title: New cerebral lesions on T2*-weighted gradient-echo imaging after cardiac valve surgery.
abstract: BACKGROUND
  It is well known that silent ischemic brain lesions on diffusion-weighted imaging (DWI) commonly occur after various interventional procedures or surgeries. However, to our knowledge, postoperative new lesions on T2*-weighted gradient-echo imaging (GRE) have never been explored.
  
  
  METHODS
  This prospective observational study enrolled 19 consecutive patients undergoing cardiac valve surgery. Preoperative and postoperative (within 7 days) GRE and DWI were performed. New GRE lesions were defined as signal loss lesions on postoperative GRE which were not observed on preoperative GRE. Long-term follow-up GRE was performed in a limited number of cases.
  
  
  RESULTS
  Twelve patients developed 26 small (<10 mm) new GRE lesions. Of these patients, 1 had a generalized seizure accompanied by confusion and facial weakness with DWI lesions, and 1 showed confusion of short duration without DWI lesions. Long-term follow-up GRE was performed 3 years after surgery in 4 patients. Of the 12 new GRE lesions in these 4 patients, 11 lesions were still observable on long-term follow-up GRE.
  
  
  CONCLUSIONS
  New cerebral lesions on GRE after cardiac valve surgery are common and are presumed to be rapidly developed microbleeds and mostly asymptomatic. Further studies are needed to investigate the precise nature and clinical implications of new GRE lesions.
authors.affiliation: Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Sang-Beom
authors.initials: SB
authors.lastname: Jeon
authors.forename: Jae-Won
authors.initials: JW
authors.lastname: Lee
authors.forename: Sang Joon
authors.initials: SJ
authors.lastname: Kim
authors.forename: Cheol-Hyun
authors.initials: CH
authors.lastname: Chung
authors.forename: Sun U
authors.initials: SU
authors.lastname: Kwon
authors.forename: Choong Gon
authors.initials: CG
authors.lastname: Choi
authors.forename: Suk-Jung
authors.initials: SJ
authors.lastname: Choo
authors.forename: Hyun-Wook
authors.initials: HW
authors.lastname: Nah
authors.forename: Jong S
authors.initials: JS
authors.lastname: Kim
authors.forename: Dong-Wha
authors.initials: DW
authors.lastname: Kang
mesh_terms: D000328:Adult; D000368:Aged; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002544:Cerebral Infarction / Q000209:etiology* / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects*; D006351:Heart Valves / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D056910:Republic of Korea; D013997:Time Factors; D016896:Treatment Outcome