Imaging Prostate Cancer with SQUID-Detected Microtesla MRI

使用 SQUID 检测的微特斯拉 MRI 对前列腺癌进行成像

• 批准号: 7448743
• 负责人: John Clarke
• 金额: $ 20.88万
• 依托单位: UNIVERSITY OF CALIF-LAWRENC BERKELEY LAB
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-04 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7448743
• 关键词: Affect; Agreement; Atrophic; Benign; Biopsy; Blinded; Brachytherapy; Cancerous; Clinical; Compatible; Comprehensive Cancer Center; Copper; Data; Detection; Development; Diagnosis; Diagnostic Neoplasm Staging; Disease; Electronics; Ensure; Facility Construction Funding Category; Frequencies; Future; Gel; Gland; Gleason Grade for Prostate Cancer; Goals; Histocompatibility Testing; Histology; Histopathology; Hyperplasia; Image; Image Guided Biopsy; Imaging Phantoms; Imaging Techniques; Imaging technology; In Situ; Inflammation; Location; Magnetic Resonance Imaging; Malignant Neoplasms; Malignant neoplasm of prostate; Maps; Measurement; Medical Surveillance; Metals; Methods; Molds; Monitor; Noise; Normal tissue morphology; Nuclear Magnetic Resonance; Numbers; Operative Surgical Procedures; Organ; Patient Monitoring; Patient observation; Patients; Performance; Peripheral; Placement; Primary Carcinoma; Procedures; Prostate; Prostatic Neoplasms; Prosthesis; Protocols documentation; Protons; Public Health; Radioactive Seed Implantation; Rate; Recurrence; Relaxation; Research; Research Infrastructure; Resolution; Seeds; Sensitivity and Specificity; Sepharose; Shapes; Signal Transduction; Source; Specificity; Specimen; Squid; Staging; System; Techniques; Technology; Testing; Three-Dimensional Image; Three-Dimensional Imaging; Time; TimeLine; Tissues; Tumor Tissue; Ultrasonography; Water; Weight; base; cancer imaging; clinical application; cryogenics; density; design; detector; expectation; improved; in vivo; magnetic field; magnetic resonance spectroscopic imaging; novel; prototype; research study; sensor; size; superconducting quantum interference device; tumor; tumor progression

DESCRIPTION (provided by applicant): Conventional magnetic resonance imaging (MRI) at 1.5 tesla and above is used increasingly for the detection, diagnosis and staging of cancer. In the case of prostate cancer, however, conventional MRI does not provide sufficient specificity for detection of prostate tumors. To take advantage of the enhanced T1 (longitudinal relaxation time) contrast available at low magnetic fields, a novel MRI system has been developed at LBNL which acquires MR images at microtesla fields, comparable to the Earth's field. In this technique, prepolarization of the proton spins in a much higher magnetic field is combined with detection of the nuclear magnetic resonance signal using a Superconducting QUantum Interference Device (SQUID) to enhance the signal-to-noise ratio. Preliminary data on ex vivo prostate specimens indicate that there is significantly enhanced contrast between prostate tumors and healthy prostate tissue. The goal of the proposed project is to assess the potential of this novel MR imaging method for the diagnosis and staging of prostate cancer. In a blinded study on ex vivo prostate specimens we will determine the T1 contrast in images of specimens containing different types of benign prostate tissue and tumors with various Gleason grades and compare the results with those from histopathology performed at the UCSF Comprehensive Cancer Center. In addition, we will improve the sensitivity of the SQUID detector and increase the magnitude of the polarizing field in our current imaging system to assess the spatial resolution and the signal to noise and contrast to noise ratios achievable with a future in vivo imaging system. To attain these goals we propose the following specific aims: Aim 1. Upgrade the detector sensitivity. Aim 2. Determine T1 contrast in images of ex vivo prostate tissue containing tumors and other prostate tissue types to determine the sensitivity and specificity for detecting prostate cancer. Aim 3. Design and build a polarizing coil suitable for in vivo imaging. Aim 4. Image three-dimensional (3D) prostate phantoms and compare the resolution with results predicted by calculations; image 2D ex vivo prostate specimens at a distance corresponding to that for in vivo imaging. Provided these experiments confirm the preliminary measurements, a prototype system could subsequently be constructed for in vivo studies of prostate cancer. This system would potentially be less expensive and more open than conventional MRI systems, and could significantly impact the diagnosis and staging of prostate cancer. Possible applications include: (i) Imaging the prostate before a biopsy to determine the location and extent of the cancer. (ii) More accurate mapping of the location of tumors to guide biopsy. (iii) Serial imaging to determine the progression of tumors during treatment or active surveillance. (iv) In situ monitoring of focal therapies, such as placement of the seeds during brachytherapy. PUBLIC HEALTH RELEVANCE: A magnetic resonance imaging (MRI) system will be developed to demonstrate the feasibility of imaging prostate tumors in very low magnetic fields. This technique offers much higher contrast between healthy and cancerous tissue compared to conventional high-field MRI, and the system is both less confining and less expensive. Clinical applications are expected to include serial monitoring of tumors during treatment or active surveillance, image guided biopsy, and monitoring of focal therapies like brachytherapy.

描述（由申请人提供）：1.5特斯拉及以上的常规磁共振成像（MRI）越来越多地用于癌症的检测、诊断和分期。然而，在前列腺癌的情况下，常规MRI不能提供用于检测前列腺肿瘤的足够特异性。为了利用在低磁场下增强的T1（纵向弛豫时间）对比度，LBNL开发了一种新型MRI系统，该系统可在微特斯拉磁场（与地球磁场相当）下采集MR图像。在这种技术中，质子自旋在高得多的磁场中的预极化与使用超导量子干涉装置（SQUID）检测核磁共振信号相结合，以提高信噪比。离体前列腺标本的初步数据表明，前列腺肿瘤和健康前列腺组织之间的对比度显着增强。该项目的目的是评估这种新型MR成像方法用于前列腺癌诊断和分期的潜力。在离体前列腺标本的盲法研究中，我们将确定含有不同类型的良性前列腺组织和具有不同Gleason分级的肿瘤的标本的图像中的T1对比度，并将结果与在UCSF综合癌症中心进行的组织病理学结果进行比较。此外，我们将提高SQUID检测器的灵敏度，并增加我们目前的成像系统中的偏振场的大小，以评估未来体内成像系统可实现的空间分辨率和信噪比以及对比度噪声比。为了实现这些目标，我们提出以下具体目标：目标1。提高探测器灵敏度。目标二。测定含有肿瘤和其他前列腺组织类型的离体前列腺组织图像中的T1对比度，以确定检测前列腺癌的灵敏度和特异性。目标3。设计并构建一个适用于活体成像的偏振线圈。目标4。对三维（3D）前列腺体模进行成像，并将分辨率与计算预测的结果进行比较;在与体内成像对应的距离处对2D离体前列腺标本进行成像。如果这些实验证实了初步的测量结果，随后可以构建一个原型系统，用于前列腺癌的体内研究。该系统可能比传统的MRI系统更便宜，更开放，并可能对前列腺癌的诊断和分期产生重大影响。可能的应用包括：（i）在活检之前对前列腺成像，以确定癌症的位置和程度。(ii)更准确地定位肿瘤位置以指导活检。(iii)连续成像，以确定治疗或主动监测期间肿瘤的进展。(iv)局部治疗的原位监测，例如近距离放射治疗期间粒子的放置。 公共卫生相关性：将开发一种磁共振成像（MRI）系统，以证明在极低磁场中对前列腺肿瘤进行成像的可行性。与传统的高场MRI相比，这种技术在健康和癌组织之间提供了更高的对比度，并且该系统限制更少，成本更低。临床应用预期包括在治疗或主动监测期间对肿瘤的连续监测、图像引导活检和局部治疗（如近距离放射治疗）的监测。