Rotational vertebrobasilar insufficiency due to dynamic compression of the dominant vertebral artery by the thyroid cartilage and occlusion of the contralateral vertebral artery at C1-2 level.

BACKGROUND: Vertebrobasilar insufficiency caused by head rotation is an uncommon event. The mechanism is obstruction of the vertebral artery resulting in flow limitation or, less frequently, thromboembolism. CASE DESCRIPTION: A 41-year-old male developed dizziness and light-headedness during chiropractic manipulation when his head was turned to the extreme right position. Computed tomography angiography (CTA) of the neck and selective digital subtraction angiography (DSA) of the vertebral arteries revealed that when the patient turned his head to the extreme right position the dominant right vertebral artery was compressed between the posterior aspect of the thyroid cartilage and anterior aspect of the right transverse process of C6 resulting in focal stenosis, while the left vertebral artery is severely compressed with significant flow limitation at the level of C1-2. Because the patient was healthy and asymptomatic, conservative management was adopted. At the 9-month follow-up visit the patient was asymptomatic and able to compensate for his problem avoiding turning his head to the extreme right position. CONCLUSIONS: We present an uncommon case of rotational vertebrobasilar insufficiency (VBI) where the dominant vertebral artery has an anomalous course compressed by the thyroid cartilage at C6 level, associated with contralateral vertebral artery rotational stenosis at C1-2. The patient was successfully managed conservatively.

Neuroendovascular magnetic navigation: clinical experience in ten patients.

INTRODUCTION: The magnetic navigation system consists of an externally generated magnetic field that is used to control and steer a magnetically tipped microguidewire. The goal of this study was to demonstrate that the use of the magnetic navigation system and its magnetic microguidewire is feasible and safe in all types of neuroendovascular procedures. METHODS: A magnetic navigation system is an interventional workstation that combines a biplanar fluoroscopy system with a computer-controlled magnetic field generator to provide both visualization and control of a magnetically activated endovascular microguidewire. Ten consecutive patients underwent a variety of neuroendovascular procedures using the magnetic guidance system and magnetic microguidewire. All patients presented with a neurovascular disease that was suitable for endovascular treatment. Multiple different devices and embolic agents were used. RESULTS: Of the ten patients, three were male and seven female. Their mean age was 53.9 years. The predominant neurovascular condition was the presence of intracranial aneurysm (nine patients). One patient had a left mandibular arteriovenous malformation. All treatments were successfully performed on the magnetic navigation system suite. The magnetic navigation system and the magnetic microguidewire allowed safe and accurate endovascular navigation allowing placement of the microcatheters in the desired location. There were no neurological complications or death in our series. CONCLUSION: The use of the magnetic navigation system and the magnetic microguidewire in the endovascular treatment of patients with neurovascular diseases is feasible and safe.

Endovascular treatment of the vertebral artery origin in patients with symptoms of vertebrobasilar ischemia.

INTRODUCTION: We report our experience with the endovascular treatment of the vertebral artery origin in patients presenting with symptomatic vertebrobasilar ischemia and compare our results with those reported in the literature. METHODS: In 25 patients, 28 procedures were performed. Patients presented with posterior circulation ischemic symptoms despite optimal medical therapy with antiplatelet drugs and had a digital subtraction angiogram demonstrating stenosis of the origin of the vertebral artery greater than 50%. Retrospective review of the medical records, clinical notes and radiologic-procedural reports was performed. RESULTS: Of the 25 patients, 18 were male and 7 female. Their ages ranged from 50 to 84 years. In 23 of the 25 patients the contralateral vertebral artery was occluded, hypoplastic, absent, or had greater than 50% stenosis. In 13 of the 25 patients angiographic evidence of significant anterior circulation disease was demonstrated. In 18 of the 25 patients the left vertebral artery was affected. The mean stenosis was 82.6%. Follow-up records were available in 19 patients. The mean follow-up was 24 months. Five of the 19 patients had recurrent symptoms of vertebrobasilar ischemia and three patients were retreated. Of the 28 procedures performed, 23 were angioplasty/stenting and 5 were angioplasties alone. Overall technical success was achieved in 26 of the 28 procedures (92.8%). No procedure-related transient ischemic attack, stroke or death was noted. CONCLUSION: Endovascular treatment of the vertebral artery origin in this patient population is feasible, safe, and effective. There are some questions regarding the long-term follow-up and rate of restenosis and clinical recurrences that are yet to be answered.

Goldvalve detachable balloon: "in vitro" assessment of safety and imaging artifacts in a 3-T MR system.

The Goldvalve balloon is the only currently available detachable balloon. We undertook a study to determine safety and imaging artifacts in a MR environment. We found no evidence for heating or deflection of the balloon in a comprehensive series of in vitro experiments at 3 T. MR imaging at field strengths up to 3 T of patients with implanted Goldvalve balloons is safe. Imaging artifacts are minimal.

Results of the 2004 survey of the American Association of Academic Chief Residents in Radiology.

RATIONALE AND OBJECTIVE: Every year, the American Association of Academic Chief Residents in Radiology (A3CR2) conducts a survey of the chief residents in accredited radiology programs in the United States and Canada. The purpose of the survey is to evaluate current residents' opinions regarding a number of different issues pertaining to their educational experience, work responsibilities, and benefits. This information is useful in monitoring patterns of change in resident attitudes toward their experiences within their residency training programs. MATERIALS AND METHODS: Online surveys were made available to the chief residents from 193 training programs in North America. For the most part, the questions were presented in a multiple-choice format, with additional space for elaboration or comments provided for many of the items. Some questions are repeated annually, addressing general topics such as salary and hospital size. However, new questions are incorporated each year. In particular, this year's survey included questions pertaining to Armed Forces Institute of Pathology course funding, and advanced cardiac life support (ACLS) /basic life support certification and changes in duty work hour and call requirements in the face of changing ACGME (Accreditation Council for Graduate Medical Education) regulations. RESULTS: The results of the survey were then tabulated, and responses to several of the repeated questions were compared with those from prior surveys dating back to 1996. This year's response rate was 55%, with 106 unique responses received. This represents an improvement since last year's survey, when the response rate was 41%. In some cases, more than one response was generated by a given residency program, in which case the questionnaire that was more thoroughly completed was used for statistical analysis. Responses were received from chief residents in 37 states and in Canada. The largest number of respondents was from New York, and 80% percent of respondents were from programs affiliated with a university. Forty-two percent were incoming chief residents with less than 3 months' experience, whereas 58% were outgoing chief residents with less than 9 months remaining in their tenure. CONCLUSION: The majority of respondents report that changes made by their respective programs as the result of new ACGME maximum duty hour standards have been viewed favorably by radiology residents. Many training programs have moved toward a night float based call system in order to maintain compliance. Nearly all programs have overnight in-house radiology resident coverage, but there has been a slight decline in the percentage of programs that provide in-house attending coverage at night. The majority of residents, however, have access to attendings after-hours by pager. Finally, resident salaries and benefits continue to increase, as has been the trend over the past several years.