title: Predicting Collateral Status With Magnetic Resonance Perfusion Parameters: Probabilistic Approach With a Tmax-Derived Prediction Model.
abstract: OBJECTIVE
  Good collateral flow is an important predictor for favorable responses to recanalization therapy and successful outcomes after acute ischemic stroke. Magnetic resonance perfusion-weighted imaging (MRP) is widely used in patients with stroke. However, it is unclear whether the perfusion parameters and thresholds would predict collateral status. The present study evaluated the relationship between hypoperfusion severity and collateral status to develop a predictive model for good collaterals using MRP parameters.
  
  
  METHODS
  Patients who were eligible for recanalization therapy that underwent both serial diffusion-weighted imaging and serial MRP were enrolled into the study. A collateral flow map derived from MRP source data was generated through automatic postprocessing. Hypoperfusion severity, presented as proportions of every 2-s Tmax strata to the entire hypoperfusion volume (Tmax≥2 s), was compared between patients with good and poor collaterals. Prediction models for good collaterals were developed with each Tmax strata proportion and cerebral blood volumes.
  
  
  RESULTS
  Among 66 patients, 53 showed good collaterals based on MRP-based collateral grading. Although no difference was noted in delays within 16 s, more severe Tmax delays (Tmax16-18 s, Tmax18-22 s, Tmax22-24 s, and Tmax>24 s) were associated with poor collaterals. The probability equation model using Tmax strata proportion demonstrated high predictive power in a receiver operating characteristic analysis (area under the curve=0.9303; 95% confidence interval, 0.8682-0.9924). The probability score was negatively correlated with the volume of infarct growth (P=0.030).
  
  
  CONCLUSIONS
  Collateral status is associated with more severe Tmax delays than previously defined. The present Tmax severity-weighted model can determine good collaterals and subsequent infarct growth.
authors: From the Departments of Neurology (M.J.L., S.J.K., S.R., G.-M.K., C.-S.C., K.H.L., O.Y.B.) and Radiology (J.C.), Samsung Medical Center, School of Medicine (M.J.L., S.J.K., S.R., G.-M.K., C.-S.C., K.H.L., O.Y.B., J.C.) and Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology (J.P.S., O.Y.B.), Sungkyunkwan University, Seoul, Korea; and Biostatistics Team, Samsung Biomedical Research Institute, Seoul, Korea (S.-Y.W.).
authors: Mi Ji
authors: MJ
authors: Lee
authors: From the Departments of Neurology (M.J.L., S.J.K., S.R., G.-M.K., C.-S.C., K.H.L., O.Y.B.) and Radiology (J.C.), Samsung Medical Center, School of Medicine (M.J.L., S.J.K., S.R., G.-M.K., C.-S.C., K.H.L., O.Y.B., J.C.) and Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology (J.P.S., O.Y.B.), Sungkyunkwan University, Seoul, Korea; and Biostatistics Team, Samsung Biomedical Research Institute, Seoul, Korea (S.-Y.W.).
authors: Jeong Pyo
authors: JP
authors: Son
authors: From the Departments of Neurology (M.J.L., S.J.K., S.R., G.-M.K., C.-S.C., K.H.L., O.Y.B.) and Radiology (J.C.), Samsung Medical Center, School of Medicine (M.J.L., S.J.K., S.R., G.-M.K., C.-S.C., K.H.L., O.Y.B., J.C.) and Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology (J.P.S., O.Y.B.), Sungkyunkwan University, Seoul, Korea; and Biostatistics Team, Samsung Biomedical Research Institute, Seoul, Korea (S.-Y.W.).
authors: Suk Jae
authors: SJ
authors: Kim
authors: From the Departments of Neurology (M.J.L., S.J.K., S.R., G.-M.K., C.-S.C., K.H.L., O.Y.B.) and Radiology (J.C.), Samsung Medical Center, School of Medicine (M.J.L., S.J.K., S.R., G.-M.K., C.-S.C., K.H.L., O.Y.B., J.C.) and Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology (J.P.S., O.Y.B.), Sungkyunkwan University, Seoul, Korea; and Biostatistics Team, Samsung Biomedical Research Institute, Seoul, Korea (S.-Y.W.).
authors: Sookyung
authors: S
authors: Ryoo
authors: From the Departments of Neurology (M.J.L., S.J.K., S.R., G.-M.K., C.-S.C., K.H.L., O.Y.B.) and Radiology (J.C.), Samsung Medical Center, School of Medicine (M.J.L., S.J.K., S.R., G.-M.K., C.-S.C., K.H.L., O.Y.B., J.C.) and Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology (J.P.S., O.Y.B.), Sungkyunkwan University, Seoul, Korea; and Biostatistics Team, Samsung Biomedical Research Institute, Seoul, Korea (S.-Y.W.).
authors: Sook-Young
authors: SY
authors: Woo
authors: From the Departments of Neurology (M.J.L., S.J.K., S.R., G.-M.K., C.-S.C., K.H.L., O.Y.B.) and Radiology (J.C.), Samsung Medical Center, School of Medicine (M.J.L., S.J.K., S.R., G.-M.K., C.-S.C., K.H.L., O.Y.B., J.C.) and Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology (J.P.S., O.Y.B.), Sungkyunkwan University, Seoul, Korea; and Biostatistics Team, Samsung Biomedical Research Institute, Seoul, Korea (S.-Y.W.).
authors: Jihoon
authors: J
authors: Cha
authors: From the Departments of Neurology (M.J.L., S.J.K., S.R., G.-M.K., C.-S.C., K.H.L., O.Y.B.) and Radiology (J.C.), Samsung Medical Center, School of Medicine (M.J.L., S.J.K., S.R., G.-M.K., C.-S.C., K.H.L., O.Y.B., J.C.) and Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology (J.P.S., O.Y.B.), Sungkyunkwan University, Seoul, Korea; and Biostatistics Team, Samsung Biomedical Research Institute, Seoul, Korea (S.-Y.W.).
authors: Gyeong-Moon
authors: GM
authors: Kim
authors: From the Departments of Neurology (M.J.L., S.J.K., S.R., G.-M.K., C.-S.C., K.H.L., O.Y.B.) and Radiology (J.C.), Samsung Medical Center, School of Medicine (M.J.L., S.J.K., S.R., G.-M.K., C.-S.C., K.H.L., O.Y.B., J.C.) and Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology (J.P.S., O.Y.B.), Sungkyunkwan University, Seoul, Korea; and Biostatistics Team, Samsung Biomedical Research Institute, Seoul, Korea (S.-Y.W.).
authors: Chin-Sang
authors: CS
authors: Chung
authors: From the Departments of Neurology (M.J.L., S.J.K., S.R., G.-M.K., C.-S.C., K.H.L., O.Y.B.) and Radiology (J.C.), Samsung Medical Center, School of Medicine (M.J.L., S.J.K., S.R., G.-M.K., C.-S.C., K.H.L., O.Y.B., J.C.) and Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology (J.P.S., O.Y.B.), Sungkyunkwan University, Seoul, Korea; and Biostatistics Team, Samsung Biomedical Research Institute, Seoul, Korea (S.-Y.W.).
authors: Kwang Ho
authors: KH
authors: Lee
authors: From the Departments of Neurology (M.J.L., S.J.K., S.R., G.-M.K., C.-S.C., K.H.L., O.Y.B.) and Radiology (J.C.), Samsung Medical Center, School of Medicine (M.J.L., S.J.K., S.R., G.-M.K., C.-S.C., K.H.L., O.Y.B., J.C.) and Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology (J.P.S., O.Y.B.), Sungkyunkwan University, Seoul, Korea; and Biostatistics Team, Samsung Biomedical Research Institute, Seoul, Korea (S.-Y.W.). ohyoung.bang@samsung.com.
authors: Oh Young
authors: OY
authors: Bang
mesh_terms: D000368:Aged; D019540:Area Under Curve; D001921:Brain / Q000098:blood supply*; D002560:Cerebrovascular Circulation / Q000502:physiology; D003097:Collateral Circulation / Q000502:physiology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D020521:Stroke / Q000473:pathology* / Q000628:therapy; D016896:Treatment Outcome
keywords: ROC curve; collateral circulation; diffusion magnetic resonance imaging; magnetic resonance imaging; stroke