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PT  - JOURNAL ARTICLE
AU  - Nael, K.
AU  - Meshksar, A.
AU  - Ellingson, B.
AU  - Pirastehfar, M.
AU  - Salamon, N.
AU  - Finn, P.
AU  - Liebeskind, D.S.
AU  - Villablanca, J.P.
TI  - Combined Low-Dose Contrast-Enhanced MR Angiography and Perfusion for Acute Ischemic Stroke at 3T: A More Efficient Stroke Protocol
AID  - 10.3174/ajnr.A3848
DP  - 2014 Jun 01
TA  - American Journal of Neuroradiology
PG  - 1078--1084
VI  - 35
IP  - 6
4099  - http://www.ajnr.org/content/35/6/1078.short
4100  - http://www.ajnr.org/content/35/6/1078.full
SO  - Am. J. Neuroradiol.2014 Jun 01; 35
AB  - BACKGROUND AND PURPOSE: There is need to improve image acquisition speed for MR imaging in evaluation of patients with acute ischemic stroke. The purpose of this study was to evaluate the feasibility of a 3T MR stroke protocol that combines low-dose contrast-enhanced MRA and dynamic susceptibility contrast perfusion, without additional contrast. METHODS: Thirty patients with acute stroke who underwent 3T MR imaging followed by DSA were retrospectively enrolled. TOF-MRA of the neck and brain and 3D contrast-enhanced MRA of the craniocervical arteries were obtained. A total of 0.1 mmol/kg of gadolinium was used for both contrast-enhanced MRA (0.05 mmol/kg) and dynamic susceptibility contrast perfusion (0.05 mmol/kg) (referred to as half-dose). An age-matched control stroke population underwent TOF-MRA and full-dose (0.1 mmol/kg) dynamic susceptibility contrast perfusion. The cervicocranial arteries were divided into 25 segments. Degree of arterial stenosis on contrast-enhanced MRA and TOF-MRA was compared with DSA. Time-to-maximum maps (&amp;gt;6 seconds) were evaluated for image quality and hypoperfusion. Quantitative analysis of arterial input function curves, SNR, and maximum T2* effects were compared between half- and full-dose groups. RESULTS: The intermodality agreements (k) for arterial stenosis were 0.89 for DSA/contrast-enhanced MRA and 0.63 for DSA/TOF-MRA. Detection specificity of &amp;gt;50% arterial stenosis was lower for TOF-MRA (89%) versus contrast-enhanced MRA (97%) as the result of overestimation of 10% (39/410) of segments by TOF-MRA. The DWI-perfusion mismatch was identified in both groups with high interobserver agreement (r = 1). There was no significant difference between full width at half maximum of the arterial input function curves (P = .14) or the SNR values (0.6) between the half-dose and full-dose groups. CONCLUSIONS: In patients with acute stroke, combined low-dose contrast-enhanced MRA and dynamic susceptibility contrast perfusion at 3T is feasible and results in significant scan time and contrast dose reductions. AIFarterial input functionCE-MRAcontrast-enhanced MRAFWHMfull width at half maximumGRAPPAgeneralized autocalibrating partially parallel acquisitionTmaxtime-to-maximum