title: Characteristics of patients with target magnetic resonance mismatch profile: data from two geographically and racially distinct populations.
abstract: BACKGROUND
  Recently, the Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution (DEFUSE) and the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET) trialists suggested that diffusion-perfusion magnetic resonance imaging (MRI) can classify patients into 4 subgroups likely to differentially experience benefit or harm from reperfusion therapies. However, there is a lack of data comparing MR mismatch profiles between different race-ethnic groups. In addition, clinical factors affecting MR mismatch profiles are not well described.
  
  
  METHODS
  We analyzed clinical and pretreatment MRI data of patients from 2 geographically and ethnically distinct study populations (Seoul, South Korea, and Los Angeles, Calif., USA) who are eligible for recanalization therapy. Diffusion-perfusion mismatch regions were classified among the 4 DEFUSE MR profiles: target mismatch, no mismatch, small lesion and malignant.
  
  
  RESULTS
  A total of 147 South Korean and 162 Southern Californian subjects (64.2% Whites) were included. Pretreatment MRIs revealed that the MR mismatch profiles were different in the 2 study populations (p < 0.001). Target mismatch was more prevalent in Southern Californian subjects (67.9%) compared with South Korean subjects (58.5%), whereas the small lesion pattern was more prevalent in the latter (9.9 vs. 23.1%). After adjusting for covariables, 3 features independently decreased the likelihood of presence of target mismatch: history of diabetes (OR 0.369, 95% CI 0.196-0.694), small versus large arterial occlusion (OR 0.052, 95% CI 0.01-0.255) and largest size (highest tertile) of diffusion-weighted imaging (DWI) lesion volume (OR 0.516, 95% CI 0.266-0.999). The one feature independently increasing target mismatch likelihood was intermediate size (middle tertile) DWI volume (OR 2.977, 95% CI 1.431-6.195).
  
  
  CONCLUSIONS
  Target mismatch profiles are present in 55-70% of patients. Target mismatch is less common in patients with diabetes, small vessel occlusion, Asian ethnicity and extensive DWI lesions, and more common in patients with DWI lesions of intermediate size.
authors.affiliation: Department of Neurology, Samsung Medical Center, Seoul, South Korea. nmboy@unitel.co.kr
authors.forename: Oh Young
authors.initials: OY
authors.lastname: Bang
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Saver
authors.forename: Kwang Ho
authors.initials: KH
authors.lastname: Lee
authors.forename: Gyeong Moon
authors.initials: GM
authors.lastname: Kim
authors.forename: Chin Sang
authors.initials: CS
authors.lastname: Chung
authors.forename: Suk Jae
authors.initials: SJ
authors.lastname: Kim
authors.forename: Bruce
authors.initials: B
authors.lastname: Ovbiagele
authors.forename: Jeffry R
authors.initials: JR
authors.lastname: Alger
authors.forename: David S
authors.initials: DS
authors.lastname: Liebeskind
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D001921:Brain / Q000098:blood supply / Q000187:drug effects / Q000473:pathology*; D002140:California / Q000453:epidemiology; D002560:Cerebrovascular Circulation / Q000187:drug effects; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D054624:Health Status Disparities; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D018579:Patient Selection; D011237:Predictive Value of Tests; D011446:Prospective Studies; D056910:Republic of Korea / Q000453:epidemiology; D012111:Residence Characteristics; D018570:Risk Assessment; D012307:Risk Factors; D020521:Stroke / Q000188:drug therapy / Q000208:ethnology* / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology; D015912:Thrombolytic Therapy / Q000009:adverse effects; D044465:White People