Primary Extracranial Fibrous Meningioma of the Maxillary Sinus: A Case Report and Literature Review

Meningioma is a common neoplasm of the central nervous system; however, primary extracranial meningioma of the paranasal sinus, especially the maxillary sinus, is rare. We report a case of primary extracranial meningioma (fibrous type) of the maxillary sinus and present a literature review of the imaging features that correlate with fibrous meningioma.

Bilateral Wallerian Degeneration of the Middle Cerebellar Peduncle and Unilateral Hypertrophic Olivary Degeneration Secondary to Pontine Hemorrhage: A Case Report

The two distinct types of axonal degeneration that occur after neuronal injury include Wallerian degeneration (WD) and transneuronal degeneration. The most commonly recognizable cause of secondary degeneration is cerebral infarction, but may also include a variety of conditions including hemorrhage, trauma, necrosis, and focal demyelination. Herein, we present a rare case of WD of the cerebellar peduncles accompanied by unilateral hypertrophic olivary degeneration following pontine hemorrhage.

Regression of in-stent restenosis after using a Wingspan stent to treat intracranial atherosclerotic stenosis: A case report and 5-year follow-up

In-stent restenosis occurs in approximately 30% of patients after receiving a Wingspan stent to treat symptomatic intracranial atherosclerosis. This report describes a 55-year-old man with intracranial atherosclerotic internal carotid artery terminus stenosis who developed significant in-stent restenosis. Follow-up angiogram 5 years later demonstrated the regression of restenosis without invasive intervention.

Comparative Analysis of Endovascular Stroke Therapy Using Urokinase, Penumbra System and Retrievable (Solitare) Stent

BACKGROUND: Higher reperfusion rates have been established with endovascular treatment for acute ischemic stroke patients. There are limited data on the comparative performance of mechanical thrombectomy devices. This study aimed to analyse the efficacy and safety of the stent retriever device (Solitaire stent) by comparing procedure time, angiographic outcome, complication rate and long term clinical outcome with previous chemical thrombolysis and mechanical thrombectomy using penumbra system. METHODS: A retrospective single-center analysis was undertaken of all consecutive patients who underwent chemical thrombolysis and mechanical thrombectomy using Penumbra or Solitaire stent retriever from March 2009 to March 2014. Baseline characteristics, rate of successful recanalization (modified Thrombolysis in Cerebral Infarction score 2b-3), symptomatic intracerebral hemorrhage, procedure time, mortality and independent functional outcomes (mRS < or =2) at 3 month were compared across the three method. RESULTS: Our cohort included 164 patients, mechanical thrombectomy using stent retriever device had a significant impact on recanalization rate and functional independence at 3 months. In unadjusted analysis mechanical thrombectomy using Solitaire stent retriever showed higher recanalization rate than Penumbra system and chemical thrombolysis (75% vs. 64.2% vs. 49.4%, p=0.03) and higher rate of functional independence at 3 month (53.1% vs. 37.7% vs. 35.4%, p=0.213). In view of the interrelationships between all predictors of variables associated with a good clinical outcome, when the chemical thrombolysis was used as a reference, in multiple logistic regression analysis, the use of Solitaire stent retriever showed higher odds of independent functional outcome [odds ratio (OR) 2.62, 95% confidence interval (CI) 0.96-7.17; p=0.061] in comparison with penumbra system (OR 1.57, 95% CI 0.63-3.90; p=0.331). CONCLUSION: Our initial data suggest that mechanical thrombectomy using stent retriever is superior to the mechanical thrombectomy using penumbra system and conventional chemical thrombolysis in achieving higher rates of reperfusion and better outcomes. Randomized clinical trials are needed to establish the actual benefit to specific patient populations.

Reversible magnetic resonance imaging findings in cycloserine-induced encephalopathy: A case report

Cycloserine is a broad spectrum antibiotic used as a second drug for treatment of drug resistant tuberculosis. Inappropriate usage in excessive doses can give rise to neurological problems. We report a case who developed aphasia, anxiety and seizure during anti-tuberculosis medication. MRI of the brain showed reversible cytotoxic edema in dentate nuclei. Clinical and MRI findings were consistent with cycloserine toxicity.

Management of Aneurysms of the Proximal (A1) Segment of the Anterior Cerebral Artery

OBJECTIVE: Aneurysms originating from the proximal segment (A1) of the anterior cerebral artery are rare; however, because of their small size, the risk of injury of perforating arteries, and the location of the aneurysm in the surgical field, they are challenging to treat. We report on 15 patients with A1 aneurysms and review surgical views according to the direction of aneurysms. METHODS: Fifteen patients were diagnosed with A1 aneurysms and underwent surgical clipping or endovascular coiling at our institution between January 2006 and March 2012. We conducted a retrospective review of clinical and radiological features of all patients with A1 aneurysms. RESULTS: Nine patients underwent surgical clipping, and six patients received endovascular coiling. Six patients (40%) had multiple aneurysms. A1 aneurysms ranged in size from 1.5 to 8.2 mm, with an average size of 3.26 mm. Most A1 aneurysms (73%) had a posterior direction. In the surgical view, A1 aneurysms projecting posteriorly were located behind the A1 trunk. The A1 aneurysm projecting posteroinferiorly was completely eclipsed by the parent artery. In A1 aneurysms with a posterosuperior or superior direction, finding and clipping the aneurysm neck was relatively easy. Thirteen patients (87%) had an excellent outcome, one had moderate disability, and one died. CONCLUSION: A1 aneurysms have certain characteristics; small size, multiple aneurysms, and, usually, a posterior direction. A1 aneurysms with a posterosuperior or superior direction are relatively easy to assess, however, clipping of A1 aneurysms with a posterior or posteroinferior direction is more difficult. Endovascular coiling is an alternative therapeutic option when surgical clipping is expected to be difficult.

Direct Relationship between Angiographic Characteristics of Carotid Atherosclerotic Plaque and Filling Defect in the Cerebral Protection Filters : Based on the Conventional Angiography

OBJECTIVE: Neurologic complications during carotid artery stenting (CAS) are usually associated with distal embolic event. These embolic incident during CAS are highly associated with the carotid plaque instability. The current study was undertaken to identify the angiographic characteristics of carotid plaque vulnerability, which was represented as filling defect in the cerebral protection filters during CAS. METHODS: A total of 107 patients underwent CAS with use of a distal protection filter. Angiographic carotid plaque surface morphology was classified as smooth, irregular, and ulcerated. To determine predictable factors of filling defect in the protection filters, 11 variables were retrospectively analyzed which might influence filling defect in the protection filters during CAS. RESULTS: Filling defects during CAS were presented in the 33 cerebral protection filters. In multivariate analysis, angiographic ulceration [odds ratio (OR), 6.60; 95% confidence interval (CI) : 2.24, 19.4; p=0.001], higher stenosis degree (OR, 1.06; 95% CI : 1.00, 1.12; p=0.039), and coexistent thrombus (OR, 7.58; 95% CI : 1.69, 34.05; p=0.08) were highly associated with filling defect in the cerebral protection devices during CAS. Among several variables, angiographic surface ulceration was the only significant factor associated with flow stagnation during CAS (OR, 4.11; 95% CI : 1.33, 12.72; p=0.014). CONCLUSION: Plaque surface morphology on carotid angiography can be a highly sensitive marker of plaque instability during CAS. The independent risk factors for filling defect in the filter devices during CAS were plaque ulceration, stenosis degree, and coexistent thrombus.

Comparative Study of Shear Wave Velocities Using Acoustic Radiation Force Impulse Technology in Hepatocellular Carcinoma: The Extent of Radiofrequency Ablation

BACKGROUND/AIMS: The purpose of this study was to assess the value of acoustic radiation force impulse (ARFI) for predicting the extent of radiofrequency ablation (RFA) in hepatocellular carcinoma (HCC) by correlating the elasticity of HCC and peritumoral parenchyma (as measured by ARFI) with the extent of ablation determined by computed tomography (CT). METHODS: From September 2009 to June 2011, 158 patients underwent RFA ablation for HCC (single, < or =3 cm). We evaluated the data of a total of 38 prospectively enrolled patients who underwent both ARFI imaging and contrast-enhanced CT after one session of 12 minutes of RFA without a change in needle position. The ARFI imaging indices, including the mean shear wave velocity (SWV) of HCC, mean SWV of the peritumoral parenchyma and tumor size, were evaluated to determine the statistical correlation with RFA extent after one session of 12 minutes of RFA. RESULTS: A stiffer liver parenchyma in patients with cirrhosis results in a smaller ablation zone. CONCLUSIONS: SWV of ARFI in liver parenchyma was well correlated with RFA extent. After evaluating the correlation between ARFI and RFA extent, we suggest that the SWV in liver parenchyma might be a non-invasive supplementary tool for predicting the extent of RFA.

Non-Mass Image-Forming Low Echoic Areas on Breast US: Pathologic Correlation

PURPOSE: We wanted to analyze the mammographic and clinical findings of the non-mass image-forming low echoic areas seen on breast ultrasonography (US) and investigate their pathologic results. MATERIALS AND METHODS: Sixty-nine patients with 72 non-mass image-forming low echoic areas seen on breast US and who had undergone mammography and biopsy were included in this study. The mammographic findings were divided into 2 groups: 1) the negative or probably benign group and 2) the suspicious for malignancy group. The US findings were divided into 3 groups: focal, segmental and diffuse distributions. The clinical findings were divided into 2 groups: the non-palpable and palpable groups. We investigated the pathologic results according to each group. RESULTS: Of the 72 lesions, 49 (68.1%) were benign and 23 (31.9%) were malignant. On the mammography, 42 (93.3%) of the 45 negative or probably benign findings and 7 (25.9%) of 27 suspicious for malignancy findings were pathologically benign (p < 0.001). On the US, 38 (76%) of the 50 focal distributions and 11 (52.4%) of 21 segmental distributions were benign (p = 0.090). Thirty (73.2%) of the 41 nonpalpable lesions and 19 (61.3%) of the 31 palpable lesions were benign (p = 0.609). CONCLUSIONS: A non-mass image-forming low echoic area seen on breast US was malignant at a higher rate when it was found in conjunction with suspicious mammographic finding. There was no significant correlation between the distribution of the non-mass image-forming low echoic areas on US or their palpability and the pathologic results.

Splenic Arteriovenous Malformation Manifestated by Thrombocytopenia in Hereditary Hemorrhagic Telangiectasia: A Case Report

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant inherited disease characterized by epistaxis, telangiectases and visceral arteriovenous malformations (AVMs). The involvement of the gastrointestinal tract, liver, lung and cerebrum for HHT has been described, whereas little is known about AVMs of the spleen. We report here the radiological findings of a case of a splenic AVM manifested by thrombocytopenia in HHT.

The MRI Findings of Skull Tuberculosis: A Case Report

The incidence of skull tuberculosis is very rare, with only a few cases reported as a result of a simple radiography and computed tomographic findings. In this study, we report the magnetic resonance image (MRI) findings of a case of skull tuberculosis, which was confirmed histologically.

The Significance of Vascular MR Contrast Enhancement in Carotid Stenosis

PURPOSE: To determine the significance of vascular MR contrast enhancement in carotid stenosis. MATERIALS AND METHODS: Forty patients that had angiographically proved carotid stenosis were selected for the study. A blind interpretation of vascular enhancement on an enhanced T1 weighted image, the lesion pattern on a DWI (diffusion weighted image), a perfusion defect on a MR perfusion image, the degree of stenosis, and collateral flow on cerebral DSA (digital subtraction angiography) was made by two observers, retrospectively. DWI lesion patterns were classified as having no high signal intensity, small PAI (perforating artery infarcts), large PAI, pial infarcts, territorial infarcts, and border zone infarcts. We evaluated the statistical correlation between vascular enhancement and the degree of stenosis, collateral flow, the DWI lesion pattern and the presence of a perfusion defect, respectively. RESULTS: The degree of carotid stenosis and the frequency of vascular enhancement correlated statistically (p=0.000). The presence of retrograde collateral flow on cerebral DSA and the border zone infarcts pattern on DWI were related with the occurrence of vascular enhancement (p=0.002, p=0.004). In 23 patients that underwent a MR perfusion study, the presence of a perfusion defect was also related to the occurrence of vascular enhancement (p=0.002). CONCLUSION: Vascular MR contrast enhancement may indicate a cerebral hypoperfusion in carotid stenosis.