Table 1.
Dielectric and thermal parameter values at 450 MHz for the various tissue types used in the simulations: electrical conductivity (σ [S/m]), relative permittivity (εr [-]), density (ρ [kg/m3]), specific heat capacity (Ct [J/(kg K)]), thermal conductivity (k [W/(m K)]) and perfusion coefficient (ω Cb [W/(m3 K)]), being the product of the volumetric perfusion rate (ω [kg/(m3 s)]) and the specific heat capacity of blood (Cb = 3600 W/(m3 K). The last column indicates whether a tissue was modelled using convective flow simulations (“yes”), or using Pennes’ equation (“no”). Parameters were obtained from the IT’IS database [50], Gabriel and Gabriel [51], and Wang et al. [52]. The perfusion value of muscle has been increased four-fold to account for vasodilation at hyperthermic temperatures, in accordance with Kok et al. [53].
| Tissue Type | σ (S/m) | εr (–) | ρ (kg/m3) | Ct (J/(kg K)) | k (W/(m K)) | ω Cb (W/(m3 K)) | Flow |
|---|---|---|---|---|---|---|---|
| tumour | 0.84 | 56.64 | 1056 | 3700 | 0.57 | 22,545 | no |
| tumour cyst | 0.84 | 56.64 | 1056 | 3700 | 0.57 | 0 | no |
| cerebrospinal fluid | 2.28 | 70.95 | 1007 | 4200 | 0.62 | 0 | yes |
| grey matter | 0.76 | 56.48 | 1038 | 3700 | 0.57 | 45,090 | no |
| white matter | 0.46 | 41.43 | 1038 | 3600 | 0.50 | 15,925 | no |
| muscle | 0.93 | 75 | 1050 | 3639 | 0.56 | 12,960 | no |
| bone | 0.095 | 13.03 | 1990 | 1300 | 0.40 | 3400 | no |
| cartilage | 0.60 | 44.94 | 1097 | 3500 | 0.47 | 9000 | no |
| skin | 0.71 | 45.70 | 1125 | 3500 | 0.42 | 8065 | no |
| vitreous humour | 1.54 | 69.00 | 1009 | 4200 | 0.60 | 0 | no |
| air | 0 | 1 | 1.293 | 10,000 | 0.024 | 0 | no |
| bolus water | 0.070 | 83.83 | 1000 | 4180 | 0.60 | 0 | no |