title: Quantitative Ultrasound Comparison of MAT and 4T1 Mammary Tumors in Mice and Rats Across Multiple Imaging Systems.
abstract: OBJECTIVE
  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.
authors.affiliation: Departments of Electrical and Computer Engineering (L.A.W., G.G., A.D.P., R.J.M., M.L.O., W.D.O.) and Statistics (Y.P., D.G.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois USA; and Department of Medical Physics, University of Wisconsin, Madison, Wisconsin USA (I.M.R.-M., K.N., J.A.Z., T.J.H.).
authors.forename: Lauren A
authors.initials: LA
authors.lastname: Wirtzfeld
authors.affiliation: Departments of Electrical and Computer Engineering (L.A.W., G.G., A.D.P., R.J.M., M.L.O., W.D.O.) and Statistics (Y.P., D.G.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois USA; and Department of Medical Physics, University of Wisconsin, Madison, Wisconsin USA (I.M.R.-M., K.N., J.A.Z., T.J.H.).
authors.forename: Goutam
authors.initials: G
authors.lastname: Ghoshal
authors.affiliation: Departments of Electrical and Computer Engineering (L.A.W., G.G., A.D.P., R.J.M., M.L.O., W.D.O.) and Statistics (Y.P., D.G.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois USA; and Department of Medical Physics, University of Wisconsin, Madison, Wisconsin USA (I.M.R.-M., K.N., J.A.Z., T.J.H.).
authors.forename: Ivan M
authors.initials: IM
authors.lastname: Rosado-Mendez
authors.affiliation: Departments of Electrical and Computer Engineering (L.A.W., G.G., A.D.P., R.J.M., M.L.O., W.D.O.) and Statistics (Y.P., D.G.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois USA; and Department of Medical Physics, University of Wisconsin, Madison, Wisconsin USA (I.M.R.-M., K.N., J.A.Z., T.J.H.).
authors.forename: Kibo
authors.initials: K
authors.lastname: Nam
authors.affiliation: Departments of Electrical and Computer Engineering (L.A.W., G.G., A.D.P., R.J.M., M.L.O., W.D.O.) and Statistics (Y.P., D.G.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois USA; and Department of Medical Physics, University of Wisconsin, Madison, Wisconsin USA (I.M.R.-M., K.N., J.A.Z., T.J.H.).
authors.forename: Yeonjoo
authors.initials: Y
authors.lastname: Park
authors.affiliation: Departments of Electrical and Computer Engineering (L.A.W., G.G., A.D.P., R.J.M., M.L.O., W.D.O.) and Statistics (Y.P., D.G.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois USA; and Department of Medical Physics, University of Wisconsin, Madison, Wisconsin USA (I.M.R.-M., K.N., J.A.Z., T.J.H.).
authors.forename: Alexander D
authors.initials: AD
authors.lastname: Pawlicki
authors.affiliation: Departments of Electrical and Computer Engineering (L.A.W., G.G., A.D.P., R.J.M., M.L.O., W.D.O.) and Statistics (Y.P., D.G.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois USA; and Department of Medical Physics, University of Wisconsin, Madison, Wisconsin USA (I.M.R.-M., K.N., J.A.Z., T.J.H.).
authors.forename: Rita J
authors.initials: RJ
authors.lastname: Miller
authors.affiliation: Departments of Electrical and Computer Engineering (L.A.W., G.G., A.D.P., R.J.M., M.L.O., W.D.O.) and Statistics (Y.P., D.G.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois USA; and Department of Medical Physics, University of Wisconsin, Madison, Wisconsin USA (I.M.R.-M., K.N., J.A.Z., T.J.H.).
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Simpson
authors.affiliation: Departments of Electrical and Computer Engineering (L.A.W., G.G., A.D.P., R.J.M., M.L.O., W.D.O.) and Statistics (Y.P., D.G.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois USA; and Department of Medical Physics, University of Wisconsin, Madison, Wisconsin USA (I.M.R.-M., K.N., J.A.Z., T.J.H.).
authors.forename: James A
authors.initials: JA
authors.lastname: Zagzebski
authors.affiliation: Departments of Electrical and Computer Engineering (L.A.W., G.G., A.D.P., R.J.M., M.L.O., W.D.O.) and Statistics (Y.P., D.G.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois USA; and Department of Medical Physics, University of Wisconsin, Madison, Wisconsin USA (I.M.R.-M., K.N., J.A.Z., T.J.H.).
authors.forename: Michael L
authors.initials: ML
authors.lastname: Oelze
authors.affiliation: Departments of Electrical and Computer Engineering (L.A.W., G.G., A.D.P., R.J.M., M.L.O., W.D.O.) and Statistics (Y.P., D.G.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois USA; and Department of Medical Physics, University of Wisconsin, Madison, Wisconsin USA (I.M.R.-M., K.N., J.A.Z., T.J.H.).
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Hall
authors.affiliation: Departments of Electrical and Computer Engineering (L.A.W., G.G., A.D.P., R.J.M., M.L.O., W.D.O.) and Statistics (Y.P., D.G.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois USA; and Department of Medical Physics, University of Wisconsin, Madison, Wisconsin USA (I.M.R.-M., K.N., J.A.Z., T.J.H.). wdo@uiuc.edu.
authors.forename: William D
authors.initials: WD
authors.lastname: O'Brien
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation* / Q000379:methods*; D015674:Mammary Neoplasms, Animal / Q000000981:diagnostic imaging*; D051379:Mice; D008807:Mice, Inbred BALB C; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013045:Species Specificity; D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods*
keywords: backscatter coefficient; mammary tumor models; quantitative ultrasound