In Vivo Measurement of Water Self Diffusion in the Human Brain by Magnetic Resonance Imaging

Abstract

A new pulse sequence for in vivo diffusion measurements by magneticresonance imaging (MRI) is introduced. The pulse sequence was testedon phantoms to evaluate the accuracy, reproducibility and inplanevariations. The sensitivity of the sequence was tested by measuringthe self diffusion coefficient of water with different temperatures.This phantom study showed that the water self diffusion could bemeasured accurately and that the inplane deviation was less than+/- 10 per cent. Seven healthy volunteers were studied with a 10mm thick slice through the lateral ventricles, clear differencesbetween grey and white matter as well as regional differences withinthe white matter were seen. In two patients with infarction, alternationsin water self diffusion were seen in the region of the infarct. Likewise,pronounced changes in brain water self diffusion were observed ina patient with benign intracranial hypertension. The results indicatethat brain water self diffusion can be measured in vivo with reasonableaccuracy. The clinical examples suggest that diffusion measurementsmay be clinically useful adding further information about in vivoMR tissue characterization.