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Quantitative Ultrasound Comparison of MAT and 4T1 Mammary Tumors in Mice and Rats Across Multiple Imaging Systems
Author(s) -
Wirtzfeld Lauren A.,
Ghoshal Goutam,
Rosado-Mendez Ivan M.,
Nam Kibo,
Park Yeonjoo,
Pawlicki Alexander D.,
Miller Rita J.,
Simpson Douglas G.,
Zagzebski James A.,
Oelze Michael L.,
Hall Timothy J.,
O'Brien William D.
Publication year - 2015
Publication title -
journal of ultrasound in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 91
eISSN - 1550-9613
pISSN - 0278-4297
DOI - 10.7863/ultra.34.8.1373
Subject(s) - ultrasound , medicine , high frequency ultrasound , ultrasonic sensor , biomedical engineering , transducer , coefficient of variation , ultrasound imaging , range (aeronautics) , nuclear medicine , pathology , radiology , acoustics , materials science , statistics , mathematics , physics , composite material
Objectives Quantitative ultrasound estimates such as the frequency‐dependent backscatter coefficient (BSC) have the potential to enhance noninvasive tissue characterization and to identify tumors better than traditional B‐mode imaging. Thus, investigating system independence of BSC estimates from multiple imaging platforms is important for assessing their capabilities to detect tissue differences. Methods Mouse and rat mammary tumor models, 4T1 and MAT, respectively, were used in a comparative experiment using 3 imaging systems (Siemens, Ultrasonix, and VisualSonics) with 5 different transducers covering a range of ultrasonic frequencies. Results Functional analysis of variance of the MAT and 4T1 BSC‐versus‐frequency curves revealed statistically significant differences between the two tumor types. Variations also were found among results from different transducers, attributable to frequency range effects. At 3 to 8 MHz, tumor BSC functions using different systems showed no differences between tumor type, but at 10 to 20 MHz, there were differences between 4T1 and MAT tumors. Fitting an average spline model to the combined BSC estimates (3–22 MHz) demonstrated that the BSC differences between tumors increased with increasing frequency, with the greatest separation above 15 MHz. Confining the analysis to larger tumors resulted in better discrimination over a wider bandwidth. Conclusions Confining the comparison to higher ultrasonic frequencies or larger tumor sizes allowed for separation of BSC‐versus‐frequency curves from 4T1 and MAT tumors. These constraints ensure that a greater fraction of the backscattered signals originated from within the tumor, thus demonstrating that statistically significant tumor differences were detected.