Detection of Brain Metastases by 3-Dimensional Magnetic Resonance Imaging at 3 T: Comparison Between T1-Weighted Volume Isotropic Turbo Spin Echo Acquisition and 3-Dimensional T1-Weighted Fluid-Attenuated Inversion Recovery Imaging

Objective: To compare the diagnostic performance in detection of brain metastases between contrast-enhanced T1-weighted-Volume ISotropic Turbo-spin-echo Acquisition (T1-VISTA) and 3-dimensional T1-weighted fluid-attenuated inversion recovery (3D-T1-FLAIR) imaging at 3T. Methods: Two neuroradiologists selected 129 true (metastases) and 70 false (vessels and artifacts) lesions on the contrast-enhanced T1-VISTA and 3D-T1-FLAIR images of 14 cancer patients with hyperintense brain lesions. Four blinded neuroradiologists distinguished between the true and false lesions, using a five-point confidence rating scale. The receiver operating characteristic analysis was performed to compare the diagnostic performance. Contrast-to-noise ratio (CNR) of the true lesions was also compared between the two sequences by using paired t-tests. Results: For lesions < 3 mm, the area under curve and sensitivity achieved by T1-VISTA imaging were significantly greater than 3D-T1-FLAIR imaging. The CNR was also significantly greater with T1-VISTA imaging. Conclusion: The contrast-enhanced T1-VISTA imaging is better suited than 3D-T1-FLAIR imaging, for detection of small metastases

Impaired integrity of the brain parenchyma in non-geriatric patients with major depressive disorder revealed by diffusion tensor imaging

Diffusion tensor imaging (DTI) is considered to be able to non-invasively quantify white matter integrity. This study aimed to use DTI to evaluate white matter integrity in non-geriatric patients with major depressive disorder (MDD) who were free of antidepressant medication. DTI was performed on 19 non-geriatric patients with MDD, free of antidepressant medication, and 19 age-matched healthy subjects. Voxel-based and histogram analyses were used to compare fractional anisotropy (FA) and mean diffusivity (MD) values between the two groups, using two-sample t tests. The abnormal DTI indices, if any, were tested for correlation with disease duration and severity, using Pearson product-moment correlation analysis. Voxel-based analysis showed clusters with FA decrease at the bilateral frontal white matter, anterior limbs of internal capsule, cerebellum, left putamen and right thalamus of the patients. Histogram analysis revealed lower peak position of FA histograms in the patients. FA values of the abnormal clusters and peak positions of FA histograms of the patients exhibited moderate correlation with disease duration and severity. These results suggest the implication of frontal-subcortical circuits and cerebellum in MDD, and the potential utility of FA in evaluation of brain parenchymal integrity. (C) 2012 Elsevier Ireland Ltd. All rights reserved