BACKGROUND AND PURPOSE:Voxel size/shape of diffusion tensor imaging (DTI) may directly affect the measurement of fractional anisotropy (FA) in regions where there are crossing fibers. The purpose of this article was to investigate the effect of voxel size/shape on measured FA by using isotropic and nonisotropic voxels.

Fiber-tracking techniques can provide information on the pathophysiologic features of motor disability in patients with periventricular leukomalacia. Early screening of patients with a history of asphyxia may facilitate early intervention (eg, rehabilitation), to achieve better motor function.

The corticospinal tracts (CSTs) crossed the lenticulostriate artery territory exclusively at the posterosuperior quadrant, and the degree of CST involvement within the infarcts was directly related to stroke severity and functional recovery.

Purpose:To compare the diagnostic performance of breast lesions by the enhancement patterns and morphologic criteria on magnetic resonance imaging (MRI). Materials and Methods:Both T1-weighted 3D gradientecho sequences with high temporal resolution and highspatial-resolution MRI were performed on 190 patients with a total of 204 enhancing lesions (144 malignant and 60 benign). The enhancement patterns and morphologic features of each mass and nonmass lesion were analyzed, and the diagnostic performance was compared. Results:The sensitivity and specificity of the morphologic criteria were statistically significantly higher than those of the enhancement patterns (sensitivity: P ϭ 0.0012, specificity: P ϭ 0.0003), and the A z values for the three observers were 0.900, 0.919, and 0.900. The diagnostic accuracy of the morphologic criteria for both types of lesions was superior, and the differences were statistically significant (mass: P ϭ 0.0001, nonmass: P ϭ 0.0389). Conclusion:The analysis of the morphologic features of enhancing breast lesions alone showed higher diagnostic performance; therefore, signal intensity (SI) time-course data may not be needed to diagnose malignant breast lesions.

Two technical challenges must be overcome before brain fiber tracking with diffusion-tensor magnetic resonance (MR) imaging can be applied to clinical practice: Imaging time must be shortened, and image distortion must be minimized. Single-shot echo-planar MR imaging with parallel imaging technique enabled both objectives to be accomplished. Twenty-three consecutive patients with brain tumors underwent MR imaging with a 1.5-T whole-body MR system. Fiber tracts on the lesion side in the brain had varying degrees of displacement or disruption as a result of the tumor. Tract disruption resulted from direct tumor involvement, compression on the tract, and vasogenic edema surrounding the tumor. This diffusion-tensor MR imaging method with the parallel imaging technique allows clinically feasible brain fiber tracking.