Usefulness of pointwise encoding time reduction with radial acquisition sequence in subtraction-based magnetic resonance angiography for follow-up of the Neuroform Atlas stent-assisted coil embolization for cerebral aneurysms.

BACKGROUND: Although time-of-flight magnetic resonance angiography (TOF-MRA) is widely used, it has limited usefulness for follow-up after stent-assisted coil embolization. Contrast-enhanced MRA (CE-MRA) and ultrashort echo time MRA have been suggested as alternative methods for visualization after this procedure. PURPOSE: To compare efficacy and usefulness of pointwise encoding time reduction with radial acquisition (PETRA) sequence in subtraction-based MRA (qMRA), TOF-MRA, and CE-MRA during the follow-up after Neuroform Atlas stent-assisted coil embolization for intracranial aneurysms. MATERIAL AND METHODS: This retrospective study included 23 patients with 24 aneurysms who underwent Neuroform Atlas stent-assisted coil embolization for intracranial aneurysms. All patients were evaluated with PETRA qMRA, TOF-MRA, and CE-MRA at the same follow-up session. The flow within stents, occlusion status, and presence of pseudo-stenosis were evaluated; inter-observer and intermodality agreements for the three methods were also graded. RESULTS: The mean score for flow visualization within the stents was significantly higher for PETRA qMRA and CE-MRA than for TOF-MRA (although no significant difference was found between PETRA qMRA and CE-MRA). Good inter-observer agreement was observed for each modality. PETRA qMRA and CE-MRA were more consistent with digital subtraction angiography (DSA) than TOF-MRA for aneurysm occlusion status. The intermodality agreement was better between PETRA qMRA and DSA, and between CE-MRA and DSA, than between DSA and TOF-MRA. Pseudo-stenosis was most frequently observed in TOF-MRA, followed by CE-MRA and PETRA qMRA. CONCLUSION: PETRA qMRA is useful for evaluating the parent artery patency and occlusion status of aneurysms after Neuroform Atlas stent-assisted coil embolization.

Thrombectomy in acute vertebrobasilar occlusion: a single-centre experience.

PURPOSE: Acute vertebrobasilar occlusion (VBO) has a grave clinical course; however, thrombectomy in VBO patients has rarely been reported. We retrospectively evaluated the clinical and radiological outcomes of thrombectomy in VBO patients. METHODS: From March 2010 to December 2017, 38 patients with 40 acute VBOs underwent thrombectomy at our hospital. Thrombectomy was performed using catheter aspiration (n = 11, 26.8%) or a stent retriever (n = 29, 70.7%). RESULTS: Good clinical outcomes (3-month modified Rankin scale (mRS) of 2 or lower) were achieved in 9 cases (22.5%), and successful recanalization (thrombolysis in cerebral infarction (TICI) grade of 2b or 3) was achieved in 35 cases (87.5%). Good clinical outcomes were significantly related to aetiologies other than atherosclerosis (p = 0.020) and lower National Institutes of Health Stroke Scale (NIHSS) scores on admission (p = 0.025). The clinical and radiological outcomes did not differ significantly between catheter aspiration and stent retriever thrombectomy (p = 1.000 and p = 0.603, respectively); however, stent retriever thrombectomy had a shorter procedure time than catheter aspiration (59.7 ± 31.2 vs. 84.5 ± 35.1 min, p = 0.037). CONCLUSION: In our series, good clinical outcomes were associated with a lower NIHSS score on admission and stroke aetiologies other than atherosclerosis. The two thrombectomy modalities showed similar clinical and radiological outcomes. However, stent retrievers seemed to allow more rapid recanalization than catheter aspiration in VBO.

Initial multicentre experience using the neuroform atlas stent for the treatment of un-ruptured saccular cerebral aneurysms.

Purpose: The Neuroform Atlas is a self-expandable and low-profiled stent that is used for aneurysm neck scaffolding and has been recently approved for clinical practice in Korea. We present our initial experiences of endovascular coiling using the Neuroform Atlas stent.Materials and methods: All cerebral aneurysms treated by stent-assisted coiling with a Neuroform atlas stent in two institutions between February and May 2018 were retrospectively evaluated. Fifty-one patients with 55 un-ruptured saccular cerebral aneurysms (mean size: 4.72 ± 1.81 mm, mean neck diameter: 3.82 ± 1.23 mm, mean dome-to-neck ratio: 1.21) were included in our study (40 females, mean age: 59.29 ± 11.96 years). Patient demographics, aneurysm characteristics, initial angiographic post procedural outcomes, and clinical and angiographic follow-up data were analysed.Results: There was one case of procedural failure due to a downward slip during stent deployment. The technical success rate was 98.2% (54/55). A post-procedure control angiogram showed complete occlusion in 27 (50%), residual neck in 16 (29.6%) and residual sac in 11 (20.4%) aneurysms. There were no procedure-related complications. In one case, a symptomatic thromboembolism with left hand grip weakness (grade IV) was observed two days after the procedure and resolved at discharge. The modified Rankin scale score at discharge was 0 in all patients. Angiographic follow-up data at a mean of 4.8 months were available for 51/54 (94.4%) aneurysms. Among them, 27 aneurysms (52.9%) were stable, 20 aneurysms (39.2%) showed progressive occlusion and 4 aneurysms showed an increased modified Raymond Roy occlusion classification score (only one of these patients was included in the recanalization criteria).Conclusion: Our findings suggest the Neuroform Atlas stent can be useful for the coiling of cerebral aneurysms without significant complications regardless of aneurysm location.

Dual-energy CT angiography-derived virtual non-contrast images for follow-up of patients with surgically clipped aneurysms: a retrospective study.

PURPOSE: To evaluate the diagnostic performance, image quality, artifacts, and radiation doses of virtual non-contrast (VNC) images, relative to true non-contrast (TNC) images, in patients with surgically clipped aneurysms. METHODS: Seventy-six patients who underwent unenhanced computed tomography (CT) and dual-energy (DE)-CT angiography after surgical clipping of 85 intracranial aneurysms were included in the study. Diagnostic performances of VNC and TNC images were compared with respect to sensitivity, specificity, and positive and negative predictive values. The results of quantitative and qualitative analyses were compared between VNC and TNC images. Radiation doses were also compared between VNC and TNC images. RESULTS: Diagnostic performance of VNC images was lower than that of TNC images; however, addition of contrast-enhanced images improved diagnostic performance. Image noise and mean attenuation of VNC images were significantly higher than those of TNC images in the centrum semiovale, cerebellum, and pons. The quality of VNC images was excellent or sufficient (85.5% for observer 1, 85.5% for observer 2), and complete acceptance of VNC images was achieved in 64.5% for observer 1 and in 71.0% for observer 2; however, the addition of contrast-enhanced images increased the level of acceptance (92.0% for observer 1, 90.9% for observer 2). Clip artifacts were significantly lower in VNC images than in TNC images. CT dose index, dose-length product, and effective dose were significantly lower without TNC images. CONCLUSION: VNC images showed lower diagnostic performance and image quality, and higher image noise than TNC images; however, VNC images could reduce clip artifacts and radiation doses.

Endovascular coiling of proximal middle cerebral artery aneurysms: is it safe and durable?

BACKGROUND: Proximal middle cerebral artery (M1 segment) aneurysms are relatively deeply located in neighboring lenticulostriate arteries, which make them unsuitable for microsurgery. We aimed to investigate the clinical and radiological outcomes of endovascular coiling of M1 segment aneurysms. METHODS: Between January 2003 and December 2014, we retrospectively reviewed the medical records of 52 patients (52 aneurysms) from four institutions who underwent endovascular coiling of M1 segment aneurysms. Patients who underwent clinical and radiologic follow-up for more than a year after the procedure were evaluated. RESULTS: The aneurysms were located in the early frontal branch, early temporal branch, and lenticulostriate artery in 28, 15, and nine patients, respectively. Endovascular coiling was achieved in 51 cases and failed in one case. Of these 51 cases, 46 (90.2%) and five (9.8%) were non-ruptured and ruptured aneurysms, respectively. Initial angiographic results revealed complete occlusion in 26 (51.0%), residual neck in 16 (31.4%), and residual sac in nine (17.6%) cases. One failed case had a symptomatic procedural complication of thromboembolism. However, there was no permanent morbidity or mortality. Two major recanalization cases (3.9%) were retreated by endovascular coiling. On multivariable logistic regression analysis, aneurysmal recurrence was significantly related to aneurysm height (OR, 1.887; 95% CI, 1.107 to 3.217; p = 0.020), width (OR, 1.836; CI, 1.127 to 2.992; p = 0.015), and neck (OR, 4.017; CI, 1.220 to 13.232, p = 0.022). CONCLUSION: Endovascular coiling of M1 segment aneurysms appeared to be a feasible treatment option with a relatively low-retreatment rate. Aneurysm size was statistically significantly associated with recurrence.

Congenital absence of the internal carotid artery with a persistent primitive trigeminal artery as a collateral pathway: a report of an anatomic variation.

Congenital absence of the internal carotid artery (ICA) is rare, and patients with such a condition are often asymptomatic throughout their lifetime, because of sufficient collateral circulation. Collateral flow is provided via various channels; however, the role of persistent embryonic vessels under conditions in which the ICA is absent or occluded is unknown. We report a rare case of congenital absence of the left ICA and describe the collateral pathway consisting of a persistent trigeminal artery.

Persistent trigeminal artery variant terminating in the posterior inferior cerebellar artery: a case report.

Persistent trigeminal artery (PTA) is a rare cerebrovascular variation of remnant fetal carotid-vertebrobasilar anastomoses. The PTA variant terminates in the cerebellar artery with no direct connection to the basilar artery. We present a rare case of a PTA variant that terminated directly into the ipsilateral posterior inferior cerebellar artery.

Brain MRI in neuropsychiatric lupus: associations with the 1999 ACR case definitions.

The purpose of this study was to identify the characteristic magnetic resonance imaging (MRI) findings in neuropsychiatric systemic lupus erythematosus (NPSLE) and to investigate the association between MRI findings and neuropsychiatric manifestations in SLE. Brain MRIs with a diagnosis of SLE from 2002 to 2013 from three tertiary university hospitals were screened. All clinical manifestations evaluated by brain MRI were retrospectively reviewed. If the clinical manifestations were compatible with the 1999 NPSLE American College of Rheumatology (ACR) nomenclature and case definitions, the brain MRIs were assessed for the presence of white matter hyperintensities, gray matter hyperintensities, parenchymal defects, atrophy, enhancement, and abnormalities in diffusion-weighted images (DWI). The number, size, and location of each lesion were evaluated. The neuropsychiatric manifestation of each brain MRI was classified according to the 1999 ACR NPSLE case definitions. The associations between MRI findings and NPSLE manifestations were examined. In total, 219 brain MRIs with a diagnosis of SLE were screened, and 133 brain MRIs met the inclusion criteria for NPSLE. The most common MRI abnormality was white matter hyperintensities, which were observed in 76 MRIs (57.1 %). Gray matter hyperintensities were observed in 41 MRIs (30.8 %). Parenchymal defects were found in 31 MRIs (23.3 %), and atrophy was detected in 20 MRIs (15.0 %). Patients who had seizures were more associated with gray matter hyperintensities than patients with other neuropsychiatric manifestations. Patients with cerebrovascular disease were more associated with gray matter hyperintensity, parenchymal defects, and abnormal DWI than patients with other neuropsychiatric manifestations. In addition to white matter hyperintensities, which were previously known as SLE findings, we also noted the presence of gray matter hyperintensities, parenchymal defects, and abnormal DWI in a substantial portion of SLE patients, particularly in those with cerebrovascular disease or seizures.

Multibanded anterior talofibular ligaments in normal ankles and sprained ankles using 3D isotropic proton density-weighted fast spin-echo MRI sequence.

OBJECTIVE: The purpose of this study is to evaluate the frequency and MRI characteristics of multibanded anterior talofibular ligaments in normal ankles and to characterize the tear types of multibanded anterior talofibular ligaments in sprained ankles using a 3D isotropic proton density (PD)-weighted fast spin-echo (FSE) MRI sequence. SUBJECTS AND METHODS: In the first session, 3D PD-weighted FSE MRI of 33 ankles was obtained from 20 asymptomatic volunteers. The number of bands in the anterior talofibular ligaments, the locations of the anterior talofibular ligaments on orthogonal planes of the 3D PD-weighted FSE images, and the signal intensity, depth, and width of each band on their multiplanar reformatted images parallel to the orientation of each band of the anterior talofibular ligament were evaluated by two readers. In the second session, 3D PD-weighted FSE MRI of 51 sprained ankles was evaluated by two readers for determining the number of bands in the anterior talofibular ligaments and the presence of tears in each band. RESULTS: In the first session, three anterior talofibular ligaments were single banded, 27 were double banded, and three were triple banded. In double-banded anterior talofibular ligaments, the superior band was about two times wider and thicker than the inferior band. The depth, width, and location of single-banded anterior talofibular ligaments and the superior band of double-banded anterior talofibular ligaments were not statistically significantly different. In the second session, the most common type of injury in double-banded anterior talofibular ligaments was a two-band tear. CONCLUSION: In an evaluation using the 3D PD-weighted FSE sequence, most anterior talofibular ligaments consisted of two bands, and tears in both bands were the most common type of injury in double-banded anterior talofibular ligaments.

Sonographic appearances of juvenile fibroadenoma of the breast.

OBJECTIVES: The purpose of this study was to evaluate characteristic features of juvenile fibroadenoma of the breast on sonography. METHODS: Our study included 34 juvenile fibroadenomas confirmed by surgical biopsy or sonographically guided 8-gauge vacuum-assisted biopsy in 23 patients (age range, 15-47 years; mean age, 25 years). Sonographic findings of the lesions were analyzed retrospectively by 2 radiologists in consensus according to the American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) lexicon. The BI-RADS final assessment category was also established. RESULTS: On sonography, all fibroadenomas presented as masses. The mean size was 30 mm. Regarding shape, there were 29 oval, 2 round, and 3 irregular masses. The margins were circumscribed in 24, indistinct in 5, microlobulated in 4, and angular in 1. Regarding echogenicity, 16 masses were hypoechoic, 16 isoechoic, and 2 complex echoic. Posterior acoustic characteristics included posterior acoustic enhancement in 22 masses (65%), posterior shadowing in 1, and no posterior acoustic features in 9; this information was not available in 2. The lesion boundary presented as an abrupt interface in 32 and an echogenic halo in 2. The orientation was parallel in 32 and nonparallel in 2. Calcifications were present in 3 cases and absent in 31. On color Doppler sonography, the masses were usually hypervascular with vessel counts of 5 or more (87%). The BI-RADS final assessment categories were 3 in 24 and 4a in 10. CONCLUSIONS: The dominant sonographic presentation of juvenile fibroadenoma is a circumscribed oval hypoechoic or isoechoic mass, which resembles that of simple fibroadenoma. Juvenile fibroadenomas frequently show posterior acoustic enhancement and hypervascularity on color Doppler sonography.

Assessing Radiation Exposure and Contrast Agent Utilization: A Comparative Analysis of the Woven EndoBridge Device and Stent-Assisted Coil Embolization for Managing Unruptured Wide-Neck Bifurcation Aneurysms.

PURPOSE: In this study, we determined whether there were significant differences in procedure time, radiation dose, fluoroscopy time, and total contrast media dose when unruptured wideneck bifurcation aneurysms (WNBAs) were treated with the Woven EndoBridge (WEB) device and stent-assisted coil (SAC) embolization. MATERIALS AND METHODS: The WEB device and SAC embolization (14:17) were used to treat 31 cases of internal carotid artery bifurcation, anterior communicating artery, middle cerebral artery bifurcation, and basilar bifurcation aneurysms between August 2021 and December 2022. The procedure time, radiation dose, fluoroscopy time, and total contrast medium dose between the 2 treatment groups were compared and analyzed. In the WEB device group, the results between operators were compared, and the follow-up radiologic outcomes were investigated. RESULTS: The procedure and fluoroscopy times were significantly shorter in the WEB device group. Radiation and total contrast media dose were also significantly smaller in the WEB device, but there was no significant difference in results between operators. The follow-up radiological outcome showed adequate occlusion in 83.3% (10/12) of cases. CONCLUSION: The WEB device can be used as an alternative treatment method among the available endovascular treatment methods for WNBAs to reduce radiation exposure and the dose of contrast media when used adequately with appropriate indications.

Imaging follow-up strategy after endovascular treatment of Intracranial aneurysms: A literature review and guideline recommendations.

OBJECTIVE: Endovascular coil embolization is the primary treatment modality for intracranial aneurysms. However, its long-term durability remains of concern, with a considerable proportion of cases requiring aneurysm reopening and retreatment. Therefore, establishing optimal follow-up imaging protocols is necessary to ensure a durable occlusion. This study aimed to develop guidelines for follow-up imaging strategies after endovascular treatment of intracranial aneurysms. METHODS: A committee comprising members of the Korean Neuroendovascular Society and other relevant societies was formed. A literature review and analyses of the major published guidelines were conducted to gather evidence. A panel of 40 experts convened to achieve a consensus on the recommendations using the modified Delphi method. RESULTS: The panel members reached the following consensus: 1. Schedule the initial follow-up imaging within 3-6 months of treatment. 2. Noninvasive imaging modalities, such as three-dimensional time-of-flight magnetic resonance angiography (MRA) or contrast-enhanced MRA, are alternatives to digital subtraction angiography (DSA) during the first follow-up. 3. Schedule mid-term follow-up imaging at 1, 2, 4, and 6 years after the initial treatment. 4. If noninvasive imaging reveals unstable changes in the treated aneurysms, DSA should be considered. 5. Consider late-term follow-up imaging every 3-5 years for lifelong monitoring of patients with unstable changes or at high risk of recurrence. CONCLUSIONS: The guidelines aim to provide physicians with the information to make informed decisions and provide patients with high-quality care. However, owing to a lack of specific recommendations and scientific data, these guidelines are based on expert consensus and should be considered in conjunction with individual patient characteristics and circumstances.

Gerstmann-Sträussler-Scheinker Disease: A Case Report.

Gerstmann-Sträussler-Scheinker (GSS) disease is a rare hereditary prion disease which is clinically characterized by a progressive cerebellar ataxia followed by cognitive impairment. We report a rare case of GSS disease in a 39-year-old male patient who complained of a progressive gait disturbance followed by dysarthria with cognitive impairment, after five months from the onset of initial symptom. His brain MRI scan revealed multifocal symmetric diffusion restricted lesions with T2/FLAIR hyperintensities in bilateral cerebral cortices, basal ganglia, and thalami. His family members also manifested similar symptoms in their 40-50s, suggesting the possibility of a genetic disease. Finally, he was genetically diagnosed with GSS disease by real-time quaking-induced conversion and prion protein (PRNP) gene sequencing test.

Correlation between contrast leakage period of procedural rupture and clinical outcomes in endovascular coiling for cerebral aneurysms.

OBJECTIVE: Intraprocedural rupture (IPR) is a fatal complication of endovascular coiling for cerebral aneurysms. We hypothesized that contrast leakage period may be related to poor clinical outcomes. This study aimed to retrospectively evaluate the relationship between clinical outcomes and contrast leakage period. METHODS: Data from patients with cerebral aneurysms treated via endovascular coiling between January 2010 and October 2018 were retrospectively assessed. The enrolled patient's demographic data, the aneurysm related findings, endovascular treatment and IPR related findings, rescue treatment, and clinical outcome were analyzed. RESULTS: In total, 2,859 cerebral aneurysms were treated using endovascular coiling during the study period, with IPR occurring in 18 (0.63 %). IPR occurred during initial frame coiling (n=4), coil packing (n=5), stent deployment (n=7), ballooning (n=1), and microcatheter removal after coiling (n=1). Tear sites included the dome (n=14) and neck (n=4). All IPRs were controlled and treated with coil packing, with or without stenting. Flow arrest of the proximal balloon was not observed. Temporary focal neurological deficits developed in two patients (11.1%). At clinical follow-up, 14 patients were classified as modified Rankin Scale (mRS) 0, three as mRS 2, and one as mRS 4. The mean contrast leakage period of IPR was 11.2 min (range: 1-31 min). Cerebral aneurysms with IPR were divided into late (n=9, mean time: 17.11 min) and early (n=9, mean time: 5.22 min) control groups based on the criteria of 10 min of contrast leakage period. No significant between-group differences regarding clinical outcomes were observed after IPR (p=1). CONCLUSIONS: In our series, all patients with IPR were controlled with further coil packing or stenting without proximal balloon occlusion within 31 min of contrast leakage. There was no difference in clinical outcomes when the long contrast leakage period group and short contrast leakage period group were compared.

Persistent Primitive Olfactory Artery Type 4 with Fusiform Aneurysm: A Case Report.

The persistent primitive olfactory artery (PPOA) is a rare variant of the anterior cerebral artery, first reported in 1979. It reportedly has a high correlation with the development of aneurysms, owing to the hemodynamic stress induced by the structural characteristics of the hairpin turn. Herein, we present a rare case of PPOA type 4 with a fusiform aneurysm at the hairpin turn segment in a 46-year-old female with occasional headaches. Time-of-flight MR angiography and transfemoral cerebral angiography revealed an unusual branch arising from the left A1 segment, running anteromedially along the ipsilateral olfactory tract, and turning the hairpin posterior to the olfactory bulb. This branch continued into the left accessory middle cerebral artery, and a fusiform aneurysm was observed at the hairpin segment. No further treatment was performed, and follow-up imaging was recommended. Nevertheless, it is essential to recognize and diagnose these rare variations.

Comparison of Safety and Diagnostic Efficacy of Iohexol 240 mgI/mL, Iopamidol 250 mgI/mL, and Iodixanol 270 mgI/mL in Cerebral Angiography: A Prospective, Multicenter Study.

PURPOSE: This multicenter prospective study aimed to evaluate the quality and diagnostic effectiveness of cerebral angiography images obtained using low-concentration iodinated contrast agents (iohexol 240 mgI/mL, iopamidol 250 mgI/mL, and iodixanol 270 mgI/mL) and to assess the safety thereof. The study addresses the need for safer contrast agent alternatives without compromising the diagnostic quality of identifying cerebrovascular disease. MATERIALS AND METHODS: Conducted in 5 medical centers in South Korea, we enrolled patients aged 19 years or older who were referred for diagnostic cerebral angiography under non-emergency conditions, excluding those with specific health conditions and sensitivities. The study design included a prospective, observational approach with a 1-way analysis of variance (ANOVA) for sample size calculation, aiming for a total sample of 231 participants for adequate power. Image quality was evaluated using a 4-level scale by 2 independent, blinded radiologists, and adverse reactions were monitored both immediately and up to 7 days post-procedure. Statistical analysis involved 1-way ANOVA and Kruskal-Wallis tests to assess the image quality and safety profiles of the contrast agents. RESULTS: Among 266 patients screened, 243 were included in the final analysis. The evaluation revealed no statistically significant differences in image quality among the 3 types of low-concentration contrast agents. Adverse events were observed in 28.8% of patients, with 27.2% experiencing acute reactions, primarily mild reactions, and 3.3% experiencing delayed reactions. The overall safety profile showed no significant changes in vital signs or electrocardiogram readings before and after contrast agent injection. CONCLUSION: Using low-concentration iodinated contrast agents for cerebral angiography provides image quality comparable to that of conventional high-concentration agents, with no significant increase in adverse events, suggesting a safer alternative for patients.

Usefulness of Pointwise Encoding Time Reduction with Radial Acquisition-Magnetic Resonance Angiography after Endovascular Treatment for Intracranial Aneurysms.

PURPOSE: Imaging follow-up after endovascular treatment is important; however, time-of-flight magnetic resonance angiography (TOF-MRA) has limitations associated with magnetic susceptibility and radiofrequency shielding caused by the stent and coils. We evaluated the diagnostic performance of pointwise encoding time reduction with radial acquisition (PETRA)-MRA after endovascular treatment for intracranial aneurysms. MATERIAL AND METHODS: A total of 186 patients with 211 aneurysms who underwent both pointwise encoding time reduction with radial acquisition- and time-of-flight magnetic resonance angiography in the same imaging session for follow-up after endovascular treatment. We subjectively graded the overall image quality, visualization of treated sites, and occlusion status. RESULTS: Although the overall image quality scores of pointwise encoding time reduction with radial acquisition-magnetic resonance angiography were significantly lower than those of time-of-flight magnetic resonance angiography for both observers (4.04 ± 0.81 vs. 4.85 ± 0.35 [observer 1], 4.60 ± 0.69 vs. 4.94 ± 0.24 [observer 2]) (both P < .001), the visibility of treated sites using pointwise encoding time reduction with radial acquisition-magnetic resonance angiography was significantly better than that of time-of-flight magnetic resonance angiography overall (4.27 ± 0.97 vs. 3.42 ± 1.01; P < .001), in the distal internal carotid artery (4.46 ± 0.79 vs. 3.40 ± 1.00; P < .001), and in the middle cerebral artery (4.19 ± 0.93 vs. 3.08 ± 0.53, P = 0.007). Pointwise encoding time reduction with radial acquisition-magnetic resonance angiography showed a higher area under the curve than time-of-flight magnetic resonance angiography for the evaluation of treated aneurysm occlusion, except for posterior circulation aneurysms. CONCLUSIONS: Pointwise encoding time reduction with radial acquisition-magnetic resonance angiography showed better visualization of treated sites and better diagnostic performance than time-of-flight magnetic resonance angiography for anterior circulation aneurysms. However, Pointwise encoding time reduction with radial acquisition-magnetic resonance angiography showed limitations in the follow-up evaluation of posterior circulation aneurysms.

Change in cortical vessel signs on susceptibility-weighted images after full recanalization in hyperacute ischemic stroke.

BACKGROUND: The cortical vessel signs (CVSs) on susceptibility-weighted images (SWIs) have been reported in patients with hyperacute ischemic stroke. We evaluated the change of this susceptibility sign on the immediate SWI after full recanalization and its clinical implications. METHODS: Nineteen hyperacute ischemic stroke patients who had acute large artery occlusion and underwent post-recanalization SWI were enrolled in this study. The patients had ICA (internal carotid artery, 2 cases), M1 (M1 segment of middle cerebral artery, 7 cases), M2 (M2 segment of middle cerebral artery, 1 cases), T (intracranial ICA bifurcation, 2 cases), ICA/M1 (4 cases) and basilar artery (3 cases) occlusion on imaging studies before thrombolysis and they underwent immediate magnetic resonance imaging, including the SWI, after full recanalization. The recanalization status was evaluated using the thrombolysis in cerebral infarction (TICI) score before and after thrombolysis. The SWI images were evaluated for the presence of asymmetry of veins over the ischemic territory and this was correlated with the site of stenosis or occlusion. The veins in the ischemic territory were classified as 'prominent' if there were more numerous veins and/or large veins with a greater signal loss observed compared with the opposite normal hemisphere, 'equal' if there were no significant difference in appearance in both the cerebral hemispheres, and 'less' if the veins were decreased in the affected area as compared with that of the normal cortex. Baseline clinical parameters and clinical outcomes were reviewed. RESULTS: The initial TICI grades were 0 in all cases. After thrombolysis, TICI grades were 3 in all cases. The pre-recanalization SWIs were obtained in 10 of 19 patients and all 10 showed prominent CVSs over the affected side, which disappeared on the post-recanalization SWI. On the post-recanalization SWI, the observed veins in the affected area were equal (10/19), less (5/19), and both equal and less (4/19). Patients with equal cortical veins in the affected area had small lesions on diffusion-weighted image (DWI) (10/19), while patients with less cortical veins had medium to large lesions on DWI (9/19). CONCLUSION: The prominent CVSs on SWI can be indicative of acute thromboembolic occlusion and its change immediately after recanalization can be used to reflect the metabolic status. After recanalization, the appearance of the equal CVS (return to normal) on SWI was associated with a favorable clinical outcome and infarction was avoided in our small series study.

Isolated Intracranial Rosai-Dorfman Disease Mimicking Meningioma: A Case Report.

Rosai-Dorfman Disease (RDD) is a rare lymphoproliferative disease, and the occurrence of isolated intracranial RDD is extremely rare. Most cases of intracranial RDDs present as dural masses showing homogenous enhancement on MRI, which makes it difficult to differentiate these masses from meningiomas before surgery unless massive cervical lymphadenopathy is observed. We herein report a rare case of isolated intracranial RDD in a 65-year-old male. Brain MRI revealed a well-defined enhancing mass-like lesion involving the right frontal convexity and subtle diffusion restriction. However, only a subtle blush was observed on the preoperative cerebral angiogram. Although instances of isolated intracranial RDD are rare, it should be considered as a potential differential diagnosis when a dural mass with hypovascularity is visualized on the cerebral angiogram.