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Objective: The purpose of this study is to discuss the evidence supporting the use of neuroimaging in adult patients presenting with new-onset seizure., Conclusion: Unenhanced CT should be the initial imaging examination performed for adults presenting with first unprovoked seizure in the acute setting to exclude conditions requiring urgent or emergent intervention. MRI has added benefits and should be considered for adults presenting acutely for whom the initial CT is negative and for those presenting with new-onset seizure in the nonacute setting.

The purpose of the study was to determine the frequency of various unenhanced computed tomography (CT) findings of early cerebral ischemia within brain parenchyma, which could be useful to the radiologist who is interpreting CT studies by indicating the CT finding that is most likely to be present in early cerebral ischemia. We analyzed articles reporting the use of unenhanced CT in acute cerebral ischemia over the period 1976-2009 for frequency of the following brain parenchyma signs: loss of insular ribbon, obscuration of lentiform nucleus, sulcal effacement, and parenchymal hypodensity. We recorded data for the 2-, 3-, 6-, and 12-h intervals after symptom onset from various studies and (1) calculated percent of time intervals in which >50% of patients exhibited the finding in any study and (2) pooled results for patients reported as having a specific CT finding during a specific time interval. We hypothesized that CT findings indicating brain swelling, which would be expected to be a relatively late phenomenon, would be detected at a lower rate in the first 6 h than changes of decreased density of brain tissue and increased density of arteries. The loss of insular ribbon sign (83% of time intervals reported) and obscuration of lentiform nucleus sign (75%) were the most common signs present in >50% patients in a time interval in any article. Pooled results showed that the two most common findings in the first few hours were loss of insular ribbon (70% at 2 h; 77% at 3 h) and obscuration of lentiform nucleus (60% at 2 h; 82% at 3 h). At 6 h, parenchymal hypodensity (53%), loss of insular ribbon (46%), and obscuration of lentiform nucleus (46%) were most common, which validated our hypothesis. At 12 h, loss of insular ribbon (65%) and sulcal effacement (63%) were most common. Loss of insular ribbon and obscuration of lentiform nucleus appear to be the most common signs of early cerebral ischemia identified on unenhanced CT.

Background and Purpose: Sixty-four-section CT scanners have recently been introduced for vascular imaging. Before such scanners reach widespread use, scanning protocol should be optimized and image quality assessed. The goals of this study were to systematically measure image quality and determine the prevalence of various types of artifacts produced by a 64-section scanner., Materials and Methods: We retrospectively reviewed CT angiography (CTA) scans obtained on a 64-section CT scanner in 100 consecutive patients presenting to the emergency department during a 2-month period with a suspected acute cerebrovascular event. We evaluated scan quality by using 2 different methods: First, we quantitatively assessed arterial opacification by measuring attenuation values in 9 arterial segments from the aortic arch to the distal cervical internal carotid artery, by using a threshold of 150 HU as an indicator of good opacification. Second, we assessed image contrast between arteries and veins by measuring attenuation within venous segments and recording the number of artery-vein-segment pairs in which the attenuation difference was 150 HU). Image contrast between artery and vein segments was also good, with 714 of 763 analyzable segment pairs (85.6%) having >50 HU difference. Artifacts obscuring arterial evaluation included streak from contrast material in the subclavian/brachiocephalic vein (32% of patients), attenuation of the x-ray beam between the shoulders (28%), beam-hardening from metallic hardware (26%), and contrast material reflux into neck veins (16%). The most clinically relevant artifacts were flow artifacts, mimicking dissection or vascular occlusion; they were seen in 14% of patients and likely are related to the rapid data acquisition for CTA on 64-section scanners (compared with the circulation of contrast material in the cervical arteries). None of the patients in our historical control group who underwent 16-section CT had flow artifacts on their CTA studies; the incidence of the other types of artifacts in this group was similar to that in patients imaged with 64-section CT., Conclusions: The 64-section CTA imaging protocol for carotid arteries yields high-quality studies in >95% of cases.

Background and Purpose: Perfusion imaging sequences are an important part of imaging studies designed to provide information to guide therapy for treatment of cerebrovascular disease. The purpose of this study was to perform a meta-analysis of the medical literature on perfusion imaging to determine its role in clinical decision making for patients with acute cerebral ischemia., Materials and Methods: We searched MEDLINE by using a strategy that combined terms related to perfusion imaging with terms related to acute cerebral ischemia and brain tumors. We identified 658 perfusion imaging articles and classified them according to the clinical usefulness criteria of Thornbury and Fryback. We found 59 articles with promise of indicating usefulness in clinical decision making. We devised and implemented a clinical decision making scoring scale more appropriate to the topic of acute cerebral ischemia., Results: Several articles provided important insights into the physiologic processes underlying acute cerebral ischemia by correlation of initial perfusion imaging deficits with clinical outcome or ultimate size of the infarct. However, most articles showed relatively low relevance to influencing decisions in implementing treatment., Conclusion: Most perfusion imaging articles are oriented toward important topics such as optimization of imaging parameters, determination of ischemia penumbra, and prediction of outcome. However, information as to the role of perfusion imaging in clinical decision making is lacking. Studies are needed to demonstrate that use of perfusion imaging changes outcome of patients with acute cerebral ischemia.

A wide variety of imaging findings can be seen in the setting of acute head trauma. The purpose of this manuscript is to review the major computed tomography and magnetic resonance imaging findings of various types of traumatic head injuries with the intent of providing the reader with a means to diagnose these lesions quickly and accurately.

Although these entities are histologically similar, recent advances in molecular genetics have allowed the distinction of central nervous system extraosseous Ewing sarcoma (CNS-EES) from central primitive neuroectodermal tumors (c-PNET) including medulloblastoma and supratentorial PNET. We present 2 cases of pathologically confirmed CNS-EES. Knowledge of CNS-EES as a distinct entity enables the neuroradiologist to suggest the proper diagnosis and the need for special immuno-histochemical and molecular studies to confirm the diagnosis. Because treatment and prognosis are vastly different, the proper diagnosis of CNS-EES versus c-PNET is critical.

We report dynamic CT perfusion imaging assessment of hemodynamics in a patient with a high-grade cerebral glioma and compare our results to those of previously published studies.

Previously reported methods of dynamic, contrast-enhanced, CT perfusion imaging in acute stroke have been promising but substantially limited by their dependence on very rapid rates of injection (typically 10-20 ml/s in an arm vein). Newly available deconvolution software permits the use of lower rates of injection (e. g., 3-4 ml/s), and rapidly provides maps of cerebral blood flow, cerebral blood volume and mean transit time. We report the potential of CT perfusion imaging performed with an injection rate of 4 ml/s to provide information on the extent of hemodynamic abnormality, and to help distinguish viable from nonviable ischemic tissue. The slower injection rates permitted by deconvolution analysis substantially enhance the practicality of CT perfusion imaging for studying stroke.

This review has highlighted some of the disease processes that produce diagnostic difficulty in the emergency neuroradiology setting. Because radiologists are often the first individuals to consider these entities, they must be familiar with the clinical features that suggest the diagnosis. Furthermore, acquaintance with the various imaging findings of these diseases will allow early diagnosis and will help limit the severe complications that follow these neurologic emergency conditions if left untreated.

Objective: The purpose of this study was to determine the spectrum of neuroradiologic findings in patients with antiphospholipid antibodies (APA) and to compare findings in systemic lupus erythematosus (SLE) and non-SLE patients., Materials and Methods: We identified 110 patients with APA who underwent CT or MR imaging, of whom 59 (54%) had abnormal studies. Of these 59 patients, abnormalities were categorized as large infarcts, cortical infarcts, lacunar infarcts, hyperintense white matter foci on T2-weighted images, or dural sinus thrombosis. White matter foci were designated as small (< 5mm) or large (> 5 mm)., Results: Large infarcts were the most common abnormality, seen in 24 of 110 (22%) patients, followed in frequency by hyperintense white matter foci, seen in 19 of 110 (17%) patients. Ninety-five percent of patients with hyperintense white matter foci had at least one large lesion, and 76% had five or more small foci, three or more large foci, or both. Small cortical infarcts and lacunar infarcts were seen in 11 of 110 (10%) and 10 of 110 (9%) patients, respectively. Dural sinus thrombosis was seen in five patients. The frequency of abnormalities was high in both the SLE (57%) and the non-SLE (41%) groups. Large infarcts were more common in the non-SLE group (26%) than in the SLE group (5%). Although hyperintense white matter foci and cortical infarcts were more common in SLE patients, the differences were not statistically significant., Conclusion: Infarcts of various sizes and hyperintense white matter foci are the most common abnormalities seen on CT and MR imaging in patients with APA. We found no significant differences in frequencies of abnormalities seen between non-SLE and SLE patients.

Purpose: To demonstrate the neuroradiologic findings in patients with polyarteritis nodosa., Methods: A review of hospital records for a 10-year period revealed 50 patients with a discharge diagnosis of polyarteritis nodosa. Thirteen patients had undergone neuroimaging, and abnormal findings were found in 5 cases; these were the subjects of this study., Results: All 5 patients had abnormal findings on CT scans, 3 had abnormal findings on MR images, and 1 had an abnormal finding on a cerebral angiogram. All patients had cerebral cortical or subcortical infarctions, and 1 also had small infarctions within the brain stem and cerebellum. One patient had cerebral angiographic findings of arteritis. The diagnosis of arteritis was considered probable or possible in 3 other patients. Three patients had echocardiographic evidence of concentric hypertrophy and a hypocontractile left ventricle resulting from polyarteritis nodosa-related hypertension. Cardiogenic embolism was considered the likely cause in 1 patient., Conclusion: Small peripheral cerebral infarctions, consistent with an arteritis involving medium-sized and small arteries, were the most common finding. However, cardiogenic embolism should also be considered as a possible cause of cerebral infarction in patients with polyarteritis nodosa who have left ventricular dysfunction.

Purpose: To demonstrate the spectrum of CT and MR imaging findings in patients with Wegener granulomatosis and to determine how often these findings could be attributed to either direct extension from paranasal or orbital disease sites, remote granulomas, or central nervous system (CNS) vasculitis., Methods: We retrospectively reviewed the CT or MR studies of 15 patients with Wegener granulomatosis., Results: Abnormal findings were seen in 7 patients (5 examined with MR imaging, 2 with CT). Findings included dural thickening and contrast enhancement (3 patients), infarcts (2 patients), regions of hyperintense signal on T2-weighted MR images (2 patients), and abnormal MR signal in the brain stem (2 patients). Three patients with imaging findings of dural enhancement and thickening were thought to have remote granulomatous lesions involving the dura. No patients had extension from sites external to the CNS or clinical findings suggestive of CNS vasculitis., Conclusion: The spectrum of CT and MR findings in Wegener granulomatosis includes dural thickening and enhancements cerebral infarction, and MR signal abnormalities in the brain stem and white matter. Presumed remote granulomatous lesions were the most common causes of CNS findings in this study. Complications related to non-CNS disease (eg, hypertension, endocarditis) also appear to have played a role in some patients.

Objective: The purpose of this study was to determine if typical clinical and neuroradiologic patterns exist in patients with spontaneous vertebral artery (VA) dissection., Materials and Methods: The medical records and neuroradiologic examinations of 14 patients with spontaneous VA dissection were reviewed. The medical records were examined to exclude patients with a history of trauma and to record evidence of a nontraumatic precipitating event ("trivial trauma") and presence of possible risk factors such as hypertension. All patients underwent conventional angiography, 13 either CT or MRI (11 both CT and MRI), and 3 MRA. Conventional arteriograms were evaluated for dissection site, evidence of fibromuscular dysplasia, luminal stenosis or occlusion, and pseudoaneurysm formation. CT examinations for the presence of infarction or subarachnoid hemorrhage. MR examinations for the presence of infarction or arterial signal abnormality, and MR angiograms for abnormality of the arterial signal column., Results: Seven patients had precipitating events within 24 h of onset of symptoms that may have been causative of dissection and five had hypertension. At catheter angiography, two patients had dissections in two arteries (both VAs in one patient, VA and internal carotid artery in one patient), giving a total of 15 VAs with dissection. Dissection sites included V1 in four patients, V2 in one patient, V3 in three patients, V4 in six patients, and both V3 and V4 in one patient. Luminal stenosis was present in 13 VAs, occlusion in 2, pseudoaneurysm in 1, and evidence of fibromuscular dysplasia in 1. Posterior circulation infarcts were found on CT or MR in five patients. Subarachnoid hemorrhage was found on CT in two patients and by lumbar puncture alone in two patients. Abnormal periarterial signal on MRI was seen in three patients. MRA demonstrated absent VA signal in one patient, pseudoaneurysm in one, and a false-negative examination in one. Repeat catheter angiography of nine VAs at an interval ranging from 2 weeks to 1 year showed progression to occlusion in two arteries, unchanged appearance in 4, and angiographic resolution in three, which did not closely correlate with clinical outcome., Conclusion: No preferred site of dissection along the course of the VA was found in this study. CT and MR examinations of the head are frequently normal in patients with VA dissections. No correlation between clinical outcome and findings at repeat angiography was demonstrated.

Fucosidosis is a rare lysosomal storage disorder with the clinical features of mental retardation, cardiomegaly, dysostosis multiplex, progressive neurologic deterioration, and early death. The neuroradiologic findings in two patients are reported, and include abnormalities within the globus pallidus (both patients) and periventricular white matter (one patient).

Objective: Our goal was to demonstrate the spectrum of neuroradiologic (CT, MR, and angiographic) findings in craniocervical arterial dissection (CAD) related to exercise or sporting activities and compare the diagnostic utility of CT, MRI, and MR angiography (MRA)., Materials and Methods: The neuroradiologic examinations of 11 patients with CAD was performed: CT was performed in 10 patients, cranial MRI in 9, cranial and cervical MRA in 4, and contrast angiography in 10. The CT examinations were assessed for the presence of an infarction or a hyperdense artery (consistent with intraluminal thrombus), MRI examinations for the presence of infarction or abnormal periarterial signal, and contrast angiograms for arterial stenosis or occlusion, luminal irregularity, pseudoaneurysm, intimal flap, or distal branch occlusions., Results: Computed tomography demonstrated infarction in four patients. At contrast angiography, a dissection was found in the artery supplying the region of infarction in all cases. A hyperdense artery was found by CT in two patients, which correlated with dissection of the artery or its parent artery on contrast angiography. Cranial MRI findings were seen in six patients (infarction in five, periarterial signal abnormality in five). Dissection was confirmed in all four patients with abnormal periarterial signal who underwent contrast angiography. Two patients with abnormal intracranial periarterial signal had corresponding abnormalities on MRA. False-negative cranial and cervical MRI and MRA studies were performed in one patient because the imaging volumes used for the cervical and intracranial MR examinations did not overlap. Four patients with normal intracranial arterial signal had dissection in the neck demonstrated by contrast angiography., Conclusion: Neuroradiologic findings of CAD can include infarction, a hyperdense artery on CT, abnormal periarterial signal on MRI, and a narrowed arterial signal column on MRA. Computed tomography is an insensitive screening examination. Proper use of MRI and MRA involves examination of both the head and the neck with overlapping imaging volumes of the two regions.