RT Journal Article
SR Electronic
T1 Contrast-Enhanced MR Imaging in Acute Ischemic Stroke: T2* Measures of Blood-Brain Barrier Permeability and Their Relationship to T1 Estimates and Hemorrhagic Transformation
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 1015
OP 1022
DO 10.3174/ajnr.A2003
VO 31
IS 6
A1 R.E. Thornhill
A1 S. Chen
A1 W. Rammo
A1 D.J. Mikulis
A1 A. Kassner
YR 2010
UL http://www.ajnr.org/content/31/6/1015.abstract
AB BACKGROUND AND PURPOSE: rtPA is an effective treatment for AIS, yet it is substantially underused due to the increased risk of HT. Recent work suggests that permeability-related information can be extracted from routine T2*-based perfusion images by measuring the rR of the contrast agent. Given that other T2*-based measures have recently been proposed, the purpose of this study was to evaluate 4 such permeability measures in identifying patients with AIS who will proceed to HT. MATERIALS AND METHODS: Eighteen patients with AIS were examined within a mean of 3.3 ± 1.4 hours postonset. Dynamic T2*-weighted imaging consisted of a single-shot EPI following a bolus of gadodiamide. HT was determined on follow-up CT or MR imaging at 24–72 hours. Mean values of rR, Peak Height, Recovery, as well as Slope were calculated and analyzed on the basis of follow-up HT status. RESULTS: Eight patients proceeded to HT. The mean rR for patients with HT was significantly greater than that for patients without HT (0.22 ± 0.06 versus 0.14 ± 0.06, P = .006), while there was a trend toward decreased %Recovery in patients with HT (76 ± 6 versus 82 ± 11%, P = .092). There was a significant negative correlation between %Recovery and rR (r = −0.88, P < .001). No significant differences or trends were detected with respect to Peak Height or Slope. CONCLUSIONS: Both rR and %Recovery can be readily extracted from a routine perfusion MR imaging dataset and show potential for identifying HT during the acute phase poststroke. ADCapparent diffusion coefficientAISacute ischemic strokeBBBblood-brain barrierDCEdynamic contrast-enhancedΔR2*deltaDWIdiffusion-weighted imagingECASSEuropean Cooperative Acute Stroke StudyEPIecho-planar imagingHIhemorrhagic infarctionHThemorrhagic transformationKPSBBB permeability coefficientmaxmaximumNIHSSNational Institutes of Health Stroke ScalePHparenchymal hematomarRrelative recirculationrtPArecombinant tissue plasminogen activatorSIsignal intensitySlopeslope of the ΔR2* versus time curve between 50 and 60 seconds postinjectionT2*relaxation rate