Impact of Baseline Tissue Status (Diffusion-Weighted Imaging Lesion) Versus Perfusion Status (Severity of Hypoperfusion) on Hemorrhagic Transformation

Abstract

for the UCLA-Samsung Stroke CollaboratorsBackground and Purpose-The frequency of hemorrhagic transformation (HT) on gradient echo imaging and its impact on stroke outcomes continues to be debated. We investigated the factors associated with HTs and the influence of the HTs observed on gradient echo imaging on the early course after a stroke. Methods-We analyzed the data from a prospectively maintained registry of patients who were eligible for recanalization therapy. Serial diffusion-weighted imaging and perfusion-weighted imaging were performed, and HTs were assessed on follow-up gradient echo imaging. Tmax perfusion lesion maps were generated and hypoperfused regions were divided into severe (Tmax Ն8 seconds) delay and mild (Tmax Ն2 seconds but Tmax Ͻ8 seconds) delay. The factors associated with HTs, including the mode of recanalization therapy, pretreatment diffusion-weighted imaging and perfusionweighted imaging lesion volumes, and reperfusion indices, were evaluated. The early clinical outcome was assessed during the first 7 days of admission. Results-A total of 184 patients were included in this study. HTs were noted in 73 (39.7%) patients. Multiple logistic regression analysis identified aggressive treatment (OR, 5.12; 95% CI, 1.73 to 15.18) and a large area of severe perfusion delay (OR for highest quartile of Tmax Ͼ8 seconds, 12.91; 95% CI, 3.69 to 45.17) as independent predictors of HTs. Neither risk factor profiles nor diffusion-weighted imaging lesion volumes were associated with HTs. There was a poor correlation between the radiological (HT types) and clinical (asymptomatic or symptomatic) categories of HTs. Even a parenchymal hematoma was not always associated with symptomatic worsening or affected the early clinical outcomes. Conclusion-The results of this study indicate that the perfusion status (severe perfusion delay) rather than the tissue status (diffusion-weighted imaging lesions) and aggressive treatment were independently associated with HTs. HT on gradient echo imaging was common but usually associated with severe hypoperfusion and not always associated with clinical deterioration. (Stroke. 2010;41:e135-e142.)

Collateral Flow Averts Hemorrhagic Transformation After Endovascular Therapy for Acute Ischemic Stroke

“…In addition, it was very recently reported that perfusion status (severe time-tomaximum delay and low cerebral blood volume) rather than diffusion-weighted imaging lesion volume was associated with HT after revascularization therapy. 5,8 Moreover, a higher rate of HT and infarct growth in patients with poor collaterals in whom therapeutic recanalization was achieved may support the concept of reperfusion injury. 3 Collateral status differs among patients with acute ischemic stroke.…”

“…5 In the present study, we evaluated whether the baseline collateral grade was an important determinant of HT after therapeutic revascularization, capitalizing on the availability of collateral status before intervention.…”

Automated Core–Penumbra Quantification in Neonatal Ischemic Brain Injury

“…24,38 While arterial spin labeling is an option, it also is more difficult to acquire and results in less accurate perfusion values. [38][39][40] In contrast to adult stroke, where penumbral hypoperfusion is reported, recent studies reported PWI hyperperfusion after neonatal HII. 24 Further, the small size of 11 day-old rat pups makes it difficult to inject contrast agents necessary to do PWI.…”

Interaction of Recanalization, Intracerebral Hemorrhage, and Cerebral Edema After Intravenous Thrombolysis

“…Few patients have been studied with detailed brain imaging, 14 only a proportion of whom have received thrombolytic therapy; animal models 19,31 may not recapitulate the human situation, and other data derive from series of late endovascular intervention. 32 Our cohort allowed the study of interactions between 24-hour recanalization, perfusion characteristics, and incidence of both ICH and early brain edema. We found ICH incidence comparable with previous literature; for example, ICH of all kinds in 34% (48% in ECASS- 2 11 ) and SICH in 5.7% (7.7% in a meta-analysis 33 ).…”