[The imaging of regional brain perfusion with dynamic magnetic resonance tomography]

Bolus injections of gadolinium-DTPA result in high contrast concentration in the distal vessels within the brain and cause a local disturbance of the magnetic field with a shortening of T2 relaxation time. Pulse frequencies were designed to demonstrate inhomogeneities in the magnetic field. The resultant reduction in T2-weighted gradient echo signals was used in order to examine changes in regional perfusion caused by pathological conditions. Cerebral tumours showed variable perfusion patterns but were always better perfused than surrounding brain tissue; oedema surrounding the tumour resulted in reduced perfusion. Ischaemic infarcts showed significant underperfusion compared with control areas. In both groups the areas involved were larger on the perfusion scans than on T2-weighted images.