Index by author

Twenty-eight patients with newly presenting glioblastoma multiforme underwent preoperative conventional imaging and T1 dynamic contrast-enhanced MRI. Parametric maps of the initial area under the contrast agent concentration curve, contrast transfer coefficient, estimate of volume of the extravascular extracellular space, and estimate of blood plasma volume were generated, and the enhancing fraction was calculated. High values of the estimate of volume of the extravascular extracellular space were associated with a fibrillary histologic pattern and increased mitotic activity. This finding is counterintuitive to the standard concept that more proliferative tumors would be more densely packed with cells and have less extracellular space. As the authors point out, this surprising finding requires more investigation to understand whether this relationship will hold, and what the underlying mechanism might be.

The authors retrospectively evaluated 109 fetuses within 25 weeks of gestational age who had undergone both prenatal and postnatal MR imaging of the brain between 2002 and 2014, and using the postnatal MRI as the reference standard, they calculated the sensitivity, specificity, positive predictive value, and negative predictive value of the prenatal MRI in detecting brain malformations. Prenatal MR imaging failed to detect correctly 11 of the 111 malformations. They conclude that diagnostic value of prenatal MRI for brain malformations within 25 weeks of GA is very high, despite limitations of sensitivity in the early detection of disorders of cortical development, such as polymicrogyria and periventricular nodular heterotopias.