Objective: The present study was aimed at evaluating the role of diffusion tensor imaging for the assessment of different patterns of white matter involvement in patients with brain tumors and the utility of this technique for differential diagnosis of such neoplasms. Materials and methods: Forty-four patients with brain tumors, including low-grade gliomas, anaplastic astrocytomas, glioblastomas multiforme and metastases, were studied with conventional and diffusion tensor magnetic resonance imaging. White matter tracts around the tumors were characterized as displaced, disrupted, infiltrated and edematous. Results: A significant overlap was observed between patterns of white matter involvement on diffusion tensor images as the displaced pattern was seen in all the types of tumor. Disrupted and infiltrated patterns were found in glioblastomas multiforme and anaplastic astrocytomas. The edematous pattern was found in the cases of metastases. Conclusion: Diffusion tensor imaging patterns of white matter involvement assists in the mapping of tracts adjacent to tumors, providing significant data about tumors extent; however, they cannot distinguish low-grade and high-grade gliomas from metastases.

Keywords: Diffusion tensor imaging; White matter; Brain tumors.

Objective: The present study was aimed at evaluating the reliability of the qualitative visual assessment of brain abnormalities using conventional brain MRI in extremely preterm infants. Materials and methods: A cohort of 45 consecutive infants with gestational age of 30 weeks or less (median of 27 weeks, ranging from 25 to 30 weeks) was enrolled in this study. Two independent, experienced neuroradiologists blindly reviewed MRI studies of the infants’ brain for diffuse and excessive high-signal intensity (DEHSI), dilated lateral ventricles, intracranial hemorrhage, areas of abnormal signal in the basal ganglia and cortex, cyst-like areas, ventricular deformities, enlargement of subarachnoid spaces, early leukoencephalomalacia, and cortical abnormalities. Results: Forty-one patients (91.1%) presented abnormalities at MRI. The most common findings were DEHSI in the white matter (75.6%) and ventricular dilatation (42.2%). The interobserver agreement was high (κ > 0.60) for most of the abnormal MRI findings. The kappa statistic values were moderate for enlargement of the subarachnoid space (κ = 0.52) and was only low for DEHSI in the white matter (κ = 0.39). Conclusion: Conventional MRI seems to be a reliable method for evaluating the most common brain abnormalities in extremely premature infants; however, the presence of DEHSI in the white matter demonstrated to be is a less reliable finding.

Keywords: Preterm; Brain; Magnetic resonance imaging; Imaging; Hypoxia.