Brain stroke is one of the most common non-traumatic cause of death all around the world. Its early diagnosis and differentiation on ischemic or haemorrhagic is crucial for the elimination of possible health consequences and for initiation of treatment. Conventional imaging techniques as CT scanner or MRI are frequently using to diagnose the stroke type but it is obvious that these methods have some limitations such as non-mobility or unavailability in every hospital. Microwave Imaging devices could be a portable device in the future which will be able to distinguish the type of stroke in order of seconds and thus enable to set the right treatment. At CTU FBME a few experimental 2D MWI systems for testing of brain stroke detection have been already developed and tested. To test microwave imaging on geometrically-realistic head phantoms it is necessary to develop 3D MWI system. The helmet-type elliptical geometry of MWI system was designed together with new H slot antenna element suitable to use in this geometry. In total 24 antennas are possible to place inside the 3D MWI system geometry. The method of 3D printing was chosen for fabrication of MWI system geometry. To ensure impedance matching of antennas a swim cap mounted on geometry was used. The space between cap and antennas will be possible to fill with coupling medium. Complete MWI system will be firstly tested on a geometrically-realistic liquid head phantom with the goal to reconstruct the distribution of complex permittivity inside the phantom with stroke phantom placed inside. Also, measurements on solid geometrically and dielectrically-realistic head phantom are planning to realize in the future.