Recombinant tissue plasminogen activator increases blood-brain barrier disruption in acute ischemic stroke: an MR imaging permeability study.
OBJECTIVE
Although thrombolytic therapy (recombinant tissue plasminogen activator [rtPA]) represents an important step forward in acute ischemic stroke (AIS) management, there is a clear need to identify high-risk patients. The purpose of this study was to investigate the role of quantitative permeability (KPS) MR imaging in patients with AIS treated with and without rtPA. We hypothesized that rtPA would increase KPS and that KPS MR imaging can be used to predict the risk of hemorrhagic transformation (HT).


METHODS
Thirty-six patients with AIS were examined within a mean of 3.6 hours of documented symptom onset. KPS MR imaging was performed as part of our AIS protocol. KPS coefficients in the stroke lesion were estimated for all patients, and the relationship between KPS and both HT and rtPA was investigated by using Student t tests. Receiver operating characteristic (ROC) curves were computed for predicting HT from KPS.


RESULTS
The occurrence rate of HT for patients who received rtPA and those who did not was 43% and 37%, respectively. Assessment of KPS in the lesion revealed significant differences between those who hemorrhaged and those who did not (P < .0001) as well as between rtPA-treated and untreated patients (P = .008). ROC analysis indicated a KPS threshold of 0.67 mL/100 g/min, with a sensitivity of 92% and a specificity of 78%.


CONCLUSIONS
The results of this study indicate that KPS is able to identify patients at higher risk of HT and may allow use of physiologic imaging rather than time from onset of symptoms to guide treatment decision.
Kassner
A
A
Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada. andrea.kassner@utoronto.ca
Roberts
T P L
TP
Moran
B
B
Silver
F L
FL
Mikulis
D J
DJ
D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001812:Blood-Brain Barrier / Q000187:drug effects*; D002545:Brain Ischemia / Q000188:drug therapy* / Q000453:epidemiology / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000009:adverse effects; D012307:Risk Factors; D012680:Sensitivity and Specificity; D020521:Stroke / Q000188:drug therapy / Q000453:epidemiology / Q000473:pathology; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage*
D011994:Recombinant Proteins; D010959:Tissue Plasminogen Activator