Table of Contents
Perspectives
Review Article
General Contents
- Lateral Asymmetry and Spatial Difference of Iron Deposition in the Substantia Nigra of Patients with Parkinson Disease Measured with Quantitative Susceptibility Mapping
The authors evaluated 24 patients with Parkinson disease and 24 age- and sex-matched healthy controls who underwent 3T MR imaging with a 3D multiecho gradient-echo sequence. On reconstructed quantitative susceptibility maps they measured the susceptibility values in the anterior, middle, and posterior parts of the substantia nigra, the whole substantia nigra, and other deep gray matter structures in both cerebral hemispheres. Susceptibility in the middle part, the posterior part, and the whole substantia nigra was significantly higher in the more and the less affected hemibrains of patients with Parkinson disease than in the healthy controls. Also, susceptibility was significantly higher in the posterior substantia nigra of the more affected hemibrain.
- Mitotic Activity in Glioblastoma Correlates with Estimated Extravascular Extracellular Space Derived from Dynamic Contrast-Enhanced MR Imaging
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.
- Cough-Associated Changes in CSF Flow in Chiari I Malformation Evaluated by Real-Time MRI
Eight symptomatic patients with Chiari I malformation and 6 healthy participants were studied by using MR pencil beam imaging with a temporal resolution of 50 ms. Patients and healthy participants were scanned in real-time during resting, coughing, and postcoughing periods. CSF flow waveform amplitude, CSF stroke volume, and CSF flow rate were compared between the patients and the control population. Real-time MR imaging noninvasively showed a transient decrease in CSF flow across the foramen magnum after coughing in symptomatic patients with Chiari I malformation.
- Pipeline Embolization Device in the Treatment of Recurrent Previously Stented Cerebral Aneurysms
Twenty-one patients with previously stented recurrent aneurysms who later underwent Pipeline Embolization Device placement (group 1) were retrospectively identified and compared with 63 patients who had treatment with the Pipeline with no prior stent placement (group 2). Pipeline treatment resulted in complete aneurysm occlusion in 55.6% of patients in group 1 versus 80.4% of patients in group 2. The retreatment rate in group 1 was 11.1% versus 7.1% in group 2. The authors conclude that the Pipeline is less effective in the management of previously stented aneurysms than when used in nonstented aneurysms.
- Brain Structural and Vascular Anatomy Is Altered in Offspring of Pre-Eclamptic Pregnancies: A Pilot Study
The authors assessed the brain structural and vascular anatomy in 7- to 10-year-old offspring of pre-eclamptic pregnancies compared with matched controls (n=10 per group). TOF-MRA and a high-resolution anatomic T1-weighted MPRAGE sequence were acquired for each participant. Offspring of pre-eclamptic pregnancies exhibited enlarged brain regional volumes of the cerebellum, temporal lobe, brain stem, and right and left amygdalae. These offspring displayed reduced cerebral vessel radii in the occipital and parietal lobes. The authors conclude that these structural and vascular anomalies may underlie the cognitive deficits reported in the pre-eclamptic offspring population.
- Diagnostic Value of Prenatal MR Imaging in the Detection of Brain Malformations in Fetuses before the 26th Week of Gestational Age
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.
