Cervical Intraepithelial Neoplasia Localization With Frequency-Difference Electrical Impedance Tomography—Simulation and Phantom Study

Abstract

Pathological investigation for addressing abnormal or precancerous cells in cervix specimens is necessary to diagnose or treat. This process is exhaustive in histologic examination and requires experienced pathologists. Detecting the presence of precancerous cells with bioimpedance is another method to help pathologists by using a small-diameter probe to measure the impedance. However, it requires several measurements and is possibly another exhaustive task. This study proposed the localization of abnormal cells in a specimen using reconstruction images with Frequency-difference Electrical Impedance Tomography (fdEIT). Due to the various shape of specimens in practice, a new approach to cope with modeling error was also proposed to enable using a generic inversion model in the reconstruction process. Simulation of cervix specimens with different orifice shapes and thicknesses was performed. The proposed method was compared with the traditional methods i.e. the simple-fdEIT and the weighted-fdEIT. Amplitude response, radius, position error and ringing ratio of the reconstruction images were determined. The image reconstruction of the proposed method showed superior performance in localization. Although the image amplitude response was smaller, the artifacts that occurred due to modeling error were significantly reduced. Even though the shape of cervix specimens is varied, the proposed method allows to use a generic model for precancerous cells localization. The influence of modeling error can be reduced. Consequentially, the ringing artifact can be significantly reduced and the position error is also slightly reduced.

Keywords

• Cervix
• loop electrosurgical excision procedure (LEEP)
• frequency-difference electrical impedance tomography (fdEIT)
• modeling error
• reconstruction