An Increase in Cellular Size Variance Contributes to the Increase in Ultrasound Backscatter During Cell Death

• Published in: Ultrasound in medicine & biology Vol. 36; no. 9; pp. 1546 - 1558
• Main Authors: Vlad, Roxana M., Saha, Ratan K., Alajez, Nehad M., Ranieri, Shawn, Czarnota, Gregory J., Kolios, Michael C.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.09.2010; Elsevier
• Subjects: Algorithms; Anticancer therapies; Antineoplastic Agents - therapeutic use; Apoptosis and mitotic arrest; Biological and medical sciences; Cell Death; Cell Line, Tumor; Cell Size; Cells, Cultured; Cellular size variance; Cellular sizes distribution; Chemotherapy; Humans; Investigative techniques, diagnostic techniques (general aspects); Leukemia, Myeloid, Acute - diagnostic imaging; Leukemia, Myeloid, Acute - drug therapy; Leukemia, Myeloid, Acute - radiotherapy; Medical sciences; Miscellaneous. Technology; Monte Carlo algorithm; Monte Carlo Method; Radiology; Radiotherapy; Scatterer distribution; Simulation; Tumor cell lines; Ultrasonic investigative techniques; Ultrasonics; Ultrasonography; Ultrasound; Ultrasound integrated backscatter; Anticancer therapies; Cellular sizes distribution; Scatterer distribution; Simulation; Monte Carlo algorithm; Cell death; Apoptosis and mitotic arrest; Cellular size variance; Ultrasound integrated backscatter; Sonography; Antineoplastic agent; Ultrasound imaging; Backscattering; Experimental study; Algorithm; Modeling; Treatment; Echography; Numerical simulation; Ultrasound; Tumor cell; Apoptosis; Biomedical engineering
• ISSN: 0301-5629; 1879-291X; 1879-291X
• DOI: 10.1016/j.ultrasmedbio.2010.05.025

This study aims to explain the contribution of changes in cellular size variance (CSV) to increases in ultrasound-integrated backscatter (UIB) measured from cell samples undergoing cell death. A Monte Carlo algorithm was used to compare simulations of 2D distributions of cells, uniform (CSV = 0) versus heterogeneous (CSV > 0) and the same mean cellular size ( M ¯ ). UIB increased in arrangements with heterogeneous cellular sizes from 3.6dB ( M ¯ = 20 μm, CSV = 0 μm/CSV = 18 μm) to 5.6 dB ( M ¯ =10 μm, CSV = 0 μm/CSV = 8 μm). Experimentally, UIB (10 to 30 MHz) was measured from cell samples of four tumor cell lines viable and undergoing cell death after radiotherapy and chemotherapy treatment. An increase of 3.8–7.5 dB ( p < 0.001) in UIB was measured from three cell lines. No increase in UIB was measured from one cell line. An increase in CSV was found for all cell samples after cell death. The results suggest that an increase in CSV could have a significant contribution to the increases measured in UIB after cell death in cell samples exposed to anticancer therapies. (E-mail: rvlad@lakeridgehealth.on.ca)