BRAIN-TISSUE VOLUME MEASUREMENT FROM MAGNETIC-RESONANCE-IMAGING - A PHANTOM STUDY

RATIONALE AND OBJECTIVES. The authors appraised the accuracy of a method for brain volume measurement from magnetic resonance images and evaluated the effects of the acquisition matrix, slice thickness. and tissue sampling on the measurement error. METHODS. The method uses two magnetic resonance imaging sequences to account explicitly for partial volume effects. The accuracy was measured with one-, two-, and three-compartmental phantoms that mimic the relaxation properties of brain tissues. The sensitivity of the method to section thickness was measured by repeated scans of human brain. RESULTS. Using a strongly T2-weighted sequence and two-compartmental phantoms, the average error was 5%, with 3% error for phantoms larger than 90 mL. In the three-compartmental phantoms the error varied from 2% to 7%. Varying the section thickness from 5 to 10 mm on three-compartmental phantoms and from 2.5 to 10 mm in the human brain did not significantly affect compartmental volumes. CONCLUSIONS. The experimental study validates the feasibility of monitoring localized volume changes in a three-compartmental model.