RT Journal Article
SR Electronic
T1 Tissue at Risk Is Overestimated in Perfusion-Weighted Imaging: MR Imaging in Acute Stroke Patients without Vessel Recanalization
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 815
OP 819
VO 26
IS 4
A1 Thomas Kucinski
A1 Dirk Naumann
A1 René Knab
A1 Volker Schoder
A1 Susanne Wegener
A1 Jens Fiehler
A1 Amitava Majumder
A1 Joachim Röther
A1 Hermann Zeumer
YR 2005
UL http://www.ajnr.org/content/26/4/815.abstract
AB BACKGROUND AND PURPOSE: The volume of decreased cerebral blood flow (CBF) in acute stroke perfusion-weighted imaging frequently overestimates final infarct volume. We hypothesized that surviving tissue exists even in patients without recanalization and tried to determine perfusion thresholds from initial MR imaging.METHODS: Stroke MR imaging including MR angiography was carried out at days 0, 1, and 7 after stroke onset in 19 patients without recanalization at least until day 1. The following lesions were defined: L0 = diffusion restriction at day 0; LG1 = lesion growth until day 1; LG7 = lesion growth until day 7; ST7 = initially hypoperfused, but surviving tissue. These lesions were transferred on initial MR imaging within 4.7 hours and perfusion values at day 0 were determined.RESULTS: Median lesion volume L0 at day 0 was 18.2 mL and increased to 39.4 and 43.8 mL at days 1 and 7. Volume of decreased rCBF not progressing to infarction was 148.5 mL (ST7). Mean ST7 perfusion values were different from L0 and LG1, but only mean relative cerebral blood volume (rCBV) was different from LG7, discriminating survival against death of tissue. A threshold value of 0.82 CBV for death versus survival was determined with a sensitivity of 0.56 and specificity of 0.95. Carotid T occlusions showed the greatest potential of lesion growth.CONCLUSION: Even when vessel occlusion persists, hypoperfused tissue on MR imaging does not necessarily progress toward infarction. The most conclusive inferences can be drawn from CBV images. The site of arterial occlusion also determines progression to infarction.