Proton MR spectroscopy of the femoral head—Evaluation of patients at risk for avascular necrosis

Authors


Abstract

Purpose

To detect alteration of the fatty component by measuring the in vivo lipid and water content of normal-looking femoral heads of patients with and without risk for avascular necrosis (AVN) by using proton MR spectroscopy (MRS).

Materials and Methods

Marrow composition was measured by proton MRS (TR/TE = 5000/20 msec) in a sample volume placed in the epiphysis of the intact femoral heads of patients with unilateral osteonecrosis of the hip (group 1, N = 61, then excluding the post-traumatic or steroid user, final N = 45) and age-matched controls (group 2, N = 49). Three response variables were derived from MRS: the lipid linewidth (LW), water LW, and lipid/water ratio.

Results

Of the three variables, the lipid and water LWs differed significantly between groups (P < 0.001 and P = 0.05, respectively; t-test). The lipid/water ratio had borderline significance (P = 0.06). The three variables differed significantly between groups when multivariate regression (P < 0.0001) was analyzed; and age and sex had no significant effect on the three dependent variables.

Conclusion

Proton MRS can depict alteration in the lipid and water composition of normal-looking femoral heads with and without AVN on the contralateral hip. Proton MRS may be a potential tool for investigating of the femoral head component in vivo and predicting the risk for development of AVN. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc.

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