The most important risk factors affecting NVCFs were osteoporosis and intervertebral discal cement leakage.

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ObjectiveTo evaluate the usefulness of time-resolved contrast enhanced magnetic resonance angiography (4D MRA) after stent-assisted coil embolization by comparing it with time of flight (TOF)-MRA.Materials and MethodsTOF-MRA and 4D MRA were obtained by 3T MRI in 26 patients treated with stent-assisted coil embolization (Enterprise:Neuroform = 7:19). The qualities of the MRA were rated on a graded scale of 0 to 4. We classified completeness of endovascular treatment into three categories. The degree of quality of visualization of the stented artery was compared between TOF and 4D MRA by the Wilcoxon signed rank test. We used the Mann-Whitney U test for comparing the quality of the visualization of the stented artery according to the stent type in each MRA method.ResultsThe quality in terms of the visualization of the stented arteries in 4D MRA was significantly superior to that in 3D TOF-MRA, regardless of type of the stent (p < 0.001). The quality of the arteries which were stented with Neuroform was superior to that of the arteries stented with Enterprise in 3D TOF (p < 0.001) and 4D MRA (p = 0.008), respectively.Conclusion4D MRA provides a higher quality view of the stented parent arteries when compared with TOF.

PurposeThe in-stent signal reduction of the stented artery caused by susceptibility artifact or radiofrequency shielding artifact limited the use of time-of-flight MR angiography (TOF-MRA) as a follow-up tool after intracranial stenting. We showed the degree of an artifact according to different stent types, and optimized MR parameters for TOF-MRA in patients with intracranial stent on 3.0 T MRI.Materials and MethodsFour stents (Neuroform, Wingspan, Solitaire, and Enterprise) were placed in a vascular flow phantom and imaged by changing flip angle (FA; 20°,30°,40°,50° and 60°) and bandwidth (BW; 31, 42 and 62.5 KHz) using TOF-MRA. Source data of each image set with different FA and BW were reconstructed with the maximal intensity projection (MIP) technique, and MIP images were used to evaluate the in-stent signal reduction of each stent according to the change of MR parameters. The in-stent signal reduction was assessed by calculating the relative in-stent signal (RIS) inside the stent as compared with background and signal intensity of the tube outside the stent. The optimal FA and BW of each stent were determined by comparing the RIS in each stent by one-sample t test. Finally, one neuroradiologist chose one image set with the best image quality.ResultsThe mean RIS for Neuroform, Wingspan, Solitaire and Enterprise stent was 66.3 ± 6.0, 44.2 ± 5.8, 22.8 ± 3.3 and 8.2 ± 2.9, respectively. The significantly high RIS of each stent was obtained with FA/BW value of 20°/31 KHz (Neuroform), 20°/31 KHz and 30°/42 KHz (Wingspan), 40°/42 KHz and 50°/31 KHz (Solitaire) and 40°/31 KHz and 50°/31 KHz (Enterprise). Among these MIP images with significantly high RIS, images with FA/BW value of 20°/31 KHz (Neuroform and Wingspan) and 50°/31 KHz (Solitaire and Enterprise) had the best image quality.ConclusionThe degree of artifact was variable according to the design of each intracranial stent. The luminal visualization of closed-cell design stents such as Solitaire and Enterprise can be improved by higher FA. Thus, MR parameter should be adjusted according to the type of intracranial stents.

Coil embolization of very small aneurysms may be technically feasible with favorable clinical/angiographic outcomes and relatively low recanalization rate during 6 months or more follow-up period.

These data suggest that genetic variation of dopamine-related genes may affect motor recovery after stroke and that COMT polymorphism could be useful for predicting motor recovery.

ObjectiveThe gyrus rectus (GR) is known as a non-functional gyrus; hence, its resection is agreed to be a safe procedure frequently practiced to achieve a better surgical view during specific surgeries. This study aimed at comparing the cognitive outcomes following GR resection in patients who underwent surgery for ruptured anterior communicating artery (ACoA) aneurysms.Materials and MethodsFrom 2012 to 2015, 39 patients underwent surgical clipping for ruptured ACoA aneurysms. Mini-mental state examinations (MMSE) were performed in 2 different periods. The statistical relationship between GR resection and MMSE results was evaluated, and further analysis of MMSE subgroup was performed.ResultsTwenty-five out of the 39 patients (64.19%) underwent GR resection. Mean initial and final MMSE scores in the GR resection group were 16.3 ± 9.8 and 20.8 ± 7.3, respectively. In the non-resection group, the mean initial and final MMSE scores were 17.1 ± 8.6 and 21.9 ± 4.5, respectively. Neither group's scores showed a significant change. Subgroup analysis of initial MMSE showed a significant difference in memory recall and language (p = 0.02) but not in the final MMSE scores.ConclusionThere was no significant relationship between the GR resection and cognitive outcomes in terms of total MMSE scores after surgery for ruptured ACoA aneurysm. However, subgroup analysis revealed a temporary negative effect of GR resection in the categories of language and memory recall. This study suggests that GR resection should be executed superficially, owing to its close anatomical relationship with the limbic system.

I n cerebral ischemia due to large-vessel occlusion, cell viability depends on the collateral perfusion status (1,2). Infarction might be complete in less than 1 hour or may not be complete for hours or days depending on the collateral perfusion status, which varies among patients (3,4). Therefore, recanalization and reperfusion treatment can be futile or even dangerous when performed in the standard optimal time window, but could be useful if performed in a later time window (5)(6)(7)(8). Studies have shown that a large ischemic core combined with poor collaterals is a strong predictor of an unfavorable response to endovascular treatment and poor functional outcomes. Hence, the exclusion of patients with a large ischemic core and poor collateral circulation could prevent administration of futile and dangerous recanalization therapy. Conversely, good collateral circulation can limit ischemic core expansion and prolong the time the penumbral tissue at risk remains salvageable until reperfusion therapy. Some studies have suggested that the time window for endovascular treatment can be successfully extended in patients with good collaterals (9-14). These results demonstrate the importance of accurately estimating the collateral perfusion status to enable patientspecific application of treatment, thereby improving functional outcomes among patients with acute ischemic stroke due to large-vessel occlusion.Recently, researchers have developed dynamic collateral imaging methods such as multiphase CT angiography and collateral flow maps derived from dynamic susceptibility contrast material-enhanced perfusion MRI (15,16). Studies evaluating these collateral imaging approaches have shown that collateral status is a strong predictor of final infarct size and functional outcomes in patients considered eligible for intra-arterial thrombectomy and intravenous thrombolysis (17,18). For intra-arterial thrombectomy, it