title: Quantification of thrombus hounsfield units on noncontrast CT predicts stroke subtype and early recanalization after intravenous recombinant tissue plasminogen activator.
abstract: OBJECTIVE
  Little is known about the factors that determine recanalization after intravenous thrombolysis. We assessed the value of thrombus Hounsfield unit quantification as a predictive marker of stroke subtype and MCA recanalization after intravenous rtPA treatment.
  
  
  METHODS
  NCCT scans and CTA were performed on patients with MCA acute stroke within 4.5 hours of symptom onset. Demographics, stroke severity, vessel hyperattenuation, occlusion site, thrombus length, and time to thrombolysis were recorded. Stroke origin was categorized as LAA, cardioembolic, or indeterminate according to TOAST criteria. Two blinded neuroradiologists calculated the Hounsfield unit values for the thrombus and contralateral MCA segment. We used ROC curves to determine the rHU cutoff point to discriminate patients with successful recanalization from those without. We assessed the accuracy (sensitivity, specificity, and positive and negative predictive values) of rHU in the prediction of recanalization.
  
  
  RESULTS
  Of 87 consecutive patients, 45 received intravenous rtPA and only 15 (33.3%) patients had acute recanalization. rHU values and stroke mechanism were the highest predictive factors of recanalization. The Matthews correlation coefficient was highest for rHU (0.901). The sensitivity, specificity, and positive and negative predictive values for lack of recanalization after intravenous rtPA for rHU ≤ 1.382 were 100%, 86.67%, 93.75%, and 100%, respectively. LAA thrombi had lower rHU than cardioembolic and indeterminate stroke thrombi (P = .004).
  
  
  CONCLUSIONS
  The Hounsfield unit thrombus measurement ratio can predict recanalization with intravenous rtPA and may have clinical utility for endovascular treatment decision making.
authors.affiliation: Department of Radiology, Girona Biomedical Research Institute, Hospital Universitari de Girona Dr Josep Trueta, Spain. jpuigalcantara@yahoo.es
authors.forename: J
authors.initials: J
authors.lastname: Puig
authors.forename: S
authors.initials: S
authors.lastname: Pedraza
authors.forename: A
authors.initials: A
authors.lastname: Demchuk
authors.forename: J
authors.initials: J
authors.lastname: Daunis-I-Estadella
authors.forename: H
authors.initials: H
authors.lastname: Termes
authors.forename: G
authors.initials: G
authors.lastname: Blasco
authors.forename: G
authors.initials: G
authors.lastname: Soria
authors.forename: I
authors.initials: I
authors.lastname: Boada
authors.forename: S
authors.initials: S
authors.lastname: Remollo
authors.forename: J
authors.initials: J
authors.lastname: Baños
authors.forename: J
authors.initials: J
authors.lastname: Serena
authors.forename: M
authors.initials: M
authors.lastname: Castellanos
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002548:Cerebral Revascularization; D003131:Combined Modality Therapy; D003287:Contrast Media; D005260:Female; D005343:Fibrinolytic Agents; D006801:Humans; D007275:Injections, Intravenous; D020767:Intracranial Thrombosis / Q000175:diagnosis* / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011994:Recombinant Proteins / Q000008:administration & dosage; D020521:Stroke / Q000145:classification / Q000175:diagnosis* / Q000628:therapy*; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D003287:Contrast Media; D005343:Fibrinolytic Agents; D011994:Recombinant Proteins; D010959:Tissue Plasminogen Activator