Computed tomography (CT) currently represents the workhorse of radiology. Recent developments permit extremely fast volume scans that can generate two-dimensional slices in all possible orientations, as well as sophisticated three-dimensional reconstructions. Nevertheless, the radiation dose remains high, thus a very strict indication for every intended CT is needed.

Ultrasonography is still the cheapest and most harmless technology in radiology, which is the reason why many physicians outside radiology use this technique. Ultrasound probes utilize acoustic energy above the audible frequency of humans in order to produce images. As there is no ionizing radiation with this modality, it is particularly useful in imaging of children and pregnant women.