MEASUREMENT OF CEREBRAL BLOOD-VOLUME VIA THE RELAXING EFFECT OF LOW-DOSE GADOPENTETATE DIMEGLUMINE DURING BOLUS TRANSIT

PURPOSE: To quantify regional cerebral blood volume (rCBV) on the basi s of the enhancement of blood proton relaxation rates after intravenou s administration of gadopentetate dimeglumine. METHODS: A series of se quential MR images of one section was recorded during bolus transit wi th a standard fast low-angle shot sequence. The signal-intensity curve s were converted into corresponding concentration-time curves from whi ch rCBV images were calculated. RESULTS: The functional parameter imag es of rCBV were calculated pixel-by-pixel for two patients who had rec eived a I-second bolus injection of 1 mmol of gadopentetate dimeglumin e. In a larger series of 62 patients, a mean blood volume of 4.6 +/- 1 .6 vol% was determined for normal brain tissue. CONCLUSIONS: The relax ing effect of a contrast agent can be used to determine blood volume q uantitatively. The results are in agreement with those obtained by nuc lear medicine techniques. The proposed method requires no special hard ware, and can thus be implemented on clinical MR scanners.