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PT  - JOURNAL ARTICLE
AU  - Ernst, M.
AU  - Forkert, N.D.
AU  - Brehmer, L.
AU  - Thomalla, G.
AU  - Siemonsen, S.
AU  - Fiehler, J.
AU  - Kemmling, A.
TI  - Prediction of Infarction and Reperfusion in Stroke by Flow- and Volume-Weighted Collateral Signal in MR Angiography
AID  - 10.3174/ajnr.A4145
DP  - 2015 Feb 01
TA  - American Journal of Neuroradiology
PG  - 275--282
VI  - 36
IP  - 2
4099  - http://www.ajnr.org/content/36/2/275.short
4100  - http://www.ajnr.org/content/36/2/275.full
SO  - Am. J. Neuroradiol.2015 Feb 01; 36
AB  - BACKGROUND AND PURPOSE: In proximal anterior circulation occlusive strokes, collateral flow is essential for good outcome. Collateralized vessel intensity in TOF- and contrast-enhanced MRA is variable due to different acquisition methods. Our purpose was to quantify collateral supply by using flow-weighted signal in TOF-MRA and blood volume–weighted signal in contrast-enhanced MRA to determine each predictive contribution to tissue infarction and reperfusion. MATERIALS AND METHODS: Consecutively (2009–2013), 44 stroke patients with acute proximal anterior circulation occlusion met the inclusion criteria with TOF- and contrast-enhanced MRA and penumbral imaging. Collateralized vessels in the ischemic hemisphere were assessed by TOF- and contrast-enhanced MRA using 2 methods: 1) visual 3-point collateral scoring, and 2) collateral signal quantification by an arterial atlas-based collateral index. Collateral measures were tested by receiver operating characteristic curve and logistic regression against 2 imaging end points of tissue-outcome: final infarct volume and percentage of penumbra saved. RESULTS: Visual collateral scores on contrast-enhanced MRA but not TOF were significantly higher in patients with good outcome. Visual collateral scoring on contrast-enhanced MRA was the best rater-based discriminator for final infarct volume < 90 mL (area under the curve, 0.81; P < .01) and percentage of penumbra saved >50% (area under the curve, 0.67; P = .04). Atlas-based collateral index of contrast-enhanced MRA was the overall best independent discriminator for final infarct volume of <90 mL (area under the curve, 0.94; P < .01). Atlas-based collateral index combining the signal of TOF- and contrast-enhanced MRA was the overall best discriminator for effective reperfusion (percentage of penumbra saved >50%; area under the curve, 0.89; P < .001). CONCLUSIONS: Visual scoring of contrast-enhanced but not TOF-MRA is a reliable predictor of infarct outcome in stroke patients with proximal arterial occlusion. By atlas-based collateral assessment, TOF- and contrast-enhanced MRA both contain predictive signal information for penumbral reperfusion. This could improve risk stratification in further studies. AUCarea under the curveCEcontrast-enhancedCIcollateral indexCScollateral scoreCVAcollateral vessel abundanceFIVfinal infarct volumePPSpercentage of penumbra savedROCreceiver operating characteristicTmaxtime-to-maximumVOLvolume