title: Density of thrombus on admission CT predicts revascularization efficacy in large vessel occlusion acute ischemic stroke.
abstract: OBJECTIVE
  Can lysability of large vessel thrombi in acute ischemic stroke be predicted by measuring clot density on admission nonenhanced CT (NECT), postcontrast enhanced CT, or CT angiogram (CTA)?
  
  
  METHODS
  We retrospectively studied 90 patients with acute large vessel ischemic strokes treated with intravenous (IV) tPA, intra-arterial (IA) tPA, and/or mechanical thrombectomy devices. Clot density [in Hounsfield unit (HU)] was measured on NECT, postcontrast enhanced CT, and CTA. Recanalization was assessed by the Thrombolysis in Cerebral Infarction grading system (TICI) on digital subtraction angiography.
  
  
  RESULTS
  Thrombus density on preintervention NECT correlated with postintervention TICI grade regardless of pharmacological (IV tPA r=0.69, IA tPA r=0.72, P<0.0001) or mechanical treatment (r=0.73, P<0.0001). Patients with TICI≥2 demonstrated higher HU on NECT (mean corrected HU IV tPA=1.58, IA tPA=1.66, mechanical treatment=1.7) compared with patients with TICI<2 (IV tPA=1.39, IA tPA=1.4, mechanical treatment=1.3) (P=0.01, 0.006, <0.0001 respectively). There was no association between recanalization and age, sex, baseline National Institute of Health Stroke Scale, treatment method, time to treatment, or clot volume.
  
  
  CONCLUSIONS
  Thrombi with lower HU on NECT appear to be more resistant to pharmacological lysis and mechanical thrombectomy. Measuring thrombus density on admission NECT provides a rapid method to analyze clot composition, a potentially useful discriminator in selecting the most appropriate reperfusion strategy for an individual patient.
authors.affiliation: Departments of Radiology and Biomedical Imaging, University of California, San Francisco, CA 94143, USA.
authors.forename: Parham
authors.initials: P
authors.lastname: Moftakhar
authors.forename: Joey D
authors.initials: JD
authors.lastname: English
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Cooke
authors.forename: Warren T
authors.initials: WT
authors.lastname: Kim
authors.forename: Charles
authors.initials: C
authors.lastname: Stout
authors.forename: Wade S
authors.initials: WS
authors.lastname: Smith
authors.forename: Christopher F
authors.initials: CF
authors.lastname: Dowd
authors.forename: Randall T
authors.initials: RT
authors.lastname: Higashida
authors.forename: Van V
authors.initials: VV
authors.lastname: Halbach
authors.forename: Steven W
authors.initials: SW
authors.lastname: Hetts
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000000981:diagnostic imaging* / Q000601:surgery; D002548:Cerebral Revascularization / Q000379:methods / Q000639:trends*; D005260:Female; D006801:Humans; D020767:Intracranial Thrombosis / Q000000981:diagnostic imaging* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010343:Patient Admission / Q000639:trends*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D020521:Stroke / Q000000981:diagnostic imaging* / Q000601:surgery; D014057:Tomography, X-Ray Computed / Q000639:trends*; D016896:Treatment Outcome