Improving liver lesion biopsy in the CT suite through fusion with PET images

描述(申请人提供)：这项建议的总体目标是通过融合呼吸补偿的PET和CT套装中的CT图像来提高肝脏病变活检的临床有效性。仅就CT成像而言，肝脏病变的定位可能具有挑战性，特别是在某些病例中，肿瘤与邻近肝实质的区分可能很困难。考虑到在相同肿瘤没有CT相关性的情况下，PET能够定位恶性肿瘤，我们相信PET-CT引导的活检将通过提供针对代谢活跃的病变或较大肝脏病变内的特定“代谢热点”的指导，来提高肝病变活检的诊断率。然而，呼吸运动伪影严重影响了使用正电子发射计算机断层扫描(即使是在PET/CT混合机上)的诊断益处。在很短的时间内采集CT数据，表示呼吸周期中的瞬时快照。另一方面，每个龙门台位置的PET数据采集平均需要3-10分钟。对于典型的程序，平均需要5-7个龙门位置。这些延长的采集时间会导致图像中出现呼吸运动伪影。这些伪影反过来会导致CT和PET数据之间的空间一致性不一致，导致肿瘤定位不准确，肿瘤分期不正确。因此，开发一种有效的PET-CT引导下的肝脏病变活检需要强大的呼吸运动校正技术。我们建议开发适用于腹部成像的呼吸运动校正和配准组件，并扩展我们的开源图像引导手术系统(IGSTK)，使其能够在CT套件中进行PET/CT引导的肝脏病变活检。呼吸运动校正算法将利用相位匹配的呼吸门控PET和CT数据以及超分辨率重建算法来生成无运动的高质量PET图像。我们将开发一种新的图像配准算法，以补偿呼吸引起的器官滑动。传统的配准方法不能很好地处理器官滑动，传统的配准方法假设一幅图像可以平滑地变形成下一幅图像。 公共卫生相关性：PET/CT成像在可疑病变的早期发现、分期和评估中起着关键作用。PET成像提供有关肿瘤功能或代谢特征的信息，而CT主要评估肿瘤的解剖和形态特征。通过融合这两种成像技术，并结合先进的图像配准和呼吸运动补偿技术，临床医生可以有效地对肝脏病变进行活检。

DESCRIPTION (provided by applicant): The broad objective of this proposal is to improve the clinical effectiveness of liver lesion biopsy by fusing respiratory-compensated PET with CT images in the CT suite. On CT imaging alone, localization of liver lesions can potentially be challenging, particularly in selected cases where differentiation of the tumor from adjacent liver parenchyma may be difficult. Given the ability of PET to localize malignancies in situations where the same tumors do not have a CT correlate, we believe that PET-CT guided biopsy would improve the diagnostic yield of liver lesion biopsies by providing guidance in targeting a metabolically active lesion or a specific "metabolic hot spot" within a larger liver lesion. However, the diagnostic benefit of using PET scans (even from hybrid PET/CT machines) is gravely affected by respiratory motion artifacts. CT data is acquired in a short time representing an instantaneous snapshot during the breathing cycle. On the other hand, PET data acquisition takes an average 3-10 minutes per gantry table position. For typical procedures, 5 -7 gantry positions are required on average. These prolonged acquisition times lead to respiratory motion artifacts in the images. These artifacts, in turn, cause discrepancy in spatial correspondence between the CT and PET data, inaccurate tumor localization, and incorrect tumor staging. Hence, development of an effective PET-CT guided biopsy for liver lesions requires a robust respiratory motion correction technique. We propose to develop respiratory motion correction and registration components suitable for abdominal imaging and extend our open source image-guided surgery system (IGSTK) to enable PET/CT guided liver lesion biopsy in the CT suite. The respiratory motion correction algorithm will utilize phase matched respiratory-gated PET and CT data and super- resolution reconstruction algorithm to generate a motion-free high quality PET image. We will develop a novel image registration algorithm that will compensate for respiration-induced organ- sliding. Organ-sliding is not handled well by traditional registration methods which assume that one image can be smoothly deformed into the next. PUBLIC HEALTH RELEVANCE: PET/CT imaging plays a key role in early detection, staging, and evaluation of suspicious lesions. PET imaging provides information on functional or metabolic characteristics of tumors, whereas CT predominately assesses the tumor's anatomical and morphological features. By fusing these two imaging techniques and incorporating advanced image registration and respiratory motion compensation techniques, clinicians can effectively biopsy liver lesions.