Editor’s Choices

Multicenter Experience with FRED Jr Flow Re-Direction Endoluminal Device for Intracranial Aneurysms in Small Arteries

Editor’s Choice

The authors assessed the clinical safety and efficacy of the Flow Re-Direction Endoluminal Device Jr (FRED Jr) dedicated to small-vessel diameters between 2.0 and 3.0 mm in 42 patients with 47 aneurysms. The primary efficacy end point of complete or near complete occlusion was reached at 1 month in 27/41 (66%), at 6 months in 21/27 (78%), and at 12 months in 11/11 (100%) aneurysms.

Concordance of Time-of-Flight MRA and Digital Subtraction Angiography in Adult Primary Central Nervous System Vasculitis

Editor’s Choice

The authors compared the diagnostic concordance of vessel imaging using 3D-TOF-MRA and DSA in 85 patients with primary central nervous system vasculitis. Among the 25 patients with abnormal DSA findings, 24 demonstrated abnormal 3D-TOF-MRA findings, whereas all 6 remaining patients with normal DSA findings had normal 3D-TOF-MRA findings. They conclude that 3D-TOF-MRA shows a high concordance with DSA in diagnostic performance when analyzing vasculature in patients with primary central nervous system vasculitis and that with negative 3T 3D-TOF-MRA findings, the added diagnostic value of DSA is limited.

3D Pseudocontinuous Arterial Spin-Labeling MR Imaging in the Preoperative Evaluation of Gliomas

Editor’s Choice

Fifty-eight patients with pathologically confirmed gliomas underwent preoperative 3D pseudocontinuous arterial spin-labeling and ROC curves were generated for parameters to distinguish high-grade from low-grade gliomas. Both maximum CBF and maximum relative CBF were significantly higher in high-grade than in low-grade gliomas. After adjustment for age, a higher maximum CBF and higher maximum relative CBF were associated with worse progression-free survival.

Hippocampal and Deep Gray Matter Nuclei Atrophy Is Relevant for Explaining Cognitive Impairment in MS: A Multicenter Study

Editor’s Choice

Brain dual-echo, 3D T1-weighted, and double inversion recovery scans were acquired at 3T from 62 patients with relapsing-remitting MS and 65 controls. Focal WM and cortical lesions were identified, and volumetric measures from WM, cortical GM, the hippocampus, and deep GM nuclei were obtained. Compared with those with who were cognitively preserved, patients with MS with cognitive impairment had higher T2 and T1 lesion volumes and a trend toward a higher number of cortical lesions. Significant brain, cortical GM, hippocampal, deep GM nuclei, and WM atrophy was found in patients with MS with cognitive impairment versus those who were cognitively preserved. The authors conclude that hippocampal and deep GM nuclei atrophy are key factors associated with cognitive impairment in MS.

Identification and Quantitative Assessment of Different Components of Intracranial Atherosclerotic Plaque by Ex Vivo 3T High-Resolution Multicontrast MRI

Editor’s Choice

Fifty-three intracranial arterial specimens with atherosclerotic plaques from 20 cadavers were imaged by 3T MR with T1, T2, and proton-density–weighted FSE and STIR sequences. The signal characteristics and areas of fibrous cap, lipid core, calcification, fibrous tissue, and healthy vessel wall were recorded on MR images and compared with histology. The signal intensity of the lipid core was significantly lower than that of the fibrous cap on T2-weighted, proton-density, and STIR sequences and was comparable on T1-weighted sequences. Optimal contrast between the lipid core and fibrous cap was found on T2-weighted images. Ex vivo 3T MR imaging can accurately identify and quantitatively assess intracranial atherosclerotic plaque components, providing a direct reference for in vivo intracranial plaque imaging.

Amide Proton Transfer Imaging Allows Detection of Glioma Grades and Tumor Proliferation: Comparison with Ki-67 Expression and Proton MR Spectroscopy Imaging

Editor’s Choice

Amide proton transfer–weighted imaging (APTWI) is a novel molecular MR imaging technique developed to detect and quantitatively visualize endogenous proteins and peptides. APTWI is usually reported in terms of asymmetry in the magnetization transfer ratio at 3.5 ppm. This study included 42 patients with low-grade (n = 28) or high-grade (n = 14) glioma, all of whom underwent conventional MR imaging, proton MR spectroscopy imaging, and amide proton transfer–weighted imaging on the same 3T scanner within 2 weeks before surgery. The asymmetric magnetization transfer ratio at 3.5 ppm values measured by different readers showed good concordance and were significantly higher in high-grade gliomas than in low-grade gliomas, with sensitivity and specificity values of 92.9% and 71.4%, respectively, at a cutoff value of 2.93%. The asymmetric magnetization transfer ratio at 3.5 ppm may serve as a potential biomarker not only for assessing proliferation, but also for predicting histopathologic grades in gliomas.

Relationship between Glioblastoma Heterogeneity and Survival Time: An MR Imaging Texture Analysis

Editor’s Choice

A group of 133 patients with primary glioblastoma who underwent postcontrast T1-weighted imaging (acquired before treatment) and whose data were filed with the survival times were selected from the Cancer Genome Atlas. On the basis of overall survival, the patients were divided into 2 groups: long-term (≥12 months, n = 67) and short-term (<12 months, n = 66) survival. To measure heterogeneity, the authors extracted 3 types of textures, co-occurrence matrix, run-length matrix, and histogram, reflecting local, regional, and global spatial variations, respectively. Then the support vector machine classification was used to determine how different texture types perform in differentiating the 2 groups. The results suggest that local and regional heterogeneity may play an important role in the survival stratification of patients with glioblastoma.

The Impact of Conscious Sedation versus General Anesthesia for Stroke Thrombectomy on the Predictive Value of Collateral Status: A Post Hoc Analysis of the SIESTA Trial

Editor’s Choice

Using imaging data from the Sedation versus Intubation for Endovascular Stroke TreAtment (SIESTA) trial, the authors assessed collateral status with the score of Tan et al and graded it from absent to good collaterals (0–3). They examined the association of collateral status with 24-hour improvement of the NIHSS score, infarct volume, and mRS at 3 months according to the sedation regimen in a cohort of 104 patients. The sedation mode, conscious sedation or general anesthesia, did not influence the predictive value of collaterals in patients with large-vessel occlusion anterior circulation stroke undergoing thrombectomy in the SIESTA trial.

Temporal and Spatial Variances in Arterial Spin-Labeling Are Inversely Related to Large-Artery Blood Velocity

Editor’s Choice

The authors performed consecutive pseudocontinuous arterial spin-labeling and phase-contrast MR imaging on 82 individuals (healthy young adults, healthy older adults, and older adults with cerebral small vessel disease or chronic stroke infarcts) and examined associations between extracranial phase-contrast hemodynamics and intracranial arterial spin-labeling characteristics, which were defined by labeling efficiency, temporal signal-to-noise ratio, and spatial coefficient of variation. Large-artery blood velocity was inversely associated with labeling efficiency, temporal SNR, and spatial coefficient of variation of arterial spin-labeling. They conclude that choosing arterial spin-labeling timing parameters with on-line knowledge of blood velocity may improve CBF quantification.

Differentiation between Treatment-Induced Necrosis and Recurrent Tumors in Patients with Metastatic Brain Tumors: Comparison among 11C-Methionine-PET, FDG-PET, MR Permeability Imaging, and MRI-ADC—Preliminary Results

Editor’s Choice

The authors evaluated the feasibility of MR permeability imaging by comparison with 11C-methionine-PET, FDG-PET, and DWI for differentiating radiation necrosis from recurrent tumors in 15 patients with 18 lesions following gamma knife radiosurgery. The area under the ROC curve for differentiating radiation necrosis from recurrent tumors was the best for the 11C-methionine ratio (0.90) followed by the contrast-enhancement ratio (0.81), maximum slope of increase (millimole/second) (0.80), and the initial area under the signal intensity–time curve (0.78). They conclude that PET using 11C-methionine may be superior to MR permeability imaging, ADC, and FDG-PET for differentiating radiation necrosis from recurrent tumors after gamma knife radiosurgery for metastatic brain tumors.