Kit-of-parts configured for visualizing by a magnetic resonance imaging technique including a functional magnetic resonance imaging (fMRI) technique, regions of a central nervous system of a patient having an implanted active implantable medical device (AIMD), the kit-of-parts comprising: • the AIMD comprising an encapsulation unit defining an inner space (Vi) sealingly separated from an outer environment by walls defined by an inner surface defining the boundaries of the inner space, wherein the walls of the encapsulation are made of a non-metallic material, wherein the inner space contains: ∘ an implanted source of communication light and an implanted communication photodetector facing a portion of wall having a given transmittance to wavelength selected within the range comprised between 380 nm and 5 μm, preferably between 600 nm and 2200 nm for optical communication with an exterior of the body, ∘ an electronic circuit for controlling the implanted source of communication light and the implanted communication photodetector, thus ensuring communication with the exterior, • an external processing unit comprising a user interface configured for entering parameters and commands, and for displaying information, • an external communication unit in communication with the external processing unit and comprising an external source of communication light, an external photodetector, and an electronic circuit configured for, ∘ controlling the external source of communication light to emit signals representative of the parameters and commands entered in the external processing unit and received by the implanted communication photodetector, and ∘ transferring to the external processing unit information representative of optical communication signals emitted by the implanted source of communication light and received by the external photodetector, characterized in that, the kit of parts comprises, • an optical communication lead comprising an optical fibre for establishing an optical communication between, ∘ the implanted source of communication light of the AIMD and the external communication photodetector of the external communication unit, and ∘ the external source of communication light of the external communication unit, and the implanted photodetector of the AIMD, thus allowing a remote optical communication between the external processing unit and the AIMD. • the AIMD comprising an encapsulation unit defining an inner space (Vi) sealingly separated from an outer environment by walls defined by an inner surface defining the boundaries of the inner space, wherein the walls of the encapsulation are made of a non-metallic material, wherein the inner space contains: ∘ an implanted source of communication light and an implanted communication photodetector facing a portion of wall having a given transmittance to wavelength selected within the range comprised between 380 nm and 5 μm, preferably between 600 nm and 2200 nm for optical communication with an exterior of the body, ∘ an electronic circuit for controlling the implanted source of communication light and the implanted communication photodetector, thus ensuring communication with the exterior, ∘ an implanted source of communication light and an implanted communication photodetector facing a portion of wall having a given transmittance to wavelength selected within the range comprised between 380 nm and 5 μm, preferably between 600 nm and 2200 nm for optical communication with an exterior of the body, ∘ an electronic circuit for controlling the implanted source of communication light and the implanted communication photodetector, thus ensuring communication with the exterior, • an external processing unit comprising a user interface configured for entering parameters and commands, and for displaying information, • an external communication unit in communication with the external processing unit and comprising an external source of communication light, an external photodetector, and an electronic circuit configured for, ∘ controlling the external source of communication light to emit signals representative of the parameters and commands entered in the external processing unit and received by the implanted communication photodetector, and ∘ transferring to the external processing unit information representative of optical communication signals emitted by the implanted source of communication light and received by the external photodetector, characterized in that, the kit of parts comprises, ∘ controlling the external source of communication light to emit signals representative of the parameters and commands entered in the external processing unit and received by the implanted communication photodetector, and ∘ transferring to the external processing unit information representative of optical communication signals emitted by the implanted source of communication light and received by the external photodetector, • an optical communication lead comprising an optical fibre for establishing an optical communication between, ∘ the implanted source of communication light of the AIMD and the external communication photodetector of the external communication unit, and ∘ the external source of communication light of the external communication unit, and the implanted photodetector of the AIMD, thus allowing a remote optical communication between the external processing unit and the AIMD. ∘ the implanted source of communication light of the AIMD and the external communication photodetector of the external communication unit, and ∘ the external source of communication light of the external communication unit, and the implanted photodetector of the AIMD,