Characteristics of Particulate Heating Mediator in RF Capacitive Heating.

Abstract

It was shown that alternative magnetic field is generated around ferromagnetic particles in 8 MHz RF electric field and that heat is generated in ferromagnetic particles due to hysteresis loss by the action of alternative magnetic field ; i. e. the same heat generation mechanism with inductive heating.

Ferucarbotran expands area treated by radiofrequency ablation in rabbit livers

“…We used ferucarbotran, which is clinically used as a contrast agent for MRI examinations, as a means of expanding the size of the RF‐ablated area in rabbit livers. Ferucarbotran is uniformly distributed throughout the entire liver after administration and the SPIO contained in the agent generates heat in an RF electric field 18–22 . In the present rabbits, the signal intensity in the liver decreased in accordance with the given volume of ferucarbotran and the diminution of intensity was homogeneous in each image slice.…”

“…Ferucarbotran is uniformly distributed throughout the entire liver after administration and the SPIO contained in the agent generates heat in an RF electric field. [18][19][20][21][22] In the present rabbits, the signal intensity in the liver decreased in accordance with the given volume of ferucarbotran and the diminution of intensity was homogeneous in each image slice. These results confirmed that the ferucarbotran had been taken equally into the hepatic parenchyma at 4 h after administration in each of the groups.…”

“…This agent is a colloid composed of SPIO micro particles (gamma‐Fe 2 O 3 ) coated with carboxydextran, and is taken up by Kupffer cells after administration and equally distributed throughout the entire liver 17 . Prior studies have demonstrated that ferromagnetite particles generate heat in an RF electric field, 18–21 and the addition of SPIO (ferumoxides, Feridex IV®; Berlex Laboratories, Wayne, NJ, USA) raised the temperature further during RFA in an in vitro phantom study 22 . The aim of the present study was to determine whether giving ferucarbotran would enlarge the size of the hepatic area ablated by RFA in a rabbit model.…”