Endorectal Prostate MRI w/Tetrahedron Tracking; Better Cancer Delineation

带四面体跟踪的直肠内前列腺 MRI；

• 批准号: 8243101
• 负责人: ehud Jeruham schmidt
• 金额: $ 18.33万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8243101
• 关键词: Air; Animals; Cancer Patient; Canis familiaris; Caring; Clinical; Diagnosis; Diffusion; Echo-Planar Imaging; Feedback; Financial compensation; Goals; Heart; Hospitals; Human; Image; Incidence; Magnetic Resonance Imaging; Magnetism; Malignant Neoplasms; Malignant neoplasm of prostate; Maps; Measures; Morphologic artifacts; Motion; Noise; Normal tissue morphology; Oncologist; Outcome Measure; Phase; Physiologic pulse; Positioning Attribute; Predisposition; Preparation; Prostate; Rectum; Relative (related person); Research; Resolution; Respiration; Role; Rotation; Scanning; Sensitivity and Specificity; Shapes; Signal Transduction; Solutions; Staging; Surface; Testing; Time; Tissues; Translations; Tumor Tissue; Ultrasonography; United States National Institutes of Health; Water; Weight; Woman; base; cohort; cost; design; experience; improved; magnetic field; novel; phase change; planetary Atmosphere; pressure; prospective; radiologist; rectal; respiratory; response; soft tissue; tumor

DESCRIPTION (provided by applicant): This research aims to improve the MRI-based diagnosis of prostate cancer, by utilizing a new MRI endorectal assembly that can improve MRI specificity and sensitivity. A novel Endorectal assembly includes a tetrahedron array of positional tracking coils, and a mechanism for compressing the prostate. The tetrahedron array provides motion compensation and magnetic field correction. The assembly enables segmented Diffusion-weighted EPI (DW-EPI) imaging with reduced distortion. A Strain imaging sequence utilizes prostate compression to differentiate tumor from normal tissue. The applications are tested in a 12-dog cohort, including 8 with prostate cancer. The Specific Aims are: AIM #1: Develop endorectal coils with integrated tetrahedron tracking coils. The new Endorectal coils will be built and tested. We add a tetrahedron-shaped array of four micro-coils. This array is kept folded during rectal insertion, so as not to occupy additional footprint, with a mechanism for expansion before use. A water-driven compression mechanism pressurizes a balloon in the assembly, delivering a short-duration compression of the prostate. Outcome measures are tracking SNR and motion correction accuracy. AIM #2: Develop DW-EPI sequences with integrated prospective motion compensation. We will develop a segmented DW-EPI sequence which utilizes the tracking tetrahedron (AIM 1) for positional and phase correction. Prostate single-shot DW-EPI suffers from geometric distortions, due to non-uniform magnetic-fields. Our solution utilizes reduced-distortion segmented EPI, which require corrections for motion and for phase changes, provided by the tracking array and transferred in real-time to the pulse sequence. Outcome measures are the spatial distortion reduction vs. efficiency cost, as observed in dogs with prostate cancer. AIM #3: Develop MRI strain sequences using hydraulic prostate compression. We will develop, optimize and test in dogs, a DENSE [Displacement Encoding with Stimulated Echo] strain pulse sequence which uses the Endorectal coil (AIM 1). Strain imaging will utilize short-duration balloon-induced compression to determine the prostate's elastic response (compliance). The tracking coils will be used to trigger the sequence during periods when respiratory motion is small. Outcome measures will be the strain SNR in the prostate, the CNR between tumor and normal tissues, the effects of respiration, and the scan's temporal efficiency. PUBLIC HEALTH RELEVANCE: Prostate cancer is the US's largest cancer by incidence, and 2nd largest by mortality1, 2. MRI's role is increasing, as seen in the major increases in prostate MRI procedures2. Initially, MRI diagnosis/staging was primarily based on soft-tissue contrast3-6 but it is increasingly apparent that higher specificity/sensitivity resides in micro-structural contrast, as seen with perfusion7 or diffusion8.

描述（由申请人提供）：本研究旨在通过使用可提高MRI特异性和灵敏度的新型MRI直肠内组件，改善前列腺癌的MRI诊断。一种新颖的直肠内组件包括位置跟踪线圈的四面体阵列和用于压缩前列腺的机构。四面体阵列提供运动补偿和磁场校正。该组件可实现分段扩散加权EPI（DW-EPI）成像，并减少失真。应变成像序列利用前列腺压迫来区分肿瘤和正常组织。这些应用程序在12只狗的队列中进行了测试，其中包括8只患有前列腺癌的狗。 具体目标是：目标#1：开发带有集成四面体跟踪线圈的直肠内线圈。将构建并测试新的直肠内弹簧圈。我们添加了一个四面体形状的四个微线圈阵列。该阵列在直肠插入期间保持折叠，以便不占用额外的占地面积，具有用于在使用前扩展的机构。水驱动的压缩机构对组件中的球囊加压，从而对前列腺进行短时间压缩。结果测量是跟踪SNR和运动校正精度。目标#2：开发具有集成前瞻性运动补偿的DW-EPI序列。我们将开发一个分段的DW-EPI序列，它利用跟踪四面体（AIM 1）的位置和相位校正。前列腺单次激发DW-EPI由于非均匀磁场而遭受几何失真。我们的解决方案利用减少失真的分段EPI，这需要对运动和相位变化进行校正，由跟踪阵列提供并实时传输到脉冲序列。结果测量是空间失真减少与效率成本，如在患有前列腺癌的狗中观察到的。目标#3：使用液压前列腺压迫开发MRI应变序列。我们将在犬中开发、优化和测试使用直肠内线圈（AIM 1）的DENSE [刺激回波位移编码]应变脉冲序列。应变成像将利用短时间球囊诱导的压缩来确定前列腺的弹性反应（顺应性）。跟踪线圈将用于在呼吸运动较小期间触发序列。结果测量将是前列腺中的应变SNR、肿瘤和正常组织之间的CNR、呼吸的影响以及扫描的时间效率。 公共卫生相关性：前列腺癌是美国发病率最高的癌症，死亡率第二高1，2。MRI的作用正在增加，如前列腺MRI程序的主要增加所示2。最初，MRI诊断/分期主要基于软组织对比3 -6，但越来越明显的是，更高的特异性/灵敏度存在于微结构对比中，如灌注7或弥散8所示。