The Use of Computer Tomography in the Diagnosis and Postoperative Observation of Cerebral Aneurysms

Coagulated blood is represented by a mean density value between 56 and 68 Hounsfield-Units (H.U.) (2, 5, 12). It thus lies clearly above the density values of normal brain tissue, 24 H.U. (white matter) and 36 H.U. (gray matter). With a density difference of nearly 30 H.U., it is possible to demonstrate lesions up to 4 mm diameter. It is thus possible to evaluate even smaller intracranial hemorrhages with computer tomography. If one takes into account the minimal burden to which this procedure subjects the patient, it becomes understandable that the computer tomogram, even in cases of spontaneous intracranial hemorrhage, represents a valuable diagnostic tool.