，因为目前尚未建立金标准工作流程。该工作流程包括获取多模态图像数据集、新型图像处理技术和锥形束 CT（CBCT）引导下的活检，以进行后续的分子亚型分析。通过结合肿瘤的形态、分子和功能信息，可以为每位患者制定特定的治疗计划。我们设计并制造了一个腹部肝脏体模，用于演示 OMD 诊断工作流程的多模态图像采集、图像处理和活检。
该人体模拟腹部体模包含一个肋骨笼、门静脉、肺、一个带有六个病变的肝脏和一个肝血管树。该体模包含三种不同类型的病变，在 CT、磁共振成像（MRI）和正电子发射断层扫描 CT（PET-CT）下具有不同的可见度，这反映了临床实际情况。该体模可穿刺，且其体腔和器官的大小与真实人体腹部相似。通过使用几种现代增材制造技术，制造过程具有可重复性，并可以纳入患者特定的解剖结构。作为 OMD 诊断工作流程的第一步，对体模进行了介入前 CT、MRI 和 PET-CT 数据集采集。使用图像配准融合图像信息，并通过图像分割提取器官信息。然后进行了 CBCT 引导下的针穿刺实验，使用同轴活检针对所有六个肝脏病变进行了穿刺。
对图像数据的定性观察和使用对比噪声比（CNR）的定量评估证实，有一种病变类型仅在 MRI 中可见，而在 CT 中不可见。另外两种病变类型在 CT 和 MRI 中都可见。使用成功融合的多模态介入前图像数据，对所有六个病变进行了 CBCT 引导下的针放置，包括那些仅在 MRI 中可见而在 CBCT 中不可见的病变。肺、骨骼和肝血管在针路径规划中起到了真实的抑制作用。
我们开发了一种可重复使用的腹部体模，用于验证标准化 OMD 诊断工作流程。利用该体模，我们已经证明了多模态成像管道有利于全面检测肝脏病变。在 CBCT 引导下的针放置实验中，我们使用注册的介入前 MRI 扫描来规划针路径，对 CBCT 中不可见的病变进行了穿刺。
