Table of Contents
Perspectives
Editorial
- Neuroradiology Fellowship Requirements: Updates in 2019
Notable changes made since the prior requirements were last revised in 2007 primarily affect the number of required procedures, the academic support defined for the program director, and modifications to the curriculum. The new requirements allow fellows to fulfill the foundational expectations for the neuroradiology fellowship and encourage programs to maintain some flexibility to teach individual specialty areas of clinical excellence.
Review Articles
General Contents
- Performance of Standardized Relative CBV for Quantifying Regional Histologic Tumor Burden in Recurrent High-Grade Glioma: Comparison against Normalized Relative CBV Using Image-Localized Stereotactic Biopsies
This study compares the predictive performance of relative CBV standardization against relative CBV normalization for quantifying recurrent tumor burden in high-grade gliomas relative to posttreatment radiation effects. The authors recruited 38 previously treated patients with high-grade gliomas (World Health Organization grades III or IV) undergoing surgical re-resection for recurrent tumor versus posttreatment radiation effects. They recovered 112 image-localized biopsies and quantified the percentage of histologic tumor content versus posttreatment radiation effects for each sample. They measured spatially matched normalized and standardized relative CBV metrics (mean, median) and fractional tumor burden for each biopsy. Across relative CBV metrics, fractional tumor burden showed the highest correlations with tumor content (0%–100%) for normalized and standardized values. With binary cutoffs, predictive accuracies were similar for both standardized and normalized metrics and across relative CBV metrics. Standardization of relative CBV achieves similar equivalent performance compared with normalized relative CBV and offers an important step toward workflow optimization and consensus methodology.
- Correction of Motion Artifacts Using a Multiscale Fully Convolutional Neural Network
The authors implement and validate an MRI motion-artifact correction method using a multiscale fully convolutional neural network. Application of the network resulted in notably improved image quality without the loss of morphologic information. For synthetic test data, the average reduction in mean squared error was 41.84%. The blinded reader study on the real-world test data resulted in significant reduction in mean artifact scores across all cases.
- SWAN-Venule: An Optimized MRI Technique to Detect the Central Vein Sign in MS Plaques
Multiple sclerosis lesions develop around small veins that are radiologically described as the so-called central vein sign. With 7T MR imaging and magnetic susceptibility-based sequences, the central vein sign has been observed in 80%–100% of MS lesions in patients' brains. However, a lower proportion ∼50% has been reported at 3T using SWAN. The authors' aim was to assess a modified version of SWAN optimized at 3T for sensitive detection of the central vein sign. Thirty subjects with MS were scanned on a 3T clinical MR imaging system. 3D T2-weighted FLAIR and optimized 3D SWAN, called SWAN-venule, were acquired after injection of a gadolinium-based contrast agent. Overall, the central vein sign was detected in 86% of the white matter lesions (periventricular, 89%; deep white matter, 95%; and juxtacortical, 78%). The SWAN-venule technique is an optimized MR imaging sequence for highly sensitive detection of the central vein sign in MS brain lesions.
- Early Detection of Cancer: Evaluation of MR Imaging Grading Systems in Patients with Suspected Nasopharyngeal Carcinoma
Dedicated nasopharyngeal MR imaging before (plain scan system) and after intravenous contrast administration (current and modified systems) was reviewed in patients from a nasopharyngeal carcinoma-endemic region, comprising 383 patients with suspected disease without nasopharyngeal carcinoma and 383 patients with nasopharyngeal carcinoma. The modified and plain scan systems refined primary tumor criteria, added a nodal assessment, and expanded the system from 4 to 5 grades. The current, modified, and plain scan MR imaging systems yielded sensitivities of 99.74%, 97.91%, and 97.65%, respectively, and specificities of 63.45%, 89.56%, and 86.42%, respectively. The modified system yielded significantly better performance than the current and plain systems. In conclusion, the authors propose a modified MR imaging grading system that improves diagnostic performance for nasopharyngeal carcinoma detection. Contrast was not valuable for low MR imaging grades, and the plain scan shows potential for use in screening programs.
- 4D–Dynamic Contrast-Enhanced MRI for Preoperative Localization in Patients with Primary Hyperparathyroidism
The authors tested the hypothesis that recently introduced 4D dynamic contrast-enhanced MR imaging with high spatial and temporal resolution has equivalent accuracy to 4D-CT for preoperative gland localization in primary hyperparathyroidism. Fifty-four patients met the inclusion criteria: 37 had single-gland disease, and 17, multigland disease—9 with double-gland hyperplasia; 3 with 3-gland hyperplasia, and 5 with 4-gland hyperplasia. For single-gland disease, the gland was correctly located in 92% of patients, with correct identification of the side in 100% and the quadrant in 92%. For multigland disease, the glands were correctly located in 74% of patients, with correct identification of the side in 74% and the quadrant in 77%. The high spatial and temporal resolution 4D dynamic contrast-enhanced MR imaging provides excellent diagnostic performance for preoperative localization in primary hyperparathyroidism.
Online Features
Letters
