- 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.
- 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.
- Delayed Leukoencephalopathy: A Rare Complication after Coiling of Cerebral Aneurysms
Delayed leukoencephalopathy is a rare complication that occurs after endovascular coiling of cerebral aneurysms and is found in the literature with several different names, such as delayed leukoencephalopathy, delayed enhancing lesions, and delayed multiple white matter lesions. Its various suggested etiologies include granulation reaction caused by foreign body emboli from the hydrophilic coating of procedural devices, contrast-induced encephalopathy, and nickel or bioactive polyglycolic/polylactic acid coil sensitivity. The authors analyzed 1754 endovascular coiling procedures of 1594 aneurysms. Sixteen procedures demonstrated delayed leukoencephalopathy on follow-up FLAIR MR imaging examinations after a median period of 71.5 days in the form of high-signal changes in the white matter at locations remote from the coil mass. Seven patients had headaches or hemiparesis, and 9 patients were asymptomatic. All imaging-associated changes improved subsequently. They found evidence of an association between delayed leukoencephalopathy and the number of microcatheters used per procedure, along with evidence suggesting that these procedures required larger median volumes of contrast medium and weak evidence regarding the need for a longer median fluoroscopy duration.