This study investigated whether or not the effect of contrast medium on diffusion tensor magnetic resonance imaging (DTI) is time-related in patients with malignant brain tumours.
Patients and methods
Twelve patients who only had malignant brain tumours were included in the study. DTI acquisitions were performed five times consecutively: twice before, once during, then twice after contrast injection. Diffusion indices were mapped and regions of interest (ROIs) were placed in the tumour, peritumoral edema and contralateral normal brain tissue. Repeated-measures ANOVA was used to investigate the effects of time on contrast medium in relation to diffusion indices.
Precontrast DTI was redefined as “pre” by averaging the two before-contrast scans, as there were no statistically significant differences between them. There were statistically significant differences at four time points for only the edema ROI for fractional anisotropy and the first-largest eigenvalue, but not for trace and the second-largest eigenvalue.
The effects of contrast medium on DTI were time-dependent for diffusion anisotropic indices. DTI obtained at>6min after contrast injection does not cause significant changes in diffusion isotropic and anisotropic values.Le texte complet de cet article est disponible en PDF.
Keywords : Diffusion tensor, Contrast medium, Time dependence, Isotropic and anisotropic diffusion, Malignant brain tumour
Abbreviations : DTI, ROI, FA, ADC, DWI, BBB, EPI, SENSE, T2WI, T1WI, FLAIR, ANOVA, MRI, Gd-DTPA, PET–CT, CSF, SD
| This study was supported by the Program of Kyung Hee University for the Young Researcher in Medical Science (KHU- 2009-1395, 2010-0708, GHJ).