Effect of age and vascular anatomy on blood flow in major cerebral vessels.

Authors

Sepideh Amin-Hanjani, Xinjian Du, Dilip K Pandey, Keith R Thulborn and Fady T Charbel

Presented

Journal of Cerebral Blood Flow & Metabolism, 2014 November 12

Summary

325 healthy adult volunteers were prospectively evaluated using NOVA qMRA to characterize the effects of age and vascular anatomy on cerebral vessel flow rates and to establish clinically useful normative reference values.

Conclusion

Cerebral vessel flows are affected by age and cerebrovascular anatomy, which has important implications for interpretation of flows in the disease state.

Effects of Extracranial Carotid Stenosis on Intracranial Blood Flow

Authors

Shakur SF, Hrbac T, Alaraj A, Du X, Aletich VA, Charbel FT, Amin-Hanjani S.

Presented

Stroke. 2014 Sep 16.

Summary

The impact of anatomic measurements of extracranial carotid stenosis relative to ipsilateral internal carotid artery (ICA) flow and ipsilateral-to-contralateral middle cerebral artery (MCA) flow ratio was assessed using NOVA qMRA.

Conclusion

Percentage stenosis and residual lumen are significantly associated with ICA but not MCA flow. The lower MCA flow ratio in symptomatic patients highlights the potential importance of distal hemodynamics in symptomatic presentation.

Quantitative MRA is Correlated with Intravascular Pressures Before and After Venous Sinus Stenting: Implications for Treatment and Monitoring.

Authors

Esfahani D, Stevenson M, Moss H, Amin-Hanjani S, Aletich V, Charbel F, Alaraj A.

Presented

J Neurointerv Surgery 2014 Jul;6 Suppl 1:A6-7

Summary

Ipsilateral and total venous quantitative flow measurements by QMRA increase after endovascular stenting and correlate with significantly improved intravascular pressures.

Conclusion

The findings establish QMRA as a useful adjunct to measure venous flow after stenting, and as valuable tool for noninvasive monitoring of stent patency.

Changes in posterior circulation arterial flows after revascularization surgery in moyamoya disease: a quantitative MRI study.

Authors

Navarro R, Feroze A, Choudhri O, Lober R, Khan N, Steinberg G

Presented

J Neurointerv Surg. 2014 Jul;6 Suppl 1:A44.

Summary

A cohort of 64 patients (78% female, mean age 38.5 years, 55% unilateral disease) had pre- and post-operative qMRA studies.

Conclusion

Quantitative MRA shows that posterior circulation arterial flows are markedly increased in patients with moyamoya disease compared with normal controls. These flows decreased significantly after revascularization. Further use of qMRA might be warranted to better understand moyamoya hemodynamics before and after surgery.

Wall Shear Stress in Major Cerebral Arteries as a Function of Age and Gender-A Study of 301 Healthy Volunteers.

Authors

Zhao X, Zhao M, Amin-Hanjani S, Du X, Ruland S, Charbel FT

Presented

J Neuroimaging 2014 Jul 4.

Summary

Volume flow and diameter obtained with quantitative magnetic resonance angiography were used to calculate mean wall shear stress via the Hagen-Poiseuille equation.

Conclusion

Mean wall shear stress decreased significantly with age in all vessels. However, a marked drop in the 48-57 and 58-67 age groups corresponded with an increase in diameter and systolic blood pressure rather than a significant drop in flow.

Cerebrovascular reactivity by quantitative magnetic resonance angiography with a Co₂ challenge. Validation as a new imaging biomarker.

Authors

Caputi L, Ghielmetti F, Faragò G, Longaretti F, Lamperti M, Anzola GP, Carriero MR, Charbel FT, Bruzzone MG, Parati E, Ciceri E

Summary

This study compared QMRA to TCD for evaluation of cerebrovascular reactivity (CVR) at rest and after a Co₂ challenge.

Conclusion

Good correlation in terms of CVR was obtained comparing TCD and QMRA. Studies regarding CVR in physiopathological conditions might consider the utilization of QMRA both in routine clinical settings and in research projects.

Combined Direct and Indirect Bypass for Moyamoya: Quantitative Assessment of Direct Bypass Flow over Time.

Authors

Amin-Hanjani S, Singh A, Rifai H, Thulborn KR, Alaraj A, Aletich V, Charbel FT.

Presented

Neurosurgery. 2013 Aug 13.

Summary

The relative contributions of direct and indirect bypass in 13 moyamoya patients and 16 hemispheres were examined using angiography and quantitative magnetic resonance angiography.

Conclusion

In this small cohort, a reciprocal relationship between direct STA bypass flow and indirect EDAS collaterals frequently occurred. This substantiates the notion that combined direct/indirect bypass can provide temporally complementary revascularization.

Advances in imaging of intracranial atherosclerotic disease and implications for treatment.

Authors

Caprio FZ; Prabhakaran S.

Presented

Curr Treat Options Cardiovasc Med. 2013 Jun;15(3):335-47

Summary

Opinion Statement. Intracranial atherosclerotic disease (ICAD) is one of the most common causes of ischemic stroke worldwide and is associated with a high risk of recurrent stroke despite aggressive therapy.

Conclusion

With advances in diagnostic testing, including qMRA, it may be possible to better delineate the specific mechanism of stroke from ICAD and identify those patients at higher risk for recurrent ischemia.

Continued concern about parent vessel steno-occlusive progression with Onyx HD-500 and the utility of quantitative magnetic resonance imaging in serial assessment.

Authors

Carlson AP, Alaraj A, Amin-Hanjani S, Charbel FT, Aletich VA.

Presented

Neurosurgery. 2013 Mar;72(3):341-52

Summary

The medical records for 17 patients treated with Onyx HD-500 between 2008 and 2011were retrospectively reviewed.

Conclusion

We observed a higher rate of parent vessel steno-occlusive progression after aneurysm embolization with Onyx HD-500 than reported in the literature, despite overall low morbidity. Quantitative vessel flow imaging was useful in subsequent medical management and decision making to perform therapeutic angioplasty/stenting to preserve flow.

The Effect of Carotid Endarterectomy on Cerebral Blood Flow and Cognitive Function.

Authors

Ghogawala Z, Amin-Hanjani S, Curran J, Ciarleglio M, Berenstein A, Stabile L, Westerveld M.

Presented

J Stroke Cerebrovasc Dis. 2012 May 1. [Epub ahead of print]

Summary

Non-invasive QMRA was used to assess the degree of flow impairment in carotid stenosis patients and to measure the flow improvement after carotid endarterectomy.

Conclusion

Patients with baseline flow impairment are more likely to show improvement in ICA and MCA blood flow after revascularization. Improvement in MCA blood flow was associated with improvement in the attention and executive functioning domains.

Extracranial carotid plaque length and parent vessel diameter significantly affect baseline ipsilateral intracranial blood flow.

Authors

Douglas AF, Christopher S, Amankulor N, Din R, Poullis M, Amin-Hanjani S, Ghogawala Z.

Presented

Neurosurgery. 2011 Oct;69(4):767-73; discussion 773.

Summary

Quantitative MRA is used to estimate parent artery flow compromise in patients with unilateral carotid stenosis.

Conclusion

Both plaque length and vessel diameter were found to be independent predictors of carotid flow compromise, in addition to degree of stenosis.

Endovascular intervention for delayed stenosis of extracranial-intracranial bypass saphenous vein grafts.

Authors

Qahwash O, Alaraj A, Aletich V, Charbel FT, Bulsara KR, Ho W, Valyi-Nagy T, Amin-Hanjani S.

Presented

J NeuroIntervent Surg (2012) doi:10.1136/neurintsurg-2011-010202.

Summary

QMRA is used to measure graft flow following EC-IC bypass.

Conclusion

Non-invasive quantitative phase contrast MR angiography was effective in predicting graft stenosis.

In Vivo Evaluation of Quantitative MR Angiography in a Canine Carotid Artery Stenosis Model

Authors

Calderon-Arnulphi M, Amin-Hanjani A, Alaraj A, Zhao M, Du X, Ruland S, Zhou XJ, Thulborn KR, Charbel FT

Presented

Am J Neuroradiol 32:1552-59. September 2011

Summary

The accuracy of non-invasive QMRA is evaluated by comparison with an invasive, gold standard ultrasonic transit time flowprobe. A vascular tourniquet was applied to the canine carotid artery to produce progressive stenosis and varying flow rates.

Conclusion

Non-invasive QMRA is accurate compared with the gold standard flowprobe in a canine arterial flow model with vessel stenosis. QMRA may be useful in evaluating the hemodynamic effects of stenosis in cerebrovascular atherosclerosis.

Endovascular implantation of covered stents in the extracranial carotid and vertebral arteries: Case series and review of the literature

Authors

Alaraj A, Wallace A, Amin-Hanjani A, Charbel FT, Aletich V

Presented

Surgical Neurology International 2011, 2:67

Summary

QMRA is used pre and post intervention to measure vessel flow

Conclusion

QMRA documents normalization of flow following endovascular placement of a covered stent graft in an extracranial cervical artery.

Clinical utility of quantitative magnetic resonance angiography in the assessment of the underlying pathophysiology in a variety of cerebrovascular disorders

Authors

Brisman JL, Pile-Spellman J, Konstas AA

Presented

Eur J Radiol. 2011 Feb 10. [epub ahead of print]

Summary

The authors review 10 patients before and after their treatments for a range of cerebrovascular diseases.

Conclusion

This study supports incorporation of QMRA into mainstream cerebrovascular practice. The technique is unique in combining anatomic assessment, volumetric flow values and physiologic waveform information in the course of a single MR examination.

Detection of Intracranial In-Stent Restenosis Using Quantitative Magnetic Resonance Angiography

Authors

Sepideh Amin-Hanjani, Ali Alaraj, Mateo Calderon-Arnulphi, Victor A. Aletich, Keith R. Thulborn, and Fady T. Charbel.

Presented

Stroke 2010;41:2534.

Summary

This study examines the value of serial vessel flow measurements using QMRA to detect in-stent restenosis (ISR).

Conclusion

In this preliminary series, a flow decrease on qMRA was highly predictive of angiographic in-stent restenosis. The degree of flow decrement also correlates with symptomatic ISR.

The Utility of Quantitative Magnetic Resonance Angiography in the Assessment of Intracranial In-Stent Stenosis

Authors

Shyam Prabhakaran MD, Lakshmi Warrior MD, Kalani R. Wells RN, Miral D Jhaveri  MD, Michael Chen MD, Demetrius K. Lopes MD

Presented

Stroke. 2009 Jan 22.

Summary

Non-invasive screening for intracranial in-stent stenosis is often limited by artifact. In order to determine the usefulness of NOVA as a screening tool, patients with intracranial stents were reviewed with both qMRA and conventional angiography.

Conclusion

Quantitative MRA is a promising screening tool to detect intracranial in-stent stenosis. Future studies should focus on whether qMRA has a role in the detection of radiographic restenosis and prediction of clinical events.

Comparison of velocity patterns in an AComA aneurysm measured with 2D phase contrast MRI and simulated with CFD

Authors

Karmonik C, Kluznik R, Benndorf G

Presented

Technol Health Care. 2008;16(2):119-28

Summary

Computational Fluid Dynamic (CFD) is increasingly used for modeling hemodynamics in intracranial aneurysms but the need for validation remains. The authors utilized NOVA to measure intra-aneurysmal velocity profiles with 2D pcMRI. CFD simulations of intra-aneurysmal velocity profiles were performed using inflow boundary conditions obtained from 2D pcMRI.

Conclusion

Results indicate the potential for CFD to help understand hemodynamic effects in cerebral aneurysms.  The velocity profiles recorded with pcMRI can serve as reference data for validation of CFD simulations.

Blood flow in cerebral aneurysms: comparison of phase contrast magnetic resonance and computational fluid dynamics - preliminary experience

Authors

Karmonik C, Kluznik R, Benndorf G.

Presented

Rofo. 2008 Mar;180(3):209-15

Summary

This investigation tests the capability of pcMRI guided by NOVA to be used as a non-invasive method to measure intra-aneurysmal blood flow patterns.  Blood flow patterns measured with pcMRI were qualitatively compared to the ones calculated with CFD.

Conclusion

Phase contrast may become a valuable complementary technique to CFD simulations.  

Quantitative Magnetic Resonance Angiography in the Evaluation of the Subclavian Steal Syndrome: Report of 5 Patients

Authors

Andrew M. Bauer MD, Sepideh Amin-Hanjani MD, Ali Alaraj MD, Fady T. Charbel MD

Presented

J Neuroimaging. Sep 20 2008

Summary

Five cases of subclavian steal are analyzed with QMRA, which provides quantitative blood flow data previously unavailable. A quantitative ischemic forearm challenge is also introduced using the QMRA technique.

Conclusion

Quantitative BA flow and basilar flow index obtained from QMRA can be used as an alternative to conventional angiography or Transcranial Doppler in the evaluation of SS. A prospective evaluation of this technique in a larger number of patients will be needed to characterize definitive threshold values for prediction of SSS.

Flow-assisted surgical cerebral revascularization

Authors

William W. Ashley, Jr. MD Ph.D., Sepideh Amin-Hanjani MD, Ali Alaraj MD, John H. Shin MD, Fady T. Charbel MD

Presented

Neurosurg Focus. 2008;24(2):E20.

Summary

Extracranial–intracranial bypass surgery has advanced from a mere technical feat to a procedure requiring careful patient selection and a justifiable decision-making model. This report reviews the use of flow measurement in cerebral revascularization, presenting algorithms for flow-assisted surgical planning, technique and surveillance.

Conclusion

A detailed understanding of flow can improve clinical outcomes by: 1) optimizing diagnosis, patient selection, and surgical planning; 2) improving technical success intraoperatively by providing a quantitative and empiric basis for decision-making, assuring immediate patency and adequate flow; and 3) improving the ability to perform postoperative surveillance of graft patency and hemodynamic improvement.

Wingspan stenting of symptomatic extracranial vertebral artery stenosis and perioperative evaluation using quantitative magnetic resonance angiography: report of two cases

Authors

Jonathan L. Brisman MD

Presented

Neurosurg Focus. 2008;24(2):E14

Summary

The author used quantitative MR angiography to study cerebral blood flow in 2 patients who underwent angioplasty and stenting for medically refractory extracranial cervical vertebral artery (VA) stenosis.

Conclusion

Extracranial cervical VA symptomatic stenosis can be treated with the new WingSpan stent and Gateway balloon system with excellent technical success. Quantitative MR angiography can effectively measure flow in the vertebrobasilar system before and after such revascularization, and such measurements correlate with angiographic findings.

Leptomeningeal Collateral Volume Flow Assessed by Quantitative Magnetic Resonance Angiography in Large-Vessel Cerebrovascular Disease

Authors

Sean Ruland, DO, Aiesha Ahmed, MD, Kurian Thomas, MD, Meide Zhao, PhD, Sepideh Amin-Hanjani, MD, Xinjian Du, MD, Fady T. Charbel, MD

Presented

J Neuroimaging. Apr 15 2008

Summary

Consecutive QMRA studies were retrospectively reviewed with the goal of determining the role of non-Willisian pathways, specifically leptomeningeal collateral flow. Studies selected showed asymmetrically higher ipsilateral PCA flow rate greater than or equal to10 mL/min in the setting of proximal hemodynamic stenosis or occlusion in the ipsilateral MCA or ICA.

Conclusion

Leptomeningeal collateral flow can be assessed with QMRA and may be substantial. The objective of this report is to describe the leptomeningeal collateral volume flow of the posterior cerebral artery (PCA).

Cognitive outcomes after carotid revascularization: the role of cerebral emboli and hypoperfusion

Authors

Zoher Ghogawala MD, Michael Westerveld MD, Sepideh Amin-Hanjani MD

Presented

Neurosurgery. Feb 2008;62(2):385-395; discussion 393-385.

Summary

The effects of carotid revascularization procedures on cognitive outcome are unclear. Understanding the mechanisms that affect cognitive outcomes after carotid revascularization will be important in the design of future comparative studies of CAS and CEA.

Conclusion

As use of CAS increases, it is important for randomized, controlled trials comparing CAS with CEA to include cognitive outcomes assessments. Furthermore, understanding the key mechanisms resulting in cognitive impairment during carotid revascularization procedures might limit injury.

In vivo validation of Quantitative MRA

Authors

Mateo Calderon-Arnulphi MD; Sepideh Amin-Hanjani MD; Ali M. Alaraj MD; Lauren Ostergren; Meide Zhao PhD; Sean Ruland DO; Xinjian MD Du; Fady T. Charbel MD

Presented

2008 International Stroke Conference. New Orleans, LA; 2008.

Summary

Four canines received ultrasonic flow probe implants around the common carotid artery. Blood flow was monitored simultaneously using both QMRA and the probe to provide statistical comparisons using Pearson product-moment correlation coefficient.

Conclusion

High correlation was shown. In vivo validation of accuracy enhances the value of QMRA as a non-invasive volumetric flow measurement.

Regional Cerebral Blood Flow Using Quantitative MR Angiography

Authors

M. Zhao, S. Amin-Hanjani, S. Ruland, A.P. Curcio, L. Ostergren, and F.T. Charbel

Presented

American Journal of Neuroradiology28:1470-1473, September 2007

Summary

The cerebral arterial network was partitioned into 12 different regions.  Regional cerebral flow was calculated from the measured flows in individual arteries of the head and neck as obtained with qMRA.

Conclusion

Regional CBF can be calculated using qMRA.  The relative distribution of blood flow to the sub-regions could provide useful information in the hemodynamic evaluation of patients with cerebrovascular disease.

Evaluation of extracranial–intracranial bypass using quantitative magnetic resonance angiography

Authors

Sepideh Amin-Hanjani, M.D., John H. Shin, M.D., Meide Zhao, Ph.D., Xinjian Du, M.D., and Fady T. Charbel, M.D.

Presented

J Neurosurg 106:291–298, 2007

Summary

The goal of this study was to assess bypass function and patency using qMRA and to address whether this modality may be an adequate replacement for standard catheter angiography in serial follow up of bypass grafts.

Conclusion

Bypass grafts can be assessed in a noninvasive fashion by using quantitative MR angiography.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Estimation of Total Cerebral Blood Flow using Cine Phase Contrast MR angiography.

Authors

Charbel F.T., Al Shatoury H., Zhao M., Du X.J.

Presented

Surg. Neurol., 2000 (in press)

A patient-specific computer model for prediction of clinical outcomes in the cerebral circulation using MR flow measurements.

Authors

Clark M.E., Zhao M., Loth F., Alperin N., Sadler L., Guppy K., Charbel F.T.

Presented

MICCAI. Cambridge, England; 1999.

Verification of accuracy for a patient-specific mathematical model in predicting cerebral blood flow.

Authors

Charbel F.T., Zhao M., Guppy K.H., Clark M.E., Loth F., Alperin N., Sadler L., Ausman J.I., Aletich V, Debrun G.

Presented

Congress of Neurological Surgeons 49th Annual Meeting. Boston, Massachusetts; October 30-November 4, 1999.

The use of the peripheral gating cine phase contrast MRI in the evaluation of the CBF in patients with balloon occlusion of the ICA.

Authors

Charbel F.T., Zhao M., Gonzales-Portillo G., Aletich V., Du X., Alperin N., Jacobson B., Debrun G.M., Ausman J.I.

Presented

67th Annual Meeting of the American Association of Neurological Surgeons. New Orleans, Louisiana; April 24-29, 1999.

The role of cine phase-contrast MR and computerized modeling in the diagnosis and choices of therapy for complex cerebrovascular disorders.

Authors

Charbel F.T., Zhao M., Clark M.E., Gonzales-Portillo G., Du X., Ausman J.I.

Presented

Joint Meeting of the Section on Cerebrovascular Surgery/American Society of Interventional and Therapeutic Neuroradiology. Nashville, Tennessee; January 31-February 3, 1999.

"Neurovascular Flow Simulation Review",

Authors

Charbel F.T., Shi J., Quek F., Zhao M., Nabhani T.,

Presented

Neurological Research 1998; 20:107-115

"Imagery Reconstruction and Robot Technology in Vascular Surgery",

Authors

Charbel F.T., Misra M., Zhao M., Nabhani T.,

Presented

in: Current Techniques in Neurosurgery, Salcman M. (Ed.). Current Science Inc., Philadelphia 1998; 3rd Edition: 153-162.

Computer-aided neurovascular simulation and phase-contrast MRI in the management of ischemic cerebrovascular diseases.

Authors

Charbel F.T., Zhao M., Gonzales-Portillo G., Ausman J.I.

Presented

60th Annual Meeting of the American Academy of Neurological Surgery (Santa Barbara, California), November 1998.

3D cerebral vessel reconstruction from magnetic resonance angiography using mathematical morphology and active contour.

Authors

Charbel F.T., Zhao M.

Presented

48th Annual Meeting of the Congress of Neurological Surgeons (Seattle, Washington), October 1998.

3D pulsatile flow patterns from cine phase contrast MR angiography in carotid artery diseases.

Authors

Charbel F.T., Zhao M., Quek F., Nabhani T., Hoffman W.E.

Presented

66th Annual Meeting of the American Association of Neurological Surgeons (Philadelphia, Pennsylvania), April 1998.

Computer Simulation of Cerebral Blood Flow in Moya-Moya and the Results of Surgical Therapies.

Authors

Charbel F.T., Misra M., W.E. Clarke and J. I. Ausman.

Presented

Journal of Clinical Neurology and Neurosurgery 1997, 99:563-573.