BLOOD-OXYGEN SATURATION ASSESSMENT IN-VIVO USING T-2-ASTERISK ESTIMATION

The feasibility of noninvasively assessing hemoglobin oxygen saturatio n of deep blood vessels in vivo by measuring blood T-2 is investigate d. Techniques for blood T-2 measurements in major arteries and veins in the presence of pulsatile blood flow are presented and validated us ing a flow phantom. Images of multiple TEs were collected in a paired fashion. Cardiac triggering was used to eliminate image artifacts caus ed by pulsatile arterial blood flow. Using these techniques, it was fo und that the T-2 of arterial blood (199 +/- 8 ms) is significantly gr eater than that of venous blood (108 +/- 6 ms) in 10 volunteers, consi stent with the fact that the oxygen saturation level of arterial blood is much larger than that of venous blood. Various oxygen saturation l evels were created in vivo in a pig and the blood T-2 was shown to in crease with oxygen saturation levels over a wide range, Preliminary re sults of this study indicate that it is feasible to assess local oxyge n saturation by measuring blood T-2 using the proposed techniques.