NDLI: P1F-7 On the Influence of Microbubble Concentration on the Assessment of Perfusion Curves Using Contrast Echography

Content Provider	IEEE Xplore Digital Library
Author	Nguyen-Dinh, C. Palanchon, P. Bourguignon, D. Hansen, C. Tranquart, F. Bouakaz, A.
Copyright Year	2006
Description	Author affiliation: Inserm, Tours (Nguyen-Dinh, C.; Palanchon, P.)
Abstract	Background: contrast ultrasound allows a perfect depiction of vessels and has shown an improvement in diagnostic accuracy for lesion characterization. Using quantitative parametric curve analysis, perfusion patterns showed to be correlated to lesion malignancy. However, the assessment of perfusion has always been performed by assuming a linear relationship between video intensity and concentration. Our purpose is to evaluate, in-vitro, the efficiency of the perfusion patterns assessment from RF signals by varying ultrasound contrast agent (UCA) concentrations. Methods: Perfusion was evaluated using the replenishment technique with a Siemens Antares scanner and a VF13-5 probe transmitting at 4 MHz in THI mode. Microbubble destruction was realized at maximum MI during 2 seconds with a frame rate of 8 fps. Perfusion was assessed with low MI (0.2) during 16 seconds. A nonrecirculating flow phantom containing a 4mm diameter vessel was used. The liquid flow varied from 40ml/h to 120ml/h. SonoVue (Bracco) microbubbles were diluted from 0.05/1000 to 9/1000. A rectangular region of interest was located at the center of the vessel. Perfusion curves were extracted from RF signals using a research interface toolbox. The experimental results were fitted to an exponential function y = A(1-exp(-betat)) where A represents the steady state and beta the replenishment rate (microbubble flow velocity). Results: the results showed that for a given flow rate and using dilutions up to 1/1000, the coefficient beta remains constant. At 80ml/h, beta was estimated to be 0.68 (SD = 0.03). This result is in accordance with the constant flow velocity. The plateau A increases linearly with the microbubble concentration, indicating a linear relationship between intensity and concentration. However, for higher concentrations (> 1.2/1000), the coefficient beta showed important variations despite a constant flow velocity. Compared to the low concentrations, the estimated flow velocity varies by up to 60%. Moreover, coefficient A reaches a saturation value although the UCA concentration has increased. Conclusions: this study shows that above a certain concentration of contrast agent, the assessment of perfusion can be biased since the coefficient beta does no longer reflect the flow velocity. Furthermore, the signal intensity cannot be related to the microbubbles concentration
Starting Page	1365
Ending Page	1368
File Size	1212844
Page Count	4
File Format	PDF
ISBN	1424402018
ISSN	10510117
DOI	10.1109/ULTSYM.2006.354
Language	English
Publisher	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Publisher Date	2006-10-02
Publisher Place	Canada
Access Restriction	Subscribed
Rights Holder	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Subject Keyword	Ultrasonic imaging Lesions Imaging phantoms In vitro Probes Pattern analysis Fluid flow Steady-state Blood flow Water resources
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