Indication and Requests for Radiological Examination

CT

Computer tomography (CT) is a technique that, similarly to conventional X-ray, uses radiation (see X-ray/CT technique module). The difference is that where a conventional X-ray shows the 2D image, a CT obtains a 3D image of the body. It is a quick investigation where in a few seconds substantial amounts of the body can be imaged. CT images have a high resolution, so small lesions can frequently be seen. In addition, the 3D images can be reconstructed to view the body in different planes and cross sections. 

Of all the imaging techniques CT gives the most information on the lung parenchyma. It can be used following an X-ray or inconclusive US. Through use of intravenous contrast, we can further image vascular structures and assess blood flow or perfusion (fig 8).