Background Hyperdense middle cerebral artery sign (HMCAS) on a non-enhanced multidetector computed tomography (MDCT) scan is considered an important radiological marker in detecting acute arterial thrombotic occlusion, and it one of the earliest signs ischemic cerebrovascular accident (CVA). This finding has been observed within 90 min symptom onset. Modern approaches to patients with infarctio...

BACKGROUND The type of neuroimaging for the evaluation of transient ischemic attack (TIA) is debatable. Many patients undergo head computed tomography (CT) with or without CT angiogram (CTA) while being at the emergency department (ED) and later magnetic resonance imaging (MRI) with MR angiogram (MRA) during admission. We hypothesized that evaluation with only one imaging modality (CT/CTA or MR...

BACKGROUND The relationship between the signal from retrograde venous flow on magnetic resonance angiography (MRA) and retrograde upward flow from the left brachiocephalic vein has not been explored. PURPOSE To reveal the frequency of jugular venous reflux using MRA and nuclear venography in patients being evaluated for cerebral volume and blood flow. MATERIAL AND METHODS A total of 229 pat...

PURPOSE To determine if contrast-enhanced (CE) MRI of intracranial lesions benefits from time-resolved MR angiography (MRA) during contrast agent injection. MATERIALS AND METHODS For 126 patients with suspected intracranial lesions undergoing routine CE MRI at 3.0T (N = 88) or 1.5T (N = 38), time-resolved CE MRA (three-dimensional [3D] time-resolved imaging of contrast kinetics [TRICKS]) was ...

OBJECTIVE To determine a preferred wavelet transform (WT) procedure for multi-resolution analysis (MRA) of auditory evoked potentials (AEP). METHODS A number of WT algorithms, mother wavelets, and pre-processing techniques were examined by way of critical theoretical discussion followed by experimental testing of key points using real and simulated auditory brain-stem response (ABR) waveforms...

Case Reversible cerebral vasoconstriction syndrome (RCVS) is an increasingly recognized and important cause of thunderclap headache. Delays in diagnosis may cause deterioration of symptoms and concomitant unnecessary investigations. However, the diagnosis of RCVS in the acute stage remains difficult.A 41-year-old man was admitted to the emergency department for severe, recurrent occipital heada...

Introduction It has been shown that the visibility of the vasculature in time-offlight (TOF) MR-angiography highly profits from increased field strengths [1-4]. To acquire truly arterial TOF data sets, the MR signal of venous blood is often saturated using spatially selective saturation pulses. Because of SAR limitations, the application of additional saturation pulses is often not possible at ...

Giant intracranial aneurysms are rare vascular pathologies associated with high morbidity and mortality. The purpose of this in vivo study was to assess giant intracranial aneurysms and their wall microstructure by 7T MR imaging, previously only visualized in histopathologic examinations. Seven giant intracranial aneurysms were evaluated, and 2 aneurysms were available for histopathologic exami...

Introduction Two-dimensional accelerated imaging [1] with acceleration factors as high as R = 8 has been applied successfully in contrastenhanced MR angiography (CE-MRA) of the brain [2, 3] and calves [4]. A key element of this implementation has been the use of multielement receiver coils which are designed for the targeted anatomic region. Multi-element coils for brain MRI are available on co...

OBJECTIVE To evaluate the prevalence of incidentally found unruptured intracranial aneurysms (UIAs) on the brain MR angiography (MRA) from a community-based general hospital. MATERIALS AND METHODS This was a prospectively collected retrospective study, carried out from January 2004 to December 2004. The subjects included 3049 persons from a community-based hospital in whom MRA was performed a...