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Dissaux B, Eugène F, Ognard J, Gauvrit JY, Gentric JC, Ferré JC. Assessment of 4D MR Angiography at 3T Compared with DSA for the Follow-up of Embolized Brain Dural Arteriovenous Fistula: A Dual-Center Study. AJNR Am J Neuroradiol 2020; 42:340-346. [PMID: 33334853 DOI: 10.3174/ajnr.a6903] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 09/27/2020] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE 4D contrast-enhanced MRA in the follow-up of treated dural arteriovenous fistulas has rarely been evaluated. Our aim was to evaluate its diagnostic performance at 3T in the follow-up of embolized dural arteriovenous fistulas using DSA as the standard of reference. MATERIALS AND METHODS Patients treated for dural arteriovenous fistulas in 2 centers between 2008 and 2019 were included if they met the following criteria: 1) dural arteriovenous fistula embolization, and 2) follow-up imaging with <6 months between DSA and 4D contrast-enhanced MRA. Two readers reviewed the 4D contrast-enhanced MRA images, first independently, then in consensus to detect any residual/recurrent dural arteriovenous fistula and to grade cases according to the Cognard classification system. Interobserver and intermodality agreement for the detection of a residual dural arteriovenous fistula and stratification of bleeding risk (0-I-IIa; IIb-IIa+b-III-IV-V) was calculated using κ coefficients. RESULTS A total of 51 pairs of examinations for 44 patients (median age, 65 years; range, 25-81 years) were analyzed. Interobserver agreement for the detection and stratification of bleeding risk was, respectively, κ = 0.8 (95% CI, 0.6-1) and κ = 0.8 (95% CI, 0.5-1). After consensus review, the sensitivity and specificity of 4D contrast-enhanced MRA for the detection of residual/recurrent dural arteriovenous fistula was 63.6% (95% CI, 40.7%-82.8%) and 96.6% (95% CI, 82.2%-99.9%), respectively. The positive and negative predictive values of 4D contrast-enhanced MRA were 93.3% (95% CI, 68.1%-99.8%) and 77.8% (95% CI, 60.8%-89.9%). Intermodality agreement for the detection and stratification of bleeding risk was good, with κ = 0.60 (95% CI, 0.3-0.8). CONCLUSIONS 4D contrast-enhanced MRA at 3T is of interest in the follow-up of treated dural arteriovenous fistulas but lacks the sensitivity to replace arteriography.
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Affiliation(s)
- B Dissaux
- From the Department of Neuroradiology (B.D., F.E., J.-Y.G., J.-C.F.), Centre Hospitalier Universitaire Rennes, Rennes, France .,Department of Medical Imaging (B.D., J.O., J.-C.G.), Centre Hospitalier Universitaire La Cavale Blanche, Brest, France.,GETBO group EA3878 (B.D., J.-C.G.), Université de Bretagne Occidentale, Brest, France
| | - F Eugène
- From the Department of Neuroradiology (B.D., F.E., J.-Y.G., J.-C.F.), Centre Hospitalier Universitaire Rennes, Rennes, France
| | - J Ognard
- Department of Medical Imaging (B.D., J.O., J.-C.G.), Centre Hospitalier Universitaire La Cavale Blanche, Brest, France.,LATIM U1101 (J.O.), INSERM, Université de Bretagne Occidentale, Brest, France
| | - J-Y Gauvrit
- From the Department of Neuroradiology (B.D., F.E., J.-Y.G., J.-C.F.), Centre Hospitalier Universitaire Rennes, Rennes, France.,Empenn Unit U1228 (J.-Y.G., J.-C.F.), INSERM, INRIA, Université Rennes 1, Rennes, France
| | - J-C Gentric
- Department of Medical Imaging (B.D., J.O., J.-C.G.), Centre Hospitalier Universitaire La Cavale Blanche, Brest, France.,GETBO group EA3878 (B.D., J.-C.G.), Université de Bretagne Occidentale, Brest, France
| | - J-C Ferré
- From the Department of Neuroradiology (B.D., F.E., J.-Y.G., J.-C.F.), Centre Hospitalier Universitaire Rennes, Rennes, France.,Empenn Unit U1228 (J.-Y.G., J.-C.F.), INSERM, INRIA, Université Rennes 1, Rennes, France
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Time-of-Arrival Parametric Maps and Virtual Bolus Images Derived From Contrast-Enhanced Time-Resolved Radial Magnetic Resonance Angiography Improve the Display of Brain Arteriovenous Malformation Vascular Anatomy. Invest Radiol 2017; 51:706-713. [PMID: 27760058 DOI: 10.1097/rli.0000000000000288] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Time-of-arrival (TOA) maps can be derived from high-resolution 4-dimensional (4D) contrast-enhanced magnetic resonance angiography (MRA) data sets to provide a quantitative description of contrast material arrival time in each voxel. This information can further be processed to create a compressed time evolution curve that virtually shortens the contrast bolus (virtual bolus [VB]). The purpose of this project was to determine whether TOA-enhanced 4D MRA and/or VB imaging improve the display of contrast kinetics in patients with vascular disease. METHODS High-resolution whole-brain contrast-enhanced 4D MRA examinations with 1.2-second temporal reconstruction were acquired by using radial acquisition and highly constrained projection reconstruction (radial 4D contrast-enhanced HYPRFlow, abbreviated as HFMRA in this article) in 10 patients (8 patients with arteriovenous malformations [AVM], 1 patient with an arteriovenous fistula, and 1 patient with a high-grade intracranial stenosis). The TOA for each voxel was defined as the time point when the signal intensity reached 20% of its maximum. In the first method, TOA maps were generated, color-encoded, and then multiplied with the time-resolved contrast-enhanced MRA images at each time frame to form new 4D MRA images (TOA-enhanced HFMRA), which contains the contrast arrival times with defined color encoding. In the second method, each time frame was weighted by a Gaussian distribution in the time domain to form a virtual 4D bolus map. This 4D bolus map was then color-coded and multiplied with the HFMRA images to form a digital subtraction angiography (DSA)-like VB, where at each time frame, only vessels with certain TOA values within the defined bolus length appear. HFMRA, TOA maps, and VB images were scored qualitatively with regard to delineation of arteries, veins, and nidus, as well as artifacts. Furthermore, diagnostic confidence and arteriovenous overlap were evaluated and compared between techniques. A comparison with DSA was performed where DSA served as the reference standard in terms of number of arterial feeders, draining veins, and Spetzler-Martin score of AVMs. In addition, TOA maps were evaluated quantitatively. RESULTS Overall, diagnostic confidence score of TOA was significantly higher compared with that of HFMRA (P = 0.03). Virtual bolus showed significantly higher scores for overall diagnostic confidence (P = 0.02) and reduced arteriovenous overlap (0.01) compared with HFMRA. Furthermore, VB-reduced arteriovenous overlap scores were significantly higher compared with TOA (P = 0.04). Agreement regarding AVM draining veins was lower between DSA and HFMRA (κ = 0.3) compared with TOA and VB (κ = 0.56). Agreement regarding Spetzler-Martin score was lower between DSA and HFMRA (κ = 0.56) compared with TOA and VB (κ = 0.74). CONCLUSIONS TOA-enhanced HFMRA provides serial images and time of arrival maps in one inclusive display. In this study, TOA mapping combined with Virtual Bolus imaging improved diagnostic confidence in AVM patients and facilitated arteriovenous separation. The VB method further reduced overlap of arterial and venous structures.
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Bak SH, Roh HG, Moon WJ, Choi JW, An HS. Appropriate Minimal Dose of Gadobutrol for 3D Time-Resolved MRA of the Supra-Aortic Arteries: Comparison with Conventional Single-Phase High-Resolution 3D Contrast-Enhanced MRA. AJNR Am J Neuroradiol 2017; 38:1383-1390. [PMID: 28473338 DOI: 10.3174/ajnr.a5176] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 02/13/2017] [Indexed: 01/25/2023]
Abstract
BACKGROUND AND PURPOSE The development of nephrogenic systemic fibrosis and neural tissue deposition is gadolinium dose-dependent. The purpose of this study was to determine the appropriate minimal dose of gadobutrol with time-resolved MRA to assess supra-aortic arterial stenosis with contrast-enhanced MRA as a reference standard. MATERIALS AND METHODS Four hundred sixty-two consecutive patients underwent both standard-dose contrast-enhanced MRA and low-dose time-resolved MRA and were classified into 3 groups; group A (a constant dose of 1 mL for time-resolved MRA), group B (2 mL), or group C (3 mL). All studies were independently evaluated by 2 radiologists for image quality by using a 5-point scale (from 0 = failure to 4 = excellent), grading of arterial stenosis (0 = normal, 1 = mild [<30%], 2 = moderate [30%-69%], 3 = severe to occlusion [≥70%]), and signal-to-noise ratio. RESULTS The image quality of time-resolved MRA was similar to that of contrast-enhanced MRA in groups B and C, but it was inferior to contrast-enhanced MRA in group A. For the grading of arterial stenosis, there was an excellent correlation between contrast-enhanced MRA and time-resolved MRA (R = 0.957 for group A, R = 0.988 for group B, R = 0.991 for group C). The SNR of time-resolved MRA tended to be lower than that of contrast-enhanced MRA in groups A and B. However, SNR was higher for time-resolved MRA compared with contrast-enhanced MRA in group C. CONCLUSIONS Low-dose time-resolved MRA is feasible in the evaluation of supra-aortic stenosis and could be used as an alternative to contrast-enhanced MRA for a diagnostic technique in high-risk populations.
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Affiliation(s)
- S H Bak
- From the Department of Radiology (S.H.B., H.G.R., W.-J.M., J.W.C.), Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea.,Department of Radiology (S.H.B.), Kangwon National University Hospital, Chuncheon, Korea
| | - H G Roh
- From the Department of Radiology (S.H.B., H.G.R., W.-J.M., J.W.C.), Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea
| | - W-J Moon
- From the Department of Radiology (S.H.B., H.G.R., W.-J.M., J.W.C.), Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea
| | - J W Choi
- From the Department of Radiology (S.H.B., H.G.R., W.-J.M., J.W.C.), Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea
| | - H S An
- Department of Radiology (H.S.A.), Armed Forces Yangju Hospital, Yangju, Korea
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Interest of HYPR flow dynamic MRA for characterization of cerebral arteriovenous malformations: comparison with TRICKS MRA and catheter DSA. Eur Radiol 2015; 25:3230-7. [DOI: 10.1007/s00330-015-3745-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Revised: 03/04/2015] [Accepted: 03/26/2015] [Indexed: 10/23/2022]
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Le Bras A, Raoult H, Ferré JC, Ronzière T, Gauvrit JY. Optimal MRI sequence for identifying occlusion location in acute stroke: which value of time-resolved contrast-enhanced MRA? AJNR Am J Neuroradiol 2015; 36:1081-8. [PMID: 25767186 DOI: 10.3174/ajnr.a4264] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 12/21/2014] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Identifying occlusion location is crucial for determining the optimal therapeutic strategy during the acute phase of ischemic stroke. The purpose of this study was to assess the diagnostic efficacy of MR imaging, including conventional sequences plus time-resolved contrast-enhanced MRA in comparison with DSA for identifying arterial occlusion location. MATERIALS AND METHODS Thirty-two patients with 34 occlusion levels referred for thrombectomy during acute cerebral stroke events were consecutively included from August 2010 to December 2012. Before thrombectomy, we performed 3T MR imaging, including conventional 3D-TOF and gradient-echo T2 sequences, along with time-resolved contrast-enhanced MRA of the extra- and intracranial arteries. The 3D-TOF, gradient-echo T2, and time-resolved contrast-enhanced MRA results were consensually assessed by 2 neuroradiologists and compared with prethrombectomy DSA results in terms of occlusion location. The Wilcoxon test was used for statistical analysis to compare MR imaging sequences with DSA, and the κ coefficient was used to determine intermodality agreement. RESULTS The occlusion level on the 3D-TOF and gradient-echo T2 images differed significantly from that of DSA (P < .001 and P = .002, respectively), while no significant difference was observed between DSA and time-resolved contrast-enhanced MRA (P = .125). κ coefficients for intermodality agreement with DSA (95% CI, percentage agreement) were 0.43 (0.3%-0.6; 62%), 0.32 (0.2%-0.5; 56%), and 0.81 (0.6%-1.0; 88%) for 3D-TOF, gradient-echo T2, and time-resolved contrast-enhanced MRA, respectively. CONCLUSIONS The time-resolved contrast-enhanced MRA sequence proved reliable for identifying occlusion location in acute stroke with performance superior to that of 3D-TOF and gradient-echo T2 sequences.
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Affiliation(s)
- A Le Bras
- From the Departments of Neuroradiology (A.L.B., H.R., J.-C.F., J.-Y.G.)
| | - H Raoult
- From the Departments of Neuroradiology (A.L.B., H.R., J.-C.F., J.-Y.G.) Unité VISAGE U746 INSERM-INRIA, IRISA UMR CNRS 6074 (H.R., J.-C.F., J.-Y.G.), University of Rennes, Rennes, France
| | - J-C Ferré
- From the Departments of Neuroradiology (A.L.B., H.R., J.-C.F., J.-Y.G.) Unité VISAGE U746 INSERM-INRIA, IRISA UMR CNRS 6074 (H.R., J.-C.F., J.-Y.G.), University of Rennes, Rennes, France
| | - T Ronzière
- Neurology (T.R.), Centre Hospitalier Universitaire Rennes, Rennes, France
| | - J-Y Gauvrit
- From the Departments of Neuroradiology (A.L.B., H.R., J.-C.F., J.-Y.G.) Unité VISAGE U746 INSERM-INRIA, IRISA UMR CNRS 6074 (H.R., J.-C.F., J.-Y.G.), University of Rennes, Rennes, France
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Wu C, Ansari SA, Honarmand AR, Vakil P, Hurley MC, Bendok BR, Carr J, Carroll TJ, Markl M. Evaluation of 4D vascular flow and tissue perfusion in cerebral arteriovenous malformations: influence of Spetzler-Martin grade, clinical presentation, and AVM risk factors. AJNR Am J Neuroradiol 2015; 36:1142-9. [PMID: 25721076 DOI: 10.3174/ajnr.a4259] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 12/11/2014] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The role of intracranial hemodynamics in the pathophysiology and risk stratification of brain AVMs remains poorly understood. The purpose of this study was to assess the influence of Spetzler-Martin grade, clinical history, and risk factors on vascular flow and tissue perfusion in cerebral AVMs. MATERIALS AND METHODS 4D flow and perfusion MR imaging was performed in 17 patients with AVMs. Peak velocity and blood flow were quantified in AVM feeding and contralateral arteries, draining veins, and the straight sinus. Regional perfusion ratios (CBF, CBV, and MTT) were calculated between affected and nonaffected hemispheres. RESULTS Regarding flow parameters, high-grade AVMs (Spetzler-Martin grade of >2) demonstrated significantly increased peak velocity and blood flow in the major feeding arteries (P < .001 and P = .004) and straight sinus (P = .003 and P = .012) and increased venous draining flow (P = .001). The Spetzler-Martin grade significantly correlated with cumulative feeding artery flow (r = 0.85, P < .001) and draining vein flow (r = 0.80, P < .001). Regarding perfusion parameters, perinidal CBF and CBV ratios were significantly lower (P < .001) compared with the remote ratios and correlated negatively with cumulative feeding artery flow (r = -0.60, P = .014 and r = -0.55, P = .026) and draining vein flow (r = -0.60, P = .013 and r = -0.56, P = .025). Multiple regression analysis revealed no significant association of AVM flow or perfusion parameters with clinical presentation (rupture and seizure history) and AVM risk factors. CONCLUSIONS Macrovascular flow was significantly associated with increasing Spetzler-Martin grade and correlated with perinidal microvascular perfusion in cerebral AVMs. Future longitudinal studies are needed to evaluate the potential of comprehensive cerebral flow and perfusion MR imaging for AVM risk stratification.
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Affiliation(s)
- C Wu
- From the Department of Biomedical Engineering (C.W., T.J.C., M.M.), McCormick School of Engineering, Northwestern University, Evanston, Illinois Departments of Radiology (C.W., S.A.A., A.R.H., P.V., M.C.H., B.R.B., J.C., T.J.C., M.M.)
| | - S A Ansari
- Departments of Radiology (C.W., S.A.A., A.R.H., P.V., M.C.H., B.R.B., J.C., T.J.C., M.M.) Neurological Surgery (S.A.A., M.C.H., B.R.B.) Neurology (S.A.A.)
| | - A R Honarmand
- Departments of Radiology (C.W., S.A.A., A.R.H., P.V., M.C.H., B.R.B., J.C., T.J.C., M.M.)
| | - P Vakil
- Departments of Radiology (C.W., S.A.A., A.R.H., P.V., M.C.H., B.R.B., J.C., T.J.C., M.M.)
| | - M C Hurley
- Departments of Radiology (C.W., S.A.A., A.R.H., P.V., M.C.H., B.R.B., J.C., T.J.C., M.M.) Neurological Surgery (S.A.A., M.C.H., B.R.B.)
| | - B R Bendok
- Departments of Radiology (C.W., S.A.A., A.R.H., P.V., M.C.H., B.R.B., J.C., T.J.C., M.M.) Neurological Surgery (S.A.A., M.C.H., B.R.B.) Otolaryngology (B.R.B.), Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - J Carr
- Departments of Radiology (C.W., S.A.A., A.R.H., P.V., M.C.H., B.R.B., J.C., T.J.C., M.M.)
| | - T J Carroll
- From the Department of Biomedical Engineering (C.W., T.J.C., M.M.), McCormick School of Engineering, Northwestern University, Evanston, Illinois Departments of Radiology (C.W., S.A.A., A.R.H., P.V., M.C.H., B.R.B., J.C., T.J.C., M.M.)
| | - M Markl
- From the Department of Biomedical Engineering (C.W., T.J.C., M.M.), McCormick School of Engineering, Northwestern University, Evanston, Illinois Departments of Radiology (C.W., S.A.A., A.R.H., P.V., M.C.H., B.R.B., J.C., T.J.C., M.M.)
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Park MG, Choi JH, Yang TI, Oh SJ, Baik SK, Park KP. Spontaneous isolated posterior inferior cerebellar artery dissection: rare but underdiagnosed cause of ischemic stroke. J Stroke Cerebrovasc Dis 2014; 23:1865-70. [PMID: 24809669 DOI: 10.1016/j.jstrokecerebrovasdis.2014.02.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 02/19/2014] [Accepted: 02/26/2014] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Spontaneous isolated posterior inferior cerebellar artery dissection (PICAD) is a very rare cause of ischemic stroke. Clinical and radiologic features of ischemic type of isolated spontaneous PICAD are not well established. METHODS We consecutively enrolled patients who had spontaneous isolated PICAD confirmed by digital subtraction cerebral angiography. Clinical manifestation, magnetic resonance imaging (MRI), and angiography were analyzed. RESULTS Seven patients were diagnosed as ischemic type of spontaneous isolated PICAD. Patients experienced an occipital headache, followed by vertigo, postural imbalance, or Wallenberg syndrome. Six showed medullar, unilateral, or bilateral cerebellar infarctions on diffusion-weighted imaging (DWI). One presented with transient cerebellar ischemia and negative on DWI. T1-weighted imaging showed high signal intensity in posterior inferior cerebellar artery in only 1 patient. Susceptibility-weighted imaging (SWI) revealed hypointense signal with blooming effect in posterior inferior cerebellar artery in 5 patients. The modified Rankin Scale score at 3 months was 0 or 1 in all patients. CONCLUSIONS Clinical manifestations in ischemic type of spontaneous isolated PICAD were similar to those of intracranial vertebral artery dissection. Clinical course was relatively stable and benign. SWI was more helpful to suspect abnormality of posterior inferior cerebellar artery than conventional MRI or magnetic resonance angiography in our small series. Cerebral angiography is recommended in patients with clinically suspected spontaneous isolated PICAD for definite diagnosis.
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Affiliation(s)
- Min-Gyu Park
- Department of Neurology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan, Republic of Korea
| | - Jae-Hwan Choi
- Department of Neurology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan, Republic of Korea
| | - Tae-Il Yang
- Department of Neurology, Dong-Eui Medical Center, Busan, Republic of Korea
| | - Se-Jin Oh
- Department of Neurology, Pohang Stroke and Spine Hospital, Pohang, Republic of Korea
| | - Seung Kug Baik
- Department of Radiology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan, Republic of Korea
| | - Kyung-Pil Park
- Department of Neurology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan, Republic of Korea.
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Raoult H, Bannier E, Robert B, Barillot C, Schmitt P, Gauvrit JY. Time-resolved Spin-labeled MR Angiography for the Depiction of Cerebral Arteriovenous Malformations: A Comparison of Techniques. Radiology 2014; 271:524-33. [DOI: 10.1148/radiol.13131252] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Ferré JC, Raoult H, Breil S, Carsin-Nicol B, Ronzière T, Gauvrit JY. Supra-aortic arteries: three-dimensional time-resolved k-t BLAST contrast-enhanced MRA using a nondedicated body coil at 3 tesla in acute ischemic stroke. J Magn Reson Imaging 2013; 40:1056-63. [PMID: 24222649 DOI: 10.1002/jmri.24466] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 09/14/2013] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To assess the image quality and diagnostic performance achieved by using supra-aortic 3D-TR-CE-k-t BLAST MRA and a nondedicated body coil as compared with conventional CE-MRA in patients with acute ischemic stroke. MATERIALS AND METHODS In this prospective study, 36 consecutive patients with a suspected acute ischemic stroke underwent both k-t BLAST MRA and conventional CE-MRA. Image quality was assessed using visual and quantitative criteria and the techniques were compared. Both techniques were compared for degree of visual and quantitative measurement of carotid stenosis. RESULTS Delineation of vessel lumen and overall diagnostic confidence were significantly better with CE-MRA, respectively 3.4 ± 0.5 and 3.3 ± 0.6 (mean score ± SD), than with k-t BLAST MRA, respectively 2.8 ± 0.4 and 2.9 ± 0.5 (P < 0.02). SNR and CNR were significantly higher for k-t BLAST MRA, respectively 33.5 ± 19.3 and 27.9 ± 19.3, than for CE-MRA, respectively 25.7 ± 10 and 20.4 ± 8.4 (P < 0.03). Intertechnique agreement was good for carotid stenosis characterization (κ = .763). For the 14 relevant stenosis, stenosis measurements were highly correlated between techniques (0.96; P < 0.0001). The Bland-Altman plot showed a low bias in assessment of the degree of stenosis (mean bias 2.1% ± 7.7). CONCLUSION k-t BLAST MRA using a nondedicated coil offering and dynamic information was a effective diagnostic tool for detection and characterization of carotid stenosis.
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Affiliation(s)
- Jean-Christophe Ferré
- CHU Rennes, Department of Neuroradiology, University Hospital of Rennes, Rennes, France
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Ract I, Ferré JC, Ronzière T, Leray E, Carsin-Nicol B, Gauvrit JY. Improving detection of ischemic lesions at 3 Tesla with optimized diffusion-weighted magnetic resonance imaging. J Neuroradiol 2013; 41:45-51. [PMID: 23764260 DOI: 10.1016/j.neurad.2013.04.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 04/08/2013] [Accepted: 04/14/2013] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE This study compared three different combinations of DWI parameters: three and six diffusion imaging directions (3dir and 6dir, respectively) using b=1000 or 2000 s/mm(2) (b1000 or b2000, respectively) to improve detection of recent ischemic lesions at 3 Tesla (3 T). MATERIALS AND METHODS A total of 47 consecutive patients underwent three DWI scans: 3dir b1000; 6dir b1000; and 6dir b2000. Qualitative visual analysis was performed by three readers based on evaluation of the number of lesions, presence of artifacts and diagnostic confidence. Interobserver agreement, sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS Forty-five lesions were detected by 3dir b1000, 52 by 6dir b1000 and 56 by 6dir b2000 in 30 patients. The additional lesions identified by 6dir b2000 were either small or located in the posterior fossa. Sensitivity with 6dir b2000 was significantly higher than with 3dir b1000 (98.1% vs 77.4%; P<0.05). CONCLUSION At 3 T, 6dir b2000 DWI detected more acute ischemic lesions than 3dir b1000, particularly small lesions and those located in the brain stem.
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Affiliation(s)
- Isabelle Ract
- CHU Rennes, Department of Neuroradiology, hôpital Pontchaillou, 2, rue Henri-Le-Guilloux, 35000 Rennes, France
| | - Jean-Christophe Ferré
- CHU Rennes, Department of Neuroradiology, hôpital Pontchaillou, 2, rue Henri-Le-Guilloux, 35000 Rennes, France.
| | - Thomas Ronzière
- CHU Rennes, Department of Neurology, hôpital Pontchaillou, 2, rue Henri-Le-Guilloux, 35000 Rennes, France
| | - Emmanuelle Leray
- École des Hautes Études en Santé Publique, Department of Epidemiology, avenue du Professeur-Léon-Bernard, 35043 Rennes, France
| | - Béatrice Carsin-Nicol
- CHU Rennes, Department of Neuroradiology, hôpital Pontchaillou, 2, rue Henri-Le-Guilloux, 35000 Rennes, France
| | - Jean-Yves Gauvrit
- CHU Rennes, Department of Neuroradiology, hôpital Pontchaillou, 2, rue Henri-Le-Guilloux, 35000 Rennes, France
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Machet A, Portefaix C, Kadziolka K, Robin G, Lanoix O, Pierot L. Brain arteriovenous malformation diagnosis: value of time-resolved contrast-enhanced MR angiography at 3.0T compared to DSA. Neuroradiology 2012; 54:1099-108. [DOI: 10.1007/s00234-012-1024-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 02/24/2012] [Indexed: 10/28/2022]
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Wu Y, Johnson K, Kecskemeti SR, Wang K, Wieben O, Aagaard-Kienitz BL, Rowley H, Korosec FR, Mistretta C, Turski P. Time resolved contrast enhanced intracranial MRA using a single dose delivered as sequential injections and highly constrained projection reconstruction (HYPR CE). Magn Reson Med 2011; 65:956-63. [PMID: 21413059 DOI: 10.1002/mrm.22792] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Revised: 11/19/2010] [Accepted: 12/02/2010] [Indexed: 11/09/2022]
Abstract
Time-resolved contrast-enhanced magnetic resonance angiography of the brain is challenging due to the need for rapid imaging and high spatial resolution. Moreover, the significant dispersion of the intravenous contrast bolus as it passes through the heart and lungs increases the overlap between arterial and venous structures, regardless of the acquisition speed and reconstruction window. An innovative technique is presented that divides a single dose contrast into two injections. Initially a small volume of contrast material (2-3 mL) is used to acquiring time-resolved weighting images with a high frame rate (2 frames/s) during the first pass of the contrast agent. The remaining contrast material is used to obtain a high resolution whole brain contrast-enhanced (CE) magnetic resonance angiography (0.57 × 0.57 × 1 mm(3) ) that is used as the spatial constraint for Local Highly Constrained Projection Reconstruction (HYPR LR) reconstruction. After HYPR reconstruction, the final dynamic images (HYPR CE) have both high temporal and spatial resolution. Furthermore, studies of contrast kinetics demonstrate that the shorter bolus length from the reduced contrast volume used for the first injection significantly improves the arterial and venous separation.
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Affiliation(s)
- Yijing Wu
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705, USA.
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