A study on resonant vibro-acoustography for tissue heating: a pathway towards breast cancer detection

Develop a new active thermography method for breast cancer detection. The computational tissue was excited at its resonant frequency using the vibro-acoustography technique. A nonlinear acoustic wave equation was solved using the finite element method to analyze the propagation of the acoustic wave within the computational phantom. The computational approach included separate calculations for the temperature in the focal region, considering both acoustic absorption and vibration effects. The study was validated through experimental tests using an agar phantom. Depending on the tissue’s attenuation coefficient, the applied ultrasonic signal generates localized heating in the target area. Malignant breast tissue typically exhibits a higher attenuation coefficient than healthy tissue. Consequently, ultrasonic signals lead to an elevated temperature in such tissue. When a focused ultrasound is applied to heterogeneous tissue for 90 seconds using a dual transducer, the temperature can increase by $$2.5^\circ \textrm{C}$$ . In contrast, using the same input power level in healthy tissue causes a temperature increase of only $$1.8^\circ \textrm{C}$$ . Enhanced temperature levels achieved through this acoustic method can improve thermal contrast in deeper tumors when thermography is employed. With the application of this acoustic force, it becomes possible to detect a tumor of 3 mm at a depth of 10 mm, whereas, in the absence of this source, such a tumor of this size can only be detected when it is located at a depth of 4 mm. Approximately 22% of the simulated temperature rise from vibrational effects can be attributed to ultrasound forces in resonant modes. The experimental results further validated the simulation results. The suggested resonant vibro-acoustography technique represents an effective approach to increasing thermal contrast between malignant and normal tissue. This approach can serve as an active thermography method for detecting breast cancer. Since the resonant frequency varies across different stages of the disease and the acoustic attenuation coefficient is higher in affected tissues than in normal ones, this technique can improve thermal contrast through vibration and acoustic absorption.