http://hdl.handle.net/10027/7119 Wed, 19 Jun 2013 22:06:33 GMT 2013-06-19T22:06:33Z http://dspace-prod-lib.cc.uic.edu:80/bitstream/id/24416/CMRR.png http://hdl.handle.net/10027/7119 http://hdl.handle.net/10027/7783 Detection of Intracranial In-Stent Restenosis Using Quantitative Magnetic Resonance Angiography Amin-Hanjani, Sepideh; Alaraj, Ali; Calderon-Arnulphi, Mateo; Aletich, Victor A.; Thulborn, Keith R.; Charbel, Fady T. BACKGROUND AND PURPOSE: In-stent restenosis (ISR) after angioplasty/stenting for intracranial stenosis has been reported in up to 25% to 30% of patients. Detection and monitoring of ISR relies primarily on serial catheter angiography, because noninvasive imaging methods are typically hampered by stent-related artifact. We examined the value of serial vessel flow measurements using quantitative magnetic resonance angiography (QMRA) in detection of ISR. Material and METHODS: Records of patients undergoing stenting for intracranial symptomatic stenosis >50% between 2005 and 2009 were retrospectively reviewed. Angiographic images were graded by a blinded neurointerventionalist for stenosis pretreatment, immediately after treatment, and during follow-up. Flow in the affected vessel measured by QMRA was recorded; > 25% reduction in flow was considered indicative of an adverse change. Clinical data regarding neurological outcome were also collected. RESULTS: Twenty-eight patients underwent stenting during the time interval studied. Of these, 12 patients (mean age, 55.5 years; 8 female) had contemporaneous angiography and QMRA and were analyzed. Median follow-up was 9 months. Six patients (50%) demonstrated angiographic restenosis 2 to 12 months after treatment; all had an analogous decrease in flow in the vessel of interest. Of 3 patients with more severe flow decrement (> 50%), 2 experienced stroke. None of the patients without angiographic ISR demonstrated a flow decrease on QMRA. CONCLUSIONS: In this preliminary series, flow decrease on QMRA is highly predictive of angiographic ISR. Additionally, the degree of flow decrement correlates with symptomatic ISR. QMRA may provide a useful noninvasive tool for serial monitoring after intracranial stenting. The original version of this publication is available through the American Heart Association (www.ahajournals.org) at DOI: 10.1161/STROKEAHA.110.594739. Fri, 01 Oct 2010 05:00:00 GMT http://hdl.handle.net/10027/7783 2010-10-01T05:00:00Z http://hdl.handle.net/10027/7232 Safety of human MRI at static fields above the FDA 8T guideline: Sodium imaging at 9.4T does not affect vital signs or cognitive ability. Atkinson, Ian C.; Renteria, Laura; Burd, Holly; Pliskin, Neil H.; Thulborn, Keith R. Purpose: To assess whether exposure to a 9.4T static magnetic field during sodium imaging at 105.92 MHz affects human vital signs and cognitive function. Materials and Methods: Measurements of human vital signs and cognitive ability made before and after exposure to a 9.4T MR scanner and a mock scanner with no magnetic field are compared using a protocol approved by the United States Food and Drug Administration. Results: Exposure to a 9.4T static magnetic field during sodium imaging did not result in a statistically significant change in the vital signs or cognitive ability of healthy normal volunteers. Conclusion: Vital sign and cognitive ability measurements made before and after sodium imaging at 9.4T suggest that performing human MRI at 105.92 MHz in a 9.4T static magnetic field does not pose a health risk. Postprint version of article may differ from published version. The definitive version is available at DOI: 10.1002/jmri.21150 Thu, 01 Nov 2007 05:00:00 GMT http://hdl.handle.net/10027/7232 2007-11-01T05:00:00Z http://hdl.handle.net/10027/7189 Vital signs and cognitive function are not affected by 23-sodium and 17-oxygen magnetic resonance imaging of the human brain at 9.4 Telsa. Atkinson, I.C.; Sonstegaard, R.; Pliskin, N.H.; Thulbor, K.R. PURPOSE: To evaluate the effect of 23-sodium ((23)Na) and 17-oxygen ((17)O) magnetic resonance imaging (MRI) at 9.4 (T) on vital signs and cognitive function of the human brain. MATERIALS AND METHODS: Vital sign and cognitive function measurements from healthy volunteers (N = 14) positioned outside and at isocenter of a 9.4 T scanner before and after (23)Na and (17)O MRI were compared for changes due to exposure to the static magnetic field and to the gradient switching and radiofrequency radiation during MRI. RESULTS: Exposure to the 9.4 T static magnetic field and (23)Na and (17)O MRI at 105.92 MHz and 54.25 MHz, respectively, did not have a statistically significant (P > 0.05) effect on the vital signs or cognitive function of healthy normal adults. CONCLUSION: (23)Na and (17)O MRI of the human brain at 9.4 T does not have any readily demonstrated health risks reflected in vital signs or change in cognitive performance. The definitive version is available at www3.interscience.wiley.com. Postprint version of article may differ from published version. http://onlinelibrary.wiley.com/doi/10.1002/jmri.22221/abstract Thu, 01 Jul 2010 05:00:00 GMT http://hdl.handle.net/10027/7189 2010-07-01T05:00:00Z