Updated: May 18, 2026

Construction of a Preclinical Multimodality Phantom Using Tissue-mimicking Materials for Quality Assurance in Tumor Size Measurement
Published on: July 29, 2013
Mingkang Zhao1, Hun Wi, Abu Hena Mostofa Kamal
1Department of Biomedical Engineering, Kyung Hee University, Yongin-si, Gyeonggi-do 446-701, Korea.
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This article describes the creation and testing of a new breast imaging device that uses electrical signals instead of X-rays. By using a high-density grid of sensors, the researchers improved image clarity to help identify breast tumors based on their unique electrical properties.
Area of Science:
Background:
Current breast cancer screening relies heavily on X-ray imaging, yet this approach faces limitations regarding tissue differentiation. Malignant growths exhibit distinct electrical impedance profiles compared to healthy breast structures. This discrepancy suggests that electrical impedance imaging could serve as a viable diagnostic alternative. However, previous iterations of this technology struggled with insufficient spatial resolution and suboptimal signal quality. Such technical constraints have hindered the widespread adoption of impedance-based screening in clinical settings. No prior work had successfully integrated high-density electrode arrays to overcome these specific hardware barriers. That uncertainty drove the development of a more sophisticated sensing architecture for breast evaluation. This study addresses the gap by introducing a system designed to enhance image precision through increased sensor density.
Purpose Of The Study:
This study aims to develop and validate a high-density trans-admittance mammography system for improved breast imaging. The researchers sought to overcome the poor spatial resolution associated with existing electrical impedance methods. By increasing the number of sensing electrodes, the team intended to provide a more precise diagnostic tool. This effort was motivated by the need for a non-invasive alternative to traditional X-ray screening. The authors addressed the challenge of signal-to-noise ratios that previously limited clinical application. They focused on creating a robust hardware architecture capable of high-fidelity data acquisition. The investigation specifically targets the technical requirements for accurate admittivity mapping in breast tissue. This work provides a detailed account of the construction and calibration processes necessary for such advanced imaging systems.
The device utilizes a top plate to apply sinusoidal voltages ranging from 50 Hz to 500 kHz, while a bottom plate with 3600 sensors captures exit currents. This configuration allows the system to map electrical admittivity changes across the breast tissue.
The hardware incorporates six switching modules, each linked to 600 electrodes. These modules utilize current-to-voltage converters, gain amplifiers, and digital phase-sensitive demodulators to process signals, whereas older systems lacked such high-density integration.
A ground potential must be maintained at the bottom plate to ensure accurate current measurement. This setup is necessary for the system to detect the subtle electrical variations between malignant and healthy tissues during the scanning process.
Main Methods:
The research team constructed a specialized imaging platform modeled after standard breast compression plates. They integrated an array of 3600 sensors to capture electrical signals passing through the target medium. The design utilizes six distinct switching modules to manage the high volume of incoming data. Each module connects to twelve ammeter channels that process signals through sequential switching. The team implemented current-to-voltage converters alongside gain amplifiers to ensure signal integrity. Digital phase-sensitive demodulators were employed to isolate relevant data from background interference. Calibration involved testing the system within a saline phantom to verify operational stability. This approach allowed the investigators to generate both time and frequency difference images for performance evaluation.
Main Results:
The system achieved an average noise level of 38 nA during testing. Investigators reported an amplitude stability of less than 0.2% across all operating frequencies. Crosstalk measurements remained better than -60 dB throughout the experimental trials. The device demonstrated a 70 dB signal-to-noise ratio across all channels. Successful imaging was performed using both time difference and frequency difference modes. These tests confirmed the ability to detect regions of interest with expected admittivity changes. The collected data indicate that the high-density electrode array effectively captures electrical variations. These performance values represent a substantial improvement over previous low-resolution impedance imaging techniques.
Conclusions:
The authors demonstrate that their high-density sensing architecture achieves significant improvements in signal quality. Their findings suggest that this hardware configuration effectively addresses previous limitations regarding spatial resolution. The system maintains stable performance across a broad range of operating frequencies. These results validate the utility of the device for detecting admittivity variations in controlled environments. The researchers propose that this platform offers a promising pathway for non-invasive breast tumor assessment. Future clinical utility depends on the successful translation of these phantom-based findings to human subjects. The study provides a clear framework for constructing and calibrating complex electrical impedance systems. This work establishes a foundation for refining diagnostic tools that rely on tissue-specific electrical signatures.
The system employs 3600 current-sensing electrodes to capture data. These sensors play a role in converting the electrical signals passing through the phantom into measurable digital values for image reconstruction.
The researchers measured an average noise level of 38 nA and a signal-to-noise ratio of 70 dB. These metrics indicate superior performance compared to previous low-resolution impedance imaging devices.
The authors propose that this technology could eventually function as a supplementary or alternative method to standard X-ray screening. They suggest that the improved resolution allows for better identification of regions of interest.