T mapping of cerebrospinal fluid: 3 T versus 7 T.

OBJECT

Cerebrospinal fluid (CSF) T mapping can potentially be used to investigate CSF composition. A previously proposed CSF T -mapping method reported a T difference between peripheral and ventricular CSF, and suggested that this reflected different CSF compositions. We studied the performance of this method at 7 T and evaluated the influence of partial volume and B and B inhomogeneity.

MATERIALS AND METHODS

T -preparation-based CSF T -mapping was performed in seven healthy volunteers at 7 and 3 T, and was compared with a single echo spin-echo sequence with various echo times. The influence of partial volume was assessed by our analyzing the longest echo times only. B and B maps were acquired. B and B dependency of the sequences was tested with a phantom.

RESULTS

T was shorter at 7 T compared with 3 T. At 3 T, but not at 7 T, peripheral T was significantly shorter than ventricular T . Partial volume contributed to this T difference, but could not fully explain it. B and B inhomogeneity had only a very limited effect. T did not depend on the voxel size, probably because of the used method to select of the regions of interest.

CONCLUSION

CSF T mapping is feasible at 7 T. The shorter peripheral T is likely a combined effect of partial volume and CSF composition.