MR relaxometry: estimating overhydration in renal failure

An MR method is described for estimating overhydration in patients suffering from renal failure. In 29 healthy volunteers, the fat content of a selected slice of the lower limb was correlated to the overall T1-relaxation time (r = -0.97, p < 0.000001). When compared with the normal T1 of the voluntary group, delta T1 was calculated having regard to the individual fat content in 74 MR studies of 22 overhydrated patients. MR results were correlated with the difference between clinically estimated dry and the actual body weight (r = 0.6, p < 0.000001). In an intraindividual follow-up (11 studies) MRI was shown to provide good correlation to the actual body weight (r = 0.9, p < 0.0005) and fluid balance (r = 0.87, p < 0.001).