Ultrasound Evaluation of Liver Steatosis

肝脏脂肪变性的超声评估

• 批准号: 10264795
• 负责人: Shigao Chen
• 金额: $ 23.85万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-16 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10264795
• 关键词: Agreement; Algorithms; American; Benchmarking; Biological Markers; Calibration; Cardiovascular Diseases; Cardiovascular system; Classification; Clinical; Detection; Diabetes Mellitus; Diagnosis; Evaluation; Fatty Liver; Fatty acid glycerol esters; Frequencies; Guidelines; Image; Individual; Intervention; Lateral; Lead; Liver; Liver Cirrhosis; Liver Fibrosis; Liver diseases; Logistic Regressions; Magnetic Resonance Imaging; Measurement; Measures; Methods; Noise; Outcome; Patients; Penetration; Population; Protons; ROC Curve; Reproducibility; Risk; Scanning; Series; Serum; Signal Transduction; Staging; Technology; Testing; Time; Transducers; Ultrasonography; United States; X-Ray Computed Tomography; attenuation; clinical practice; clinical translation; cost; cost effective; density; diabetes management; improved; improved outcome; liver biopsy; liver imaging; new technology; nonalcoholic steatohepatitis; novel; patient population; screening; screening guidelines

PROJECT SUMMARY About 75-100 million Americans are estimated to have fatty liver disease, which can lead to nonalcoholic steatohepatitis (NASH) and liver fibrosis. Detection of liver steatosis is important for diagnosis of NASH at early stage for timely intervention to improve outcome. Diagnosis of hepatic steatosis is also important for management of diabetes and cardiovascular disease. Serum biomarkers, computed tomography, and B-mode ultrasound have limited sensitivity for detecting steatosis. Proton Density Fat Fraction (PDFF) measured by MRI has high accuracy, but is limited by accessibility and cost. The value of ultrasound attenuation coefficient (UAC) for steatosis evaluation has been confirmed by many studies. Therefore, technologies that are compatible with clinical ultrasound scanners to measure UAC can meet this critical need by providing a low- cost, widely accessible, and accurate staging of steatosis. Here we propose a novel technology, Spectrum Normalization Attenuation Measurement (SNAM), to measure liver UAC. SNAM does not require a calibration phantom, and instead uses the ratio of spectra at two nearby frequencies to cancel the effects of focusing and depth-dependent gain for accurate measurement of UAC. SNAM is compatible with clinical ultrasound scanners and can provide 2D UAC images. In phantom studies, SNAM measurements using focused beams or plane waves matched well with calibrated values. SNAM results obtained in 10 patients had a correlation coefficient of 0.97 with PDFF, showing its high promise. Specific Aim 1: Optimization of SNAM. We will use phantom and patient studies to optimize SNAM on the GE Logiq E9 and the Verasonics scanners, which represent the wide spectrum of commercial scanners (with focused beam or plane wave imaging) used in clinical practice. Acquisition parameters of fundamental and harmonic imaging modes and post-processing algorithms will be optimized. A novel noise subtraction method will be studied to suppress noise and improve SNAM penetration. Signal-to-noise ratio will be calculated to guide automatic selection of frequency range used for SNAM measurements. Specific Aim 2: Patient study. We will use the SNAM optimized in Aim 1 to study 50 patients with clinically indicated PDFF-MRI to investigate the efficacy of SNAM for steatosis grading. Each patient will be scanned twice by two sonographers. The intraclass correlation coefficient will be used to assess the reproducibility of SNAM measurements. Correlation analysis will be performed to assess the association of the UAC obtained via SNAM with PDFF. Steatosis will also be categorized as S0, S1, S2, and S3 according to PDFF. Receiver operating characteristic analyses will be performed to establish SNAM cut-points which detect ≥S1, ≥S2, and ≥S3. The agreement between SNAM and PDFF classification will be evaluated using the Kappa statistic. Successful completion of this project will result in a safe, cost-effective, and easily accessible ultrasound technology for frequent and accurate evaluation of liver steatosis.

项目概要 据估计，大约有 75-1 亿美国人患有脂肪肝，这可能导致非酒精性肝病 脂肪性肝炎（NASH）和肝纤维化。肝脏脂肪变性的检测对于NASH的早期诊断很重要 及时干预以改善结果的阶段。肝脂肪变性的诊断也很重要 糖尿病和心血管疾病的管理。血清生物标志物、计算机断层扫描和 B 模式 超声检测脂肪变性的敏感性有限。质子密度脂肪分数 (PDFF) 测量方法 MRI 具有较高的准确性，但受到可及性和成本的限制。超声衰减系数值 （UAC）用于脂肪变性评估已被许多研究证实。因此，技术是 与临床超声扫描仪兼容来测量UAC可以通过提供低功耗来满足这一关键需求 成本、广泛可及性和准确的脂肪变性分期。 在这里，我们提出了一种新技术，即频谱归一化衰减测量（SNAM）来测量 肝UAC。 SNAM 不需要校准模型，而是使用两个附近的光谱比 频率来消除聚焦和深度相关增益的影响，从而精确测量 UAC。 SNAM 与临床超声扫描仪兼容，可以提供 2D UAC 图像。在幻象研究中， 使用聚焦光束或平面波的 SNAM 测量与校准值非常匹配。 SNAM 在 10 名患者中获得的结果与 PDFF 的相关系数为 0.97，显示出其很高的前景。 具体目标 1：SNAM 的优化。我们将使用模型和患者研究来优化 SNAM GE Logiq E9 和 Verasonics 扫描仪，代表了广泛的商用扫描仪（带有 聚焦光束或平面波成像）在临床实践中使用。采集基本参数和 谐波成像模式和后处理算法将得到优化。一种新颖的噪声消除方法 将研究抑制噪声并提高 SNAM 渗透率。信噪比将计算为 指导自动选择用于 SNAM 测量的频率范围。 具体目标 2：患者研究。我们将使用目标 1 中优化的 SNAM 来研究 50 名患有临床症状的患者 表明 PDFF-MRI 来研究 SNAM 对脂肪变性分级的功效。每位患者都会接受扫描 由两名超声医师进行两次。组内相关系数将用于评估重复性 SNAM 测量。将进行相关分析以评估所获得的 UAC 的关联性 通过 SNAM 和 PDFF。根据 PDFF，脂肪变性也分为 S0、S1、S2 和 S3。接收者 将进行操作特性分析来建立 SNAM 切点，检测 ≥S1、≥S2 和 ≥S3。 SNAM 和 PDFF 分类之间的一致性将使用 Kappa 统计量进行评估。 该项目的成功完成将带来安全、具有成本效益且易于获取的超声波 频繁、准确评估肝脏脂肪变性的技术。