Provided is a simple, portable, real-time, and in vivo THz imaging device for imaging a target, e.g., a tooth in the subject. Moreover, the scanning based THz imaging device is much sufficiently sensitive as compared with the common X-ray imaging device. Therefore, the scanning based THz imaging device has the potential to operate in the density for early detection problems such as dental caries or demineralization of the enamel in the teeth. Also provided is a method for diagnosing or imaging the target in the subject by using the scanning based THz imaging device of the present disclosure. |