This study aimed to verify whether the open-ended coaxial line tumor sensor with radio frequency was effective or not in detecting the differences in permittivity and conductivity between the breast malignant tissues and adjacent tissues. Sixteen breast infiltrating ductal carcinoma samples were freshly obtained from the department of general surgery in Zhujiang Hospital. The permittivity and conductivity of cancerous nidus points of breast samples, 3 cm adjacent tissue points and 5 cm adjacent tissue points were detected respectively by the open-ended coaxial line tumor sensor with radio frequency noninvasively in conjunction with vector network analyzer at the frequency ranging from 42.85~500 MHz. All the detected points were marked. After finishing the detection, we conducted postoperative pathological examinations on all the marked points. According to the statistics, there were statistically significant differences between the breast cancerous tissues and the 3 cm adjacent tissues for the dielectric properties (P < 0.01). There were statistically significant differences between the breast cancerous tissues and the 5 cm adjacent tissues for the dielectric properties (P < 0.01). There was no statistically significant difference in the dielectric properties between the 3 cm adjacent tissues and 5 cm adjacent tissues (P > 0.05). Both the 3 cm adjacent tissues and 5 cm adjacent tissues were found no breast cancer cell infiltration. The results indicated that the open-ended coaxial line tumor sensor at radio frequency could be effective in detecting the differences in permittivity and conductivity between breast cancerous tissues and adjacent tissues and, therefore, it may have a potential prospect in making a final diagnosis to confirm whether the detected breast tissue is malignant or not.
Through magnetic resonance electrical properties tomography (MR-EPT), electrical conductivity and permittivity of biological tissues could be reconstructed based on radio frequency field of magnetic resonance imaging (MRI) system. High precision and high resolution image could be obtained without current injection. In this study, XFDTD software was used to establish a finite element model of the human breast. Simulation was delivered at the Larmor frequency of 128 MHz by a 16-channel radio frequency coil. Conductivity and permittivity of the mammary tissue was reconstructed according to the B1+ field's amplitude and phase of forward problem. Anti-noise performance of the algorithm was studied by adding noise to B1+ field. The conductivity and permittivity's average relative error between simulation results and dielectric constant was 4.71% and 11.32%, respectively. With a signal-to-noise ratio of >30 dB, the noise added would not affect imaging results. This study demonstrated that high precision and high resolution image could be obtained by MR-EPT without excitation. MR-EPT had excellent feasibility and developing potential in early detection of diseases.