DEUTERIUM MR SPECTROSCOPY AT 4.7-T - QUANTIFICATION OF TUMOR AND SUBCUTANEOUS TISSUE BLOOD-FLOW IN ANIMAL-MODELS

Deuterium MR spectroscopy was used for the determination of tissue blo od flow (TBF). The tracer D2O was injected into the tissue of interest , and tracer washout was followed using a 4.7 T spectroscopy/imaging u nit. Normal subcutaneous tissue in rats was studied, as well as tissue influenced by vasoactive agents (papaverine and adrenaline). The vaso active agents introduced changes of 40% in TBF, compared with normal t issue. Normal tissue measurements were repeated using various D2O inje ction volumes (5-400 mu l). The injection volume 5 mu l gave TBF 11.7 +/- 2.0 ml/100 g.min (mean +/- 1 SD), This value was 40% higher than c orresponding values observed at larger injection volumes (200-400 mu l ). This injection volume effect is probably partly due to a capillary dilution caused by tracer administration, and partly related to the no n-physiological deuterium signal decrease observed in dead rats. Blood flow measurements in human colon tumours implanted in nude mice showe d a rather poor reproducibility, not improved by the use of a multiple site injection technique.