Preliminary study of MR elastography in brain tumors / 中华放射学杂志

ABSTRACT

Objective To investigate the potential values of magnetic resonance elastography (MRE)for evaluating the brain tumor consistency in vivo.Methods Fourteen patients with known solid brain tumor(5 male,9 female;age range16-63 years)underwent brain MRE studies.Informed consent was obtained from all patients.A dedicated external force actuator for brain MRE study Was developed.The actuator was fixed to the head coil.During scan.one side of the actuator was attached to the patients'head.Low frequency oscillation Was produced by the actuator and caused shear waves propagating into brain tissue.The pulse sequence used in the study Writs phase-contrast gradient-echo sequence.Phase images of the brain were obtained and the shear waves within the brain were directly imaged.Phase images were processed with local frequency estimation (LFE) technique to obtain the elasticity image.Consistency of brain tumors Was evaluated at surgery and Was classified as soft,intermediate,or hard with comparison to the white matter of the brain.Correspondence of MRE evaluation with operative results was studied.Results The elastic modulus of the tumor Was lower than that of white matter in 1 patient,higher inll patients,and similar in 2 patients.At surgery,the tumor manifested a soft consistency in I patient,hard consistency in 11 patients,intermediate consistency in 2 patients.The elasticity of tumors in 14 patients evaluated by MRE was correlated with the tumor consistency on the operation.Conclusion MRE Can noninvasively display the elasticity of brain tumors in vivo,and evaluate the brain tumor consistency before operation.