Trends in the development of reconstruction tomography in neuroradiology.

Because of the new uses of CT, it is difficult to accurately forecast the future balance between it and conventional radiologic techniques. However, the relatively low frequency resolution of CT makes it unlikely that conventional radiology will be completely replaced. Photon noise and the iodine concentration of the contrast medium limit the size of the cerebral vessels which can be studied by CT. Thus angiography is likely to remain the method of choice for fine-detail study of these vessels. For optimal measurements and comparative studies, improved head fixation is required. Given precisely reporducible positioning, stereotaxic surgery and radiation therapy become a reality.