| Title |
Hemispheric Revascularization in the Setting of Carotid Occlusion and Subclavian Steal: A Diagnostic and Management Role for Quantitative Magnetic Resonance Angiography |
| Authors |
David J. Langer, M.D.; Daniel R. Lefton, M.D.; Lauren Ostergren, B.S.; Carolyn D. Brockington, M.D.; Joon Song, M.D.; Yasunari Niimi, M.D.; Peeyush Bhargava, M.D.; Alejandro Berenstein, M.D. |
| Presented |
Neurosurgery 58:528-533, 2006 |
| Summary |
Non-invasive assessment of the quantity and direction of blood flow revealed a previously unsuspected subclavian steal in the presence of carotid occlusion and anterior circulation ischemia. |
| Conclusion |
In the setting of a patent posterior communicating artery, an extracranial interventional procedure allowed indirect revascularization of the intracranial anterior circulation. Pre-operatively, NOVA was useful in planning the interventional strategy. Post-operatively, NOVA documented a successful revascularization of the right hemisphere following angioplasty and stenting of the left subclavian occlusion. |
back to top
| Title |
Transarterial embolization of vein of Galen malformations: the use of magnetic resonance imaging noninvasive optimal vessel analysis to quantify shunt reduction. Report of two cases. |
| Authors |
David J. Langer, Joon K. Song, Yasunari Niimi, Markus Chwajol, Daniel R. Lefton, Jonathan L. Brisman, Walter Molofsfy, Mark J. Kupersmith and Alejandro Berenstein |
| Presented |
Journal of Neurosurgery. Volume 104 Number 1, 2006. |
| Summary |
In patients with Vein of Galen Malformations (VOGM), high-flow shunting decreases cerebral perfusion. Quantifying pre- and post-embolization shunt blood flow may help determine the optimal timing and efficacy of embolization and may provide prognostic information. The athors used MR non-invasive optimal vessel analysis (NOVA) as a new way to measure volumetric blood flow through Galenic shunts in a neonate and an infant before and after embolization. |
| Conclusion |
The authors have shown the feasibility of measuring arteriovenous fistulous volume blood flow in infants with VOGM using non-invasive MR NOVA. In addition to increased understanding of the hemodynamics of arteriovenous malformations, measuring volume blood flow with NOVA in VOGM and other brain AVM patients may be a valuable tool in determining the need, monitoring the effects, and predicting outcomes after treatment. |
back to top
| Title |
Blood Flow in Major Cerebral Vessels: Effect of Age, Blood Pressure and Vascular Anatomy |
| Authors |
Sepideh Amin-Hanjani, MD; Xinjian Du; Meide Zhao, PhD; Nada Mlinarevich, RN; Sean Ruland,m DO; Fady T. Charbel, MD |
| Presented |
AANS/CNS Cerebrovascular Section and the American Society of Interventional & Therapeutic Neuroradiology. Poster Session. 9 th Joint Annual Meeting, February 17-20, 2006, Orlando, FL |
| Summary |
The range of normative vessel flows in patients was evaluated using quantitative magnetic resonance angiography (QMRA), assessing the effects of mean blood pressure (MBP), age and anatomic variations of the Circle of Willis. |
| Conclusion |
Cerebral blood flow diminishes with older age, but is not affected by normal range MBP. Flow variations within intracranial vessels can be dependent on the patient's specific vascular anatomy. These normative data carry important implications for interpretation of vessel flow in cerebrovascular disease. |
back to top
| Title |
Reproducibility of Cerebral Blood flow Analysis Using Quantitative Magnetic Resonance Angiography |
| Authors |
Sean Ruland, DO; Meide Zhao, PhD; Dilip Pandey, MD, PhD, Lauren Ostergren; Sepideh Amin-Hanjani, MD; Anthony Curcio; Fady T. Charbel, MD |
| Presented |
AANS/CNS Cerebrovascular Section and the American Society of Interventional & Therapeutic Neuroradiology. Poster Session. 9 th Joint Annual Meeting, February 17-20, 2006, Orlando, FL |
| Summary |
Cerebral vessel blood flow can be quantified non-invasively with quantitative magnetic resonance angiography (QMRA). The reproducibility of the technique was evaluated in healthy volunteers. |
| Conclusion |
Using a 3D TOF reconstructed model for proper vessel identification and scan alignment, cerebral vessel blood flow can be measured using QMRA with good reproducibility. This is a promising technique for enhancing our understanding of the natural course and optimal management of large vessel cerebrovascular disease. |
back to top
| Title |
Use of Quantitative Magnetic Resonance Angiography to Stratify Stroke Risk in Symptomatic Vertebobasilar Disease |
| Authors |
Amin-Hanjani, S., Du X., Zhao M., Walsh K., Malisch, T., and Charbel FT. |
| Presented |
Stroke 2005;36:1140-1145 |
| Summary |
The authors sought to determine if quantitative hemodynamic assessment with NOVA could identify patients at high risk for stroke and guide the need for intervention. Using the quantitative flow measurements from QMRA NOVA, the authors were able to stratify the patients based on the presence or absence of distal flow compromise. The patients with low distal flow were offered intervention in addition to standard medical therapy. The patients designated as having normal distal flow according to NOVA had a stroke and stroke/TIA free survival rate of 100% and 96% respectively at 2 years. Patients with low distal flow had a 71% and 53% event free survival, demonstrating a significantly higher risk of recurrent ischemia. |
| Conclusion |
A management algorithm using distal blood flow measurements appears to stratify patients with symptomatic VBD into 2 groups: 1) no distal flow flow compromise; unlikely to benefit from flow augmentation and carrying a low risk on medical therapy and 2) distal flow compromise, regional hemodynamic compromise, potentially benefiting from flow augmentation. |
back to top
| Title |
Patient Computer Model to Predict Outcomes of the Balloon Occlusion Test. |
| Authors |
Charbel F.T.,M.D., Zhao M.,Ph.D.,Amin-Hanjani S.,M.D., Hoffman W., Ph.D., Du X., M.D., Clark M.E., Ph.D. |
| Presented |
Journal of Neurosurgery101:977-988, 2004 |
| Summary |
Balloon occlusion tests (BOTs) are performed to identify patients who are at risk for ischemia and stroke following permanent internal carotid artery (ICA) occlusion. The object of this work was to determine whether patient-specific blood flow modeling could be used to identify patients in whom the BOT would not be tolerated. |
| Conclusion |
A decrease in blood flow in both the middle cerebral and anterior cerebral arteries that was greater than 20%, calculated by flow modeling of the BOT, was 100% sensitive and 100% specific in identifying patients who could not tolerate the BOT. |
back to top
| Title |
Hemodynamic Evaluation of Basilar and Vertebral Artery Angioplasty |
| Authors |
Kern H Guppy, M.D., Ph.D., Fady T.Charbel, M.D., Luke A.Corsten,M.D., Meide Zhao,Ph.D.and Gerard Debrun, M.D. |
| Presented |
Neurosurgery 51: 327-334, 2002 |
| Summary |
This article demonstrates the usefulness of phase contrast magnetic resonance angiography in evaluating the hemodynamic changes that occur after angioplasty of the basilar and vertebral arteries. |
| Conclusion |
PCMRA provides a noninvasive method for measuring arterial flow rates with far-reaching implications in neurosurgery. |
back to top
| Title |
Computerized Hemodynamic Evaluation of the Cerebral Circulation for Bypass |
| Authors |
Kern H Guppy, M.D., Ph.D., Fady T.Charbel, M.D., Luke A.Corsten,M.D., Meide Zhao,Ph.D.and Gerard Debrun, M.D. |
| Presented |
Neurosurgery Clinics of North America 36: 499-508, July 2001 |
| Summary |
The article describes two case studies illustrating the use of phase contrast magnetic resonance imaging and cerebral computer simulation to evaluate the cerebral circulation for bypass. |
| Conclusion |
Computer simulation of cerebral blood flow allows different scenarios of bypass alternatives to be applied and to determine their hemodynamic effects. PCMR imaging helps in the determination of intracranial and extracranial arterial flow rates and thus provides a method of evaluating the present hemodynamic state of the bypass as well as for post-operative follow up. |
back to top
| Title |
Computer Assisted Neuro-Vascular Analysis and Simulation for Prevention, Diagnosis and Treatment Prediction of Complex Cerebrovascular Disorders. |
| Authors |
Charbel F.T., Zhao M., Clark M.E., Hoffman W. CANVAS Group |
| Presented |
University of Illinois at Chicago, July 30, 2001. |
back to top
| Title |
Improved Phase-Contrast Flow Quantification by Three-Dimensional Vessel Localization. |
| Authors |
Zhao M, Charbel F.T., Alperin N, Loth F, Clark ME. |
| Presented |
Mag. Reson. Imag., 2000; 18/6 697-706. |
back to top
|
