A non-invasive, safe method of breast examination, intended for visualisation and diagnostics of pathological changes occurring in mammary gland tissues.
The examination is carried out using the electroimpedance mammography. The device facilitates the following, using the Electric Impedance Tomography (EIT) device
- visualisations of the electrical conductivity distribution in biological tissues in several transections of the monitored part of a patient’s body and subsequent identification of tumours in the obtained images in various depths.
- identification of breast structure type – juvenile, reproductive, premenopausal, postmenopausal
- visualisation, diagnostics and detection of anomalous foci in the mammary gland even in early stages of tumour development.
Example: A carcinoma “in situ“– “on site“ is a tumour in the initial developmental stage which is practically unidentifiable by the native X-ray mammography due to its size and often also due to the breast tissue density. In the mammary gland, a CIS frequently occurs in ductal passages or lobular parenchyma of the breast. A tumour cell also produces lactic acid as a secondary metabolite product, while using the glycolysis in the production of ATP, a high-energy molecule. Subsequently, lactic acid dissociates, causing thus pH change in the intra- and extra-cellular environment of the tumour, i.e. the conductivity of a newly forming focus of tumour proliferation. A small amount of tumour cells, unidentifiable by other methods, can produce a sufficient amount of acid required for the identification of a tumour focus in the in situ stage by the electroimpedance method.
The device possesses considerable advantages, compared to the systems performing the two-dimensional screening of electric conductivity. These systems do not provide spatial differentiation to the depth. Skin condition (bruises, birthmarks, moisturising conditions) can significantly affect the scanned images. The MEIK system, however, comprises the inbuilt execution approach which uses the feedback processing for Maxwell equations in the quasistatic approximation. This method facilitates the reconstruction of 3D distribution of electric conductivity (in form of tomographic cross-sections in various depths), providing thus the images of higher quality and more detailed representations. The used scheme of measurements makes the results of visualisation practically insensitive to the skin surface condition.
Course of and preparation for an examination:
The measurement of electroimpendance is carried out by attaching a sensor to the mammary gland, so that the largest possible number of electrodes touch the skin, and by pushing the probes gently against the ribs. During the scanning, the device alternately injects low AC current into a patient’s body (0.5 mA) with the frequency of 50 kHz and scans respective distribution of electric potentials on the surface. Obtained data are then used for the reconstruction of electroimpendance imaging while using mathematic algorithms. A panel with 256 electrodes contains a light diode with a light spot that facilitates accurate placement of the matrix centre above the required part of a patient’s body.
The measurement takes about 20 seconds, the signal is immediately processed and visualised by the computer. This computer-assisted processing makes the diagnostics much easier.
Preparation for an examination: Breasts must be clean, without deodorants and creams, body lotions
Advantages of this diagnostics:
- absolute harmlessness – without the X-radiation
- unlimited quantity and frequency of examinations – important in the differential diagnostics of mastopathy
- high informative value
- painless – the breast is not pressed as in the native mammography
- for girls and women without any age limitation
- Very efficient for the diagnostics of benign and malign tumours of the mammary gland.
Sensitivity (percentage of patients with the disease of determined symptom frequencies) – more than 76%, specificity (evaluate no symptoms in healthy individuals) 75%. For the comparison purposes, sensitivity of X-ray mammography, 71% – 86.8%, specificity – 37.8%.
- suitable for the assessment of tissue changes in mastalgia (breast pain) when other breast examination methods are not accessible
- monitoring of breasts with implants
- monitoring of breasts during lactation
- diagnostics of single or repeated cysts in mammary glands
- diagnostics of breast fibroadenoma
Reproductive breast type, 39 years, without pathological changes
Examples of pathologies:
31 years, left breast, a cyst at 5 h, diam. 9×5 mm
38 years. Fibroadenoma, left breast at 1h (0.9×5 mm)
EIM. 66 years. Finding at 14h, diam. 15x15x10 mm
Author: Mgr. Mrenková Lucia