Medical imaging is of great importance for patients affected by stroke. Common systems like magnetic resonance imaging (MRI) or computed tomography (CT) are precise, but stationary and therefore not ideally suited for the early analysis of stroke. The presented multiport vector network analyzer (MPVNA) system uses electromagnetic tomography (EMT) as an alternative imaging technique. It consists of a network of distributed electronic sensor nodes which improve important parameters. A 200-port S-parameter matrix can be measured below 200ms and it is possible to measure signal levels down to -150 dBm. The electronics allow a compact packaging, leading the way for future portable devices. The possibility of building portable setups, which can be even applied to patients inside an ambulance, makes EMT a suitable alternative for early stroke detection.