In this work we present a stand-alone, portable system for high resolution real-time THz imaging. The total weight of the apparatus is less than 15 kg and its physical dimension is of ~(65 cm)3. A quantum cascade laser emitting at 3.4 THz laser based on a third-order distributed feedback cavity is used as source. It operates in continuous-wave at 50 K with more than 1 mW output power and less than 300 mW of power consumption. High resolution real-time THz imaging is reported: resolution of 2.5 times the wavelength is demonstrated.