MR angiographic findings of aberrant right subclavian artery with agenesis of the left common carotid artery and anomalous origin of the vertebral arteries.

Introduction: Congenital aortic arch anomalies and variants have been extensively characterized in the medical literature. Proper identification of these anomalies is important when surgical or percutaneous interventions are indicated.

Case Presentation: We present a case of a 48-year old male who presented to the emergency department with altered mental status.

Detection of subthreshold atrophy in crossed cerebellar degeneration via two-compartment mathematical modeling of cell density in DWI: A proof of concept study.

Crossed cerebellar diaschisis (CCD) refers to transneuronal degeneration of the corticopontocerebellar pathway, resulting in atrophy of cerebellum contralateral to supratentorial pathology. CCD is traditionally diagnosed on nuclear medicine studies. Our aim is to apply a biexponential diffusion model, composed of intracellular and extracellular compartments, to the detection of subthreshold CCD on DWI, with the calculated fraction of the intracellular compartment as a proposed measure of cell density.

An unusual case of cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy with occipital lobe involvement.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an autosomal dominant angiopathy caused by a mutation in the notch 3 gene on chromosome 19. Clinically, patients may be asymptomatic or can present with recurrent ischemic episodes and strokes leading to dementia, depression, pseudobulbar palsy, and hemi- or quadraplegia. Additional manifestations that have been described include migraine (mostly with aura), psychiatric disturbances, and epileptic seizures.

Complex imaging features of accidental cerebral intraventricular gadolinium administration.

Gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) is a contrast agent commonly used for enhancing MRI. In this paper, the authors report on 2 cases of postoperative inadvertent administration of Gd-DTPA directly into a ventriculostomy tubing side port that was mistaken for intravenous tubing. Both cases demonstrated a low signal on MRI throughout the ventricular system and dependent portions of the subarachnoid spaces, which was originally believed to be CSF with areas of T1 shortening in the nondependent portions of the subarachnoid spaces, and misinterpreted as basal leptomeningeal enhancement and meningitis.

Parameter optimization for quantitative signal-concentration mapping using spoiled gradient echo MRI.

Rationale and Objectives. Accurate signal to tracer concentration maps are critical to quantitative MRI. The purpose of this study was to evaluate and optimize spoiled gradient echo (SPGR) MR sequences for the use of gadolinium (Gd-DTPA) as a kinetic tracer.

A medley of midbrain maladies: a brief review of midbrain anatomy and syndromology for radiologists.

The midbrain represents the uppermost portion of the brainstem, containing numerous important nuclei and white matter tracts, most of which are involved in motor control, as well as the auditory and visual pathways. Notable midbrain nuclei include the superior and inferior colliculus nuclei, red nucleus, substantia nigra, oculomotor nuclear complex, and trochlear nucleus. In addition, white matter tracts include the brachium conjunctivum, medial and lateral lemniscus, spinothalamic tracts, and the fiber tracts within the cerebral peduncles.

Dominant posterior-variant alien hand syndrome after acute left parietal infarction.

Alien hand syndrome (AHS) is a complex clinical disorder in which patients develop a sense of estrangement from, and loss of volitional control of, an affected limb and non-purposeful complex motor actions of the same limb. Several forms of AHS exist, including frontal, callosal, and posterior types with a series of different associated neuroanatomical lesions and clinical symptoms. Most commonly, the lesions associated with AHS occur in the frontal lobes and corpus callosum.

Midbrain ataxia: an introduction to the mesencephalic locomotor region and the pedunculopontine nucleus.

Objective: Although gait ataxia is usually associated with cerebellar lesions, we review a less familiar cause. We present three patients with dorsal midbrain lesions and correlate these presentations with recent findings in the functional anatomy of the midbrain.

Conclusion: We suggest that these lesions involve a well-studied but generally unfamiliar area of the dorsal midbrain known as the mesencephalic locomotor region.

Sonographic NASCET index: a new doppler parameter for assessment of internal carotid artery stenosis.

Background And Purpose: Established Doppler parameters for carotid stenosis assessment do not reflect North American Symptomatic Carotid Endarterectomy Trial (NASCET)-style methodology. We derived a Doppler parameter, termed sonographic NASCET index (SNI), and hypothesized that the SNI would provide greater angiographic correlation and better accuracy in predicting stenosis of 70% or greater than that of currently used peak systolic velocity (PSV) measurements.

Methods: Inclusion criteria of angiographically proved carotid stenoses of 40-95% and measured proximal and distal internal carotid artery Doppler PSV values were established.

Accuracy of contrast-enhanced MR angiography in predicting angiographic stenosis of the internal carotid artery: linear regression analysis.

Background And Purpose: We sought to assess whether contrast-enhanced MR angiography is able to predict the degree of angiographic stenosis of the internal carotid artery within a clinically acceptable margin of error, thereby decreasing the need for angiography. In addition, we sought to assess whether adding ultrasound peak systolic velocity (PSV) as an additional regressor improves the accuracy of prediction.

Methods: A retrospective review of our institution's records for a 4-year period was conducted to identify all patients who had undergone evaluation of their carotid arteries using digital subtraction angiography, contrast-enhanced MR angiography, and ultrasonography.

Symptom spread to contiguous body parts as a presentation of cerebral ischemia.

Background: Ischemic stroke commonly presents with sudden onset of focal deficit that is maximal at onset. Symptom onset marked by the spread of symptoms to contiguous body parts may suggest migraine, seizure or cerebral amyloid angiopathy (CAA) that is mimicking ischemic symptoms.

Objective: To assess (1) if the spread of symptoms to contiguous body parts is an uncommon presentation of ischemic stroke and transient ischemic attack (TIA) and (2) if patients presenting with this symptom complex frequently have migraine, seizure or CAA mimicking stroke or TIA.