NDLI: Noninvasive estimation of dynamic pressures in vitro and in vivo using the subharmonic response from microbubbles

Content Provider	IEEE Xplore Digital Library
Author	Dave, J.K. Halldorsdottir, V.G. Eisenbrey, J.R. Liu, J. McDonald, M.E. Dickie, K. Leung, C. Forsberg, F.
Copyright Year	2011
Description	Author affiliation: Ultrasonix Med. Corp., Richmond, BC, Canada (Dickie, K.; Leung, C.) \|\| Radiologic Sci., Thomas Jefferson Univ., Philadelphia, PA, USA (McDonald, M.E.) \|\| Depts. of Radiol., Thomas Jefferson Univ., Philadelphia, PA, USA (Dave, J.K.; Halldorsdottir, V.G.; Eisenbrey, J.R.; Liu, J.; Forsberg, F.)
Abstract	In this work, the development of subharmonic emission based noninvasive pressure estimation technique is presented. In vitro, ambient pressures were varied (between 0 and 120 mmHg) in a closed-loop flow system circulating 0.2 ml Sonazoid microbubbles (GE Healthcare, Oslo, Norway) suspended in 750 ml of isotonic diluent and recorded by a Millar pressure catheter as the reference standard. Simultaneously, a SonixRP ultrasound scanner (Ultrasonix Medical Corp., Richmond, BC, Canada) operating in pulse inversion mode $(f_{transmit}:$ 2.5 MHz) was used to acquire unprocessed RF data at five different incident acoustic pressures (from 76 kPa to 897 kPa; n=3). The subharmonic data for each pulse was extracted using band-pass filtering with averaging, and subsequently, processed to eliminate noise. The incident acoustic pressure most sensitive to ambient pressure fluctuations was determined; then the ambient pressure was tracked over 20 seconds. Regression analysis compared subharmonic and catheter pressure values. In vivo validation of this technique was performed noninvasively for tracking left ventricular (LV) pressures of two canines using similar post processing as in vitro. The subharmonic signal tracked ambient pressures with $r^{2}$ = 0.922 for 20 seconds in vitro. In vivo the subharmonic signal tracked the LV pressures with $r^{2}$ >; 0.7P90. Maximum errors in estimating clinically relevant systolic and diastolic pressures ranged from 0.22 to 2.84 mmHg using this subharmonic technique relative to Millar catheter pressures. Clinical validation and real time implementation of this technique may ultimately lead to the first noninvasive cardiac pressure monitoring tool.
Sponsorship	IEEE Ultrasonics, Ferroelectrics Frequency Control Soc.
Starting Page	176
Ending Page	179
File Size	1441868
Page Count	4
File Format	PDF
ISBN	9781457712531
ISSN	19485727
e-ISBN	9781457712524
DOI	10.1109/ULTSYM.2011.0044
Language	English
Publisher	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Publisher Date	2011-10-18
Publisher Place	USA
Access Restriction	Subscribed
Rights Holder	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Subject Keyword	Acoustics Ultrasonic imaging Catheters Shape Estimation In vitro In vivo in vivo pressure estimation Subharmonic aided pressure estimation noninvasive pressure estimation ultrasound contrast agents
Content Type	Text
Resource Type	Article

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in