Atlantoaxial posterior screw fixation using intra-operative spinal navigation with three-dimensional isocentric C-arm fluoroscopy.

Purpose: Intra-operative image acquisition coupled with navigation aims to increase screw placement accuracy, and it is particularly helpful in complex spinal procedures. The aim of this study is to analyze the accuracy and reliability of posterior atlanto-axial fixation using spinal navigation combined with intra-operative 3D isocentric C-arm.

Methods: We retrospectively reviewed all patients presenting with C1-C2 instability and treated by posterior atlanto-axial fixation in our center between December 2016 and September 2018.

Patterns of convexal subarachnoid haemorrhage: clinical, radiological and outcome differences between cerebral amyloid angiopathy and other causes.

Background: Cerebral amyloid angiopathy (CAA) is a common aetiology of convexal subarachnoid haemorrhage (cSAH) but little is known about its specific characteristics in comparison with cSAH from other causes. In this study we compared patients with CAA vs. non-CAA-related cSAH.

COBOLD assessment of moyamoya syndrome: Validation with single photon emission computed tomography and positron emission tomography imaging.

Aim: To compare the assessment of cerebrovascular reserve (CVR) using COBOLD magnetic resonance imaging (MRI) positron emission tomography (PET) and single photon emission computed tomography (SPECT) as reference standard.

Methods: Ten consecutive patients (8 women, mean age of 41 ± 26 years) with moyamoya syndrome underwent 14 pre-surgical evaluations for external-internal carotid artery bypass surgery. CVR was assessed using COBOLD and PET (4)/SPECT (11) with a maximum interval of 36 d, and evaluated by two experienced neuroradiologists.

Dynamic Contrast-Enhanced MR Perfusion of Intradural Spinal Lesions.

Fifteen patients with intradural spinal lesions were examined with an optimized dynamic contrast-enhanced MR perfusion sequence at 1.5T and 3T. SNR and mean contrast-to-noise ratio were better on 3T compared with 1.

Acute Convexity Subarachnoid Hemorrhage Related to Cerebral Amyloid Angiopathy: Clinicoradiological Features and Outcome.

Background: The specificities of acute convexity subarachnoid hemorrhage (cSAH) related to cerebral amyloid angiopathy (CAA) and its evolution are not well known. We aimed to describe the clinicoradiological pattern, the magnetic resonance imaging (MRI) evolution, and the risk of recurrent bleeding in such patients.

Methods: Among consecutive patients with an acute nontraumatic cSAH, subjects with available MRI who meet the modified Boston criteria for probable CAA were included.

Diagnosis of acute ischemia using dual energy CT after mechanical thrombectomy.

Background And Purpose: To assess the performance of dual energy unenhanced CT in the detection of acute ischemia after mechanical thrombectomy.

Methods: Retrospective study, approved by the local institutional review board, including all patients that underwent intra-arterial thrombectomy in our institution over a period of 2 years. The presence of acute ischemia and hemorrhage was evaluated by three readers.

Arterial embolization with Onyx of head and neck paragangliomas.

Object: To report the morbidity and long term results in the treatment of paragangliomas by transarterial embolization with ethylene vinyl alcohol (Onyx), either as preoperative or palliative treatment.

Methods: Between September 2005 and 2012, 18 jugulotympanic, 7 vagal, and 4 carotid body paragangliomas (CBPs) underwent Onyx embolization, accordingly to our head and neck multidisciplinary team's decision. CBPs were embolized preoperatively.

State-of-the-art MRI techniques in neuroradiology: principles, pitfalls, and clinical applications.

This article reviews the most relevant state-of-the-art magnetic resonance (MR) techniques, which are clinically available to investigate brain diseases. MR acquisition techniques addressed include notably diffusion imaging (diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), and diffusion kurtosis imaging (DKI)) as well as perfusion imaging (dynamic susceptibility contrast (DSC), arterial spin labeling (ASL), and dynamic contrast enhanced (DCE)). The underlying models used to process these images are described, as well as the theoretic underpinnings of quantitative diffusion and perfusion MR imaging-based methods.

Embolic and Hemodynamic Transcranial Doppler Characteristics in Patients with Acute Ischemic Stroke due to Carotid Occlusive Disease: Contribution to the Different Infarct Patterns on MRI.

Background And Purpose: Whether hemodynamic and/or embolic transcranial Doppler (TCD) features of internal carotid artery (ICA) stenosis contribute to the classification of stroke patterns on MRI.

Patients And Methods: Consecutive patients presenting symptomatic ≥50% ICA stenosis were included. Microembolic signals (MES) detection and measurement of cerebral vasoreactivity (VR) were performed by TCD.

Safety and accuracy of robot-assisted versus fluoroscopy-guided pedicle screw insertion for degenerative diseases of the lumbar spine: a matched cohort comparison.

Object: Recent years have been marked by efforts to improve the quality and safety of pedicle screw placement in spinal instrumentation. The aim of the present study is to compare the accuracy of the SpineAssist robot system with conventional fluoroscopy-guided pedicle screw placement.

Methods: Ninety-five patients suffering from degenerative disease and requiring elective lumbar instrumentation were included in the study.

Do brain T2/FLAIR white matter hyperintensities correspond to myelin loss in normal aging? A radiologic-neuropathologic correlation study.

Background: White matter hyperintensities (WMH) lesions on T2/FLAIR brain MRI are frequently seen in healthy elderly people. Whether these radiological lesions correspond to irreversible histological changes is still a matter of debate. We report the radiologic-histopathologic concordance between T2/FLAIR WMHs and neuropathologically confirmed demyelination in the periventricular, perivascular and deep white matter (WM) areas.

In situ evidence of JC virus control by CD8+ T cells in PML-IRIS during HIV infection.

Objective: To determine the pathophysiologic features of progressive multifocal leukoencephalopathy (PML) associated with immune reconstitution inflammatory syndrome (PML-IRIS) in HIV-infected patients.

Methods: In a cross-sectional study, we retrospectively analyzed 11 HIV-infected patients with a firm diagnosis of PML-IRIS. Brain biopsies were collected from 5 patients and their histopathologic features were compared to those of 4 HIV-infected patients with classic PML.

Imaging of the cavernous sinus lesions.

This educational paper reviews the normal anatomy of the cavernous sinus (CS) and the imaging findings of common and uncommon lesions of this region. CS lesions may arise from different components of the CS or from adjacent structures and spaces. They can be classified as tumoral, inflammatory/infectious, vascular and congenital.

3D fat-saturated T1 SPACE sequence for the diagnosis of cervical artery dissection.

Introduction: This study aims to demonstrate the added value of a 3D fat-saturated (FS) T1 sampling perfection with application-optimised contrast using different flip angle evolutions (SPACE) sequence compared to 2D FS T1 spin echo (SE) for the diagnosis of cervical artery dissection.

Methods: Thirty-one patients were prospectively evaluated on a 1.5-T MR system for a clinical suspicion of acute or subacute cervical artery dissection with 3D T1 SPACE sequence.

Peripheral nerves, tumors, and hybrid PET-MRI.

The study of peripheral nerves (PN) is a challenge because of the orientation, size, and also because of the fact that these pathologies are not well known. The diagnosis of PN damage was based exclusively on clinical examination and electrophysiologic testing until few years ago. MRI is the examination of choice for studying peripheral nerves; recently, magnetic resonance neurography has been added as a part of clinical routine.

Magnetic resonance imaging of metabolic diseases of the cerebral white matter.

Metabolic diseases of the brain are a rare occurrence. They may be either occurring as inherited diseases causing a destruction of myelin, or they may be the result of toxicity. Neuroimaging, especially magnetic resonance imaging, plays an important role in the detection and classification of these rare diseases.

Cortical subarachnoid haemorrhage in the elderly: a recurrent event probably related to cerebral amyloid angiopathy.

Objective: Isolated, non-traumatic, cortical subarachnoid haemorrhage (cSAH) is a rare type of cerebrovascular disease caused by various disorders. In a few cases, especially in the elderly, no apparent cause can be identified. We report a case series of patients without apparent cause of cSAH.

Toxoplasmic encephalitis IRIS in HIV-infected patients: a case series and review of the literature.

Background: Toxoplasmic encephalitis associated with immune reconstitution inflammatory syndrome (TE-IRIS) is rarely described.

Methods: To identify TE-IRIS cases, the authors performed a retrospective study of all HIV-infected patients diagnosed as having TE in our unit between January 2000 and June 2009, and a review of published cases.

Results: Three patients out of 65 toxoplasmic encephalitis (TE) cases, together with six from the literature, fulfilled the unmasking TE-IRIS definition.

Isolated acute nontraumatic cortical subarachnoid hemorrhage.

Our aim was to review the etiologic background of isolated acute nontraumatic cSAH. While SAH located in the basal cisterns originates from a ruptured aneurysm in approximately 85% of cases, a broad spectrum of vascular and even nonvascular pathologies can cause acute nontraumatic SAH along the convexity. Arteriovenous malformations or fistulas, cortical venous and/or dural sinus thrombosis, and distal and proximal arteriopathies (RCVS, vasculitides, mycotic aneurysms, Moyamoya, or severe atherosclerotic carotid disease) should be sought by noninvasive imaging methods or/and conventional angiography.