Prediction of hemorrhagic transformation in acute ischemic stroke using texture analysis of postcontrast T1-weighted MR images.
OBJECTIVE
To test the hypothesis that texture analysis of postcontrast T1-weighted MR images will predict hemorrhagic transformation (HT) in patients with acute ischemic stroke (AIS) with better accuracy than visual evidence of contrast-enhancement (VE).


METHODS
Thirty-four AIS patients were examined within 3.5 +/- 1.5 h after stroke. T1-weighted MR images were acquired 19 +/- 7 min postcontrast injection. HT was determined by follow-up imaging at 24-72 h. Postcontrast images were evaluated for VE. Four second-order textural features were extracted (f1, f2, f3, and f9) for each patient. Receiver operating characteristic (ROC) curves were constructed for VE and for textural features, with HT as the outcome measure.


RESULTS
The f2 for HT patients (n = 12) was significantly lower than in non-HT patients (1058 +/- 356 versus 1568 +/- 527; P = 0.005); the converse was true for f3 (0.67 +/- 0.12 versus 0.54 +/- 0.13; P = 0.007). ROC analysis indicated that the f2 and f3 textural features were the only two significant predictors of HT (P = 0.0018 and P = 0.0042). The addition of VE to either f2 or f3 did not result in a significant improvement in accuracy.


CONCLUSIONS
Texture analysis of postcontrast T1-weighted images may be superior to visual evidence of enhancement for the prediction of HT.
Division of Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, ON, Canada. andrea.kassner@utoronto.ca
Andrea
A
Kassner
Fang
F
Liu
Rebecca E
RE
Thornhill
George
G
Tomlinson
David J
DJ
Mikulis
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000473:pathology*; D003287:Contrast Media / Q000494:pharmacology; D005260:Female; D006470:Hemorrhage / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D020521:Stroke / Q000473:pathology*
D003287:Contrast Media