title: Initial 'TTP Map-Defect' of Computed Tomography Perfusion as a Predictor of Hemorrhagic Transformation of Acute Ischemic Stroke.
abstract: BACKGROUND
  Hemorrhagic transformation (HT) following acute ischemic stroke is a major problem, especially for the indication of reperfusion therapy including intravenous administration of recombinant tissue plasminogen activator (IV rt-PA). The specific predictive factors of HT have not yet been established. The present study evaluated the findings of computed tomography perfusion (CTP) images as predictors of subsequent HT to identify patients with low HT risk for reperfusion therapy such as IV rt-PA.
  
  
  METHODS
  We retrospectively reviewed 68 consecutive stroke patients (41 males; mean age 72.9 years) with steno-occlusive lesions in the major trunk, including 10 patients who underwent IV rt-PA. Each HT was detected on a follow-up T2*-weighted magnetic resonance image until 2 weeks after stroke onset and categorized into four groups [hemorrhagic infarction (HI) type 1 and 2, and parenchymal hematoma (PH) type 1 and 2] according to the European Cooperative Acute Stroke Study (ECASS) classification. We assessed clinical features and radiological findings between the HT and non-HT groups or the PH2 and non-PH2 groups. The efficacy of initial time to peak (TTP) mapping of CTP for predicting HT or PH2 was evaluated.
  
  
  RESULTS
  Thirty-four patients (50%) developed subsequent HT: 18 (52.9%) had HI and 16 (47.1%) had PH, including 9 PH2 patients (13.2%). IV rt-PA was not significantly associated with HT or PH2 occurrence. Forty of the 68 patients (59%) revealed defect areas on the initial TTP mapping (TTP map-defect), and 34 of these 40 patients (85%) developed secondary HT and 9 patients (22.5%) developed PH2. Initial 'TTP map-defect' was significantly associated with the occurrence of HT (p < 0.0001) and PH2 (p = 0.0070). Thirty of the 34 patients (88.2%) in the HT group experienced delayed recanalization of the occluded vessels, in contrast to only 8 of the 34 patients (23.6%) in the non-HT group. All patients of the PH2 group showed recanalization (p = 0.0042). In 40 'TTP map-defect'-positive patients, delayed recanalization was associated with the occurrence of HT (p < 0.0001) and PH2 (p = 0.0491). All 28 patients without 'TTP map-defect' did not develop HT, including 8 patients (28.6%) with delayed recanalization.
  
  
  CONCLUSIONS
  Initial 'TTP map-defect' of CTP could accurately predict HT risk including PH2 risk and identify low-risk patients even in the delayed period.
authors: Department of Neurosurgery, Nakamura Memorial Hospital, Sapporo, Japan ; Department of Neurosurgery, Yamaguchi University School of Medicine, Yamaguchi, Japan.
authors: Mizuya
authors: M
authors: Shinoyama
authors: Jyoji
authors: J
authors: Nakagawara
authors: Hiroshi
authors: H
authors: Yoneda
authors: Michiyasu
authors: M
authors: Suzuki
authors: Hidetoshi
authors: H
authors: Ono
authors: Ichiro
authors: I
authors: Kunitsugu
authors: Kenji
authors: K
authors: Kamiyama
authors: Toshiaki
authors: T
authors: Osato
authors: Hirohiko
authors: H
authors: Nakamura
keywords: Computed tomography perfusion; Hemorrhagic transformation; Ischemic stroke; Time to peak
references: Stroke. 2010 Nov;41(11):2512-8
references: 20947842
references: Ann Neurol. 2006 Nov;60(5):508-17
references: 17066483
references: Stroke. 1997 Jun;28(6):1198-202
references: 9183351
references: Ann Neurol. 2002 Apr;51(4):417-32
references: 11921048
references: Cerebrovasc Dis. 2009;28(1):72-9
references: 19468218
references: Stroke. 2002 May;33(5):1392-8
references: 11988620
references: Stroke. 1994 Feb;25(2):298-303
references: 8303735
references: N Engl J Med. 1995 Dec 14;333(24):1581-7
references: 7477192
references: Cerebrovasc Dis. 2011;32(4):334-41
references: 21921596
references: J Cereb Blood Flow Metab. 1999 Jan;19(1):99-108
references: 9886360
references: Nat Rev Neurol. 2011 Jun 14;7(7):400-9
references: 21670766
references: Stroke. 1988 Oct;19(10):1216-22
references: 3176080
references: JAMA. 1995 Oct 4;274(13):1017-25
references: 7563451
references: Stroke. 2006 Jul;37(7):1810-5
references: 16763187
references: Ann Neurol. 1996 Aug;40(2):216-26
references: 8773603
references: Stroke. 2001 Feb;32(2):438-41
references: 11157179
references: J Neurol Neurosurg Psychiatry. 2008 Oct;79(10):1093-9
references: 18223014
references: Cerebrovasc Dis. 2012;33(1):8-15
references: 22143195
references: Cerebrovasc Dis. 2011;32(3):227-33
references: 21860235
references: Neuroradiology. 2001 Mar;43(3):223-6
references: 11305754
references: Stroke. 2010 Jan;41(1):82-8
references: 19959537
references: Stroke. 2009 Aug;40(8):2945-8
references: 19478221
references: J Cereb Blood Flow Metab. 2001 Aug;21(8):964-71
references: 11487732
references: Stroke. 2011 Jul;42(7):1952-5
references: 21636813
references: Stroke. 2008 Feb;39(2):366-72
references: 18096843
references: Stroke. 2010 Mar;41(3):461-5
references: 20075341
references: Stroke. 2009 Feb;40(2):469-75
references: 19109547
references: Stroke. 2010 Jan;41(1):72-7
references: 19926841
references: Cerebrovasc Dis. 2007;24(1):1-10
references: 17519538
references: AJNR Am J Neuroradiol. 1999 Nov-Dec;20(10):1842-50
references: 10588107
references: Neurol Res. 2002;24 Suppl 1:S17-26
references: 12074432
references: Stroke. 2004 Dec;35(12):2843-7
references: 15514190
references: Eur Neurol. 1994;34(2):64-77
references: 8174597
references: J Cereb Blood Flow Metab. 2011 Feb;31(2):448-56
references: 20588314
references: Stroke. 2001 Jun;32(6):1330-5
references: 11387495
references: Radiology. 2009 Mar;250(3):867-77
references: 19244051
references: Stroke. 2007 Aug;38(8):2275-8
references: 17569874
references: N Engl J Med. 2008 Sep 25;359(13):1317-29
references: 18815396