Labelled microspheres assessment using 1.5T scanner for embolization follow up

Controlled fibroids and tumors embolization with magnetic resonance imaging (MRI) remain challenging due to the absence of effective detection with another imaging modality. The objectives of this paper were to assess by 1.5T MRI the detectability of superparamagnetic iron oxide (SPIO) labelled microspheres (LB*MSs) with the help of three models. Four size ranges of LB*MSs were firstly injected into 8 ex vivo sheep kidneys or were secondly embedded in a hydrogel of a Petri dish as different grouping. The feasibility of in vivo assessment was thirdly determined in in vitro model according to LB*MSs size, coils, FOV, and sequence. LB*MSs appeared as black spots in MRI sheep Kidney images, different grouping of LB*MSs appeared as a single black spot in MRI images of Petri dishes, and a positive visualization in in vivo conditions. Our models demonstrate the efficiency of LB *MSs assessment, in vitro and in vivo conditions, with MRI according to different sizes.