Compound speckle model detects anti-angiogenic tumor response in preclinical nonlinear contrast-enhanced ultrasonography.

Autor: Lowerison MR; Department of Medical Biophysics, Western University, London, ON, N6A 3K7, Canada.; Robarts Research Institute, Western University, London, ON, N6A 5B7, Canada., Tse JJ; Department of Medical Biophysics, Western University, London, ON, N6A 3K7, Canada.; Robarts Research Institute, Western University, London, ON, N6A 5B7, Canada., Hague MN; London Regional Cancer Program, London Health Sciences Centre, London, ON, N6A 4L6, Canada., Chambers AF; London Regional Cancer Program, London Health Sciences Centre, London, ON, N6A 4L6, Canada.; Departments of Oncology and Medical Biophysics, Western University, London, ON, N6A 3K7, Canada., Holdsworth DW; Robarts Research Institute, Western University, London, ON, N6A 5B7, Canada.; Departments of Surgery, and Medical Biophysics, Western University, London, ON, N6A 3K7, Canada., Lacefield JC; Robarts Research Institute, Western University, London, ON, N6A 5B7, Canada.; Departments of Electrical and Computer Engineering, and Medical Biophysics, Western University, London, ON, N6A 3K7, Canada.
Jazyk: angličtina
Zdroj: Medical physics [Med Phys] 2017 Jan; Vol. 44 (1), pp. 99-111.
DOI: 10.1002/mp.12030
Abstrakt: Purpose: This paper proposes a method for analyzing the first-order speckle statistics of nonlinear contrast-enhanced ultrasound images from tumors.
Methods: Contrast signal intensity is modeled as a compound distribution of exponential probability density functions with a gamma weighting function. The gamma probability weighting function serves as an approximation for log-normally distributed flow velocities in a vascular network. The model was applied to sub-harmonic bolus-injection images acquired from a mouse breast cancer xenograft model treated with murine version bevacizumab.
Results: The area under curve produced using the compound statistical model could more accurately discriminate anti-VEGF-treated tumors from untreated tumors than conventional contrast-enhanced ultrasound image processing. This result was validated with gold standard histological measures of microvascular density. Fractal vessel geometry was estimated using the gamma weighting function and tested against micro-CT perfusion casting. Treated tumors had a significantly lower vascular fractal dimension than control tumors. Vascular complexity estimated using the ultrasound compound statistical model performed similarly to micro-CT fractal dimension for discriminating treated from control tumors.
Conclusion: The proposed technique can quantify tumor perfusion and provide an index of vascular complexity, making it a potentially useful addition for clinical detection of vascular normalization in anti-angiogenic trials.
(© 2016 American Association of Physicists in Medicine.)
Databáze: MEDLINE
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