TY - JOUR
T1 - Attenuation coefficient and propagation speed estimates of rat and pig intercostal tissue as a function of temperature
AU - Towa, Rene T.
AU - Miller, Rita J.
AU - Frizzell, Leon A.
AU - Zachary, James F.
AU - O'Brien, William D.
N1 - Funding Information:
Manuscript received August 27, 2001; accepted May 15, 2002. This work was supported by NIH Grant HL58218 awarded to WDO and JFZ.
PY - 2002/10
Y1 - 2002/10
N2 - Attenuation coefficient and propagation speed of intercostal tissues were estimated as functions of temperature (22, 30, and 37°C) from fresh chest walls from eight 10- to 11-week-old female Sprague-Dawley (SD) rats, eight 21- to 24-week-old female Long-Evans (LE) rats, and ten 6- to 10-week-old mixed sex Yorkshire (York) pigs. The primary purpose of the study was to estimate the temperature dependence of the intercostal tissue's attenuation coefficient so that accurate estimates of the in situ (at the pleural surface) acoustic pressure levels could be made for our ultrasound-induced lung hemorrhage studies. The attenuation coefficient of intercostal tissue for both species was independent of the temperature at the discrete frequencies of 3.1 MHz (-0.0076, 0.0065, and 0.016 dB/cm/°C for SD rats, LE rats, and York pigs, respectively) and 6.2 MHz (-0.015, 0.014, and 0.014 dB/cm/°C for SD rats, LE rats, and York pigs, respectively). However, the temperature-dependent regressions yielded a significant temperature dependency of the intercostal tissue attenuation coefficients in SD and LE rats (over the 3.1 to 9.6 MHz frequency range); there was no temperature dependency in York pigs (over the 3.1 to 8.6 MHz frequency range). There was no significant temperature dependency of the intercostal tissue propagation speed in SD rats; there was a temperature dependency in LE rats and York pigs (-0.59, -1.6, and -2.9 m/s/°C for SD rats, LE rats, and York pigs, respectively). Even though the attenuation coefficient's temperature dependency was significant from the linear regression functions, the differences were not very great (-0.040 to -0.13, 0.011 to 0.18, and 0.055 to 0.10 dB/cm/°C for SD rats, LE rats, and York pigs, respectively, over the data frequency range). These findings suggest that it is not necessary to determine the attenuation coefficient of intercostal tissue at body temperature (37°C), but rather it is sufficient to determine the attenuation coefficient at room temperature (22°C), a much easier experimental procedure.
AB - Attenuation coefficient and propagation speed of intercostal tissues were estimated as functions of temperature (22, 30, and 37°C) from fresh chest walls from eight 10- to 11-week-old female Sprague-Dawley (SD) rats, eight 21- to 24-week-old female Long-Evans (LE) rats, and ten 6- to 10-week-old mixed sex Yorkshire (York) pigs. The primary purpose of the study was to estimate the temperature dependence of the intercostal tissue's attenuation coefficient so that accurate estimates of the in situ (at the pleural surface) acoustic pressure levels could be made for our ultrasound-induced lung hemorrhage studies. The attenuation coefficient of intercostal tissue for both species was independent of the temperature at the discrete frequencies of 3.1 MHz (-0.0076, 0.0065, and 0.016 dB/cm/°C for SD rats, LE rats, and York pigs, respectively) and 6.2 MHz (-0.015, 0.014, and 0.014 dB/cm/°C for SD rats, LE rats, and York pigs, respectively). However, the temperature-dependent regressions yielded a significant temperature dependency of the intercostal tissue attenuation coefficients in SD and LE rats (over the 3.1 to 9.6 MHz frequency range); there was no temperature dependency in York pigs (over the 3.1 to 8.6 MHz frequency range). There was no significant temperature dependency of the intercostal tissue propagation speed in SD rats; there was a temperature dependency in LE rats and York pigs (-0.59, -1.6, and -2.9 m/s/°C for SD rats, LE rats, and York pigs, respectively). Even though the attenuation coefficient's temperature dependency was significant from the linear regression functions, the differences were not very great (-0.040 to -0.13, 0.011 to 0.18, and 0.055 to 0.10 dB/cm/°C for SD rats, LE rats, and York pigs, respectively, over the data frequency range). These findings suggest that it is not necessary to determine the attenuation coefficient of intercostal tissue at body temperature (37°C), but rather it is sufficient to determine the attenuation coefficient at room temperature (22°C), a much easier experimental procedure.
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U2 - 10.1109/TUFFC.2002.1041082
DO - 10.1109/TUFFC.2002.1041082
M3 - Article
C2 - 12403142
AN - SCOPUS:0036771563
SN - 0885-3010
VL - 49
SP - 1411
EP - 1420
JO - IRE Transactions on Ultrasonic Engineering
JF - IRE Transactions on Ultrasonic Engineering
IS - 10
ER -