Retrospective study using MRI to measure depths of acupuncture points in neck and shoulder region.

OBJECTIVES: There are safety issues associated with acupuncture treatment. Previous studies regarding needling depth of acupuncture points revealed inconsistent results due to vague depth definition, acupuncture point localisation and measuring tools. The objective of this study is to find and compare the differences of the mean depths of 11 acupuncture points in the neck and shoulder region between subjects, with variables including gender and body mass index (BMI). SETTING: This study was conducted at a single medical center in Taiwan. PARTICIPANTS: Three hundred and ninety-four participants were included in this study. Participants were grouped according to gender and BMI. Acupuncture points were localised by WHO standard and measured by MRI. OUTCOME MEASURES: The distance from the needle insertion point (surface of the skin) to any tissues that would cause possible/severe complications. RESULTS: Mean depths of 11 points were obtained in groups of different BMI and gender. Mean depths of all participants regardless of BMI and gender are as follows, in centimetres: GB21=5.6, SI14=5.2, SI15=8.8, GV15=4.9, GV16=4.6, GB20=5.0, ST9=1.6, SI16=1.8, SI17=2.4, TE16=3.1, LI18=1.3. Participants with higher BMI had greater measured depths in both gender groups. Male participants had larger mean depths than female participants regardless of BMI except in SI17 and LI18. When taking BMI into consideration, depths in male participants are greater than in female participants in most of the points except the following: GB21, TE16 in obesity group; ST9 in underweight and obesity group; SI16 in ideal body weight, overweight and obesity group; SI17, LI18 in each group. CONCLUSIONS: Participants with higher BMI had greater measured depths and males tended to have greater depths in most of the points. Clinical practitioners are recommended to consider this information to prevent complications when applying acupuncture treatment to their patients.

Hematoma shape, hematoma size, Glasgow coma scale score and ICH score: which predicts the 30-day mortality better for intracerebral hematoma?

PURPOSE: To investigate the performance of hematoma shape, hematoma size, Glasgow coma scale (GCS) score, and intracerebral hematoma (ICH) score in predicting the 30-day mortality for ICH patients. To examine the influence of the estimation error of hematoma size on the prediction of 30-day mortality. MATERIALS AND METHODS: This retrospective study, approved by a local institutional review board with written informed consent waived, recruited 106 patients diagnosed as ICH by non-enhanced computed tomography study. The hemorrhagic shape, hematoma size measured by computer-assisted volumetric analysis (CAVA) and estimated by ABC/2 formula, ICH score and GCS score was examined. The predicting performance of 30-day mortality of the aforementioned variables was evaluated. Statistical analysis was performed using Kolmogorov-Smirnov tests, paired t test, nonparametric test, linear regression analysis, and binary logistic regression. The receiver operating characteristics curves were plotted and areas under curve (AUC) were calculated for 30-day mortality. A P value less than 0.05 was considered as statistically significant. RESULTS: The overall 30-day mortality rate was 15.1% of ICH patients. The hematoma shape, hematoma size, ICH score, and GCS score all significantly predict the 30-day mortality for ICH patients, with an AUC of 0.692 (P = 0.0018), 0.715 (P = 0.0008) (by ABC/2) to 0.738 (P = 0.0002) (by CAVA), 0.877 (P<0.0001) (by ABC/2) to 0.882 (P<0.0001) (by CAVA), and 0.912 (P<0.0001), respectively. CONCLUSION: Our study shows that hematoma shape, hematoma size, ICH scores and GCS score all significantly predict the 30-day mortality in an increasing order of AUC. The effect of overestimation of hematoma size by ABC/2 formula in predicting the 30-day mortality could be remedied by using ICH score.

Intrasinus thrombolysis by mechanical and urokinase for severe cerebral venous sinus thrombosis : a case report.

PURPOSE: Cerebral venous and sinus thrombosis (CVST) is a rare stroke disorder, which requires prompt recognition and appropriate intervention to prevent a devastating outcome. Intrasinus thrombolysis is an alternative and effective method to anticoagulant therapy for the treatment of CVST, but is rarely used in Taiwan. CASE REPORT: A 46-year-old man presented with a one-week history of intractable headache and progressive weakness of his right lower limb. Magnetic resonance venography of the brain confirmed a diagnosis of extensive venous sinus thrombosis. The patient was successfully treated by direct intrasinus thrombolysis with urokinase. CONCLUSION: This case highlights the benefit of early intrasinus thrombolysis for the treatment of CVST.

Comparison of the 2010 and 2005 versions of the McDonald MRI criteria for dissemination-in-time in Taiwanese patients with classic multiple sclerosis.

In 2010, the International Panel on the Diagnosis of Multiple Sclerosis revised the 2005 version of the McDonald criteria. The revisions to MRI dissemination-in-time criteria include adoption of a new criterion by demonstration of simultaneous asymptomatic gadolinium-enhancing and nonenhancing lesions on baseline MRI scans. The purpose of this study was to demonstrate the diagnostic validity of the modified MRI dissemination-in-time criteria. We collected 80 patients with an initial clinical attack suggestive of an acute central nervous system demyelinating disease. The patients were followed for at least two years or until the development of definite multiple sclerosis. The nonconverters were taken as negative cases. Their baseline and follow-up brain MRI studies were retrospectively reviewed by two neuroradiologists. The 2010 version had higher sensitivity (68.2% vs. 45.5%), slightly lower specificity (80.6% vs. 83.3%), and higher accuracy (73.8% vs. 62.5%) than the 2005 version, but the differences were without statistical significance. The new criteria are more sensitive and accurate and specific just as the old criteria. They allow the diagnosis of definite multiple sclerosis in 34.1% patients at first presentation of the clinically isolated syndrome.

Acute bilateral hearing loss as a "worsening sign" in a patient with critical basilar artery stenosis.

We report a patient who presented with an acute-onset transient vertigo and unsteady gait with bilateral hearing loss. Brain MRI revealed a critical basilar artery (BA) stenosis at the lower pons and infarction in various areas on both sides in the territories of the posterior inferior cerebellar arteries (PICA). Further, we could not visualize the right anterior inferior cerebellar artery (AICA). The bilateral hearing loss may be ascribed to stroke due to the critical BA stenosis, causing hypoperfusion injury extending from the PICA to the AICA on both sides. Local intra-arterial thrombolytic therapy with the administration of 1×10(6) IU of urokinase aided partial recanalization of the BA, after which the right AICA reappeared. The neurological function of the patient recovered to normal, and no hemorrhagic complications were observed. Therefore, practitioners should be alert when treating patients with acute bilateral hearing loss, which may be related to an underlying catastrophic stroke.

Delayed parkinsonism after CO intoxication: evaluation of the substantia nigra with inversion-recovery MR imaging.

PURPOSE: To quantitatively investigate signal alterations of the substantia nigra in patients with delayed parkinsonism following CO intoxication, as seen on gray matter (GM)-suppressed inversion-recovery (IR) magnetic resonance (MR) images. MATERIALS AND METHODS: This prospective study was approved by the local institutional review board, and written informed consent was obtained from all subjects. Thirteen patients with delayed onset of CO-induced parkinsonism (nine men and four women; mean age, 40.3 years), 13 age-matched CO-intoxicated patients without parkinsonism, and 13 age-matched healthy volunteers were examined with GM-suppressed IR MR imaging. The signal intensity of the substantia nigra was normalized to the adjacent normal-appearing white matter in the temporal lobe, followed by semiautomatic segmentation into medial, middle, and lateral parts by using a skeleton-based algorithm. Multivariate and univariate analyses and Spearman rank correlation test were performed to examine the relationships between variables. Clinical severity was assessed with the modified Hoehn and Yahr rating scale. RESULTS: The normalized signal ratios in the middle and lateral segments of the substantia nigra were significantly higher in those with CO-induced parkinsonism, compared with those with CO intoxication without parkinsonism or normal volunteers (P=.02). For the medial segments, the ratios showed no significant differences among the groups. The normalized signal ratios of substantia nigra were correlated with the severity of parkinsonism, particularly in the lateral segments (ρ=0.927, P<.001). CONCLUSION: CO toxicity to the substantia nigra plays a role in pathophysiologic mechanisms of CO-induced parkinsonism. GM-suppressed IR MR imaging is a useful tool in depicting substantia nigra injury following CO intoxication.

Local intra-arterial thrombolysis with urokinase for acute ischemic stroke before and after the approval of intravenous tissue plasminogen activator treatment in Taiwan.

BACKGROUND: Local intra-arterial thrombolysis (LIT) has been previously suggested as an effective therapy for acute ischemic stroke. In this study, we describe our experience of using LIT for the treatment of Taiwanese patients with ischemic stroke at different vascular locations, before and after Alteplase was approved as a first-line treatment in Taiwan. The criteria required for the initiation of LIT have become more stringent after the approval of Alteplase (AA). METHODS: A retrospective analysis of medical records was conducted for 20 ischemic stroke patients treated with LIT; including 10 patients treated before and 10 patients treated after AA (we did not treat any of the patients in this study with AA). Urokinase was used for LIT treatment. Outcome measures included patient demographics, clinical characteristics, and clinical outcomes before and after LIT. Clinical outcomes were evaluated using four different stroke scales. RESULTS: The median National Institutes of Health stroke scale score (NIHSS) before treatment was reported to be 19.2 (range: 8-30). After AA, only one patient who had an occluded internal carotid artery (ICA) was treated with LIT. Among the 20 patients, 11 (55%) (five before AA and six after AA) reported having favorable or good clinical outcomes within 3 months of treatment, whereas five reported having poor outcomes (three before AA and two after AA), and the rest four patients died following treatment (two before AA and two after AA). Arterial recanalization was reported as complete in 10 patients (50%; seven middle cerebral artery [MCA] and three basilar artery; six before AA and four after AA), as incomplete in four patients (20%; one MCA and three basilar artery; one before AA and three after AA), and it failed in the remaining six patients (30%; two MCA and four ICA; three before AA and three after AA). Five patients (one MCA and four ICA) in whom recanalization had failed reported having poor outcomes, including one ICA patient who subsequently succumbed to the illness. Intracranial hemorrhagic and intraventricular hemorrhage transformation occurred in three and two patients, respectively. A case of intraventricular hemorrhage transformation after AA was also reported. CONCLUSION: On the basis of our experience, we found that LIT was of limited value in patients with ICA occlusion before AA approval. After AA, the outcomes in acute stroke patients, who were receiving urokinase therapy and who were carefully selected on the basis of the site of occlusion, were improved.

Modifications to the McDonald MRI dissemination in space criteria for use in Asians with classic multiple sclerosis: the Taiwanese experience.

BACKGROUND: The McDonald MRI dissemination in space criteria have been found to be less sensitive when applied to Asians with classic multiple sclerosis. The Asian neurological community thus proposed modifications to the criteria with reduction of minimal number of T2 lesions from nine to four, and removal of restriction on spinal cord lesion length and morphology for use in Asians. OBJECTIVE: The study is to examine the accuracy of modified MRI dissemination in space criteria for prediction of conversion from clinically isolated syndrome to definite multiple sclerosis according to patients' baseline MRI. METHODS: From 2001 to 2007, we recruited 67 patients with clinically isolated syndrome. They had been followed-up until development of definite multiple sclerosis or remaining as clinically isolated syndrome for more than 2 years. The non-converters were taken as negative cases. The 67 patients' baseline MRIs were evaluated by two radiologists and determined as either fulfilling or not fulfilling McDonald and modified MRI criteria for dissemination in space. RESULTS: Thirty-two patients converted to definite multiple sclerosis and 35 did not. The modified criteria are slightly more sensitive (53.1% vs. 50.0%) and accurate (77.6% vs. 76.1%) as compared with McDonald criteria. However, further reduction of the cutoff of abnormal MRI criteria from three of four to two of four criteria yields best sensitivity (71.9%) and accuracy (83.6%). CONCLUSIONS: Modifications to the McDonald MRI dissemination in space criteria (by using fewer T2 lesions, removal of the restriction on the spinal cord lesion and reduction of the cutoff of MRI criteria) are more appropriate for use in the Taiwanese population for the diagnosis of classic multiple sclerosis.

Do aggressive imaging features correlate with advanced histopathological grade in meningiomas?

Atypical and malignant meningiomas are more likely to recur than benign meningiomas. We aimed to distinguish atypical and malignant meningiomas from benign meningiomas based on imaging findings. Between 2004 and 2007, a total of 75 patients with resected intracranial meningiomas were retrospectively reviewed. Histopathological grades were assigned as benign and atypical/malignant meningiomas according to the World Health Organization (WHO) classification. All patients received preoperative CT scans and MRI studies. Six aggressive imaging features were evaluated and compared between the two groups: (i) intratumoral cystic change; (ii) hyperostosis of the adjacent skull; (iii) bony destruction; (iv) extracranial tumor extension through the skull base foramina; (v) arterial encasement; and (vi) peritumoral brain edema. There were 59 benign and 16 atypical/malignant meningiomas. Only intratumoral cystic change and extracranial tumor extension through the skull base foramina were more prevalent in atypical/malignant meningiomas (p=0.001). Hence, these two imaging features might be potential markers of atypical/malignant meningiomas.

T2-enhanced tensor diffusion trace-weighted image in the detection of hyper-acute cerebral infarction: comparison with isotropic diffusion-weighted image.

BACKGROUND AND PURPOSE: Although isotropic diffusion-weighted imaging (isoDWI) is very sensitive to the detection of acute ischemic stroke, it may occasionally show diffusion negative result in hyper-acute stroke. We hypothesize that high diffusion contrast diffusion trace-weighted image with enhanced T2 may improve stroke lesion conspicuity. METHODS: Five hyper acute stroke patients (M:F=0:5, average age=61.8+/-20.5 y/o) and 16 acute stroke patients (M:F=11:5, average age=67.7+/-12 y/o) were examined six-direction tensor DWIs at b=707s/mm(2). Three different diffusion-weighted images, including isotropic (isoDWI), diffusion trace-weighted image (trDWI) and T2-enhanced diffusion trace-weighted image (T2E_trDWI), were generated. Normalized lesion-to-normal ratio (nLNR) and contrast-to-noise ratio (CNR) of three diffusion images were calculated from each patient and statistically compared. RESULTS: The trDWI shows better nLNR than isoDWI on both hyper-acute and acute stroke lesions, whereas no significant improvement in CNR. Nevertheless, the T2E_trDWI has statistically superior CNR and nLNR than those of isoDWI and trDWI in both hyper-acute and acute stroke. CONCLUSIONS: We concluded that tensor diffusion trace-weighted image with T2 enhancement is more sensitive to stroke lesion detection, and can provide higher lesion conspicuity than the conventional isotropic DWI for early stroke lesion delineation without the need of high-b-value technique.

Salivary glands: echo-planar versus PROPELLER Diffusion-weighted MR imaging for assessment of ADCs.

PURPOSE: To compare the image distortion and the quantification variation in parotid gland apparent diffusion coefficients (ADCs) on periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) versus echo-planar diffusion-weighted (DW) magnetic resonance (MR) images and to investigate the relationship between parotid gland ADC and parotid gland fat content. MATERIALS AND METHODS: This prospective study was approved by a local institutional review board. Written informed consent was obtained from all 33 enrolled healthy volunteers (15 men, 18 women; mean age, 36.4 years +/- 11.8 [standard deviation]). All participants underwent 1.5-T non-fat-saturated and fat-saturated PROPELLER DW MR imaging as well as 1.5-T nonaccelerated and twofold-accelerated echo-planar DW MR imaging. Image distortion on the DW images was qualitatively scored, and parotid ADC was quantitatively analyzed. The correlation between parotid ADC and parotid fat content was evaluated by using linear regression analysis. Wilcoxon signed rank and t tests were used for statistical analysis, with Bonferroni correction applied for multiple comparisons. RESULTS: Echo-planar DW images showed distortion, which was completely eliminated on the PROPELLER DW images. The mean parotid ADCs measured with non-fat-saturated PROPELLER (0.670 x 10(-3) mm(2) +/- 0.149), nonaccelerated echo-planar (0.892 x 10(-3) mm(2) +/- 0.128), twofold-accelerated echo-planar (1.088 x 10(-3) mm(2) +/- 0.124), and fat-saturated PROPELLER (1.307 x 10(-3) mm(2) +/- 0.217) DW imaging differed significantly from one another (P < .001 for all comparisons). Parotid ADC had a significant negative correlation with parotid fat content (x) measured at non-fat-saturated PROPELLER DW imaging: ADC = -0.0087x + 1.1173 (r = 0.80, P < .001). CONCLUSION: PROPELLER DW imaging pulse sequences can yield distortion-free images for parotid ADC measurements and enable quantitative evaluation of the relationship between parotid ADC and parotid fat content. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.2531082228/-/DC1.

(99m)Tc-TRODAT-1 and (123)I-IBZM SPECT studies in a patient with extrapontine myelinolysis with parkinsonian features.

Osmotic demyelination syndrome can result from the rapid correction of hyponatremia, and is categorized by central pontine myelinolysis and extrapontine myelinolysis (EPM). Magnetic resonance imaging (MRI) is currently the most useful modality for visualizing EPM lesions. However, MRI is unable to delineate the severity of involvement in the nigrostriatal dopaminergic pathway. The authors describe the case of a 48-year-old woman who developed isolated EPM with predominantly right-sided parkinsonian symptoms after rapid correction of hyponatremia. MRI revealed symmetrical demyelinating lesions in the bilateral striatum without central pontine involvement. (99m)Tc-TRODAT-1 and (123)I-iodobenzamide ((123)I-IBZM) single-photon emission computed tomography (SPECT) images showed unequally decreased uptake in the bilateral striatum. Treatment with carbidopa/levodopa improved the clinical parkinsonian symptoms. (99m)T(C)-TRODAT-1 and (123)I-IBZM SPECT images provide presynaptic and postsynaptic molecular information of the nigrostriatal dopaminergic pathway. The lesions demonstrated in the (99m)T(C)-TRODAT-1 and (123)I-IBZM SPECT images show higher correlation with the severity of clinical features in EPM than MRI, and the modalities may be useful in the evaluation of patients with parkinsonian symptoms.

Volume-dependent overestimation of spontaneous intracerebral hematoma volume by the ABC/2 formula.

BACKGROUND: Although the ABC/2 formula has been widely used to estimate the volume of intracerebral hematoma (ICH), the formula tends to overestimate hematoma volume. The volume-related imprecision of the ABC/2 formula has not been documented quantitatively. PURPOSE: To investigate the volume-dependent overestimation of the ABC/2 formula by comparing it with computer-assisted volumetric analysis (CAVA). MATERIAL AND METHODS: Forty patients who had suffered spontaneous ICH and who had undergone non-enhanced brain computed tomography scans were enrolled in this study. The ICH volume was estimated based on the ABC/2 formula and also calculated by CAVA. Based on the ICH volume calculated by the CAVA method, the patients were divided into three groups: group 1 consisted of 17 patients with an ICH volume of less than 20 ml; group 2 comprised 13 patients with an ICH volume of 20 to 40 ml; and group 3 was composed of 10 patients with an ICH volume larger than 40 ml. RESULTS: The mean estimated hematoma volume was 43.6 ml when using the ABC/2 formula, compared with 33.8 ml when using the CAVA method. The mean estimated difference was 1.3 ml, 4.4 ml, and 31.4 ml for groups 1, 2, and 3, respectively, corresponding to an estimation error of 9.9%, 16.7%, and 37.1% by the ABC/2 formula (P<0.05). CONCLUSION: The ABC/2 formula significantly overestimates the volume of ICH. A positive association between the estimation error and the volume of ICH is demonstrated.

Perfusion characteristics of late radiation injury of parotid glands: quantitative evaluation with dynamic contrast-enhanced MRI.

We aimed to quantitatively investigate the alteration of parotid perfusion after irradiation using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) based on a two-compartment tracer kinetic model. This study enrolled 19 patients (53.2 +/- 14.9 years) treated by head and neck radiotherapy and 19 age-relevant and sex-matched subjects as a control group. Perfusion parameters (K ( el ), k (21) and A) of parotid glands were analyzed based on the Brix model from T1-weighted DCE-MRI. Suitability of the Brix model was evaluated via Monte Carlo simulation for the goodness-of-fit. Analysis of nonlinear goodness-of-fit showed that the Brix model is appropriate in evaluating the parotid perfusion (R(2) = 0.938 +/- 0.050). The irradiated parotid glands showed significantly lower K ( el ) (P < 0.0005) and k (21) (P < 0.05) and consequently significantly higher value of peak enhancement (P < 0.0005) and time-to-peak (P < 0.0005) compared with non-irradiated ones, suggestive of gradual and prolonged accumulation and delayed wash-out of contrast agent due to increased extracellular extravascular space and decreased vascular permeability in the irradiated glands. Linear regression analysis showed dose-dependent perfusion changes of the irradiated parotid glands. We conclude that quantitative DCE-MRI is a potential tool in investigating parotid gland perfusion changes after radiotherapy.

A thrombophilic patient with a dural arteriovenous fistula presenting sensory aphasia and complicated with an acute pulmonary embolism.

BACKGROUND: Neuropsychiatric symptoms as the initial presentation of dural arteriovenous fistula (DAVF) are unusual. Anticoagulation therapy may be warranted for prevention of further thromboembolism if an underlying thrombophilia condition is diagnosed. CASE REPORT: We present a 70-year-old woman with sensory aphasia, who was diagnosed with a DAVF, Cognard type II a + b, by cerebral angiography. Her stroke-like syndrome resolved after transarterial embolization of the left occipital and middle meningeal arteries. Meanwhile, hypercoagulability was found because of hyperhomocysteinemia and the presence of a lupus anticoagulant. One month later, she suffered an acute pulmonary embolism and was started on anticoagulation therapy before stereotactic radiosurgery. CONCLUSION: Sensory aphasia may be the initial manifestation of a transverse-sigmoid sinus DAVF even if there are no symptoms such as headache or tinnitus. We postulate that early anticoagulation therapy is indicated for preventing thromboembolism in DAVF patients with thrombophilia because the possibility of intracranial bleeding has been reduced by embolization.

Diffuse Cerebral Vasculopathy in a HIV-Positive Patient with Recurrent Strokes.

The causes of ischemic stroke in the young adult are diverse. Human immunodeficiency virus (HIV) infection-related vasculopathy is usually not included in the list of differential diagnoses. HIV-positive patients may present with acute neurologic dysfunction of different causes, among which cerebral infarction is an uncommon one. Herein, we report a HIV-infected young man who suffered from recurrent ischemic strokes with evidence of cerebral vasculopathy on serial magnetic resonance images.

Brain injury after acute carbon monoxide poisoning: early and late complications.

OBJECTIVE: The purposes of this article are to illustrate the variable CT and MRI features of carbon monoxide-induced brain injury and to discuss the underlying pathogenesis. CONCLUSION: Carbon monoxide can produce different patterns of brain injury in the acute and delayed stages. CT and MRI are valuable in the delineation of disease extent and helpful for understanding the pathophysiologic mechanisms.

Detection of suspicious malignant cervical lymph nodes of unknown origin: diagnostic accuracy of ultrasound-guided fine-needle aspiration biopsy with nodal size and central necrosis correlate.

OBJECTIVE: To assess the role of ultrasound-guided fine-needle aspiration biopsy (US-guided FNAB) in the diagnostic workup of suspicious malignant cervical lymph nodes in patients with palpable neck masses and without known primary cancer. The diagnostic accuracy of imaging morphologic criteria, including sizes and central necrosis for assessing suspicious malignant nodes, were also examined. METHODS: This is a retrospective study of 426 patients with palpable neck masses from an outpatient department evaluated with computed tomography, magnetic resonance imaging, or US. US-guided FNABs were performed in 102 patients with suspicious malignant cervical lymph nodes at a single institution. Cytologically positive lymph nodes (n = 12) were further validated with excisional biopsy. Negative lymph nodes (n = 90) were either excised (n = 10) or followed up by imaging studies for at least one year (n = 80). The diagnostic accuracy of the FNABs along with the imaging findings of nodal sizes and presence of central necrosis, which were classified by a consensus of 2 radiologists, were assessed. RESULTS: Twelve malignant nodes were detected with US-guided FANB with one false-positive and one false-negative result. The overall sensitivity, specificity, and accuracy for FNAB were 91.7%, 98.9%, and 98.0%, respectively. The sensitivity, specificity, and accuracy were 66.7%, 30.0%, and 34.3% for size criterion and 75.0%, 83.3%, and 82.3% for central necrosis criterion. CONCLUSIONS: The size of cervical lymph node does not appear to be an important imaging criterion for assessing suspicious malignant lymph nodes, compared with the criterion of central necrosis. US-guided FNAB is highly specific and sensitive in the diagnostic workup of suspicious malignant cervical lymph nodes in patients without known primary cancers.

Typical Meningioma with Atypical MR Imaging Features Masquerading Malignancy. A Case Report.

Meningiomas are the most common extraaxial tumors of intracranial neoplasms. They are usually benign with characteristic pathologic and imaging features. However, a histologically typical meningioma can have unusual or misleading imaging features that may not be suggestive of meningioma. Unusual imaging features such as large meningeal cysts, ring enhancement, and various metaplastic changes can be particularly misleading. Here we present a fibrous meningioma with atypical magnetic resonance (MR) imaging features in a 76-year-old woman.

Diffusion-weighted magnetic resonance imaging of spontaneous venous infarction and cortical hemorrhage complicating dural arteriovenous fistula.

Dural arteriovenous fistula (DAVF) is an abnormal arteriovenous shunt that occurs in the dura matter within or near a dural sinus. The clinical manifestations vary. The authors report herein a rare case of type III DAVF presenting with coexisting intracranial hemorrhage (ICH) and venous infarction evidenced by computed tomography (CT) and diffusion-weighted magnetic resonance imaging. Conventional angiography proved that the right middle meningeal artery and the occipital artery supplied the DAVF, with direct drainage into the cortical veins and superior sagittal sinus.