Category Archives: Editor’s Choices
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This study assesses the risk of being female in addition to the well-known factors of age and apolipoprotein E ε4 status in the development and progression of Alzheimer disease based on longitudinal brain atrophy, cognitive decline, and CSF markers. APOE ε4 accelerated rates of decline, especially in women. The gender effect was at least as important as APOE ε4 status and showed weaker relationships to CSF markers.
BACKGROUND AND PURPOSE
Age and the apolipoprotein E ε4 allele are well-known risk factors for Alzheimer disease, but whether female sex is also a risk … Continue reading >>
T1 Gadolinium Enhancement of Intracranial Atherosclerotic Plaques Associated with Symptomatic Ischemic Presentations
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The degree of contrast enhancement was assessed in 22 high-grade intracranial stenoses that were either symptomatic or asymptomatic. Seventy percent of symptomatic plaques showed contrast enhancement whereas this was seen in only 8% of those that were asymptomatic. This study suggests that intracranial stenoses can be evaluated with conventional MRI protocols and that there is a strong association between plaque contrast enhancement and ischemic symptoms.
BACKGROUND AND PURPOSE
Contrast enhancement of intracranial atherosclerotic plaques has recently been investigated using high field and high resolution MR imaging as a risk factor in the … Continue reading >>
Perfusion Deficits Detected by Arterial Spin-Labeling in Patients with TIA with Negative Diffusion and Vascular Imaging • X.J. Qiao, N. Salamon, D.J.J. Wang, R. He, M. Linetsky, B.M. Ellingson, and W.B. Pope
The current definition of TIA calls for normal imaging including DWI. Here the authors used arterial spin-labeling perfusion to detect abnormalities in nearly 50 patients within 24 hours of symptom onset and in 36 controls. The sensitivity and specificity of ASL in TIA diagnosis was 55.8% and 90.7%, respectively, and in nearly 94% of readings abnormalities that matched the clinical neurologic deficits were identified by the … Continue reading >>
Metabolic Changes in Patients with Aneurysmal Subarachnoid Hemorrhage Apart from Perfusion Deficits: Neuronal Mitochondrial Injury? • M. Wagner, A. Jurcoane, C. Hildebrand, E. Güresir, H. Vatter, F.E. Zanella, J. Berkefeld, U. Pilatus, and E. Hattingen
Because perfusion deficits may not account for all neuronal damage seen in subarachnoid hemorrhage, these authors measured cerebral metabolites in 58 patients with SAH without perfusion defects and/or infarctions. Using MR spectroscopy they discovered that NAA was significantly low in all patients, choline was elevated, and glutamate/glutamine was also decreased. The authors believe that these findings reflect neuronal mitochondrial injury.
Super-Resolution Track Density Imaging of Glioblastoma: Histopathologic Correlation • R.F. Barajas, Jr, C.P. Hess, J.J. Phillips, C.J. Von Morze, J.P. Yu, S.M. Chang, S.J. Nelson, M.W. McDermott, M.S. Berger, and S. Cha
Track density is a new imaging technique that allows submillimeter voxel resolution. These investigators used TDI to image 34 GBMs and correlated their findings with histopathology. TDI was elevated in tissues containing aggressive features and, regardless of contrast enhancement, these regions showed cellular proliferation, architectural disruption, and hypoxia. Thus, TDI may be helpful in identifying tumor infiltration in nonenhancing components of GBM.
Simple fMRI Postprocessing Suffices for Normal Clinical Practice • S. González-Ortiz, L. Oleaga, T. Pujol, S. Medrano, J. Rumiá, L. Caral, T. Boget, J. Capellades, and N. Bargalló
Here, 2 postprocessing methods for fMRI were tested: a simple commercially available one against one commonly used for more advanced research. The authors compared visual concordance, image quality, voxel size, and radiologist preferences and concluded that widely available commercial fMRI software can provide reliable information for therapeutic management, meaning sophisticated, less widely available software is unnecessary in most cases. (See the accompanying commentary by Pillai.)
Diagnostic Accuracy of PET for Recurrent Glioma Diagnosis: A Meta-Analysis • T. Nihashi, I.J. Dahabreh, and T. Terasawa
These authors compared the diagnostic accuracy of PET with that of CT and MRI in the diagnosis of recurrent glioma in 26 previously published articles. PET studies with either FDG or carbon methionine were obtained once glioma recurrence was suspected on CT and/or MRI. Diagnostic accuracies were heterogeneous and studies did not compare PET with other imaging modalities. Despite these limitations, PET with both tracers appears to have a moderately good accuracy as an add-on test for diagnosing recurrent glioma.… Continue reading >>
Anatomic MR Imaging and Functional Diffusion Tensor Imaging of Peripheral Nerve Tumors and Tumorlike Conditions • A. Chhabra, R.S. Thakkar, G. Andreisek, M. Chalian, A.J. Belzberg, J. Blakeley, A. Hoke, G.K. Thawait, J. Eng, and J.A. Carrino
In this study 29 patients underwent anatomic and functional imaging (DWI and DTI) of peripheral nerve masses in an attempt to improve their characterization. ADC values were lower in malignant tumors, the involved nerves had lower fractional anisotropy, and DTI showed differences between benign and malignant tumors. The authors concluded that tractography and fractional anisotropy provide insight into neural integrity while … Continue reading >>
Apolipoprotein E ε4 Does Not Modulate Amyloid-β–Associated Neurodegeneration in Preclinical Alzheimer Disease • R.S. Desikan, L.K. McEvoy, D. Holland, W.K. Thompson, J.B. Brewer, P.S. Aisen, O.A. Andreassen, B.T. Hyman, R.A. Sperling, A.M. Dale, and for the Alzheimer’s Disease Neuroimaging Initiative
These authors investigated the relationship between amyloid-β, phosphorylated tau, and apolipoprotein E in preclinical Alzheimer disease in 170 patients and controls who had serial imaging up to 3.5 years after the initial study. Global volumes as well as volumes in brain regions known to be involved in the chronic stages of the disease were assessed. Their results led … Continue reading >>