CAN CEREBROVASCULAR REACTIVITY BE ASSESSED BY DYNAMIC SUSCEPTIBILITY CONTRAST-ENHANCED MRI

The acetazolamide (ACZ) test is performed to evaluate the decrease in cerebral perfusion pressure (CPP) by investigation of vasomotor reacti vity (VMR), Our aim was to study cerebral blood flow and blood volume changes induced by the ACZ test in healthy control subjects using dyna mic susceptibility contrast-enhanced gradient-echo MRI (DSC-MRI), A FL ASH sequence was used to produce susceptibility-weighted images during an intravenous injection of 0.1 mmol/kg gadopentetate dimeglumine (Gd -DTPA). After the first dynamic study, 1g acetazolamide was given intr avenously and 10 min later a second bolus of Gd-DTPA, was injected, Us ing the indicator-dilution theory, relative cerebral blood volume and relative cerebral blood flow were estimated. In healthy subjects the A CZ test induced a significant increase in relative blood volume (from 80.5 +/- 10.7 to 113.4 +/- 11.9) and relative blood flow (from 5.73 +/ - 0.96 to 7.5 +/- 0.97), symmetrically in the cerebral hemispheres. Th is approach might be promising in the understanding of cerebral haemod ynamics in patients with vascular disorders.