PUBLICATIONS
| Title | 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. |
| Title | 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. |
| Title | 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. |
| Title | 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). |
| Title | 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. |
| Title | 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. |
| Title | 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 DOI 10.3174/ajnr.A0582 |
| 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.
Unlike individual vessel flows, which are subject to wide variability based on anatomic variations in the Circle of Willis, regional flows may provide a more reliable measure of hemodynamic status. |
| 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. |
| Title | 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. This
imaging modality provides not only information regarding patency as shown by conventional angiography, but also a
quantitative assessment of bypass function. In this study, a low or rapidly decreasing flow was indicative of a shrunken or stenotic graft. Quantitative MR angiography may provide an alternative to standard angiography for serial follow up of bypass grafts. |