We describe a technique for broadband measurements of the attenuation coefficient and phase velocity of highly attenuating liquid suspensions. To validate the technique we apply it to the ultrasound contrast agent Albunex® at concentrations ranging from 0.69×106 particles/mL to 364×106 particles/mL. These longitudinal wave measurements were performed on Albunex suspensions maintained at 37 °C in a special time-domain reflectometer designed and constructed in our laboratory. The frequency-dependent attenuation coefficients and phase velocities obtained in the reflectometer are compared to broadband through-transmission measurements of these same quantities, which were also performed in our laboratory. Although comparison data between the two techniques are only available at lower concentrations, the agreement is quite good and serves to validate the methods described in this paper.

1.
J. N.
Marsh
,
C. S.
Hall
,
M. S.
Hughes
,
J.
Mobley
,
J. G.
Miller
, and
G. H.
Brandenburger
, “Broadband through-transmission signal loss measurements of Albunex suspensions at concentrations approaching in vivo does,”
J. Acoust. Soc. Am.
101
,
1155
1161
(
1997
).
2.
J.
Mobley
,
J. N.
Marsh
,
C. S.
Hall
,
M. S.
Hughes
,
G. H.
Brandenburger
, and
J. G.
Miller
, “Broadband measurements of phase velocity in Albunex,”
J. Acoust. Soc. Am.
103
,
2145
2153
(
1998
).
3.
J. N.
Marsh
,
M. S.
Hughes
,
C. S.
Hall
,
S. H.
Lewis
,
R. L.
Trousil
,
G. H.
Brandenburger
,
H.
Levene
, and
J. G.
Miller
, “Frequency and concentration dependence of the backscatter coefficient of the ultrasound contrast agent Albunex,”
J. Acoust. Soc. Am.
104
,
1654
1666
(
1998
).
4.
N. de Jong, “Acoustic properties of contrast agents,” Ph.D. Thesis, Rotterdam (1993).
5.
N.
de Jong
,
N.
Ten Cate
,
F. J.
Lancee
,
C. T.
Roelandt
,
J. R. C. T.
, and
N.
Bom
, “Principles and recent developments in ultrasound contrast agents,”
Ultrasonics
29
,
324
330
(
1991
).
6.
N.
de Jong
,
L.
Hoff
,
T.
Skotland
, and
N.
Bom
, “Absorption and scatter of encapsulated gas filled microspheres, theoretical considerations and some measurements,”
Ultrasonics
15
,
95
103
(
1992
).
7.
N.
de Jong
and
L.
Hoff
, “Ultrasound scatter properties of albunex microspheres,”
Ultrasonics
31
,
175
181
(
1992
).
8.
T. G. Leighton, The Acoustic Bubble (Academic, New York, 1994).
9.
C. C.
Church
, “The effects of an elastic solid surface layer on the radial pulsations of gas bubbles,”
J. Acoust. Soc. Am.
97
,
1510
1521
(
1995
).
10.
J. G.
Miller
and
D. I.
Bolef
, “Technique for the study of highly attenuated ultrasonic waves in gases,”
Rev. Sci. Instrum.
41
,
1305
1306
(
1970
).
11.
J. N. Marsh, “Qualitative acoustic characterization of ultrasonic contrast agents,” Ph. D. Thesis, Washington University in St. Louis (1998).
12.
P. O.
Lipovko
and
V. M.
Lube
, “Acoustical testing of the properties of a medium by measurement of its characteristic impedance,”
Sov. Phys. Acoust.
17
,
135
137
(
1971
).
13.
J. J. Brown, V. E. Stubblefield, and J. G. Miller, “Optimizing signal-to-error ratio in standing wave ultrasonic measurements,” Proceedings of the 1974 IEEE Symposium in Ultrasonics, 74CH0896-1SU, pp. 549–554.
14.
A.
Selfridge
, “Approximate material properties in isotropic materials,”
IEEE Trans. Sonics Ultrason.
SU-32
,
381
394
(
1985
).
15.
R. D. Corsaro and J. D. Klunder, “A filled silicone rubber materials system with selectable acoustic properties for molding and coating applications at ultrasonic frequencies,” NRL Report 8301 (1979).
16.
J. R.
Lovett
, “Comments concerning the determination of absolute sound speeds in distilled and seawater and Pacific Sofar speeds,”
J. Acoust. Soc. Am.
45
,
1051
1052
(
1969
).
17.
M. S.
Hughes
,
J. N.
Marsh
,
N. A.
Schmich
,
A. L.
Klibanov
,
G. L.
Cantrell
,
J. G.
Miller
, and
G. H.
Brandenburger
, “Behavior of resonant peak of attenuation of albunex at varying power levels and durations,”
Ultrason. Imaging
20
,
544
545
(
1998
).
This content is only available via PDF.
You do not currently have access to this content.