Compact Representations of Dynamic Liver MRI

描述（由申请人提供）：肝细胞癌（HCC）是最常见的恶性肝癌，在过去十年中发病率呈上升趋势。当患者符合一定的标准时，肝节段性切除和肝移植是有效的治疗选择，这依赖于对HCC病变的敏感和早期发现和影像学特征。由于肝脏病变严重，无法承受大面积切除或供体肝脏数量不足，这些治疗方法对大部分患者无效。对于这些患者，其他治疗方案包括全身化疗。虽然治疗反应通常是根据肿瘤大小的变化来衡量的，但这可能需要几个月的时间。因此，对治疗反应的敏感和早期测量预计也将对治疗产生重大影响。正是在这种情况下，定量磁共振成像发挥越来越大的作用。高时间和空间分辨率动态成像已被引入到对比增强肝脏MRI中，以克服注射时间问题，并捕获传统上用于诊断的所需增强阶段。然而，目前的方法仍然局限于屏气或非常适度的呼吸运动。此外，读者将看到大量的图像，从中手动选择典型的动脉、门静脉和延迟期是必要的。我们的长期目标是将MRI发展成为一种诊断肝脏疾病的可靠方法。作为这一目标的一部分，本应用的目的是将动态肝脏对比增强MRI转化为肝癌存在和进展的定量测量。我们的中心假设是，直接从原始MRI数据估计的肝动脉血流和丸剂到达时间的定量动力学参数图（KPM）在检测HCC方面比传统的多期MRI具有更好的诊断性能。所提出的研究的基本原理是，由此产生的kpi能够紧凑地表示对比度增强行为，这种行为是可重复的，并且适合于患者内部和患者之间的比较。我们计划通过以下目标来验证我们的假设：(1)开发一种成像方法，将获得的MR数据直接映射到定量动力学参数图上；(2)评估所开发的定量方法在肝移植患者中的诊断性能。本研究的预期结果是在早期发现和随访中更好地表征肝脏肿瘤。这种技术很可能产生积极的影响，因为它是预期的

DESCRIPTION (provided by applicant): Hepatocellular carcinoma (HCC), the most prevalent malignant liver cancer, has seen an increasing incidence rate over the last decade. Segmental liver resection and liver transplantation are curative options shown to be effective when the patient meets certain criteria, which rely on a sensitive and early detection and characterization of HCC lesions with imaging. Because the liver may be too diseased to tolerate a large resection or due to insufficient numbers of donor livers, these treatments are not available for a major part of the patient population. For these patients, other treatment options are considered including systemic chemotherapy. While treatment response is conventionally measured based on tumor size change, this may take several months to occur. A sensitive and early measurement of treatment response is therefore expected to significantly impact treatment as well. It is in this context that quantitative MR imaging plays an increasing role. High temporal and spatial resolution dynamic imaging has been introduced into contrast-enhanced liver MRI to overcome bolus-timing problems and to capture the desired enhancement phases traditionally used for diagnosis. However, current methods are still limited to breath-holds or very moderate amounts of respiratory motion. Additionally, the reader is presented with a large number of images, from which a manual selection of the typical arterial, portal-venous and delayed phases is necessary. Our long-term goal is to develop MRI into a robust method for the diagnosis of liver disease. As part of this goal, it is the objective of this application is to transform dynami liver contrast enhanced MRI into a quantitative measure of liver cancer presence and progression. Our central hypothesis is that a quantitative kinetic parametric map (KPM) of hepatic arterial blood flow and bolus arrival time estimated directly from the raw MRI data will have a better diagnostic performance for detecting HCC than conventional multiple phase MRI. The rationale for the proposed research is that the resulting KPMs enable a compact representation of the contrast enhancement behavior that is reproducible and lends itself to intra- and inter-patient comparisons. We plan to test our hypothesis by pursuing the following aims: (1) develop an imaging method that maps the acquired MR data directly onto quantitative kinetic parametric maps, and (2) evaluate the diagnostic performance of the developed quantitative method in patients undergoing liver transplantation. The expected outcome of this research of this research is a better method for characterizing liver tumors during initial detection and follow-up. Such a technique is likely to have a positive impact, since it is expected to allow a quantitative measure of cancer burden, allow an early measurement of treatment success or failure and reduce the need for liver biopsy.