Journal article
Processing of Subharmonic Signals from Ultrasound Contrast Agents to Determine Ambient Pressures
Ultrasonic imaging, v 34(2), pp 81-92
01 Apr 2012
PMID: 22724314
Featured in Collection : UN Sustainable Development Goals @ Drexel
Abstract
Subharmonic-aided pressure estimation (SHAPE) is a technique that utilizes the subharmonic emissions, occurring at half the insonation frequency, from ultrasound contrast agents to estimate ambient pressures. The purpose of this work was to compare the performance of different processing techniques for the raw radiofrequency (rf) data acquired for SHAPE. A closed loop flow system was implemented circulating reconstituted Sonazoid (GE Healthcare, Oslo, Norway; 0.2 ml for 750 ml diluent) and the beam-formed unprocessed rf data were obtained from a 4 mm diameter lumen of a Doppler flow phantom (ATS Laboratories, Inc., Bridgeport, CT) using a SonixRP scanner (Ultrasonix, Richmond, BC, Canada). The transmit frequency and incident acoustic pressures were set to 2.5 MHz and 0.22 MPa, respectively, in order to elicit Sonazoid subharmonic emissions that arc ambient-pressure sensitive. The time-varying ambient pressures within the flow phantom were recorded by a Millar pressure catheter. Four techniques for extracting the subharmonic amplitude from the rf data were tested along with two noise filtering techniques to process this data. Five filter orders were tested for the noise removing filters. The performance was evaluated based on the least root-mean-square errors reported after linear least-square regression analyses of the subharmonic data and the pressure catheter data and compared using a repeated ANOVA. When the subharmonic amplitudes were extracted as the mean value within a 0.2 MHz bandwidth about 1.25 MHz and when the resulting temporally-varying subharmonic signal was median filtered with an order of 500, the filtered subharmonic signal significantly predicted the ambient pressures (r(2) = 0.90; p < 0.001) with the least error. The resulting root mean square and mean absolute errors were 8.16 +/- 0.26 mmHg and 6.70 +/- 0.17 mmHg, respectively. Thus, median processing the subhannonic data extracted as the mean value within a 0.2 MHz bandwidth about the theoretical subhannonic frequency turned out to be the best technique to process acoustic data for SHAPE. The implementation of this technique on ultrasound scanners may permit real-time SHAPE applications.
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Details
- Title
- Processing of Subharmonic Signals from Ultrasound Contrast Agents to Determine Ambient Pressures
- Creators
- Jaydev K. Dave - Thomas Jefferson UniversityValgerdur G. Halldorsdottir - Thomas Jefferson UniversityJohn R. Eisenbrey - Thomas Jefferson UniversityFlemming Forsberg - Thomas Jefferson University
- Publication Details
- Ultrasonic imaging, v 34(2), pp 81-92
- Publisher
- DYNAMEDIA INC
- Number of pages
- 12
- Grant note
- 0655441U / American Heart Association R21HL081892 / NATIONAL HEART, LUNG, AND BLOOD INSTITUTE; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA; NIH National Heart Lung & Blood Institute (NHLBI) W81XWH-08-1-0503 / U.S. Army Medical Research Material Command; U.S. Army Medical Research & Materiel Command (USAMRMC) Kris Dickie and Corina Leung at Ultrasonix Medical Corp. R21 HL081892; RC1 DK087365 / NIH; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- School of Biomedical Engineering, Science, and Health Systems
- Web of Science ID
- WOS:000304798100002
- Scopus ID
- 2-s2.0-84864011007
- Other Identifier
- 991019350670804721
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InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Collaboration types
- Domestic collaboration
- Web of Science research areas
- Acoustics
- Engineering, Biomedical
- Radiology, Nuclear Medicine & Medical Imaging