BACKGROUND AND PURPOSE:Color has been shown to facilitate both visual search and recognition tasks. It was our purpose to examine the impact of a color-coding algorithm on the interpretation of 2D-DSA acquisitions by experienced and inexperienced observers.

BACKGROUND AND PURPOSE: Conventional 3D-DSA volumes are reconstructed from a series of projections containing temporal information. It was our purpose to develop a technique which would generate fully time-resolved 3D-DSA vascular volumes having better spatial and temporal resolution than that which is available with CT or MR angiography.

BACKGROUND AND PURPOSE: Arteriovenous malformations have a high lifetime risk of hemorrhage; however, treatment carries a significant risk of morbidity and mortality, including permanent neurologic sequelae. WSS and other hemodynamic parameters are altered in patients with symptomatic AVMs, and analysis of hemodynamics may have value in stratifying patients into different risk groups. In this study, we examined hemodynamic data from patients with stable symptoms and those who presented with acute symptoms to identify trends which may help in risk stratification. MATERIALS AND METHODS: Phase-contrast MRA using a radial readout (PC-VIPR) is a fast, high-resolution technique that can acquire whole-brain velocity-encoded angiograms with scan times of approximately 5 minutes. Ten patients with AVMs were scanned using PC-VIPR; velocity, area, flow, and WSS in vessels feeding the AVMs and normal contralateral vessels were calculated using velocity data from the phase-contrast acquisition. RESULTS: Patients with an asymptomatic presentation or mild symptoms (n = 4) had no significant difference in WSS in feeding vessels compared with normal contralateral vessels, whereas patients presenting with hemorrhage, severe headaches/seizures, or focal neurologic deficits (n = 6) had significantly higher WSS in feeding vessels compared with contralateral vessels. CONCLUSIONS: In this study, we demonstrate that estimates of WSS and other hemodynamic parameters can be obtained noninvasively in patients with AVMs in clinically useful imaging times. Variation in WSS between feeders and normal vessels appears to relate to the clinical presentation of the patient. Further analysis of hemodynamic changes may improve characterization and staging of AVM patients, when combined with existing risk factors.

Objective To report three unique cases of cranial neuropathy after super-selective arterial embolization of jugular foramen vascular tumors with ethylene vinyl alcohol. Study Design Clinical capsule report Setting Three tertiary academic referral hospitals Patients Three patients who underwent superselective arterial embolization (SSE) of head and neck paragangliomas with ethylene vinyl alcohol are described. One individual was treated with primary SSE, while the remaining tumors were treated with preoperative SSE followed by surgical extirpation within 72 hours. All patients were found to have new cranial nerve deficits following SSE. Results One patient with isolated complete cranial nerve VII palsy demonstrated no return of function. One individual experienced cranial nerve VII, X, and XII palsies and demonstrated partial recovery of function of the involved facial nerve after 19 months. One subject experienced ipsilateral cranial nerve X and XI palsies after SSE and recovered full function of the spinal accessory nerve within one week, but failed to demonstrate mobility of the ipsilateral true vocal fold. Conclusion We present the first report documenting facial and lower cranial neuropathies after super-selective embolization of head and neck paragangliomas with EVA. Although it is difficult to draw conclusions from this small number of cases, it is plausible that use of ethylene vinyl alcohol during SSE may result in a higher risk of permanent cranial neuropathy than the use of other well-established and more temporary agents. Knowledge of the arterial supply to the cranial nerves can help the clinician to choose the embolization agent that will provide maximal occlusion while minimizing the risk of complications.

BACKGROUND AND PURPOSE:Currently, more reliable parameters to predict the risk of aneurysmal rupture are needed. Intra-aneurysmal pressure gradients and flow maps could provide additional information regarding the risk of rupture. Our hypothesis was that phase contrast with vastly undersampled isotropic projection reconstruction (PC-VIPR), a novel 3D MR imaging sequence, could accurately assess intra-aneurysmal pressure gradients in a canine aneurysmal model when compared with invasive measurements.