Flavius D. Raslau

Surveillance imaging after intracranial stent implantation: non-invasive imaging compared with digital subtraction angiography

Background Digital subtraction angiography (DSA) is the gold standard imaging for detection of in-stent restenosis (ISR) but there is limited literature on optimal non-invasive surveillance imaging. In this study, the ability of CT angiography (CTA) and MR angiography (MRA) compared with DSA in recognizing ISR was assessed. Methods A single center database of patients treated with stent implantation for ICAD was accessed. All patients who underwent follow-up imaging with DSA paired with either MRA or CTA within 30 days were included. Two angiography readers and two non-invasive imaging readers measured restenosis with a submillimeter digital caliper. ISR was categorized as: none/minimal, mild (<50%), moderate (≥50–70%) or severe (≥70%). Analysis was performed with weighted κ statistics. Results 17 cases of individual stents that underwent surveillance imaging with paired DSA and CTA and five stents with paired DSA and MRA were identified. Of those undergoing DSA and CTA, inter-reader agreement produced κ=0.68 (95% CI 0.40 to 0.95) for DSA and κ=0.75 (95% CI 0.55 to 0.95) for CTA. Agreement across CTA and DSA was κ=0.36 (95% CI 0.26 to 0.52). Of those undergoing DSA and MRA, inter-reader agreement produced κ=0.71 (95% CI 0.27 to 1.00) for DSA and κ=1.00 (95% CI 1.00 to 1.00) for MRA. Agreement across MRA and DSA was κ=0.34 (95% CI 0.18 to 0.51). Conclusions Good inter-reader agreement exists within DSA, CTA and MRA. However, when comparing non-invasive imaging (CTA and MRA) with DSA, only fair agreement exists. These data suggest that CTA and MRA are not comparable to DSA for evaluation of ISR.

Memory Part 3: The Role of the Fornix and Clinical Cases

The fornix is the major white matter outflow tract from the hippocampus, and pathology involving the fornix would be expected to affect memory. Pathologic processes that affect the hippocampal formation and parahippocampal gyrus, including the entorhinal cortex, correlate with specific types of

DTI for Presurgical Mapping

While there are many current and potential applications for diffusion tensor imaging (DTI), the ability to map white matter tracts prior to surgical resection of brain tumors is responsible for the emergence of this powerful technology into the clinical realm. Dramatic successes have propelled the clinical translation. By defining spatial relationships between the lesion and functional white matter networks, DTI plays a critical role in creating a patient-specific neurosurgical plan and guiding intraoperative assessments. When used effectively, DTI can improve surgical outcomes, maximizing tumor resections while minimizing postsurgical deficits. Optimal utilization and interpretation of DTI require an understanding of the technique, data visualization methods, normal white matter anatomy, effect of pathological processes, and limitations.

Surfer’s myelopathy without surfing: a report of two pediatric patients

Introduction:Surfer’s myelopathy (SM) is a rare disorder described in subjects presenting with acute paraparesis while learning how to surf. It is thought to be secondary to spinal ischemia triggered by hyperextension. Spinal magnetic resonance imaging (MRI) shows changes consistent with spinal cord ischemia on T2-weighted and diffusion-weighted imaging (DWI).Case Presentation:We report two patients who presented with acute onset paraplegia shortly after spinal hyperextension. They had no physical or radiological evidence of soft tissue injury. Their clinical and imaging findings closely resemble those described in SM.Discussion:We propose the use of the term ‘acute hyperextension myelopathy’ to categorize patients with spinal cord infarction secondary to hyperextension. DWI sequencing on MRI should be considered to evaluate for early signs of spinal cord ischemia in these patients. Use of a broader term for diagnostic classification can help include patients with spinal cord infarction due to a common mechanism.

Memory Part 2: The Role of the Medial Temporal Lobe

The medial temporal lobe plays a central role in memory processing and is more than just the hippocampus.[1][1] The hippocampal formation, which forms the upper segment of the medial temporal lobe, is a heterogeneous structure consisting of the Ammon horn or Cornus Ammonis (Cornus Ammonis area 1 to

Memory Part 1: Overview

A common laymans conception of memory is the simple storage and retrieval of learned information that often evokes comparison to a filing system. Our everyday experience of memory, however, is in fact a complicated multifactorial process that consists of both conscious and unconscious components,

Teaching NeuroImages: Leber hereditary optic neuropathy masquerading as neuromyelitis optica

A 22-year-old woman presented with photopsia, sensory loss, and paresthesia over both lower extremities, visual scotomas, and painless binocular vision loss over 5 months. MRI showed T2 hyperintensities near the optic chiasm (figure 1, B and C), floor of the fourth ventricle and the colliculi (figure 2, A–F), and central gray matter of the spinal cord (figure 1A). CSF analysis was notable for elevated glucose and lactate; oligoclonal bands, immunoglobulin G index, and aquaporin-4 antibodies were negative. Her maternal uncle has Leber hereditary optic neuropathy (LHON) and a genetic analysis confirmed an m.3460 G>A mitochondrial DNA point mutation.

Reversible manifestations of extraparenchymal neurocysticercosis

Movement disorders are uncommon manifestations of neurocysticercosis. When present, most are secondary to parenchymal lesions in the basal ganglia. Rarely, movement disorders can occur in racemose/extraparenchymal neurocysticercosis, an aggressive variant frequently associated with cerebrospinal fluid outflow obstruction and hydrocephalus. Appropriate treatment can reverse neurological manifestations.

Pearls & Oy-sters: An uncommon initial presentation of thyrotoxicosis

Venous thrombosis is common in patients with thyrotoxicosis, with the cerebral venous system being frequently involved.

Imaging of Functional and Dysfunctional Episodic Memory

A foundational framework for understanding functional and dysfunctional imaging of episodic memory emerges from the last 3 decades of human and animal research. This comprehensive review is presented from the vantage point of the fornix, a white matter bridge that occupies a central position in this functional network. Salient insights are identified, spanning topics such as hippocampal efferent and afferent networks, input and processing streams, hemispheric specialization, dysfunctional effects of pathologic and surgical injury, optimization of functional magnetic resonance imaging design and neuropsychological tests, and rehabilitation strategies. Far-reaching implications are considered for radiologists, whose clinical effect stretches beyond imaging and interfaces with neurosurgeons, neuropsychologists, and other neurospecialists.