Evaluation of Soft Tissue Sarcoma Tumors Electrical Conductivity Anisotropy Using Diffusion Tensor Imaging for Numerical Modeling on Electroporation.
BACKGROUND
There is many ways to assessing the electrical conductivity anisotropy of a tumor. Applying the values of tissue electrical conductivity anisotropy is crucial in numerical modeling of the electric and thermal field distribution in electroporation treatments. This study aims to calculate the tissues electrical conductivity anisotropy in patients with sarcoma tumors using diffusion tensor imaging technique.


METHODS
A total of 3 subjects were involved in this study. All of patients had clinically apparent sarcoma tumors at the extremities. The T1, T2 and DTI images were performed using a 3-Tesla multi-coil, multi-channel MRI system. The fractional anisotropy (FA) maps were performed using the FSL (FMRI software library) software regarding the DTI images. The 3D matrix of the FA maps of each area (tumor, normal soft tissue and bone/s) was reconstructed and the anisotropy matrix was calculated regarding to the FA values.


RESULTS
The mean FA values in direction of main axis in sarcoma tumors were ranged between 0.475-0.690.  With assumption of isotropy of the electrical conductivity, the FA value of electrical conductivity at each X, Y and Z coordinate axes would be equal to 0.577. The gathered results showed that there is a mean error band of 20% in electrical conductivity, if the electrical conductivity anisotropy not concluded at the calculations. The comparison of FA values showed that there is a significant statistical difference between the mean FA value of tumor and normal soft tissues (P<0.05).


CONCLUSIONS
DTI is a feasible technique for the assessment of electrical conductivity anisotropy of tissues.  It is crucial to quantify the electrical conductivity anisotropy data of tissues for numerical modeling of electroporation treatments.
PhD student of Medical Physics, Tarbiat Modares University, Medical Physics Department, Tehran, Iran.
K
K
Ghazikhanlou-Sani
Professor of Biomedical Engineering, Tarbiat Modares University, Medical Physics Department, Tehran, Iran.
S M P
SM
Firoozabadi
Assistant Professor of Radiology, Department of Radiology, School of Medicine and Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.
L
L
Agha-Ghazvini
Assistant Professor of General Surgery, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran.
H
H
Mahmoodzadeh
Anisotropy; Diffusion Tensor Imaging; Electrical conductivity; Sarcoma tumors
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