Improved ultrasound imaging using elevated acoustic output

使用提高的声输出改进超声成像

基本信息

批准号：
9083203
负责人：
Kathryn Radabaugh Nightingale
金额：
$ 46.83万
依托单位：
DUKE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-03-01 至 2019-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9083203
关键词：
Abdomen Acoustics Acute American Body Image Clinical Custom Data Detection Development Diagnosis Diagnostic Diagnostic Imaging Failure Frequencies Gases Generations Geometry Goals Guidelines Hepatic Mass Image Imagery In Situ Institutes Lead Lesion Link Malignant - descriptor Manufacturer Name Measurement Mechanics Medicine Methods Modality Noise Obesity Output Overweight Pain Patient Schedules Patients Penetration Performance Physiologic pulse Power Sources Primary carcinoma of the liver cells Property Pulse Pressure Reporting Research Research Design Resolution Risk Shapes Signal Transduction Source Structure System Time Tissues Transducers Ultrasonics Ultrasonography United States Water Work abdominal wall attenuation base design disease diagnosis imaging modality imaging system improved in vivo indexing patient population pressure prototype public health relevance screening second harmonic simulation success tool

项目摘要

DESCRIPTION (provided by applicant): Ultrasonic imaging is among the most widely used abdominal imaging modalities in the United States. However, ultrasonic image quality is reported to be insufﬁcient for diagnosis in up to 40% of patients, a challenge often correlated with obesity. The major problems are lack of penetration and reverberation clutter. We hypothesize that increasing the Mechanical Index (MI) from the current limit of 1.9 to values in the 2.4-3.4 range, with concomitant transmit pulse pressure increases from 40 to 200%, will markedly improve B-mode, har- monic, and Doppler image quality. We have designed this proposal to focus on harmonic imaging. Tissue harmonic imaging (THI) is a nonlinear method that is more robust to reverberation clutter and off-axis scattering than fundamental imaging, and has found great success in improving ultrasonic image quality. However, har- monic signal levels are 15-20 dB lower than fundamental signals, which leads to challenges with signal-to-noise ratio and depth penetration in difﬁcult-to-image patients. The in situ pressures used in diagnostic ultrasound imaging have been subject to a de facto upper limit established by the United States FDA guidelines for the Mechanical Index (MI<1.9), a value which is based upon historic values, rather than being linked to scientiﬁc evidence of bioeffects. In tissues without gas bodies, cavitation based bioeffects have only been reported at diagnostic frequencies and pulse durations using MI values greater than 5.0. The American Institute of Ul- trasound in Medicine (AIUM) recently concluded that exceeding the recommended maximum MI given in the FDA guidance up to an estimated in situ value of 4.0, could be warranted without concern for increased risk of cavitation in non-fetal tissues without gas bodies, if imaging in this heretofore unexplored output regime were associated with a corresponding signiﬁcant clinical beneﬁt. We have obtained preliminary in vivo data using elevated MI harmonic imaging demonstrating +20 dB increases in harmonic signal level, penetration depth increases of up to 40%, and structural contrast-to-noise ratio increases from 12-500%, enabling visualization of additional structures. The primary goals of this work are to optimize elevated MI harmonic image quality and to quantify the resulting image quality improvements. There are 3 speciﬁc aims: 1) To extend our 3D nonlinear simulation tools to perform a parametric analysis of varying tissue properties and transducer conﬁgurations to optimize harmonic signal generation and image quality in elevated MI pulse inversion har- monic imaging, and to determine the relationship between water-based estimates and in situ measurements in the elevated MI output regime. 2) To design and implement a real-time prototype elevated MI system using commercial curvilinear abdominal arrays and a custom designed prototype large aperture low frequency diag- nostic array on a commercial grade scanner. 3) To quantify improvements in imaging performance afforded by the use of elevated MIs in patients scheduled for ultrasonic abdominal imaging studies, and in patients known to have malignant liver masses.